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Sample records for 3d woven composite

  1. Impact Damage of 3D Orthogonal Woven Composite Circular Plates

    NASA Astrophysics Data System (ADS)

    Ji, Changgan; Sun, Baozhong; Qiu, Yiping; Gu, Bohong

    2007-11-01

    The damages of 3D orthogonal woven composite circular plate under quasi-static indentation and transverse impact were tested with Materials Test System (MTS) and modified split Hopkinson bar (SHPB) apparatus. The load vs. displacement curves during quasi-static penetration and impact were obtained to study the energy absorption of the composite plate. The fluctuation of the impact stress waves has been unveiled. Differences of the load-displacement curves between the quasi-static and impact loading are discussed. This work also aims at establishing a unit-cell model to analyze the damage of composites. A user material subroutine which named VUMAT for characterizing the constitutive relationship of the 3-D orthogonal woven composite and the damage evolution is incorporated with a finite element code ABAQUS/Explicit to simulate the impact damage process of the composite plates. From the comparison of the load-displacement curves and energy absorption curves of the composite plate between experimental and FEM simulation, it is shown that the unit-cell model of the 3D woven composite and the VUMAT combined with the ABAQUS/Explicit can calculate the impact responses of the circular plate precisely. Furthermore, the model can also be extended to simulate the impact behavior of the 3D woven composite structures.

  2. Ultrasonic impact damage assessment in 3D woven composite materials

    NASA Astrophysics Data System (ADS)

    Mannai, E.; Lamboul, B.; Roche, J. M.

    2015-03-01

    An ultrasonic nondestructive methodology is proposed for the assessment of low velocity impact damage in a 3D woven composite material. The output data is intended for material scientists and numerical scientists to validate the damage tolerance performance of the manufactured materials and the reliability of damage modeling predictions. A depth-dependent threshold based on the reflectivity of flat bottom holes is applied to the ultrasonic data to remove the structural noise and isolate echoes of interest. The methodology was applied to a 3 mm thick 3D woven composite plate impacted with different energies. An artificial 3D representation of the detected echoes is proposed to enhance the spatial perception of the generated damage by the end user. The paper finally highlights some statistics made on the detected echoes to quantitatively assess the impact damage resistance of the tested specimens.

  3. 3-D woven, mullite matrix, composite filter

    SciTech Connect

    Lane, J.E.; Painter, C.J.; Radford, K.C. LeCostaouec, J.F.

    1995-12-01

    Westinghouse, with Techniweave as a major subcontractor, is conducting a three-phase program aimed at providing advanced candle filters for a 1996 pilot scale demonstration in one of the two hot gas filter systems at Southern Company Service`s Wilsonville PSD Facility. The Base Program (Phases I and II) objective is to develop and demonstrate the suitability of the Westinghouse/Techniweave next generation composite candle filter for use in Pressurized Fluidized Bed Combustion (PFBC) and/or Integrated Gasification Combined Cycle (IGCC) power generation systems. The Optional Task (Phase M, Task 5) objective is to fabricate, inspect and ship to Wilsonville Hot gas particulate filters are key components for the successful commercializaion of advanced coal-based power-generation systems such as Pressurized Fluidized-bed Combustion (PFBC), including second-generation PFBC, and Integrated Gasification Combined Cycles (IGCC). Current generation monolithic ceramic filters are subject to catastrophic failure because they have very low resistance to crack propagation. To overcome this problem, a damage-tolerant ceramic filter element is needed.

  4. Modeling of 3-D Woven Ceramic Matrix Composites

    NASA Technical Reports Server (NTRS)

    Murthy, Pappu L. N.; Sullivan, Roy M.; Mital, Subodh K.

    2003-01-01

    Three different approaches are being pursued at the NASA Glenn Research Center to predict the nanostructural behavior of three-dimensional woven ceramic matrix composites. These are: a micromechanics-based approach using W-CEMCAN (Woven Ceramic Matrix Composite Analyzer), a laminate analogy method and a structural frame approach (based on the finite element method). All three techniques are applied to predict the thermomechanical properties of a three-dimensional woven angle interlock C/SiC composite. The properties are predicted for room temperature and 1100 C and the predicted properties are compared to measurements. General observations regarding the three approaches for three-dimensional composite modeling are discussed.

  5. Manufacture and performance of carbon/epoxy 3-D woven composites

    NASA Technical Reports Server (NTRS)

    Brandt, J.; Drechsler, K.; Mohamed, Mansour; Gu, PU

    1992-01-01

    This paper evaluates 3-D orthogonal woven carbon/epoxy composites. Preforms were manufactured on an automatic 3-D weaving machine developed at N.C. State University. Matrix infiltration was conducted at MBB Central Laboratories. Testing was carried out at both locations and the joint results will be reported. The properties investigated include: interlaminar shear strength, compression, compression after impact, bending, tensile and penetration resistance. The 3-D orthogonal woven composites were compared with laminated and other 3-D composites made with preforms having interlock structure. C-scans were used to examine the quality of infiltration and the damage area after impact. The performance of the composites made from the 3-D orthogonal preforms showed superior properties compared to the other composites. The penetration resistance test showed unexpectedly very good performance.

  6. Properties of multiaxial and 3-D orthogonal woven carbon/epoxy composites

    SciTech Connect

    Bilisik, A.K.; Mohamed, M.H.

    1995-06-01

    A new three-dimensional multiaxial weaving technique was developed at NCSU. Rectangular cross-sectional preforms were fabricated. The preforms have five sets of yarn: these are warp, filling, Z-yarn and {+-}45{degree} yarns. The preforms which are made from carbon fibers were consolidated by vacuum impregnation molding at N.C. A and T State University. Epoxy/resin was used as the matrix. The unit cell of the multiaxial 3-D woven structure has been described. Mechanical tests were carried out on multiaxial 3-D woven and orthogonal woven carbon/epoxy composites. The tests included bending, interlaminar shear and in-plane shear. Test results for both structures were compared and are presented.

  7. Polymer optical fibers integrated directly into 3D orthogonal woven composites for sensing

    NASA Astrophysics Data System (ADS)

    Hamouda, Tamer; Seyam, Abdel-Fattah M.; Peters, Kara

    2015-02-01

    This study demonstrates that standard polymer optical fibers (POF) can be directly integrated into composites from 3D orthogonal woven preforms during the weaving process and then serve as in-situ sensors to detect damage due to bending or impact loads. Different composite samples with embedded POF were fabricated of 3D orthogonal woven composites with different parameters namely number of y-/x-layers and x-yarn density. The signal of POF was not affected significantly by the preform structure. During application of resin using VARTM technique, significant drop in backscattering level was observed due to pressure caused by vacuum on the embedded POF. Measurements of POF signal while in the final composites after resin cure indicated that the backscattering level almost returned to the original level of un-embedded POF. The POF responded to application of bending and impact loads to the composite with a reduction in the backscattering level. The backscattering level almost returned back to its original level after removing the bending load until damage was present in the composite. Similar behavior occurred due to impact events. As the POF itself is used as the sensor and can be integrated throughout the composite, large sections of future 3D woven composite structures could be monitored without the need for specialized sensors or complex instrumentation.

  8. Hybrid Three-Dimensional (3-D) Woven Thick Composite Architectures in Bending

    NASA Astrophysics Data System (ADS)

    Pankow, Mark; Quabili, Ashiq; Yen, Chian-Fong

    2013-11-01

    In this study, three 3-dimensional (3-D) woven composite materials were examined to determine how yarn tow configurations affect the flexural response of the structure. Woven fabric preforms were manufactured with a Z-fiber architecture in 2-3 in. thicknesses. These preforms contained S-2 Glass (AGY, Aiken, SC, USA), carbon, and Twaron (Teijin Aramid, Arnhem, The Netherlands) yarns in different architectures creating a hybrid material system. Due to the thickness of the material, these samples required a significant span length (30 in.). The results showed a change in the strength and degradation after failure with the addition of carbon layers in tension.

  9. 3-D woven ceramic composite hot gas filter development

    SciTech Connect

    Lane, Jay E.; LeCostaouec, Jean-Francois; LeCostaouec, J.F., Westinghouse

    1998-01-01

    Westinghouse, with Techniweave as a major subcontractor, is conducting a three-phase program aimed at providing advanced candle filters for a 1997 pilot-scale demonstration in one of the two hot- gas filter systems at Southern Company Service`s Wilsonville PSD Facility. The Base Program (Phases I and 11) goal is to develop and demonstrate the suitability of the Westinghouse/ Techniweave next- generation, composite, candle filter for use in Pressurized Fluidized- Bed Combustion (PFBC) and/or Integrated Gasification Combined-Cycle (IGCC) power generation systems. The Optional Task (Phase 111, Task 5) objective is to fabricate, inspect, and ship to Wilsonville 50 advanced candle filters for pilot-scale testing.

  10. Meso-Scale Modeling to Characterize Moisture Absorption of 3D Woven Composite

    NASA Astrophysics Data System (ADS)

    Yuan, Yuan; Zhou, Chu-wei

    2016-03-01

    For polymer-matrix composites, moisture is expected to degrade their mechanical properties due to matrix plasticization and moisture introduced micro-scale defects. In this study, the moisture absorptions of bulk epoxy, unidirectional composite (UD) and 3D woven composite (3D WC) were tested. Two-stage features have been observed for all these three materials. Moisture properties for UD and 3D WC were found not in simple direct proportion to their matrix volume fractions. The moisture approach of UD was modeled including the effect of fiber/matrix interphase which promotes the moisture uptake. Then, meso-scale FE model for 3D WC was established to characterize the inhomogeneous moisture diffusion. The moisture properties of resin-rich region and fiber bundle in 3D WC were determined from water uptake experiments of bulk epoxy and UD, respectively. Through homogenizing moisture properties of surface and interior weave structures, a simplified theoretical sandwich moisture diffusion approach was established. The moisture weight gains of 3D WC predicted by both meso-scale FE model and simplified sandwich approach were well agreed with the experimental data.

  11. Meso-Scale Modeling to Characterize Moisture Absorption of 3D Woven Composite

    NASA Astrophysics Data System (ADS)

    Yuan, Yuan; Zhou, Chu-wei

    2016-08-01

    For polymer-matrix composites, moisture is expected to degrade their mechanical properties due to matrix plasticization and moisture introduced micro-scale defects. In this study, the moisture absorptions of bulk epoxy, unidirectional composite (UD) and 3D woven composite (3D WC) were tested. Two-stage features have been observed for all these three materials. Moisture properties for UD and 3D WC were found not in simple direct proportion to their matrix volume fractions. The moisture approach of UD was modeled including the effect of fiber/matrix interphase which promotes the moisture uptake. Then, meso-scale FE model for 3D WC was established to characterize the inhomogeneous moisture diffusion. The moisture properties of resin-rich region and fiber bundle in 3D WC were determined from water uptake experiments of bulk epoxy and UD, respectively. Through homogenizing moisture properties of surface and interior weave structures, a simplified theoretical sandwich moisture diffusion approach was established. The moisture weight gains of 3D WC predicted by both meso-scale FE model and simplified sandwich approach were well agreed with the experimental data.

  12. Effect of tow alignment on the mechanical performance of 3D woven textile composites

    NASA Technical Reports Server (NTRS)

    Norman, Timothy L.; Allison, Patti; Baldwin, Jack W.; Gracias, Brian K.; Seesdorf, Dave

    1993-01-01

    Three-dimensional (3D) woven preforms are currently being considered for use as primary structural components. Lack of technology to properly manufacture, characterize and predict mechanical properties, and predict damage mechanisms leading to failure are problems facing designers of textile composite materials. Two material systems with identical specifications but different manufacturing approaches are investigated. One manufacturing approach resulted in an irregular (nonuniform) preform geometry. The other approach yielded the expected preform geometry (uniform). The objectives are to compare the mechanical properties of the uniform and nonuniform angle interlock 3D weave constructions. The effect of adding layers of laminated tape to the outer surfaces of the textile preform is also examined. Damage mechanisms are investigated and test methods are evaluated.

  13. Three-Axis Distributed Fiber Optic Strain Measurement in 3D Woven Composite Structures

    NASA Technical Reports Server (NTRS)

    Castellucci, Matt; Klute, Sandra; Lally, Evan M.; Froggatt, Mark E.; Lowry, David

    2013-01-01

    Recent advancements in composite materials technologies have broken further from traditional designs and require advanced instrumentation and analysis capabilities. Success or failure is highly dependent on design analysis and manufacturing processes. By monitoring smart structures throughout manufacturing and service life, residual and operational stresses can be assessed and structural integrity maintained. Composite smart structures can be manufactured by integrating fiber optic sensors into existing composite materials processes such as ply layup, filament winding and three-dimensional weaving. In this work optical fiber was integrated into 3D woven composite parts at a commercial woven products manufacturing facility. The fiber was then used to monitor the structures during a VARTM manufacturing process, and subsequent static and dynamic testing. Low cost telecommunications-grade optical fiber acts as the sensor using a high resolution commercial Optical Frequency Domain Reflectometer (OFDR) system providing distributed strain measurement at spatial resolutions as low as 2mm. Strain measurements using the optical fiber sensors are correlated to resistive strain gage measurements during static structural loading. Keywords: fiber optic, distributed strain sensing, Rayleigh scatter, optical frequency domain reflectometry

  14. Three-axis distributed fiber optic strain measurement in 3D woven composite structures

    NASA Astrophysics Data System (ADS)

    Castellucci, Matt; Klute, Sandra; Lally, Evan M.; Froggatt, Mark E.; Lowry, David

    2013-03-01

    Recent advancements in composite materials technologies have broken further from traditional designs and require advanced instrumentation and analysis capabilities. Success or failure is highly dependent on design analysis and manufacturing processes. By monitoring smart structures throughout manufacturing and service life, residual and operational stresses can be assessed and structural integrity maintained. Composite smart structures can be manufactured by integrating fiber optic sensors into existing composite materials processes such as ply layup, filament winding and three-dimensional weaving. In this work optical fiber was integrated into 3D woven composite parts at a commercial woven products manufacturing facility. The fiber was then used to monitor the structures during a VARTM manufacturing process, and subsequent static and dynamic testing. Low cost telecommunications-grade optical fiber acts as the sensor using a high resolution commercial Optical Frequency Domain Reflectometer (OFDR) system providing distributed strain measurement at spatial resolutions as low as 2mm. Strain measurements using the optical fiber sensors are correlated to resistive strain gage measurements during static structural loading.

  15. Modeling and characterization of through-the-thickness properties of 3D woven composites

    NASA Technical Reports Server (NTRS)

    Hartranft, Dru; Pravizi-Majidi, Azar; Chou, Tsu-Wei

    1995-01-01

    The through-the-thickness properties of three-dimensionally (3D) woven carbon/epoxy composites have been studied. The investigation aimed at the evaluation and development of test methodologies for the property characterization in the thickness direction, and the establishment of fiber architectures were studied: layer-to-layer Angle Interlock, through-the-thickness Orthogonal woven preform with surface pile was also designed and manufactured for the fabrication of tensile test coupons with integrated grips. All the preforms were infiltrated by the resin transfer molding technique. The microstructures of the composites were characterized along the warp and fill (weft) directions to determine the degree of yarn undulations, yarn cross-sectional shapes, and microstructural dimensions. These parameters were correlated to the fiber architecture. Specimens were designed and tested for the direct measurement of the through-the-thickness tensile, compressive and shear properties of the composites. Design optimization was conducted through the analysis of the stress fields within the specimen coupled with experimental verification. The experimentally-derived elastic properties in the thickness direction compared well with analytical predictions obtained from a volume averaging model.

  16. Plasma penetration depth and mechanical properties of atmospheric plasma-treated 3D aramid woven composites

    NASA Astrophysics Data System (ADS)

    Chen, X.; Yao, L.; Xue, J.; Zhao, D.; Lan, Y.; Qian, X.; Wang, C. X.; Qiu, Y.

    2008-12-01

    Three-dimensional aramid woven fabrics were treated with atmospheric pressure plasmas, on one side or both sides to determine the plasma penetration depth in the 3D fabrics and the influences on final composite mechanical properties. The properties of the fibers from different layers of the single side treated fabrics, including surface morphology, chemical composition, wettability and adhesion properties were investigated using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), contact angle measurement and microbond tests. Meanwhile, flexural properties of the composites reinforced with the fabrics untreated and treated on both sides were compared using three-point bending tests. The results showed that the fibers from the outer most surface layer of the fabric had a significant improvement in their surface roughness, chemical bonding, wettability and adhesion properties after plasma treatment; the treatment effect gradually diminished for the fibers in the inner layers. In the third layer, the fiber properties remained approximately the same to those of the control. In addition, three-point bending tests indicated that the 3D aramid composite had an increase of 11% in flexural strength and 12% in flexural modulus after the plasma treatment. These results indicate that composite mechanical properties can be improved by the direct fabric treatment instead of fiber treatment with plasmas if the fabric is less than four layers thick.

  17. An Evaluation of 3D Woven Orthogonal Composites' Potential in the Automotive Supply Chain

    NASA Astrophysics Data System (ADS)

    Taylor, Dalia

    The automotive supply chain and its management can be a very complex process and comprises a long dynamic and complex network that consists of four primary segments: original equipment manufacturers (OEMs), first tier suppliers, sub tiers suppliers, and infrastructure suppliers. During the analysis of the current automotive industry it was identified that textile industry importance is considerable increasing as a part of the global automotive supply chain, because textile products are used for interior, exterior and even suspension parts and components. Automotive industry has an increasing demand for higher quality exterior panels with better functional properties and reduced weight. One of the main potentials for this demand is based on the three-dimensional woven composites technology innovations which can replace an existing technology. The new role of the textile industry could make important changes in the automotive supply chain industry, such as: changes in the size of the supply chain, the time to the market and the position of textile industry in the automotive supply chain structure. 3D composite materials from high performance fibers, such as glass and carbon, have been used for automotive applications in a limited way due to the low production rate and the lack of research and development. This research will contribute to the understanding of textile composites in transportation and the textile parameters that affect the performance characteristics of these materials. The research examines the performance characteristics of lighter and stronger 3D woven fabric composites made from fiberglass with the aim to improve fuel efficiency by reducing the total vehicle weight while maintaining safety standards. The performance characteristics of the 3D woven fabric composite can be designed by changing different construction parameters, such as picks density, pick roving linear density, arrangements of warp and z-yarns, and the number of warp and picks layers

  18. A methodology to mesh mesoscopic representative volume element of 3D interlock woven composites impregnated with resin

    NASA Astrophysics Data System (ADS)

    Ha, Manh Hung; Cauvin, Ludovic; Rassineux, Alain

    2016-04-01

    We present a new numerical methodology to build a Representative Volume Element (RVE) of a wide range of 3D woven composites in order to determine the mechanical behavior of the fabric unit cell by a mesoscopic approach based on a 3D finite element analysis. Emphasis is put on the numerous difficulties of creating a mesh of these highly complex weaves embedded in a resin. A conforming mesh at the numerous interfaces between yarns is created by a multi-quadtree adaptation technique, which makes it possible thereafter to build an unstructured 3D mesh of the resin with tetrahedral elements. The technique is not linked with any specific tool, but can be carried out with the use of any 2D and 3D robust mesh generators.

  19. Performance of Composites from 3D Orthogonal Woven Preforms in terms of Architecture and Sample Location during Resin Infusion

    NASA Astrophysics Data System (ADS)

    Ince, Mehmet Erdem

    Geometric modeling of woven preforms is a useful tool to predict preform thickness, preform areal density and fiber volume fraction (FVF) of constituent yarns. Previous geometrical models of 3D orthogonal woven preforms, which are extensively reviewed in Chapter 2, were limited to plain weave interlacing pattern in jammed case. In this study, generalized geometric models in terms of weave design (represented by a numerical value termed "weave factor") were developed. The models cover both jammed and non-jammed cases, consider circular, racetrack, and rectangular yarn cross-sectional shapes. The models predict thickness, constituent yarn weights, and FVFs of 3D orthogonal woven preforms. The models illustrated fabric architecture potential of 3D orthogonal woven preforms. Numerical results for hypothetical structures showed how to control through the thickness components of the z-yarn and total FVF, that have direct effect on the in-plane and out-of-plane properties, with interlacing pattern (weave factor) and z-yarn linear density. The models were demonstrated as an essential design tool that may be used to develop composites with predicted level of structural parameters and performance. Broad range of 3D orthogonal woven preforms from glass fibers with different architectures were woven and consolidated by vacuum infusion process (VIP) with different z-yarn interlacing pattern, number of y-yarn layers, and x-yarn spacing to verify the model for filament yarns. Dry preform thickness and weight of in-plane yarns predicted by the geometric model for filament yarns correlated well with experimental results. Z-yarn weight of dry preform was 24.3% overestimated by the model due to shortening of z-yarn at cross overs in real preforms due to the flattening of x-yarns caused by the tension of z-yarns. Total FVF of actual dry preform was 0.4% greater than model prediction. However, total FVF of composite was 5.4% overestimated by the model, which is within the experimental

  20. Fabrication and characterization of nanoclay modified PMR type polyimide composites reinforced with 3D woven basalt fabric

    NASA Astrophysics Data System (ADS)

    Xie, Jianfei; Qiu, Yiping

    2009-07-01

    Nanoclay modified PMR type polyimide composites were prepared from 3D orthogonal woven basalt fiber performs and nanoclay modified polyimide matrix resin, which derived from methylene dianiline (MDA), dimethyl ester of 3,3',4,4'- oxydiphthalic acid (ODPE), monomethyl ester of cis-5-norbornene-endo-2,3-dicarboxylic acid (NE) and nanoclay. The Na+-montmorillonite was organically treated using a 1:1 molar ratio mixture of dodecylamine (C12) and MDA. The rheological properties of neat B-stage PMR polyimide and 2% clay modified B-stage PMR polyimide were investigated. Based on the results obtained from the rheological tests, a two step compression molding process can be established for the composites. In the first step, the 3D fabric preforms were impregnated with polyimide resin in a vacuum oven and heated up for degassing the volatiles and by-products. In the second step, composites were compressed. The internal structure of the composites was observed by a microscope. Incorporation of 2% clay showed an improvement in the Tg and stiffness of the PMR polyimide. The resulting composites exhibited high thermal stability and good mechanical properties.

  1. A Numerical Study on the Thermal Conductivity of 3D Woven C/C Composites at High Temperature

    NASA Astrophysics Data System (ADS)

    Shigang, Ai; Rujie, He; Yongmao, Pei

    2015-12-01

    Experimental data for Carbon/Carbon (C/C) constituent materials are combined with a three dimensional steady state heat transfer finite element analysis to demonstrate the average in-plane and out-of-plane thermal conductivities (TCs) of C/C composites. The finite element analysis is carried out at two distinct length scales: (a) a micro scale comparable with the diameter of carbon fibres and (b) a meso scale comparable with the carbon fibre yarns. Micro-scale model calculate the TCs at the fibre yarn scale in the three orthogonal directions ( x, y and z). The output results from the micro-scale model are then incorporated in the meso-scale model to obtain the global TCs of the 3D C/C composite. The simulation results are quite consistent with the theoretical and experimental counterparts reported in references. Based on the numerical approach, TCs of the 3D C/C composite are calculated from 300 to 2500 K. Particular attention is given in elucidating the variations of the TCs with temperature. The multi-scale models provide an efficient approach to predict the TCs of 3D textile materials, which is helpful for the thermodynamic property analysis and structure design of the C/C composites.

  2. Micromechanical Modeling of Woven Metal Matrix Composites

    NASA Technical Reports Server (NTRS)

    Bednarcyk, Brett A.; Pindera, Marek-Jerzy

    1997-01-01

    This report presents the results of an extensive micromechanical modeling effort for woven metal matrix composites. The model is employed to predict the mechanical response of 8-harness (8H) satin weave carbon/copper (C/Cu) composites. Experimental mechanical results for this novel high thermal conductivity material were recently reported by Bednarcyk et al. along with preliminary model results. The micromechanics model developed herein is based on an embedded approach. A micromechanics model for the local (micro-scale) behavior of the woven composite, the original method of cells (Aboudi), is embedded in a global (macro-scale) micromechanics model (the three-dimensional generalized method of cells (GMC-3D) (Aboudi). This approach allows representation of true repeating unit cells for woven metal matrix composites via GMC-3D, and representation of local effects, such as matrix plasticity, yarn porosity, and imperfect fiber-matrix bonding. In addition, the equations of GMC-3D were reformulated to significantly reduce the number of unknown quantities that characterize the deformation fields at the microlevel in order to make possible the analysis of actual microstructures of woven composites. The resulting micromechanical model (WCGMC) provides an intermediate level of geometric representation, versatility, and computational efficiency with respect to previous analytical and numerical models for woven composites, but surpasses all previous modeling work by allowing the mechanical response of a woven metal matrix composite, with an elastoplastic matrix, to be examined for the first time. WCGMC is employed to examine the effects of composite microstructure, porosity, residual stresses, and imperfect fiber-matrix bonding on the predicted mechanical response of 8H satin C/Cu. The previously reported experimental results are summarized, and the model predictions are compared to monotonic and cyclic tensile and shear test data. By considering appropriate levels of porosity

  3. 3D geometric modelling of hand-woven textile

    NASA Astrophysics Data System (ADS)

    Shidanshidi, H.; Naghdy, F.; Naghdy, G.; Conroy, D. Wood

    2008-02-01

    Geometric modeling and haptic rendering of textile has attracted significant interest over the last decade. A haptic representation is created by adding the physical properties of an object to its geometric configuration. While research has been conducted into geometric modeling of fabric, current systems require time-consuming manual recognition of textile specifications and data entry. The development of a generic approach for construction of the 3D geometric model of a woven textile is pursued in this work. The geometric model would be superimposed by a haptic model in the future work. The focus at this stage is on hand-woven textile artifacts for display in museums. A fuzzy rule based algorithm is applied to the still images of the artifacts to generate the 3D model. The derived model is exported as a 3D VRML model of the textile for visual representation and haptic rendering. An overview of the approach is provided and the developed algorithm is described. The approach is validated by applying the algorithm to different textile samples and comparing the produced models with the actual structure and pattern of the samples.

  4. Development of 3D Woven Ablative Thermal Protection Systems (TPS) for NASA Spacecraft

    NASA Technical Reports Server (NTRS)

    Feldman, Jay D.; Ellerby, Don; Stackpoole, Mairead; Peterson, Keith; Venkatapathy, Ethiraj

    2015-01-01

    The development of a new class of thermal protection system (TPS) materials known as 3D Woven TPS led by the Entry Systems and Technology Division of NASA Ames Research Center (ARC) will be discussed. This effort utilizes 3D weaving and resin infusion technologies to produce heat shield materials that are engineered and optimized for specific missions and requirements. A wide range of architectures and compositions have been produced and preliminarily tested to prove the viability and tailorability of the 3D weaving approach to TPS.

  5. Failure mechanisms of 3-D woven SiC/SiC composites under tensile and flexural loading at room and elevated temperatures

    SciTech Connect

    Chulya, A.; Gyekenyesi, J.Z.; Gyekenyesi, J.P.

    1992-08-01

    Nicalon silicon carbide 3D yarn with silicon carbide matrix composites made through a chemical vapor infiltration (CVI) process were investigated under tensile and flexural loading at 23, 1200 and 1550 C in air. The effectiveness of a chemical vapor deposition (CVD) SiC surface coating was also evaluated in severe oxidizing environment. Acoustic emission sensors and in situ optical microscopy were used at room temperature to monitor the failure mechanisms. It is shown that the level of tensile stress at which nonlinear behavior begins is not drastically reduced at 1200 and 1550 C when composites were protected by a SiC surface coating. Extensive fiber pull-out was observed only in the 1550 C specimen. Similar behaviors were also found in flexural specimens. 14 refs.

  6. Comparison of Failure Modes in 2-D and 3-D Woven Carbon Phenolic Systems

    NASA Technical Reports Server (NTRS)

    Rossman, Grant A.; Stackpoole, Mairead; Feldman, Jay; Venkatapathy, Ethiraj; Braun, Robert D.

    2013-01-01

    NASA Ames Research Center is developing Woven Thermal Protection System (WTPS) materials as a new class of heatshields for entry vehicles (Stackpoole). Currently, there are few options for ablative entry heatshield materials, none of which is ideally suited to the planetary probe missions currently of interest to NASA. While carbon phenolic was successfully used for the missions Pioneer Venus and Galileo (to Jupiter), the heritage constituents are no longer available. An alternate carbon phenolic would need to be qualified for probe missions, which is most efficient at heat fluxes greater than those currently of interest. Additional TPS materials such as Avcoat and PICA are not sufficiently robust for the heat fluxes required. As a result, there is a large TPS gap between the materials efficient at very high conditions (carbon phenolic) and those that are effective at low-moderate conditions (all others). Development of 3D Woven TPS is intended to fill this gap, targeting mid-density weaves that could with withstand mid-range heat fluxes between 1100 W/sq cm and 8000 W/sq cm (Venkatapathy (2012). Preliminary experimental studies have been performed to show the feasibility of WTPS as a future mid-range TPS material. One study performed in the mARC Jet Facility at NASA Ames Research Center characterized the performance of a 3D Woven TPS sample and compared it to 2D carbon phenolic samples at ply angles of 0deg, 23.5deg, and 90deg. Each sample contained similar compositions of phenolic and carbon fiber volume fractions for experimental consistency. The goal of this study was to compare the performance of the TPS materials by evaluating resulting recession and failure modes. After exposing both samples to similar heat flux and pressure conditions, the 2D carbon phenolic laminate was shown to experience significant delamination between layers and further pocketing underneath separated layers. The 3D Woven TPS sample did not experience the delamination or pocketing

  7. Abradability testing of Bn-Nextel{trademark} 312/Blackglas{trademark} 3-D woven composites and the effect on retained strength

    SciTech Connect

    Wildman, D.; Khandelwal, P.

    1996-12-31

    The low pressure (LP) turbine interstage seal for the Allison Engine Company AE 3007 turbofan engine is the component selected for the Low Cost Ceramic Composite (LC{sup 3}) program. The AE 3007 engine is a 7200 lb thrust turbofan engine with both military and commercial applications. The goals of the LP turbine interstage seal design are to provide a directly interchangeable design that will meet the 12,000 hours service life requirement with an approximate 74% weight reduction as well as initial acquisition cost and life cycle cost savings. The current LP turbine interstage seal design is comprised of a Hastelloy X honeycomb compliant seal member brazed to an INCO 718 structural member. Two approaches were used for the ceramic matrix composite (CMC) version of the interstage seal. The first approach entailed developing a process for brazing the Hastelloy X honeycomb material to the CMC with provisions for accommodating the differential thermal expansion ratio of 4:1. The second approach was to evaluate the abradability/conformability of the CMC material by conducting high speed, high temperature, rub rig testing as well as mechanical testing of the rub specimens to evaluate the retained mechanical strength. In the event the direct rub testing proved to be successful, the need for the Hastelloy X honeycomb and braze joint would be eliminated, resulting in a significant component fabrication cost reduction.

  8. Flexural performance of woven hybrid composites

    NASA Astrophysics Data System (ADS)

    Maslinda, A. B.; Majid, M. S. Abdul; Dan-mallam, Y.; Mazawati, M.

    2016-07-01

    This paper describes the experimental investigation of the flexural performance of natural fiber reinforced polymer composites. Hybrid composites consist of interwoven kenaf/jute and kenaf/hemp fibers was prepared by infusion process using epoxy as polymer matrix. Woven kenaf, jute and hemp composites were also prepared for comparison. Both woven and hybrid composites were subjected to three point flexural test. From the result, bending resistance of hybrid kenaf/jute and kenaf/hemp composites was higher compared to their individual fiber. Hybridization with high strength fiber such as kenaf enhanced the capability of jute and hemp fibers to withstand bending load. Interlocking between yarns in woven fabric make pull out fibers nearly impossible and increase the flexural performance of the hybrid composites.

  9. 3D Woven-Like Carbon Micropattern Decorated with Silicon Nanoparticles for Use in Lithium-Ion Batteries.

    PubMed

    Kang, Da-Young; Kim, Cheolho; Gueon, Donghee; Park, Gyulim; Kim, Jung Sub; Lee, Joong Kee; Moon, Jun Hyuk

    2015-10-26

    Carbon/silicon composite materials are a promising anode substrate for use in lithium-ion batteries. In this study, we suggest a new architecture for a composite electrode made of a woven-like carbon material decorated with silicon nanoparticles. The 3D woven-like carbon (WLC) structure was fabricated using direct carbonization of multi-beam interference lithography polymer patterns. Subsequent solution coating was applied to decorate the WLC with silicon nanoparticles (SiNPs). The SiNP/WLC electrode exhibited a specific capacity of 930 mAh g(-1) , which is three times higher than the specific capacity of the bare electrode. Specifically, the SiNP/WLC electrode exhibited an outstanding retention capacity of 81 % after 50 cycles and a Coulombic efficiency of more than 98 %. This rate capability performance was attributed to the WLC structure and the uniform decoration of the SiNPs. PMID:26383881

  10. Micromechanics of fatigue in woven and stitched composites

    NASA Technical Reports Server (NTRS)

    Cox, B. N.; Carter, W. C.; Dadkhah, M. S.; Morris, W. L.

    1994-01-01

    The goals of this research program were to: (1) determine how microstructural factors, especially the architecture of reinforcing fibers, control stiffness, strength, and fatigue life in 3D woven composites; (2) identify mechanisms of failure; (3) model composite stiffness; (4) model notched and unnotched strength; and (5) model fatigue life. We have examined a total of eleven different angle and orthogonal interlock woven composites. Extensive testing has revealed that these 3D woven composites possess an extraordinary combination of strength, damage tolerance, and notch insensitivity in compression and tension and in monotonic and cyclic loading. In many important regards, 3D woven composites far outstrip conventional 2D laminates or stitched laminates. Detailed microscopic analysis of damage has led to a comprehensive picture of the essential mechanisms of failure and how they are related to the reinforcement geometry. The critical characteristics of the weave architecture that promote favorable properties have been identified. Key parameters are tow size and the distributions in space and strength of geometrical flaws. The geometrical flaws should be regarded as controllable characteristics of the weave in design and manufacture. In addressing our goals, the simplest possible models of properties were always sought, in a blend of old and new modeling concepts. Nevertheless, certain properties, especially regarding damage tolerance, ultimate failure, and the detailed effects of weave architecture, require computationally intensive stochastic modeling. We have developed a new model, the 'binary model,' to carry out such tasks in the most efficient manner and with faithful representation of crucial mechanisms. This is the final report for contract NAS1-18840. It covers all work from April 1989 up to the conclusion of the program in January 1993.

  11. Computational Simulation of Damage Propagation in Three-Dimensional Woven Composites

    NASA Technical Reports Server (NTRS)

    Huang, Dade; Minnetyan, Levon

    2005-01-01

    Three dimensional (3D) woven composites have demonstrated multi-directional properties and improved transverse strength, impact resistance, and shear characteristics. The objective of this research is to develop a new model for predicting the elastic constants, hygrothermal effects, thermomechanical response, and stress limits of 3D woven composites; and to develop a computational tool to facilitate the evaluation of 3D woven composite structures with regard to damage tolerance and durability. Fiber orientations of weave and braid patterns are defined with reference to composite structural coordinates. Orthotropic ply properties and stress limits computed via micromechanics are transformed to composite structural coordinates and integrated to obtain the 3D properties. The various stages of degradation, from damage initiation to collapse of structures, in the 3D woven structures are simulated for the first time. Three dimensional woven composite specimens with various woven patterns under different loading conditions, such as tension, compression, bending, and shear are simulated in the validation process of this research. Damage initiation, growth, accumulation, and propagation to fracture are included in these simulations.

  12. 3D Printable Graphene Composite.

    PubMed

    Wei, Xiaojun; Li, Dong; Jiang, Wei; Gu, Zheming; Wang, Xiaojuan; Zhang, Zengxing; Sun, Zhengzong

    2015-01-01

    In human being's history, both the Iron Age and Silicon Age thrived after a matured massive processing technology was developed. Graphene is the most recent superior material which could potentially initialize another new material Age. However, while being exploited to its full extent, conventional processing methods fail to provide a link to today's personalization tide. New technology should be ushered in. Three-dimensional (3D) printing fills the missing linkage between graphene materials and the digital mainstream. Their alliance could generate additional stream to push the graphene revolution into a new phase. Here we demonstrate for the first time, a graphene composite, with a graphene loading up to 5.6 wt%, can be 3D printable into computer-designed models. The composite's linear thermal coefficient is below 75 ppm·°C(-1) from room temperature to its glass transition temperature (Tg), which is crucial to build minute thermal stress during the printing process. PMID:26153673

  13. Nondestructive characterization of woven fabric ceramic composites

    SciTech Connect

    Hsu, D.K.; Saini, V.; Liaw, P.K.; Yu, N.; Miriyala, N.; McHargue, C.J.; Snead, L.L.; Lowden, R.A.

    1995-10-01

    Woven fabric ceramic composites fabricated by the chemical vapor infiltration method are susceptible to high void content and inhomogeneity. The condition of such materials may be characterized nondestructively with ultrasonic methods. In this work, longitudinal and shear waves were used in the quantitative determination of elastic constants of Nicalon{trademark}/SiC composites as a function of volume percent of porosity. Elastic stiffness constants were obtained for both the in-plane and out-of-plane directions with respect to fiber fabric. The effect of porosity on the modulus of woven fabric composites was also modeled and compared to the measured results. Scan images based on the amplitude and time-of-flight of radio frequency (RF) ultrasonic pulses were used for evaluating the material homogeneity for the purpose of optimizing the manufacturing process and for correlation with the mechanical testing results.

  14. In vitro generation of mechanically functional cartilage grafts based on adult human stem cells and 3D-woven poly(ε-caprolactone) scaffolds

    PubMed Central

    Valonen, P.K.; Moutos, F.T.; Kusanagi, A.; Moretti, M.; Diekman, B.O.; Welter, J.F.; Caplan, A.I.; Guilak, F.

    2009-01-01

    Three-dimensionally woven poly(ε-caprolactone)(PCL) scaffolds were combined with adult human mesenchymal stem cells (hMSC) to engineer mechanically functional cartilage constructs in vitro. The specific objectives were to: (i) produce PCL scaffolds with cartilage-like mechanical properties, (ii) demonstrate that hMSCs formed cartilage after 21-days of culture on PCL scaffolds, and (iii) study effects of scaffold structure (loosely vs. tightly woven), culture vessel (static dish vs. oscillating bioreactor), and medium composition (chondrogenic additives with or without serum). Aggregate moduli of 21-day constructs approached normal articular cartilage for tightly woven PCL cultured in bioreactors, were lower for tightly woven PCL cultured statically, and lowest for loosely woven PCL cultured statically (p<0.05). Construct DNA, total collagen, and glyocosaminoglycans (GAG) increased in a manner dependent on time, culture vessel, and medium composition. Chondrogenesis was verified histologically by rounded cells within a hyaline-like matrix that immunostained for collagen type II but not type I. Bioreactors yielded constructs with higher collagen content (p<0.05) and more homogenous matrix than static controls. Chondrogenic additives yielded constructs with higher GAG (p<0.05) and earlier expression of collagen II mRNA if serum was not present in medium. These results show feasibility of functional cartilage tissue engineering from hMSC and 3D woven PCL scaffolds. PMID:20034665

  15. 3D Printable Graphene Composite

    NASA Astrophysics Data System (ADS)

    Wei, Xiaojun; Li, Dong; Jiang, Wei; Gu, Zheming; Wang, Xiaojuan; Zhang, Zengxing; Sun, Zhengzong

    2015-07-01

    In human being’s history, both the Iron Age and Silicon Age thrived after a matured massive processing technology was developed. Graphene is the most recent superior material which could potentially initialize another new material Age. However, while being exploited to its full extent, conventional processing methods fail to provide a link to today’s personalization tide. New technology should be ushered in. Three-dimensional (3D) printing fills the missing linkage between graphene materials and the digital mainstream. Their alliance could generate additional stream to push the graphene revolution into a new phase. Here we demonstrate for the first time, a graphene composite, with a graphene loading up to 5.6 wt%, can be 3D printable into computer-designed models. The composite’s linear thermal coefficient is below 75 ppm·°C-1 from room temperature to its glass transition temperature (Tg), which is crucial to build minute thermal stress during the printing process.

  16. 3D Printable Graphene Composite

    PubMed Central

    Wei, Xiaojun; Li, Dong; Jiang, Wei; Gu, Zheming; Wang, Xiaojuan; Zhang, Zengxing; Sun, Zhengzong

    2015-01-01

    In human being’s history, both the Iron Age and Silicon Age thrived after a matured massive processing technology was developed. Graphene is the most recent superior material which could potentially initialize another new material Age. However, while being exploited to its full extent, conventional processing methods fail to provide a link to today’s personalization tide. New technology should be ushered in. Three-dimensional (3D) printing fills the missing linkage between graphene materials and the digital mainstream. Their alliance could generate additional stream to push the graphene revolution into a new phase. Here we demonstrate for the first time, a graphene composite, with a graphene loading up to 5.6 wt%, can be 3D printable into computer-designed models. The composite’s linear thermal coefficient is below 75 ppm·°C−1 from room temperature to its glass transition temperature (Tg), which is crucial to build minute thermal stress during the printing process. PMID:26153673

  17. Dry spun 3D woven carbon nanotube anode electrode for Li-lon batteries.

    PubMed

    Ryu, Seongwoo; Kim, Yunkyoung; Lee, Haeshin; Hong, Soon Hyung

    2014-12-01

    Although carbon nanotubes (CNTs) have extraordinary mechanical, thermal, and electrical properties, application of CNTs remains limited due to their unique nano-sized tubular forms. CNT electrodes have relatively high sheet resistance, which does not meet the industrial requirements of various electrode materials. Thus, there are still challenges for improving the performance of CNTs in real applications, particularly in terms of satisfying industrial requirements. In this study, to utilize CNTs in bulk scale electrode applications, we developed a dry spinning technique. The dry spinning technique is a solid state fiber spinning technique that provides an adjustable aligned structure. The dry spinning approach also offers a facile and inexpensive fabrication process, factors which are favorable for industrial scalability for fabricating electrodes. We demonstrate a multilayer stacking process for enhancing the performance for Li-ion batteries. Multi-layer CNT textiles have low sheet resistance and a 3D woven structure provides high surface area. The fabricated 3D woven structured electrode delivers a higher reversible capacity of more than 400 mA hr/g with high cycle stabilities. PMID:25971028

  18. Analysis of woven and braided fabric reinforced composites

    NASA Technical Reports Server (NTRS)

    Naik, Rajiv A.

    1994-01-01

    A general purpose micromechanics analysis that discretely models the yarn architecture within the textile repeating unit cell, was developed to predict overall, three dimensional, thermal and mechanical properties. This analytical technique was implemented in a user-friendly, personal computer-based, windows compatible code called Textile Composite Analysis for Design (TEXCAD). TEXCAD was used to analyze plain, 5-harness satin, and 8-harness satin weave composites along with 2-D braided and 2x2, 2-D triaxial braided composites. The calculated overall stiffnesses correlated well with available 3-D finite element results and test data for both the woven and the braided composites. Parametric studies were performed to investigate the effects of yarn size on the yarn crimp and the overall thermal and mechanical constants for plain weave composites. The effects of braid angle were investigated for the 2-D braided composites. Finally, the effects of fiber volume fraction on the yarn undulations and the thermal and mechanical properties of 2x2, 2-D triaxial braided composites were also investigated.

  19. Characterising Mechanical Properties of Braided and Woven Textile Composite Beams

    NASA Astrophysics Data System (ADS)

    Dauda, Benjamin; Oyadiji, S. Olutunde; Potluri, Prasad

    2009-02-01

    The focus of this paper is on the manufacture of textile composite beams and on the determination of their mechanical properties. This includes investigating the effects of fibre orientation on the mechanical properties of braided and woven textile composites. Composites were manufactured from nominally identical constituents and identical consolidation processes, leaving as the only variables, variations caused by the different fibre architecture of the preform. The repeatability and, hence, reliability of this approach is demonstrated. Results obtained show that fibre architecture affects composite strength and extensibility. Composites with woven preforms are practically linear up to catastrophic failure while composites with braided preforms exhibit non-linearity prior to failure. Also the mechanical properties of the textile composite beams were determined. Results show that by tailoring the braid angle and pick density of braided and woven composite performs, the mechanical properties of the composite beams can be controlled to suit end-use requirement.

  20. Modeling the Stress Strain Behavior of Woven Ceramic Matrix Composites

    NASA Technical Reports Server (NTRS)

    Morscher, Gregory N.

    2006-01-01

    Woven SiC fiber reinforced SiC matrix composites represent one of the most mature composite systems to date. Future components fabricated out of these woven ceramic matrix composites are expected to vary in shape, curvature, architecture, and thickness. The design of future components using woven ceramic matrix composites necessitates a modeling approach that can account for these variations which are physically controlled by local constituent contents and architecture. Research over the years supported primarily by NASA Glenn Research Center has led to the development of simple mechanistic-based models that can describe the entire stress-strain curve for composite systems fabricated with chemical vapor infiltrated matrices and melt-infiltrated matrices for a wide range of constituent content and architecture. Several examples will be presented that demonstrate the approach to modeling which incorporates a thorough understanding of the stress-dependent matrix cracking properties of the composite system.

  1. Effect of Hybridization on Stiffness Properties of Woven Textile Composites

    NASA Astrophysics Data System (ADS)

    Bejan, Liliana; Taranu, Nicolae; Sîrbu, Adriana

    2013-04-01

    The present study focuses on stiffness properties of woven textile reinforced polymeric composites with respect to hybridization, and geometry of reinforcement. The analyzed composites represent combinations of different fibre materials (E-glass, Kevlar 49, carbon HM) in a predetermined fabric geometry (a plane weave embedded in thermosetting polymeric resin) serving controlled properties and required performance. The effects of hybridization on the stiffness properties of woven textile composites have been studied with respect to the fibres materials, the unbalancing degree of fabrics, and the variation of compactness and undulation of yarns. Some undesirable effects in fabric geometry can be overcome by the combined effects of hybridization and compactness.

  2. Mechanisms of compressive failure in woven composites and stitched laminates

    NASA Technical Reports Server (NTRS)

    Cox, B. N.; Dadkhah, M. S.; Inman, R. V.; Morris, W. L.; Schroeder, S.

    1992-01-01

    Stitched laminates and angle interlock woven composites have been studied in uniaxial, in-plane, monotonic compression. Failure mechanisms have been found to depend strongly on both the reinforcement architecture and the degree of constraint imposed by the loading grips. Stitched laminates show higher compressive strength, but are brittle, possessing no load bearing capacity beyond the strain for peak load. Post-mortem inspection shows a localized shear band of buckled and broken fibers, which is evidently the product of an unstably propagating kink band. Similar shear bands are found in the woven composites if the constraint of lateral displacements is weak; but, under strong constraint, damage is not localized but distributed throughout the gauge section. While the woven composites tested are weaker than the stitched laminates, they continue to bear significant loads to compressive strains of approx. 15 percent, even when most damage is confined to a shear band.

  3. Rubber Impact on 3D Textile Composites

    NASA Astrophysics Data System (ADS)

    Heimbs, Sebastian; Van Den Broucke, Björn; Duplessis Kergomard, Yann; Dau, Frederic; Malherbe, Benoit

    2012-06-01

    A low velocity impact study of aircraft tire rubber on 3D textile-reinforced composite plates was performed experimentally and numerically. In contrast to regular unidirectional composite laminates, no delaminations occur in such a 3D textile composite. Yarn decohesions, matrix cracks and yarn ruptures have been identified as the major damage mechanisms under impact load. An increase in the number of 3D warp yarns is proposed to improve the impact damage resistance. The characteristic of a rubber impact is the high amount of elastic energy stored in the impactor during impact, which was more than 90% of the initial kinetic energy. This large geometrical deformation of the rubber during impact leads to a less localised loading of the target structure and poses great challenges for the numerical modelling. A hyperelastic Mooney-Rivlin constitutive law was used in Abaqus/Explicit based on a step-by-step validation with static rubber compression tests and low velocity impact tests on aluminium plates. Simulation models of the textile weave were developed on the meso- and macro-scale. The final correlation between impact simulation results on 3D textile-reinforced composite plates and impact test data was promising, highlighting the potential of such numerical simulation tools.

  4. Analysis of woven fabrics for reinforced composite materials

    NASA Technical Reports Server (NTRS)

    Dow, Norris F.; Ramnath, V.; Rosen, B. Walter

    1987-01-01

    The use of woven fabrics as reinforcements for composites is considered. Methods of analysis of properties are reviewed and extended, with particular attention paid to three-dimensional constructions having through-the-thickness reinforcements. Methodology developed is used parametrically to evaluate the performance potential of a wide variety of reinforcement constructions including hybrids. Comparisons are made of predicted and measured properties of representative composites having biaxial and triaxial woven, and laminated tape lay-up reinforcements. Overall results are incorporated in advanced weave designs.

  5. 3-D textile reinforcements in composite materials

    SciTech Connect

    Miravete, A.

    1999-11-01

    Laminated composite materials have been used in structural applications since the 1960s. However, their high cost and inability to accommodate fibers in the laminate`s thickness direction greatly reduce their damage tolerance and impact resistance. The second generation of materials--3-D textile reinforced composites--offers significant cost reduction, and by incorporating reinforcement in the thickness direction, dramatically increases damage tolerance and impact resistance. However, methods for predicting mechanical properties of 3-D textile reinforced composite materials tend to be more complex. These materials also have disadvantages--particularly in regard to crimps in the yarns--that require more research. Textile preforms, micro- and macromechanical modeling, manufacturing processes, and characterization all need further development. As researchers overcome these problems, this new generation of composites will emerge as a highly competitive family of materials. This book provides a state-of-the-art account of this promising technology. In it, top experts describe the manufacturing processes, highlight the advantages, identify the main applications, analyze methods for predicting mechanical properties, and detail various reinforcement strategies, including grid structure, knitted fabric composites, and the braiding technique. Armed with the information in this book, readers will be prepared to better exploit the advantages of 3-D textile reinforced composites, overcome its disadvantages, and contribute to the further development of the technology.

  6. Woven graphite epoxy composite test specimens with glass buffer strips

    NASA Technical Reports Server (NTRS)

    Bonnar, G. R.; Palmer, R. J.

    1982-01-01

    Woven unidirectional graphite cloth with bands of fiberglass replacing the graphite in discrete lengthwise locations was impregnated with epoxy resin and used to fabricate a series of composite tensile and shear specimens. The finished panels, with the fiberglass buffer strips, were tested. Details of the fabrication process are reported.

  7. Modeling Woven Polymer Matrix Composites with MAC/GMC

    NASA Technical Reports Server (NTRS)

    Bednarcyk, Brett A.; Arnold, Steven M. (Technical Monitor)

    2000-01-01

    NASA's Micromechanics Analysis Code with Generalized Method of Cells (MAC/GMC) is used to predict the elastic properties of plain weave polymer matrix composites (PMCs). The traditional one step three-dimensional homogertization procedure that has been used in conjunction with MAC/GMC for modeling woven composites in the past is inaccurate due to the lack of shear coupling inherent to the model. However, by performing a two step homogenization procedure in which the woven composite repeating unit cell is homogenized independently in the through-thickness direction prior to homogenization in the plane of the weave, MAC/GMC can now accurately model woven PMCs. This two step procedure is outlined and implemented, and predictions are compared with results from the traditional one step approach and other models and experiments from the literature. Full coupling of this two step technique with MAC/ GMC will result in a widely applicable, efficient, and accurate tool for the design and analysis of woven composite materials and structures.

  8. Failure analysis of woven and braided fabric reinforced composites

    SciTech Connect

    Naik, R.A.

    1994-09-01

    A general purpose micromechanics analysis that discretely models the yarn architecture within the textile repeating unit cell was developed to predict overall, three dimensional, thermal and mechanical properties, damage initiation and progression, and strength. This analytical technique was implemented in a user-friendly, personal computer-based, menu-driven code called Textile Composite Analysis for Design (TEXCAD). TEXCAD was used to analyze plain weave and 2x2, 2-D triaxial braided composites. The calculated tension, compression, and shear strengths correlated well with available test data for both woven and braided composites. Parametric studies were performed on both woven and braided architectures to investigate the effects of parameters such as yarn size, yarn spacing, yarn crimp, braid angle, and overall fiber volume fraction on the strength properties of the textile composite.

  9. Failure analysis of woven and braided fabric reinforced composites

    NASA Technical Reports Server (NTRS)

    Naik, Rajiv A.

    1994-01-01

    A general purpose micromechanics analysis that discretely models the yarn architecture within the textile repeating unit cell was developed to predict overall, three dimensional, thermal and mechanical properties, damage initiation and progression, and strength. This analytical technique was implemented in a user-friendly, personal computer-based, menu-driven code called Textile Composite Analysis for Design (TEXCAD). TEXCAD was used to analyze plain weave and 2x2, 2-D triaxial braided composites. The calculated tension, compression, and shear strengths correlated well with available test data for both woven and braided composites. Parametric studies were performed on both woven and braided architectures to investigate the effects of parameters such as yarn size, yarn spacing, yarn crimp, braid angle, and overall fiber volume fraction on the strength properties of the textile composite.

  10. A three-dimensional computational model for unidirectional fiber and woven textile-reinforced composite systems

    NASA Astrophysics Data System (ADS)

    McGlockton, Michael Andre

    1998-12-01

    Models for the behavior of unidirectional fiber reinforced ceramic matrix composites with weak interfaces and 3D woven textile composites are presented as an assemblage of coarse 3D effective medium elements and 1D spring elements. The models are used to simulate the stochastic failure process leading to ultimate stress and the transition to post peak extension. Monte Carlo methods assign fracture nuclei strengths to the 1D spring elements which fail with increasing load. Interface mechanics mechanism are incorporated to transfer load from failed elements to remaining intact elements. For unidirectional CMCs the model predicts the peak stress sustained is comparable to the value expected from global load sharing for a wide range of values of interface shear and constituent elastic properties due to sparse damage in the composite at ultimate load and low stress concentrations. Toughness is predicted from simple pullout laws. For 3D woven textile composites the ultimate strength and toughness are determined by lockup of undulations at the interface of inplane reinforcements. The strength of the lockup is modulated by the presence of through thickness reinforcements which survive after the inplane reinforcements fail.

  11. Micromechanical modeling of laminated composites with interfaces and woven composites using the boundary element method

    NASA Technical Reports Server (NTRS)

    Goldberg, Robert K.; Hopkins, Dale A.

    1993-01-01

    The boundary element method is utilized to analyze the effects of fiber/matrix interfaces on the micromechanical behavior of laminated composites as well as the elastic behavior of woven composites. Effective composite properties are computed for laminated SiC/RBSN and SiC/Ti-15-3 composites, as well as a woven SiC/SiC composite. The properties calculated using the computerized tool BEST-CMS match the experimental results well.

  12. Investigation of woven composites as potential cryogenic tank materials

    NASA Astrophysics Data System (ADS)

    Islam, Md. S.; Melendez-Soto, E.; Castellanos, A. G.; Prabhakar, P.

    2015-12-01

    In this paper, carbon fiber and Kevlar® fiber woven composites were investigated as potential cryogenic tank materials for storing liquid fuel in spacecraft or rocket. Towards that end, both carbon and Kevlar® fiber composites were manufactured and tested with and without cryogenic exposure. The focus was on the investigation of the influence of initial cryogenic exposure on the degradation of the composite. Tensile, flexural and inter laminar shear strength (ILSS) tests were conducted, which indicate that Kevlar® and carbon textile composites are potential candidates for use under cryogenic exposure.

  13. Fatigue strength of woven kenaf fiber reinforced composites

    NASA Astrophysics Data System (ADS)

    Ismail, A. E.; Aziz, M. A. Che Abdul

    2015-12-01

    Nowadays, green composites provide alternative to synthetic fibers for non-bearing and load-bearing applications. According to literature review, lack of information is available on the fatigue performances especially when the woven fiber is used instead of randomly oriented fibers. In order to overcome this problem, this paper investigates the fatigue strength of different fiber orientations and number of layers of woven kenaf fiber reinforced composites. Four types of fiber orientations are used namely 0°, 15°, 30° and 45°. Additionally, two numbers of layers are also considered. It is revealed that the fatigue life has no strong relationship with the fiber orientations. For identical fiber orientations, the fatigue life can be predicted considerably using the normalized stress. However as expected, the fatigue life enhancement occur when the number of layer is increased.

  14. A biomimetic three-dimensional woven composite scaffold for functional tissue engineering of cartilage

    NASA Astrophysics Data System (ADS)

    Moutos, Franklin T.; Freed, Lisa E.; Guilak, Farshid

    2007-02-01

    Tissue engineering seeks to repair or regenerate tissues through combinations of implanted cells, biomaterial scaffolds and biologically active molecules. The rapid restoration of tissue biomechanical function remains an important challenge, emphasizing the need to replicate structural and mechanical properties using novel scaffold designs. Here we present a microscale 3D weaving technique to generate anisotropic 3D woven structures as the basis for novel composite scaffolds that are consolidated with a chondrocyte-hydrogel mixture into cartilage tissue constructs. Composite scaffolds show mechanical properties of the same order of magnitude as values for native articular cartilage, as measured by compressive, tensile and shear testing. Moreover, our findings showed that porous composite scaffolds could be engineered with initial properties that reproduce the anisotropy, viscoelasticity and tension-compression nonlinearity of native articular cartilage. Such scaffolds uniquely combine the potential for load-bearing immediately after implantation in vivo with biological support for cell-based tissue regeneration without requiring cultivation in vitro.

  15. 3D Non-Woven Polyvinylidene Fluoride Scaffolds: Fibre Cross Section and Texturizing Patterns Have Impact on Growth of Mesenchymal Stromal Cells

    PubMed Central

    Schellenberg, Anne; Ross, Robin; Abagnale, Giulio; Joussen, Sylvia; Schuster, Philipp; Arshi, Annahit; Pallua, Norbert; Jockenhoevel, Stefan; Gries, Thomas; Wagner, Wolfgang

    2014-01-01

    Several applications in tissue engineering require transplantation of cells embedded in appropriate biomaterial scaffolds. Such structures may consist of 3D non-woven fibrous materials whereas little is known about the impact of mesh size, pore architecture and fibre morphology on cellular behavior. In this study, we have developed polyvinylidene fluoride (PVDF) non-woven scaffolds with round, trilobal, or snowflake fibre cross section and different fibre crimp patterns (10, 16, or 28 needles per inch). Human mesenchymal stromal cells (MSCs) from adipose tissue were seeded in parallel on these scaffolds and their growth was compared. Initial cell adhesion during the seeding procedure was higher on non-wovens with round fibres than on those with snowflake or trilobal cross sections. All PVDF non-woven fabrics facilitated cell growth over a time course of 15 days. Interestingly, proliferation was significantly higher on non-wovens with round or trilobal fibres as compared to those with snowflake profile. Furthermore, proliferation increased in a wider, less dense network. Scanning electron microscopy (SEM) revealed that the MSCs aligned along the fibres and formed cellular layers spanning over the pores. 3D PVDF non-woven scaffolds support growth of MSCs, however fibre morphology and mesh size are relevant: proliferation is enhanced by round fibre cross sections and in rather wide-meshed scaffolds. PMID:24728045

  16. Damage Accumulation in SiC/SiC Composites with 3D Architectures

    NASA Technical Reports Server (NTRS)

    Morscher, Gregory N.; Yun, Hee-Mann; DiCarlo, James A.

    2003-01-01

    The formation and propagation of multiple matrix cracks in relatively dense ceramic matrix composites when subjected to increasing tensile stress is necessary for high strength and tough composites. However, the occurrence of matrix cracks at low stresses may limit the usefulness of some non-oxide composite systems when subjected to oxidizing environments for long times at stresses sufficient to cause matrix cracking. For SiC fiber-reinforced composites with two-dimensional woven architectures and chemically vapor infiltrated (CVI) SiC matrix and melt-infiltrated (MI) Si/SiC matrix composites, the matrix cracking behavior has been fairly well characterized for different fiber-types and woven architectures. It was found that the occurrence, degree, and growth of matrix cracks depends on the material properties of the composite constituents as well as other physical properties of the composite or architecture, e.g., matrix porosity and size of the fiber bundle. In this study, matrix cracking in SiC fiber reinforced, melt-infiltrated SiC composites with a 3D orthogonal architecture was determined for specimens tested in tension at room temperature. Acoustic emission (AE) was used to monitor the matrix cracking activity, which was later confirmed by microscopic examination of specimens that had failed. The determination of the exact location of AE demonstrated that initial cracking occurred in the matrix rich regions when a large z-direction fiber bundle was used. For specimens with large z-direction fiber tows, the earliest matrix cracking could occur at half the stress for standard 2D woven composites with similar constituents. Damage accumulation in 3D architecture composites will be compared to damage accumulation in 2D architecture composites and discussed with respect to modeling composite stress-strain behavior and use of these composites at elevated temperatures.

  17. 3-D stamp forming of thermoplastic matrix composites

    NASA Astrophysics Data System (ADS)

    Hou, M.; Friedrich, K.

    1994-03-01

    In this investigation a mould with hemispherical cavity and 80 kN hydraulic press, allowing variable stamping speeds, are employed for experimentally studying of the 3-D stamp forming process of continuous fiber reinforced thermoplastic laminates. In particular, glass fiber (GF) reinforced polyetherimide (PEI) woven fabric made of sheath surrounded, polymer powder impregnated fiber bundles manufactured by Enichem, Italy, is used. Pre-consolidated laminates are heated by contact heating in an external heater up to about 120°C above the glass transition temperature ( T g) of the polymer matrix; they are then stamp formed in a cold matched metal tool. Typical cycle times (including preheating time of the preconsolidated laminates) are in the range of 3 min. Useful processing conditions, such as stamping temperature, stamping velocity and hold-down pressure required for stamp forming of this composite are determined. In addition the effect of die geometries (deformation radian) and original laminate dimensions are studied. The results describe the correlations between processing parameters and fiber buckling. Finally the thickness distribution in stamped parts are investigated in relation to different directions of fiber orientation.

  18. Experimental Characterization and Micromechanical Modeling of Woven Carbon/Copper Composites

    NASA Technical Reports Server (NTRS)

    Bednarcyk, Brett A.; Pauly, Christopher C.; Pindera, Marek-Jerzy

    1997-01-01

    The results of an extensive experimental characterization and a preliminary analytical modeling effort for the elastoplastic mechanical behavior of 8-harness satin weave carbon/copper (C/Cu) composites are presented. Previous experimental and modeling investigations of woven composites are discussed, as is the evolution of, and motivation for, the continuing research on C/Cu composites. Experimental results of monotonic and cyclic tension, compression, and Iosipescu shear tests, and combined tension-compression tests, are presented. With regard to the test results, emphasis is placed on the effect of strain gauge size and placement, the effect of alloying the copper matrix to improve fiber-matrix bonding, yield surface characterization, and failure mechanisms. The analytical methodology used in this investigation consists of an extension of the three-dimensional generalized method of cells (GMC-3D) micromechanics model, developed by Aboudi (1994), to include inhomogeneity and plasticity effects on the subcell level. The extension of the model allows prediction of the elastoplastic mechanical response of woven composites, as represented by a true repeating unit cell for the woven composite. The model is used to examine the effects of refining the representative geometry of the composite, altering the composite overall fiber volume fraction, changing the size and placement of the strain gauge with respect to the composite's reinforcement weave, and including porosity within the infiltrated fiber yarns on the in-plane elastoplastic tensile, compressive, and shear response of 8-harness satin C/Cu. The model predictions are also compared with the appropriate monotonic experimental results.

  19. Mechanically fastened joints in woven fabric composites

    NASA Technical Reports Server (NTRS)

    Wilson, D. W.; Bozarth, M. J.; Pipes, R. B.

    1983-01-01

    Strength analysis for composite bolted joints involves the mating of a stress analysis with an appropriate mode specific failure criterion for each of the primary failure modes. The stress analysis and failure criteria are independent of each other and can be manipulated separately in order to optimize the strength analysis package formed by their coupling. Material properties tests were conducted on rubber toughened graphite-epoxy material to measure the basic strength and stiffness in the warp and fill directions and in shear. Test matrices are summarized for investigations of laminate configuration, stacking sequence, fastener diameter, edge distance, fastener half spacing, laminate thickness, and fastener torque. A three dimensional finite element analysis computer program was written and failure criteria for net tension, shearout, and bearing were determined.

  20. The interlaminar fracture toughness of woven graphite/epoxy composites

    NASA Technical Reports Server (NTRS)

    Funk, Joan G.; Deaton, Jerry W.

    1989-01-01

    The interlaminar fracture toughness of 2-D graphite/epoxy woven composites was determined as a function of stacking sequence, thickness, and weave pattern. Plain, oxford, 5-harness satin, and 8-harness satin weaves of T300/934 material were evaluated by the double cantilever beam test. The fabric material had a G (sub Ic) ranging from 2 to 8 times greater than 0 degrees unidirectional T300/934 tape material. The interlaminar fracture toughness of a particular weave style was dependent on whether the stacking sequence was symmetric or asymmetric and, in some cases, on the fabric orientation.

  1. Analytical Failure Prediction Method Developed for Woven and Braided Composites

    NASA Technical Reports Server (NTRS)

    Min, James B.

    2003-01-01

    Historically, advances in aerospace engine performance and durability have been linked to improvements in materials. Recent developments in ceramic matrix composites (CMCs) have led to increased interest in CMCs to achieve revolutionary gains in engine performance. The use of CMCs promises many advantages for advanced turbomachinery engine development and may be especially beneficial for aerospace engines. The most beneficial aspects of CMC material may be its ability to maintain its strength to over 2500 F, its internal material damping, and its relatively low density. Ceramic matrix composites reinforced with two-dimensional woven and braided fabric preforms are being considered for NASA s next-generation reusable rocket turbomachinery applications (for example, see the preceding figure). However, the architecture of a textile composite is complex, and therefore, the parameters controlling its strength properties are numerous. This necessitates the development of engineering approaches that combine analytical methods with limited testing to provide effective, validated design analyses for the textile composite structures development.

  2. Chiral braided and woven composites: design, fabrication, and electromagnetic characterization

    NASA Astrophysics Data System (ADS)

    Wheeland, Sara; Bayatpur, Farhad; Amirkhizi, Alireza V.; Nemat-Nasser, Sia

    2011-04-01

    This work presents a new chiral composite composed of copper wires braided with Kevlar and nylon to form conductive coils integrated among structural fiber. To create a fabric, these braids were woven with plain Kevlar fiber. This yielded a composite with all coils possessing the same handedness, producing a chiral material. The electromagnetic response of this fabric was first simulated using a finite element full-wave simulation. For the electromagnetic measurement, the sample was placed between two lens-horn antennas connected to a Vector Network Analyzer. The frequency response of the sample was scanned between 5.5 and 8GHz. The measured scattering parameters were then compared to those of the simulated model. The measured parameters agreed well with the simulation results, showing a considerable chirality within the measured frequency band. The new composite combines the strength and durability of traditional composites with an electromagnetic design to create a multifunctional material.

  3. Failure mechanisms of woven carbon and glass composites

    SciTech Connect

    Alif, N.; Carlsson, L.A.

    1997-12-31

    Stress-strain responses in tension, compression, and shear of a five-harness satin-weave carbon/epoxy composite and a four-harness satin-weave glass/epoxy composite have been examined. Damage progression under tension was examined by optical microscopic inspection of the polished edges of the specimens. Models for elastic property and failure predictions of woven-fabric composites were examined and correlated with the experimental data. Damage inspection of the carbon/epoxy composite under tension revealed that the initial failure was cracking of pure matrix regions followed by transverse bundle cracking. Fill/weft debonding and longitudinal splits of the fill bundles occurred close to ultimate failure of the composite. The glass/epoxy composite displayed damage in the form of fill/weft debonding and longitudinal splits, but no transverse yarn cracking. The damage observed in both composites was confined to the region where ultimate failure occurred. Elastic properties of the composites were overall in good agreement with micromechanical predictions based on uniform strain, but failure stress predictions were less accurate.

  4. Durability and Damage Development in Woven Ceramic Matrix Composites

    NASA Technical Reports Server (NTRS)

    Haque, A.; Rahman, M.; Tyson, O. Z.; Jeelani, S.; Verrilli, Michael J. (Technical Monitor)

    2001-01-01

    Damage development in woven SiC/SiNC ceramic matrix composites (CMC's) under tensile and cyclic loading both at room and elevated temperatures have been investigated for the exhaust nozzle of high-efficient turbine engines. The ultimate strength, failure strain, proportional limit and modulus data at a temperature range of 23 to 1250 C are generated. The tensile strength of SiC/SiNC woven composites have been observed to increase with increased temperatures up to 1000 C. The stress/strain plot shows a pseudo-yield point at 25 percent of the failure strain (epsilon(sub r)) which indicates damage initiation in the form of matrix cracking. The evolution of damage beyond 0.25 epsilon(sub f), both at room and elevated temperature comprises multiple matrix cracking, interfacial debonding, and fiber pullout. Although the nature of the stress/strain plot shows damage-tolerant behavior under static loading both at room and elevated temperature, the life expectancy of SiC/SiNC composites degrades significantly under cyclic loading at elevated temperature. This is mostly due to the interactions of fatigue damage caused by the mechanically induced plastic strain and the damage developed by the creep strain. The in situ damage evolutions are monitored by acoustic event parameters, ultrasonic C-scan and stiffness degradation. Rate equations for modulus degradation and fatigue life prediction of ceramic matrix composites both at room and elevated temperatures are developed. These rate equations are observed to show reasonable agreement with experimental results.

  5. Comparative Study of 3-Dimensional Woven Joint Architectures for Composite Spacecraft Structures

    NASA Technical Reports Server (NTRS)

    Jones, Justin S.; Polis, Daniel L.; Rowles, Russell R.; Segal, Kenneth N.

    2011-01-01

    The National Aeronautics and Space Administration (NASA) Exploration Systems Mission Directorate initiated an Advanced Composite Technology (ACT) Project through the Exploration Technology Development Program in order to support the polymer composite needs for future heavy lift launch architectures. As an example, the large composite structural applications on Ares V inspired the evaluation of advanced joining technologies, specifically 3D woven composite joints, which could be applied to segmented barrel structures needed for autoclave cured barrel segments due to autoclave size constraints. Implementation of these 3D woven joint technologies may offer enhancements in damage tolerance without sacrificing weight. However, baseline mechanical performance data is needed to properly analyze the joint stresses and subsequently design/down-select a preform architecture. Six different configurations were designed and prepared for this study; each consisting of a different combination of warp/fill fiber volume ratio and preform interlocking method (Z-fiber, fully interlocked, or hybrid). Tensile testing was performed for this study with the enhancement of a dual camera Digital Image Correlation (DIC) system which provides the capability to measure full-field strains and three dimensional displacements of objects under load. As expected, the ratio of warp/fill fiber has a direct influence on strength and modulus, with higher values measured in the direction of higher fiber volume bias. When comparing the Z-fiber weave to a fully interlocked weave with comparable fiber bias, the Z-fiber weave demonstrated the best performance in two different comparisons. We report the measured tensile strengths and moduli for test coupons from the 6 different weave configurations under study.

  6. The inhibition by interleukin 1 of MSC chondrogenesis and the development of biomechanical properties in biomimetic 3D woven PCL scaffolds

    PubMed Central

    Ousema, Paul H.; Moutos, Franklin T.; Estes, Bradley T.; Caplan, Arnold I.; Lennon, Donald P.; Guilak, Farshid; Weinberg, J. Brice

    2012-01-01

    Tissue-engineered constructs designed to treat large cartilage defects or osteoarthritic lesions may be exposed to significant mechanical loading as well as an inflammatory environment upon implantation in an injured or diseased joint. We hypothesized that a three-dimensionally (3D) woven poly(ε-caprolactone) (PCL) scaffold seeded with bone marrow-derived mesenchymal stem cells (MSCs) would provide biomimetic mechanical properties in early stages of in vitro culture as the MSCs assembled a functional, cartilaginous extracellular matrix (ECM). We also hypothesized that these properties would be maintained even in the presence of the pro-inflammatory cytokine interleukin-1 (IL-1), which is found at high levels in injured or diseased joints. MSC-seeded 3D woven scaffolds cultured in chondrogenic conditions synthesized a functional ECM rich in collagen and proteoglycan content, reaching an aggregate modulus of ~0.75 MPa within 14 days of culture. However, the presence of pathophysiologically relevant levels of IL-1 limited matrix accumulation and inhibited any increase in mechanical properties over baseline values. On the other hand, the mechanical properties of constructs cultured in chondrogenic conditions for 4 weeks prior to IL-1 exposure were protected from deleterious effects of the cytokine. These findings demonstrate that IL-1 significantly inhibits the chondrogenic development and maturation of MSC-seeded constructs; however, the overall mechanical functionality of the engineered tissue can be preserved through the use of a 3D woven scaffold designed to recreate the mechanical properties of native articular cartilage. PMID:22999467

  7. Multi-scale modelling of strongly heterogeneous 3D composite structures using spatial Voronoi tessellation

    NASA Astrophysics Data System (ADS)

    El Said, Bassam; Ivanov, Dmitry; Long, Andrew C.; Hallett, Stephen R.

    2016-03-01

    3D composite materials are characterized by complex internal yarn architectures, leading to complex deformation and failure development mechanisms. Net-shaped preforms, which are originally periodic in nature, lose their periodicity when the fabric is draped, deformed on a tool, and consolidated to create geometrically complex composite components. As a result, the internal yarn architecture, which dominates the mechanical behaviour, becomes dependent on the structural geometry. Hence, predicting the mechanical behaviour of 3D composites requires an accurate representation of the yarn architecture within structural scale models. When applied to 3D composites, conventional finite element modelling techniques are limited to either homogenised properties at the structural scale, or the unit cell scale for a more detailed material property definition. Consequently, these models fail to capture the complex phenomena occurring across multiple length scales and their effects on a 3D composite's mechanical response. Here a multi-scale modelling approach based on a 3D spatial Voronoi tessellation is proposed. The model creates an intermediate length scale suitable for homogenisation to deal with the non-periodic nature of the final material. Information is passed between the different length scales to allow for the effect of the structural geometry to be taken into account on the smaller scales. The stiffness and surface strain predictions from the proposed model have been found to be in good agreement with experimental results. The proposed modelling framework has been used to gain important insight into the behaviour of this category of materials. It has been observed that the strain and stress distributions are strongly dependent on the internal yarn architecture and consequently on the final component geometry. Even for simple coupon tests, the internal architecture and geometric effects dominate the mechanical response. Consequently, the behaviour of 3D woven

  8. Structural effects of three-dimensional angle-interlock woven composite undergoing bending cyclic loading

    NASA Astrophysics Data System (ADS)

    Jin, LiMin; Yao, Yao; Yu, YiMin; Rotich, Gideon; Sun, BaoZhong; Gu, BoHong

    2014-03-01

    This paper reports the structural effects of three-dimensional (3-D) angle-interlock woven composite (3DAWC) undergoing three-point bending cyclic loading from experimental and finite element analysis (FEA) approaches. In experiment, the fatigue tests were conducted to measure the bending deflection and to observe the damage morphologies. By the FEA approach, a micro-structural unit-cell model of the 3DAWC was established at the yarn level to simulate the fatigue damage. The stress degradation at the loading condition of constant deformation amplitude was calculated to show the degradation of mechanical properties. In addition, the stress distribution, fatigue damage evolution and critical damage regions were also obtained to qualitatively reveal the structural effects and damage mechanisms of the 3DAWC subjected to three-point bending cyclic loading.

  9. 3D-printing of lightweight cellular composites.

    PubMed

    Compton, Brett G; Lewis, Jennifer A

    2014-09-10

    A new epoxy-based ink is reported, which enables 3D printing of lightweight cellular composites with controlled alignment of multiscale, high-aspectratio fiber reinforcement to create hierarchical structures inspired by balsa wood. Young's modulus values up to 10 times higher than existing commercially available 3D-printed polymers are attainable, while comparable strength values are maintained. PMID:24942232

  10. Quantifying Effects of Voids in Woven Ceramic Matrix Composites

    NASA Technical Reports Server (NTRS)

    Goldsmith, Marlana B.; Sankar, Bhavani V.; Haftka, Raphael T.; Goldberg, Robert K.

    2013-01-01

    Randomness in woven ceramic matrix composite architecture has been found to cause large variability in stiffness and strength. The inherent voids are an aspect of the architecture that may cause a significant portion of the variability. A study is undertaken to investigate the effects of many voids of random sizes and distributions. Response surface approximations were formulated based on void parameters such as area and length fractions to provide an estimate of the effective stiffness. Obtaining quantitative relationships between the properties of the voids and their effects on stiffness of ceramic matrix composites are of ultimate interest, but the exploratory study presented here starts by first modeling the effects of voids on an isotropic material. Several cases with varying void parameters were modeled which resulted in a large amount of variability of the transverse stiffness and out-of-plane shear stiffness. An investigation into a physical explanation for the stiffness degradation led to the observation that the voids need to be treated as an entity that reduces load bearing capabilities in a space larger than what the void directly occupies through a corrected length fraction or area fraction. This provides explanation as to why void volume fraction is not the only important factor to consider when computing loss of stiffness.

  11. 3D Oxide/Oxide Composite Filter

    SciTech Connect

    Lane, J.E.; LeCostaouec, J.; Painter, C.J.; Su, Wei-Fang A.; Radford, K.C.

    1996-12-31

    Hot gas particulate filters are key components for the successful commercialization of advanced coal-based power-generation systems such as Pressurized Fluidized-bed Combustion (PFBC), including second- generation PFBC, and Integrated Gasification Combined Cycles (IGCC). Current generation monolithic ceramic filters are subject to catastrophic failure because they have very low resistance to crack propagation. To overcome this problem, a damage -tolerant ceramic filter element is needed. Westinghouse, with Techniweave as a major subcontractor, is conducting a three-phase program aimed at providing advanced candle filters for a 1996 pilot scale demonstration in one of the two hot gas filter systems at Southern Company Service`s Wilsonville PSD Facility. The Base Program (Phases I and II) objective is to develop and demonstrate the suitability of the Westinghouse/Techniweave next generation composite candle filter for use PFBC and/or IGCC power generation systems. The optional Task (Phase III, Task 5) objective is to fabricate, inspect and ship to Wilsonville 50 advanced candle filters for pilot scale testing.

  12. Evaluation and design considerations of woven composite flywheel materials constructions

    SciTech Connect

    Sapowith, A.D.; Handy, W.E.; Gurson, A.L.; Lerner, G.R.

    1981-06-15

    Work performed from November 1979 to June 1981 on projects for evaluating the specific energy density capability of bidirectional woven flywheel materials and for developing design approaches for the optimization of those materials is reported. After demonstrating the basic geometry needed to construct a constant stress composite flywheel, a method of construction that can integrate radial and hoop fibers, control the relative stiffness in these two principal directions, and offer low cost in production is explained. Such a construction can be accomplished by weaving the radial fibers with the hoop fibers to form a cloth with a circular or spiral configuration. In this design, the warp fibers become the hoops and the pick fibers become the radials. The varying of radial stiffness is controlled by the choice of the pick pattern. In order to evaluate the circular weave, 0.2-in.-thick discs of approximately 20 in.-dia. were molded using S-glass weave and an epoxy matrix. Tensile specimens cut from the discs in both the radial and hoop directions were tested to failure. Further analyses and tests were performed to determine the optimum weave arrangement and the percent of fiber volume needed to optimize the specific material strength. These analyses show that there is a relatively wide range of pick to warp ratios which achieve optimum specific energy densities and that this range includes ratios that are relatively simple to fabricate. The tensile test data show that specific strengths of the fiberglass circular weave approximate 2.5 x 10/sup 6/ in. which results in energy densities at burst of 35 to 40 W-h/lb. A percent of active composite encompassed by the OD for the composite of 78% has been demonstrated. Fiberglass data suggest that the circular weave flywheel can operate over a life cycle equivalent to 10/sup 6/ deep cycles at the energy density level of 15 W-h/lb. (LCL)

  13. FR3D: finding local and composite recurrent structural motifs in RNA 3D structures.

    PubMed

    Sarver, Michael; Zirbel, Craig L; Stombaugh, Jesse; Mokdad, Ali; Leontis, Neocles B

    2008-01-01

    New methods are described for finding recurrent three-dimensional (3D) motifs in RNA atomic-resolution structures. Recurrent RNA 3D motifs are sets of RNA nucleotides with similar spatial arrangements. They can be local or composite. Local motifs comprise nucleotides that occur in the same hairpin or internal loop. Composite motifs comprise nucleotides belonging to three or more different RNA strand segments or molecules. We use a base-centered approach to construct efficient, yet exhaustive search procedures using geometric, symbolic, or mixed representations of RNA structure that we implement in a suite of MATLAB programs, "Find RNA 3D" (FR3D). The first modules of FR3D preprocess structure files to classify base-pair and -stacking interactions. Each base is represented geometrically by the position of its glycosidic nitrogen in 3D space and by the rotation matrix that describes its orientation with respect to a common frame. Base-pairing and base-stacking interactions are calculated from the base geometries and are represented symbolically according to the Leontis/Westhof basepairing classification, extended to include base-stacking. These data are stored and used to organize motif searches. For geometric searches, the user supplies the 3D structure of a query motif which FR3D uses to find and score geometrically similar candidate motifs, without regard to the sequential position of their nucleotides in the RNA chain or the identity of their bases. To score and rank candidate motifs, FR3D calculates a geometric discrepancy by rigidly rotating candidates to align optimally with the query motif and then comparing the relative orientations of the corresponding bases in the query and candidate motifs. Given the growing size of the RNA structure database, it is impossible to explicitly compute the discrepancy for all conceivable candidate motifs, even for motifs with less than ten nucleotides. The screening algorithm that we describe finds all candidate motifs whose

  14. FR3D: finding local and composite recurrent structural motifs in RNA 3D structures

    PubMed Central

    Sarver, Michael; Stombaugh, Jesse; Mokdad, Ali; Leontis, Neocles B.

    2010-01-01

    New methods are described for finding recurrent three-dimensional (3D) motifs in RNA atomic-resolution structures. Recurrent RNA 3D motifs are sets of RNA nucleotides with similar spatial arrangements. They can be local or composite. Local motifs comprise nucleotides that occur in the same hairpin or internal loop. Composite motifs comprise nucleotides belonging to three or more different RNA strand segments or molecules. We use a base-centered approach to construct efficient, yet exhaustive search procedures using geometric, symbolic, or mixed representations of RNA structure that we implement in a suite of MATLAB programs, “Find RNA 3D” (FR3D). The first modules of FR3D preprocess structure files to classify base-pair and -stacking interactions. Each base is represented geometrically by the position of its glycosidic nitrogen in 3D space and by the rotation matrix that describes its orientation with respect to a common frame. Base-pairing and base-stacking interactions are calculated from the base geometries and are represented symbolically according to the Leontis/Westhof basepairing classification, extended to include base-stacking. These data are stored and used to organize motif searches. For geometric searches, the user supplies the 3D structure of a query motif which FR3D uses to find and score geometrically similar candidate motifs, without regard to the sequential position of their nucleotides in the RNA chain or the identity of their bases. To score and rank candidate motifs, FR3D calculates a geometric discrepancy by rigidly rotating candidates to align optimally with the query motif and then comparing the relative orientations of the corresponding bases in the query and candidate motifs. Given the growing size of the RNA structure database, it is impossible to explicitly compute the discrepancy for all conceivable candidate motifs, even for motifs with less than ten nucleotides. The screening algorithm that we describe finds all candidate motifs

  15. Numerical and Experimental Investigations on Deep Drawing of G1151 Carbon Fiber Woven Composites

    NASA Astrophysics Data System (ADS)

    Gherissi, A.; Abbassi, F.; Ammar, A.; Zghal, A.

    2016-06-01

    This study proposes to simulate the deep drawing on carbon woven composites in order to reduce the manufacturing cost and waste of composite material during the stamping process, The multi-scale anisotropic approach of woven composite was used to develop a finite element model for simulating the orientation of fibers accurately and predicting the deformation of composite during mechanical tests and forming process. The proposed experimental investigation for bias test and hemispherical deep drawing process is investigated in the G1151 Interlock. The mechanical properties of carbon fiber have great influence on the deformation of carbon fiber composites. In this study, shear angle-displacement curves and shear load-shear angle curves were obtained from a bias extension test. Deep drawing experiments and simulation were conducted, and the shear load-displacement curves under different forming depths and shear angle-displacement curves were obtained. The results showed that the compression and shear between fibers bundles were the main deformation mechanism of carbon fiber woven composite, as well as the maximum shear angle for the composites with G1151 woven fiber was 58°. In addition, during the drawing process, it has been found that the forming depth has a significant influence on the drawing force. It increases rapidly with the increasing of forming depth. In this approach the suitable forming depth deep drawing of the sheet carbon fiber woven composite was approximately 45 mm.

  16. Effects of assumed tow architecture on the predicted moduli and stresses in woven composites

    NASA Technical Reports Server (NTRS)

    Chapman, Clinton Dane

    1994-01-01

    This study deals with the effect of assumed tow architecture on the elastic material properties and stress distributions of plain weave woven composites. Specifically, the examination of how a cross-section is assumed to sweep-out the tows of the composite is examined in great detail. The two methods studied are extrusion and translation. This effect is also examined to determine how sensitive this assumption is to changes in waviness ratio. 3D finite elements were used to study a T300/Epoxy plain weave composite with symmetrically stacked mats. 1/32nd of the unit cell is shown to be adequate for analysis of this type of configuration with the appropriate set of boundary conditions. At low waviness, results indicate that for prediction of elastic properties, either method is adequate. At high waviness, certain elastic properties become more sensitive to the method used. Stress distributions at high waviness ratio are shown to vary greatly depending on the type of loading applied. At low waviness, both methods produce similar results.

  17. Woven type smart soft composite beam with in-plane shape retention

    NASA Astrophysics Data System (ADS)

    Wu, Renzhe; Han, Min-Woo; Lee, Gil-Yong; Ahn, Sung-Hoon

    2013-12-01

    Shape memory alloy (SMA) wire embedded composites (SMAECs) are widely used as morphing structures in small-size and high-output systems. However, conventional SMAECs cannot keep deformed shapes without additional energy. In this paper, a new kind of smart structure named the woven type smart soft composite (SSC) beam is introduced, which is not only capable of morphing, but also maintaining its deformed shape without additional energy. The woven type SSC beam consists of two parts: woven wires and matrix. The selected woven wires are nitinol (Ni-Ti) SMA wires and glass fibers, while the matrix part is polydimethylsiloxane (PDMS). In order to evaluate the performance of the woven type SSC beam in areas such as in-plane deformation, blocking force and repeatability, a beam-shape specimen is prepared of size 100 mm (length) × 8 mm (width) ×3 mm (thickness). The fabricated SSC beam achieved 21 mm deformation and 16 mm shape retention. Blocking force was measured using a dynamometer, and was about 60 mN. In the repeatability test, it recovered almost the same position when its cooling time was 90 s more. Consequently, the woven type SSC beam can be applied to bio-mimicking, soft morphing actuators, consuming less energy than traditional SMAECs.

  18. Nano-Composite Material Development for 3-D Printers

    SciTech Connect

    Satches, Michael Randolph

    2015-10-14

    The objectives of the project was to create a graphene reinforced polymer nano-composite viable in a commercial 3-D printer; study the effects of ultra-high loading of graphene in polymer matrices; and determine the functional upper limit of graphene loading.

  19. Estimate Interface Shear Stress of Woven Ceramic Matrix Composites from Hysteresis Loops

    NASA Astrophysics Data System (ADS)

    Li, Longbiao; Song, Yingdong

    2013-12-01

    An approach to estimate the fiber/matrix interface shear stress of woven ceramic matrix composites during fatigue loading has been developed in this paper. Based on the analysis of the microstructure, the woven ceramic matrix composites were divided into four elements of 0o warp yarns, 90o weft yarns, matrix outside of the yarns and the open porosity. When matrix cracking and fiber/matrix interface debonding occur upon first loading to the peak stress, it is assumed that fiber slipping relative to matrix in the interface debonded region of the 0o warp yarns is the mainly reason for the occurrence of the hysteresis loops of woven ceramic matrix composiets during unloading and subsequent reloading. The unloading interface reverse slip length and reloading interface new slip length are determined by the interface slip mechanisms. The hysteresis loops of three different cases have been derived. The hysteresis loss energy for the strain energy lost per volume during corresponding cycle is formulated in terms of the fiber/matrix interface shear stress. By comparing the experimental hysteresis loss energy with the computational values, the fiber/matrix interface shear stress of woven ceramic matrix composites corresponding to different cycles can then be derived. The theoretical results have been compared with experimental data of two different woven ceramic composites.

  20. Micromechanics of fatigue in woven and stitched composites

    NASA Technical Reports Server (NTRS)

    Cox, B. N.; Dadkhah, M. S.; Inman, R. V.; Mitchell, M. R.; Morris, W. L.; Schroeder, S.

    1991-01-01

    The goal is to determine how microstructural factors, especially the architecture of microstructural factors, control fatigue damage in 3D reinforced polymer composites. Test materials were fabricated from various preforms, including stitched quasi-isotropic laminates, and through-the-thickness angle interlock, layer-to-layer angle interlock, and through-the-thickness stitching effect weaves. Preforms were impregnated with a tough resin by a special vacuum infiltration method. Most tests are being performed in uniaxial compression/compression loading. In all cases to date, failure has occurred not by delamination, but by shear failure, which occurs suddenly rather than by gradual macroscopic crack growth. Some theoretical aspects of bridging are also examined.

  1. Mesoscopic Strains Maps in Woven Composite Laminas During Off-axis Tension

    NASA Astrophysics Data System (ADS)

    Anzelotti, G.; Nicoletto, G.; Riva, E.

    2010-06-01

    The mechanics of woven carbon-fiber reinforced plastic (CFRP) composites is influenced by the complex architecture of the reinforcement phase. Computational (i.e. finite element based) approaches have been used increasingly to model not only the global laminate stiffness, but also damage evolution and laminate strength. The modeling combines the identification of the architectural unit cell (UC), the selection of suitable constitutive models of the different phases, the creation of a fine discretization of the UC in finite elements, the application of an incremental solution procedure that solves iteratively for the stresses and strains in the UC, [1]. The experimental validation of computational models is carried out mainly at the macroscopical level, i.e. simulation of the macroscopic stress-strain curve. Damage, however, is a localized, straindependent phenomenon and therefore only accurate strain distribution within the UC (at the mesolevel) can identify critical conditions in terms of damage location, extension and evolution. The validation of computational damage procedures is a key task and full-field optical strain analysis methods appear the ideal instrument. However, only limited examples of direct finte element method (FEM) vs experimental strain correlation are found because of the limited sensitivity and spatial resolution of some techniques and the complexity and applicative difficulty of others. The aim of the present paper is to present the application of the digital image correlation (DIC) technique, [2], to the full-field strain analysis at the mesoscopic level (i.e. within the UC) of a woven CFRP lamina when the direction of loading forms an angle to the material direction. The material under consideration is a woven carbon fiber reinforced epoxy composite. Orthogonal yarns, each made of of several thousand fibers, are woven according the twill-weave architecture is shown in Fig. 1a. Single-ply laminas were manufactured and tested to eliminate

  2. Multimaterial magnetically assisted 3D printing of composite materials

    NASA Astrophysics Data System (ADS)

    Kokkinis, Dimitri; Schaffner, Manuel; Studart, André R.

    2015-10-01

    3D printing has become commonplace for the manufacturing of objects with unusual geometries. Recent developments that enabled printing of multiple materials indicate that the technology can potentially offer a much wider design space beyond unusual shaping. Here we show that a new dimension in this design space can be exploited through the control of the orientation of anisotropic particles used as building blocks during a direct ink-writing process. Particle orientation control is demonstrated by applying low magnetic fields on deposited inks pre-loaded with magnetized stiff platelets. Multimaterial dispensers and a two-component mixing unit provide additional control over the local composition of the printed material. The five-dimensional design space covered by the proposed multimaterial magnetically assisted 3D printing platform (MM-3D printing) opens the way towards the manufacturing of functional heterogeneous materials with exquisite microstructural features thus far only accessible by biological materials grown in nature.

  3. Multimaterial magnetically assisted 3D printing of composite materials

    PubMed Central

    Kokkinis, Dimitri; Schaffner, Manuel; Studart, André R.

    2015-01-01

    3D printing has become commonplace for the manufacturing of objects with unusual geometries. Recent developments that enabled printing of multiple materials indicate that the technology can potentially offer a much wider design space beyond unusual shaping. Here we show that a new dimension in this design space can be exploited through the control of the orientation of anisotropic particles used as building blocks during a direct ink-writing process. Particle orientation control is demonstrated by applying low magnetic fields on deposited inks pre-loaded with magnetized stiff platelets. Multimaterial dispensers and a two-component mixing unit provide additional control over the local composition of the printed material. The five-dimensional design space covered by the proposed multimaterial magnetically assisted 3D printing platform (MM-3D printing) opens the way towards the manufacturing of functional heterogeneous materials with exquisite microstructural features thus far only accessible by biological materials grown in nature. PMID:26494528

  4. Multimaterial magnetically assisted 3D printing of composite materials.

    PubMed

    Kokkinis, Dimitri; Schaffner, Manuel; Studart, André R

    2015-01-01

    3D printing has become commonplace for the manufacturing of objects with unusual geometries. Recent developments that enabled printing of multiple materials indicate that the technology can potentially offer a much wider design space beyond unusual shaping. Here we show that a new dimension in this design space can be exploited through the control of the orientation of anisotropic particles used as building blocks during a direct ink-writing process. Particle orientation control is demonstrated by applying low magnetic fields on deposited inks pre-loaded with magnetized stiff platelets. Multimaterial dispensers and a two-component mixing unit provide additional control over the local composition of the printed material. The five-dimensional design space covered by the proposed multimaterial magnetically assisted 3D printing platform (MM-3D printing) opens the way towards the manufacturing of functional heterogeneous materials with exquisite microstructural features thus far only accessible by biological materials grown in nature. PMID:26494528

  5. Ballistic Impact Properties of Zr-Based Amorphous Alloy Composites Reinforced with Woven Continuous Fibers

    NASA Astrophysics Data System (ADS)

    Kim, Gyeong Su; Son, Chang-Young; Lee, Sang-Bok; Lee, Sang-Kwan; Song, Young Buem; Lee, Sunghak

    2012-03-01

    This study aims at investigating ballistic impact properties of Zr-based amorphous alloy (LM1 alloy) matrix composites reinforced with woven stainless steel or glass continuous fibers. The fiber-reinforced composites with excellent fiber/matrix interfaces were fabricated without pores and misinfiltration by liquid pressing process, and contained 35 to 41 vol pct of woven continuous fibers homogeneously distributed in the amorphous matrix. The woven-STS-continuous-fiber-reinforced composite consisted of the LM1 alloy layer of 1.0 mm in thickness in the upper region and the fiber-reinforced composite layer in the lower region. The hard LM1 alloy layer absorbed the ballistic impact energy by forming many cracks, and the fiber-reinforced composite layer interrupted the crack propagation and blocked the impact and traveling of the projectile, thereby resulting in the improvement of ballistic performance by about 20 pct over the LM1 alloy. According to the ballistic impact test data of the woven-glass-continuous-fiber-reinforced composite, glass fibers were preferentially fragmented to form a number of cracks, and the amorphous matrix accelerated the fragmentation of glass fibers and the initiation of cracks. Because of the absorption process of ballistic impact energy by forming very large amounts of cracks, fragments, and debris, the glass-fiber-reinforced composite showed better ballistic performance than the LM1 alloy.

  6. Instability and Wave Propagation in Structured 3D Composites

    NASA Astrophysics Data System (ADS)

    Kaynia, Narges; Fang, Nicholas X.; Boyce, Mary C.

    2014-03-01

    Many structured composites found in nature possess undulating and wrinkled interfacial layers that regulate mechanical, chemical, acoustic, adhesive, thermal, electrical and optical functions of the material. This research focused on the complex instability and wrinkling pattern arising in 3D structured composites and the effect of the buckling pattern on the overall structural response. The 3D structured composites consisted of stiffer plates supported by soft matrix on both sides. Compression beyond the critical strain led to complex buckling patterns in the initially straight plates. The motivation of our work is to elaborate the formation of a system of prescribed periodic scatterers (metamaterials) due to buckling, and their effect to interfere wave propagation through the metamaterial structures. Such metamaterials made from elastomers enable large reversible deformation and, as a result, significant changes of the wave propagation properties. We developed analytical and finite element models to capture various aspects of the instability mechanism. Mechanical experiments were designed to further explore the modeling results. The ability to actively alter the 3D composite structure can enable on-demand tunability of many different functions, such as active control of wave propagation to create band-gaps and waveguides.

  7. 3D Guided Wave Motion Analysis on Laminated Composites

    NASA Technical Reports Server (NTRS)

    Tian, Zhenhua; Leckey, Cara; Yu, Lingyu

    2013-01-01

    Ultrasonic guided waves have proved useful for structural health monitoring (SHM) and nondestructive evaluation (NDE) due to their ability to propagate long distances with less energy loss compared to bulk waves and due to their sensitivity to small defects in the structure. Analysis of actively transmitted ultrasonic signals has long been used to detect and assess damage. However, there remain many challenging tasks for guided wave based SHM due to the complexity involved with propagating guided waves, especially in the case of composite materials. The multimodal nature of the ultrasonic guided waves complicates the related damage analysis. This paper presents results from parallel 3D elastodynamic finite integration technique (EFIT) simulations used to acquire 3D wave motion in the subject laminated carbon fiber reinforced polymer composites. The acquired 3D wave motion is then analyzed by frequency-wavenumber analysis to study the wave propagation and interaction in the composite laminate. The frequency-wavenumber analysis enables the study of individual modes and visualization of mode conversion. Delamination damage has been incorporated into the EFIT model to generate "damaged" data. The potential for damage detection in laminated composites is discussed in the end.

  8. Nano-Composite Material Development for 3-D Printers

    SciTech Connect

    Satches, Michael Randolph

    2015-12-01

    Graphene possesses excellent mechanical properties with a tensile strength that may exceed 130 GPa, excellent electrical conductivity, and good thermal properties. Future nano-composites can leverage many of these material properties in an attempt to build designer materials for a broad range of applications. 3-D printing has also seen vast improvements in recent years that have allowed many companies and individuals to realize rapid prototyping for relatively low capital investment. This research sought to create a graphene reinforced, polymer matrix nano-composite that is viable in commercial 3D printer technology, study the effects of ultra-high loading percentages of graphene in polymer matrices and determine the functional upper limit for loading. Loadings varied from 5 wt. % to 50 wt. % graphene nanopowder loaded in Acrylonitrile Butadiene Styrene (ABS) matrices. Loaded sample were characterized for their mechanical properties using three point bending, tensile tests, as well as dynamic mechanical analysis.

  9. 3D Printing of Biocompatible Supramolecular Polymers and their Composites.

    PubMed

    Hart, Lewis R; Li, Siwei; Sturgess, Craig; Wildman, Ricky; Jones, Julian R; Hayes, Wayne

    2016-02-10

    A series of polymers capable of self-assembling into infinite networks via supramolecular interactions have been designed, synthesized, and characterized for use in 3D printing applications. The biocompatible polymers and their composites with silica nanoparticles were successfully utilized to deposit both simple cubic structures, as well as a more complex twisted pyramidal feature. The polymers were found to be not toxic to a chondrogenic cell line, according to ISO 10993-5 and 10993-12 standard tests and the cells attached to the supramolecular polymers as demonstrated by confocal microscopy. Silica nanoparticles were then dispersed within the polymer matrix, yielding a composite material which was optimized for inkjet printing. The hybrid material showed promise in preliminary tests to facilitate the 3D deposition of a more complex structure. PMID:26766139

  10. Designing bioinspired composite reinforcement architectures via 3D magnetic printing

    PubMed Central

    Martin, Joshua J.; Fiore, Brad E.; Erb, Randall M.

    2015-01-01

    Discontinuous fibre composites represent a class of materials that are strong, lightweight and have remarkable fracture toughness. These advantages partially explain the abundance and variety of discontinuous fibre composites that have evolved in the natural world. Many natural structures out-perform the conventional synthetic counterparts due, in part, to the more elaborate reinforcement architectures that occur in natural composites. Here we present an additive manufacturing approach that combines real-time colloidal assembly with existing additive manufacturing technologies to create highly programmable discontinuous fibre composites. This technology, termed as ‘3D magnetic printing', has enabled us to recreate complex bioinspired reinforcement architectures that deliver enhanced material performance compared with monolithic structures. Further, we demonstrate that we can now design and evolve elaborate reinforcement architectures that are not found in nature, demonstrating a high level of possible customization in discontinuous fibre composites with arbitrary geometries. PMID:26494282

  11. Composite panels based on woven sandwich-fabric preforms

    NASA Astrophysics Data System (ADS)

    van Vuure, Aart Willem

    A new type of sandwich material was investigated, based on woven sandwich-fabric preforms. Because of the integrally woven nature of the sandwich-fabric the skin-core debonding resistance of panels and structures based on the preform is very high. As the sandwich-fabrics are produced by a large scale textile weaving process (velvet weaving or distance weaving) and already a preform of a sandwich is available, the cost of the final panel or structure can potentially stay limited. Most attention in this work is focussed on the mechanical performance of sandwich-fabric panels. The high skin-core debonding resistance was verified and also indications were found of a good damage tolerance. Both unfoamed and foamed panels were evaluated and compared with existing sandwich panels. Microstructural parameters investigated for unfoamed cores are pile length, pile density, woven pile angles, degree of pile stretching, tilt angles of the piles induced during panel production and resin content and distribution. For foamed panels it is especially the foam density which has an important influence. There appears to be a synergistic effect between piles and foam in the sandwich core, leading to very acceptable mechanical properties. For panels for (semi) structural applications, foaming is almost indispensable once the panel thickness is higher than about 15 mm. To understand the behaviour of foamed panels, attention was paid to the modelling of the mechanics of pure foam. The foam microstructure was modelled with the model of an anisotropic tetrakaidecahedron. The mechanical properties of unfoamed panels were modelled with the help of finite elements. A detailed geometrical description of the core layout was made which was incorporated into a preprocessing program for a finite element code. Attention is paid to the production of panels based on the woven preforms. A newly developed Adhesive Foil Stretching process was investigated. Also the foaming of panels was studied. A lot of

  12. The deformation response of three-dimensional woven composites subjected to high rates of loading

    NASA Astrophysics Data System (ADS)

    Pankow, Mark Robert

    The use of polymer matrix composites is widespread, with development in automotive, aerospace and recreational equipment. These applications have produced loading scenarios which are unfamiliar and not well understood. Several applications involve impact loading, which produces large strain rates and delamination failure. New manufacturing methods have led to three dimensional (3D) weave geometries that provide composites with damage protection. This is accomplished through elimination of delamination, and localizing the extent of damage. The present work is a combined experimental and computational study aimed at developing a mechanism based deformation response model for 3D woven composites, including the prediction of failure strengths at high loading rates. Three unique experimental configurations have been developed; along with finite element based simulations to predict the material response and failure mechanisms that are experimentally observed. End Notch Flexure (ENF) tests were used to determine the effectiveness of the Z-fiber at resisting crack propagation. The crack propagation was found to have rate dependent properties, with architecture based parameters required to predict the strength and resistance. The computational results reinforced the experimental observations. A new FE implementation captured the effectiveness of the Z-fiber reinforcement bridging the growing crack. Shock impact testing was performed to simulate the effects of blast loading on the material. New experimental measurement methods were utilized to record the deformations and strains which led to observations of matrix micro-cracking, the first failure mode. Computational models were developed to predict the material behavior subjected to shock loading, including matrix micro-cracking, which was predicted accurately. Finally, split Hopkinson pressure bar (SHPB) testing was done to understand the high strain rate behavior of the material in compression in all three directions. The

  13. Evaluation of Solid Modeling Software for Finite Element Analysis of Woven Ceramic Matrix Composites

    NASA Technical Reports Server (NTRS)

    Nemeth, Noel N.; Mital, Subodh; Lang, Jerry

    2010-01-01

    Three computer programs, used for the purpose of generating 3-D finite element models of the Repeating Unit Cell (RUC) of a textile, were examined for suitability to model woven Ceramic Matrix Composites (CMCs). The programs evaluated were the open-source available TexGen, the commercially available WiseTex, and the proprietary Composite Material Evaluator (COMATE). A five-harness-satin (5HS) weave for a melt-infiltrated (MI) silicon carbide matrix and silicon carbide fiber was selected as an example problem and the programs were tested for their ability to generate a finite element model of the RUC. The programs were also evaluated for ease-of-use and capability, particularly for the capability to introduce various defect types such as porosity, ply shifting, and nesting of a laminate. Overall, it was found that TexGen and WiseTex were useful for generating solid models of the tow geometry; however, there was a lack of consistency in generating well-conditioned finite element meshes of the tows and matrix. TexGen and WiseTex were both capable of allowing collective and individual shifting of tows within a ply and WiseTex also had a ply nesting capability. TexGen and WiseTex were sufficiently userfriendly and both included a Graphical User Interface (GUI). COMATE was satisfactory in generating a 5HS finite element mesh of an idealized weave geometry but COMATE lacked a GUI and was limited to only 5HS and 8HS weaves compared to the larger amount of weave selections available with TexGen and WiseTex.

  14. 3D nanotube-based composites produced by laser irradiation

    SciTech Connect

    Ageeva, S A; Bobrinetskii, I I; Nevolin, Vladimir K; Podgaetskii, Vitalii M; Selishchev, S V; Simunin, M M; Konov, Vitalii I; Savranskii, V V; Ponomareva, O V

    2009-04-30

    3D nanocomposites have been fabricated through self-assembly under near-IR cw laser irradiation, using four types of multiwalled and single-walled carbon nanotubes produced by chemical vapour deposition, disproportionation on Fe clusters and cathode sputtering in an inert gas. The composites were prepared by laser irradiation of aqueous solutions of bovine serum albumin until the solvent was evaporated off and a homogeneous black material was obtained: modified albumin reinforced with nanotubes. The consistency of the composites ranged from paste-like to glass-like. Atomic force microscopy was used to study the surface morphology of the nanomaterials. The nanocomposites had a 3D quasi-periodic structure formed by almost spherical or toroidal particles 200-500 nm in diameter and 30-40 nm in visible height. Their inner, quasi-periodic structure was occasionally seen through surface microfractures. The density and hardness of the nanocomposites exceed those of microcrystalline albumin powder by 20% and by a factor of 3-5, respectively. (nanostructures)

  15. Modeling the Elastic Modulus of 2D Woven CVI SiC Composites

    NASA Technical Reports Server (NTRS)

    Morscher, Gregory N.

    2006-01-01

    The use of fiber, interphase, CVI SiC minicomposites as structural elements for 2D-woven SiC fiber reinforced chemically vapor infiltrated (CVI) SiC matrix composites is demonstrated to be a viable approach to model the elastic modulus of these composite systems when tensile loaded in an orthogonal direction. The 0deg (loading direction) and 90deg (perpendicular to loading direction) oriented minicomposites as well as the open porosity and excess SiC associated with CVI SiC composites were all modeled as parallel elements using simple Rule of Mixtures techniques. Excellent agreement for a variety of 2D woven Hi-Nicalon(TradeMark) fiber-reinforced and Sylramic-iBN reinforced CVI SiC matrix composites that differed in numbers of plies, constituent content, thickness, density, and number of woven tows in either direction (i.e, balanced weaves versus unbalanced weaves) was achieved. It was found that elastic modulus was not only dependent on constituent content, but also the degree to which 90deg minicomposites carried load. This depended on the degree of interaction between 90deg and 0deg minicomposites which was quantified to some extent by composite density. The relationships developed here for elastic modulus only necessitated the knowledge of the fractional contents of fiber, interphase and CVI SiC as well as the tow size and shape. It was concluded that such relationships are fairly robust for orthogonally loaded 2D woven CVI SiC composite system and can be implemented by ceramic matrix composite component modelers and designers for modeling the local stiffness in simple or complex parts fabricated with variable constituent contents.

  16. On the Effect of Woven Glass Fabric Orientations on Wear and Friction Properties of Polyester Composite

    NASA Astrophysics Data System (ADS)

    Yousif, B. F.; El-Tayeb, N. S. M.

    In this work, tribological investigations on the neat polyester (NP) and woven (600 g/m2)-glass fabric reinforced polyester (WGRP) composite were carried out. Friction and wear characteristics of the WGRP composite were measured in three principal orientations, i.e., sliding directions relative to the woven glass fabric (WGF) orientations in the composites. These are longitudinal (L), transverse (T), and parallel (P) orientations. The experiments were conducted using a pin-on-disc (POD) machine under dry sliding conditions against a smooth stainless steel counterface. Results of friction coefficient and wear resistance of the composites were presented as function of normal loads (30-100 N) and sliding distances (0.5-7 km) at different sliding velocities, 1.7, 2.8, and 3.9 m/s. Scanning electron microscopy (SEM) was used to study the mechanisms of worn surfaces. Experimental results revealed that woven glass fabric improved the tribological performance of neat polyester in all three tested orientations. In L-orientation, at a low velocity of 1.7 m/s, WGRP exhibited significant improvements to wear resistance of the polyester composite compared to other orientations. Meanwhile, at high velocities (2.8 and 3.9 m/s), T-orientation gave higher wear resistance. SEM microphotographs showed different damage features on the worn surfaces, i.e., deformation, cracks, debonding of fiber, and microcracks.

  17. Mechanical Behavior and Analytical Modeling of Melt-Infiltrated SiC/SiC Woven Composite

    NASA Technical Reports Server (NTRS)

    Lang, J.; Sankar, J.; Kelkar, A. D.; Bhatt, R. T.; Baaklini, G.; Lua, J.

    1998-01-01

    The desirable properties in ceramic matrix composites (CMCs), such as high temperature strength, corrosion resistance, high toughness, low density, or good creep resistance have led to increased use of CMCs in high-speed engine structural components and structures that operate in extreme temperature and hostile aero-thermo-chemical environments. Ceramic matrix composites have been chosen for turbine material in the design of 21st century civil propulsion systems to achieve high fuel economy, improved reliability, extended life, and reduced cost. Most commercial CMCs are manufactured using a chemical vapor infiltration (CVI) process. However, a lower cost fabrication known as melt-infiltration process is also providing CMCs marked for use in hot sections of high-speed civil transports. Limited samples of a SiC/SiC melt-infiltrated woven composites are being investigated at room and elevated temperature below and above matrix cracking. These samples show graceful failure and toughness at room temperature with a reduction in strength and modulus at elevated temperatures. A generic finite element model is also being developed to predict monotonic and cyclic loading behavior of the woven composite. Use of the initial test data from the woven composite is being used for the development of the analytical model. This model is the first of a iterative process leading towards the development the model's capability to predict behavior at room and elevated temperature for monotonic and cyclic loading. The purpose of this paper is to report on the material and mechanical findings of the SiC/SiC melt-infiltrated woven composite and progress on the development of the finite element model.

  18. The possibility of E-glass woven roving as reinforcement of GFRP composite sheet roof

    NASA Astrophysics Data System (ADS)

    Setyanto, Djoko

    2016-03-01

    The 1.25 mm thickness of opaque glass fiber reinforced polymer (GFRP) composite sheet roof that is produced by an Indonesia company at Tangerang, consists of two layers of 300 g/m2 E-glass chopped strand mat as reinforcement and unsaturated polyester resin as matrix. A layer of 300 g/m2 E-glass chopped strand mat is replaced by a layer of 400 g/m2 E-glass woven roving as reinforcement to study the possibility use as sheet roof material. The properties of the two samples of GFRP composite materials were compared. Barcol hardness and flexure strength of the two samples relatively not significance change. Tensile strength and elastic modulus of the new sample which contains a layer of woven roving reinforcement is greater than the other one. On the other hand the waviness of the new sample is greater, but cheaper. In general, a layer of E-glass woven roving and a layer of E-glass chopped strand mat can be considered as an alternative reinforcement of two layers reinforcement of GFRP composite material of sheet roof.

  19. Modeling of nonlinear constitutive relations of woven ceramic composites

    SciTech Connect

    Kuo, Wen-Shyong; Chou, Tsu-Wei

    1991-08-01

    The linear and nonlinear tensile behavior of SiC/SiC composites is examined. This analysis is based on the observed stress-strain behavior and damage evolution from a series of loading and unloading tensile tests. Stress distribution of the composite with transverse cracks in the transverse yarns is examined, and the nonlinearity of the composite stress-strain relation due to the presence of transverse cracks is predicted by application of a maximum failure strain criterion for the transverse yarn. 7 refs.

  20. Composite three-dimensional woven scaffolds with interpenetrating network hydrogels to create functional synthetic articular cartilage.

    PubMed

    Liao, I-Chien; Moutos, Franklin T; Estes, Bradley T; Zhao, Xuanhe; Guilak, Farshid

    2013-12-17

    The development of synthetic biomaterials that possess mechanical properties that mimic those of native tissues remains an important challenge to the field of materials. In particular, articular cartilage is a complex nonlinear, viscoelastic, and anisotropic material that exhibits a very low coefficient of friction, allowing it to withstand millions of cycles of joint loading over decades of wear. Here we show that a three-dimensionally woven fiber scaffold that is infiltrated with an interpenetrating network hydrogel can provide a functional biomaterial that provides the load-bearing and tribological properties of native cartilage. An interpenetrating dual-network "tough-gel" consisting of alginate and polyacrylamide was infused into a porous three-dimensionally woven poly(ε-caprolactone) fiber scaffold, providing a versatile fiber-reinforced composite structure as a potential acellular or cell-based replacement for cartilage repair. PMID:24578679

  1. Computational simulation of surface waviness in graphite/epoxy woven composites due to initial curing

    NASA Technical Reports Server (NTRS)

    Sanfeliz, Jose G.; Murthy, Pappu L. N.; Chamis, Christos C.

    1992-01-01

    Several models simulating plain weave, graphite/epoxy woven composites are presented, along with the effects that the simultaneous application of pressure and thermal loads have on their surfaces. The surface effects created by moisture absorption are also examined. The computational simulation consisted of using a two-dimensional finite element model for the composite. The properties of the finite element (FE) model are calculated by using the in-house composite mechanics computer code ICAN (Integrated Composite ANalyzer). MSC/NASTRAN is used for the FE analysis which yields the composite's top surface normalized displacements. These results demonstrate the importance of parameters such as the cure temperature (T sub o) and the resin content in the curing process of polymer-matrix composites. The modification of these parameters will help tailor the composite system to the desired requirements and applications.

  2. High-strength cellular ceramic composites with 3D microarchitecture

    PubMed Central

    Bauer, Jens; Hengsbach, Stefan; Tesari, Iwiza; Schwaiger, Ruth; Kraft, Oliver

    2014-01-01

    To enhance the strength-to-weight ratio of a material, one may try to either improve the strength or lower the density, or both. The lightest solid materials have a density in the range of 1,000 kg/m3; only cellular materials, such as technical foams, can reach considerably lower values. However, compared with corresponding bulk materials, their specific strength generally is significantly lower. Cellular topologies may be divided into bending- and stretching-dominated ones. Technical foams are structured randomly and behave in a bending-dominated way, which is less weight efficient, with respect to strength, than stretching-dominated behavior, such as in regular braced frameworks. Cancellous bone and other natural cellular solids have an optimized architecture. Their basic material is structured hierarchically and consists of nanometer-size elements, providing a benefit from size effects in the material strength. Designing cellular materials with a specific microarchitecture would allow one to exploit the structural advantages of stretching-dominated constructions as well as size-dependent strengthening effects. In this paper, we demonstrate that such materials may be fabricated. Applying 3D laser lithography, we produced and characterized micro-truss and -shell structures made from alumina–polymer composite. Size-dependent strengthening of alumina shells has been observed, particularly when applied with a characteristic thickness below 100 nm. The presented artificial cellular materials reach compressive strengths up to 280 MPa with densities well below 1,000 kg/m3. PMID:24550268

  3. Mesoscopic strain fields in woven composites: Experiments vs. finite element modeling

    NASA Astrophysics Data System (ADS)

    Nicoletto, Gianni; Anzelotti, Giancarlo; Riva, Enrica

    2009-03-01

    Detailed determination of strain in woven composite materials is fundamental for understanding their mechanics and for validating sophisticated computational models. The digital image correlation technique is briefly presented and applied to the full-field strain determination in a twill-weave carbon-fiber-reinforced-plastic (CFRP) composite under in-plane loading. The experimental results are used to assess companion results obtained with an ad hoc finite element-based model. The DIC vs. FEM comparison is carried out at the mesoscopic scale.

  4. Application of a Fiber Optic Distributed Strain Sensor System to Woven E-Glass Composite

    NASA Technical Reports Server (NTRS)

    Anastasi, Robert F.; Lopatin, Craig

    2001-01-01

    A distributed strain sensing system utilizing a series of identically written Bragg gratings along an optical fiber is examined for potential application to Composite Armored Vehicle health monitoring. A vacuum assisted resin transfer molding process was used to fabricate a woven fabric E-glass/composite panel with an embedded fiber optic strain sensor. Test samples machined from the panel were mechanically tested in 4-point bending. Experimental results are presented that show the mechanical strain from foil strain gages comparing well to optical strain from the embedded sensors. Also, it was found that the distributed strain along the sample length was consistent with the loading configuration.

  5. Characterization of impact damage in woven fiber composites using fiber Bragg grating sensing and NDE

    NASA Astrophysics Data System (ADS)

    Hiche, Cristobal; Liu, Kuang C.; Seaver, Mark; Wei, Jun; Chattopadhyay, Aditi

    2009-03-01

    Woven fiber composites are currently being investigated due to their advantages over other materials, making them suitable for low weight, high stiffness, and high interlaminar fracture toughness applications such as missiles, body armor, satellites, and many other aerospace applications. Damage characterization of woven fabrics is a complex task due to their tendency to exhibit different failure modes based on the weave configuration, orientation, ply stacking and other variables. A multiscale model is necessary to accurately predict progressive damage. The present research is an experimental study on damage characterization of three different woven fiber laminates under low energy impact using Fiber Bragg Grating (FBG) sensors and flash thermography. A correlation between the measured strain from FBG sensors and the damaged area obtained from flash thermography imaging has been developed. It was observed that the peak strain in the fabrics were strongly dependent on the weave geometry and decreased at different rates as damage area increased due to dissimilar failure modes. Experimental observations were validated with the development of a multiscale model. A FBG sensor placement model was developed which showed that FBG sensor location and orientation plays a key role in the sensing capabilities of strain on the samples.

  6. Delamination of woven E-glass fabric composites

    SciTech Connect

    Dunn, M.L.; Reedy, E.D. Jr.; Guess, T.R.

    1993-11-01

    An experimental/analytical study investigating delamination growth in E-glass fabric/polyester composites has been carried out. Double cantilever beam and end-notched flexure delamination specimens were tested and the measured data was compared to calculated results. A stacked shell finite element methodology has been developed to perform the analysis. This approach breaks the composite into sublaminate shells connected by springs spanning the delamination plane. The stacked shell analyses can use either a critical stress or a critical energy release rate criterion to propagate the delamination, and both criteria are shown to yield similar predictions. Role of connecting springs, and proper choice for spring constants has also been investigated in detail. The spring constants must be chosen in a physically meaningful way to develop consistent values of energy release rate, compliance, and the stress distribution ahead of the delamination. Calculated results for the double cantilever beam and end-notched flexure specimens are in good agreement with measured test data and continuum finite element solutions.

  7. Thermo-elastic behavior of deformed woven fabric composites at elevated temperatures: Part 1

    SciTech Connect

    Vu-Khanh, T.; Liu, B.

    1994-12-31

    This paper presents the results of a study on the effects of temperature on the thermo-elastic properties of woven fabric composites. The thermo-mechanical behavior of woven fabric composites is characterized by a laminate composed of four fictional unidirectional plies, called the sub-plies model. The model allows determination of the thermo-elastic properties of deformed fabric composites (non-orthogonal structure) and direct use of layered shell elements in finite element codes. A special procedure is also proposed to measure the fiber undulation effect and to predict the on-axis thermo-elastic coefficients of the equivalent constituent plies. The thermo-elastic behavior at elevated temperature was investigated on graphite/epoxy fabric composites. Experimental measurements were carried out from 23 C to 177 C. The results revealed that the equivalent thermal expansion coefficients of the sub-plies remain almost constant over a wide range of temperature. However, the equivalent elastic moduli and Poison`s ratio of the sub-plies vary nonlinearly with temperature. Semiempirical equations based on the experimental data were also developed to predict the equivalent on-axis thermo-elastic properties of the fictional constituent plies in the sub-plies model as a function of temperature.

  8. Mechanical properties and fabrication of small boat using woven glass/sugar palm fibres reinforced unsaturated polyester hybrid composite

    NASA Astrophysics Data System (ADS)

    Misri, S.; Leman, Z.; Sapuan, S. M.; Ishak, M. R.

    2010-05-01

    In recent years, sugar palm fibre has been found to have great potential to be used as fibre reinforcement in polymer matrix composites. This research investigates the mechanical properties of woven glass/sugar palm fibres reinforced unsaturated polyester hybrid composite. The composite specimens made of different layer of fibres such as strand mat, natural and hand woven of sugar palm fibres. The composites were fabricated using a compression moulding technique. The tensile and impact test was carried out in accordance to ASTM 5083 and ASTM D256 standard. The fibre glass boat is a familiar material used in boat industry. A lot of research on fabrication process such as lay-up, vacuum infusion mould and resin transfer mould has been conducted. Hybrid material of sugar palm fibre and fibre glass was used in fabricating the boat. This research investigates the method selection for fabrication of small boat application of natural fibre composites. The composite specimens made of different layer of fibres; woven glass fibre, strand mat, natural and hand woven of woven sugar palm fibres were prepared. The small boat were fabricated using a compression moulding and lay up technique. The results of the experiment showed that the tensile strength, tensile modulus, elongation at break value and impact strength were higher than the natural woven sugar palm fibre. The best method for fabricating the small boat was compression moulding technique. As a general conclusion, the usage of glass fibre had improved the tensile properties sugar palm fibre composites and compression moulding technique is suitable to be used in making a small boat application of natural fibre composites.

  9. High Temperature Si-doped BN Interphases for Woven SiC/SiC Composites

    NASA Technical Reports Server (NTRS)

    Morscher, Gregory N.; Hurwitz, Frances; Yun, Hee Mann; Gray, Hugh R. (Technical Monitor)

    2002-01-01

    The hydrolytic stability of high-temperature deposited Si-doped BN has been shown in the past to be superior in comparison to "pure" BN processed at similar or even higher temperatures. This type of material would be very desirable as a SiC/SiC composite interphase that is formed by chemical infiltration into multi-ply woven preform. However, due to rapid deposition on the preform outer surface at the high processing temperature, this has proven very difficult. To overcome this issue, single plies of woven fabric were infiltrated with Si-doped BN. Three composite panels of different SiC fiber types were fabricated with Si-doped BN interphases including Sylramic, Hi-Nicalon Type S and Sylramic-iBN fiber-types. The latter fiber-type possesses a thin in-situ grown BN layer on the fiber surface. High Si contents (approx. 7 to 10 a/o) and low oxygen contents (less than 1 a/o) were achieved. All three composite systems demonstrated reasonable debonding and sliding properties. The coated Sylramic fabric and composites were weak due to fiber degradation apparently caused during interphase processing by the formation of TiN crystals on the fiber surface. The Hi-Nicalon Type S composites with Si-doped BN interphase were only slightly weaker than Hi-Nicalon Type S composites with conventional BN when the strength on the load-bearing fibers at failure was compared. On the other hand, the Sylramic-iBN fabric and composites with Si-doped BN showed excellent composite and intermediate temperature stress-rupture properties. Most impressive was the lack of any significant interphase oxidation on the fracture surface of stress-ruptured specimens tested well above matrix cracking at 815C.

  10. Modeling the Effect of Multiple Matrix Cracking Modes on Cyclic Hysteresis Loops of 2D Woven Ceramic-Matrix Composites

    NASA Astrophysics Data System (ADS)

    Longbiao, Li

    2016-08-01

    In this paper, the effect of multiple matrix cracking modes on cyclic loading/unloading hysteresis loops of 2D woven ceramic-matrix composites (CMCs) has been investigated. The interface slip between fibers and the matrix existed in matrix cracking mode 3 and mode 5, in which matrix cracking and interface debonding occurred in longitudinal yarns, are considered as the major reason for hysteresis loops of 2D woven CMCs. The effects of fiber volume content, peak stress, matrix crack spacing, interface properties, matrix cracking mode proportion and interface wear on interface slip and hysteresis loops have been analyzed. The cyclic loading/unloading hysteresis loops of 2D woven SiC/SiC composite corresponding to different peak stresses have been predicted using the present analysis. It was found that the damage parameter, i.e., the proportion of matrix cracking mode 3 in the entire cracking modes of the composite, increases with increasing peak stress.

  11. Modeling the Effect of Multiple Matrix Cracking Modes on Cyclic Hysteresis Loops of 2D Woven Ceramic-Matrix Composites

    NASA Astrophysics Data System (ADS)

    Longbiao, Li

    2016-02-01

    In this paper, the effect of multiple matrix cracking modes on cyclic loading/unloading hysteresis loops of 2D woven ceramic-matrix composites (CMCs) has been investigated. The interface slip between fibers and the matrix existed in matrix cracking mode 3 and mode 5, in which matrix cracking and interface debonding occurred in longitudinal yarns, are considered as the major reason for hysteresis loops of 2D woven CMCs. The effects of fiber volume content, peak stress, matrix crack spacing, interface properties, matrix cracking mode proportion and interface wear on interface slip and hysteresis loops have been analyzed. The cyclic loading/unloading hysteresis loops of 2D woven SiC/SiC composite corresponding to different peak stresses have been predicted using the present analysis. It was found that the damage parameter, i.e., the proportion of matrix cracking mode 3 in the entire cracking modes of the composite, increases with increasing peak stress.

  12. Numerical study on 3D composite morphing actuators

    NASA Astrophysics Data System (ADS)

    Oishi, Kazuma; Saito, Makoto; Anandan, Nishita; Kadooka, Kevin; Taya, Minoru

    2015-04-01

    There are a number of actuators using the deformation of electroactive polymer (EAP), where fewer papers seem to have focused on the performance of 3D morphing actuators based on the analytical approach, due mainly to their complexity. The present paper introduces a numerical analysis approach on the large scale deformation and motion of a 3D half dome shaped actuator composed of thin soft membrane (passive material) and EAP strip actuators (EAP active coupon with electrodes on both surfaces), where the locations of the active EAP strips is a key parameter. Simulia/Abaqus Static and Implicit analysis code, whose main feature is the high precision contact analysis capability among structures, are used focusing on the whole process of the membrane to touch and wrap around the object. The unidirectional properties of the EAP coupon actuator are used as input data set for the material properties for the simulation and the verification of our numerical model, where the verification is made as compared to the existing 2D solution. The numerical results can demonstrate the whole deformation process of the membrane to wrap around not only smooth shaped objects like a sphere or an egg, but also irregularly shaped objects. A parametric study reveals the proper placement of the EAP coupon actuators, with the modification of the dome shape to induce the relevant large scale deformation. The numerical simulation for the 3D soft actuators shown in this paper could be applied to a wider range of soft 3D morphing actuators.

  13. Shear Characteristics of Hybrid Composites with Non-Woven Carbon Tissue

    NASA Astrophysics Data System (ADS)

    Lee, Seung-Hwan; Noguchi, Hiroshi

    Mechanical shear characteristics of hybrid composites with non-woven carbon tissue (NWCT) are investigated under uni-axial static tensile loadings. In-plane characteristics were studied on [±45]3S angle-ply CFRP laminates and [+45/-45/+45/-45/+45/-45]S angle-ply hybrid laminates. Here, the symbol “/” means that the NWCT is located at an interface between CFRP layers. A new estimation method was proposed for the stiffness of hybrid composites. Chord shear modulus and 0.2%-offset shear strength of hybrid laminates were compared with those of CFRP laminates. Results estimated with the new method were compared with results of experiments and an ordinary rule of mixtures, and then the validity was confirmed. The hybrid angle-ply laminate seems to be effective to improve the shear characteristics. The damage and failure mechanisms of the hybrid composites were discussed through observation results with an optical microscope.

  14. Graphene/polyaniline woven fabric composite films as flexible supercapacitor electrodes

    NASA Astrophysics Data System (ADS)

    Zang, Xiaobei; Li, Xiao; Zhu, Miao; Li, Xinming; Zhen, Zhen; He, Yijia; Wang, Kunlin; Wei, Jinquan; Kang, Feiyu; Zhu, Hongwei

    2015-04-01

    We report the design and preparation of graphene and polyaniline (PANI) woven-fabric composite films by in situ electropolymerization. The introduction of PANI greatly improves the electrochemical properties of solid-state supercapacitors which possess capacitances as high as 23 mF cm-2, and exhibit excellent cycling stability with ~100% capacitance retention after 2000 cycles. The devices have displayed superior flexibility with improved areal specific capacitances to 118% during deformation.We report the design and preparation of graphene and polyaniline (PANI) woven-fabric composite films by in situ electropolymerization. The introduction of PANI greatly improves the electrochemical properties of solid-state supercapacitors which possess capacitances as high as 23 mF cm-2, and exhibit excellent cycling stability with ~100% capacitance retention after 2000 cycles. The devices have displayed superior flexibility with improved areal specific capacitances to 118% during deformation. Electronic supplementary information (ESI) available: SEM image, Raman spectrum and electrochemical characterizations. See DOI: 10.1039/c5nr00584a

  15. Forming simulation of woven composite fibers and its influence on structural performance

    NASA Astrophysics Data System (ADS)

    Divine, Vincent; Beauchesne, Erwan; Roy, Subir; Palaniswamy, Hariharasudhan

    2013-12-01

    In recent years, the interest in composite material as a replacement for metals has been growing. The automotive industry, in its constant quest for weight reduction, is now seriously considering composite materials as a substitute for sheet metal components to meet future fuel consumption standards. However, composite forming processes are expensive and difficult to control because of its complex composition with fiber and matrix layers or plies and its dependency on many parameters, such as non-linearity of tensile stiffness, effect of shear rate, temperature and friction. Hence, numerical simulation could be a viable approach to predict material behavior during composite forming. The objective of this study is to highlight capabilities of RADIOSS®, a non-linear finite element analysis based structural solver commonly used for stamping and crash analyses, to simulate forming simulation of composite plies made from woven fibers. For validation the well-known double dome model is used with material data published in NUMISHEET'05 proceedings. It is modeled as a woven fabric with an elastic anisotropic fabric material law available in RADIOSS. This material law is able to consider properties along the two directions of anisotropy, warp and weft. The compared result is the shear angle after stamping that is, the variation of angle between warp and weft fibers, at several prescribed points on the ply. The variation of this angle has a strong impact on material characteristics which severely deteriorates when a critical value is reached. Hence, a study on crash simulations is performed, after mapping fibers angles from stamping simulation.

  16. Thick fibrous composite reinforcements behave as special second-gradient materials: three-point bending of 3D interlocks

    NASA Astrophysics Data System (ADS)

    Madeo, Angela; Ferretti, Manuel; dell'Isola, Francesco; Boisse, Philippe

    2015-08-01

    In this paper, we propose to use a second gradient, 3D orthotropic model for the characterization of the mechanical behavior of thick woven composite interlocks. Such second-gradient theory is seen to directly account for the out-of-plane bending rigidity of the yarns at the mesoscopic scale which is, in turn, related to the bending stiffness of the fibers composing the yarns themselves. The yarns' bending rigidity evidently affects the macroscopic bending of the material and this fact is revealed by presenting a three-point bending test on specimens of composite interlocks. These specimens differ one from the other for the different relative direction of the yarns with respect to the edges of the sample itself. Both types of specimens are independently seen to take advantage of a second-gradient modeling for the correct description of their macroscopic bending modes. The results presented in this paper are essential for the setting up of a correct continuum framework suitable for the mechanical characterization of composite interlocks. The few second-gradient parameters introduced by the present model are all seen to be associated with peculiar deformation modes of the mesostructure (bending of the yarns) and are determined by inverse approach. Although the presented results undoubtedly represent an important step toward the complete characterization of the mechanical behavior of fibrous composite reinforcements, more complex hyperelastic second-gradient constitutive laws must be conceived in order to account for the description of all possible mesostructure-induced deformation patterns.

  17. Three-dimensional microstructural design of woven fabric composite material by homogenization method

    SciTech Connect

    Takano, Naoki; Zako, Masaru

    1995-11-01

    The strength of woven fabric composite materials depends on the microstructural geometry. However, the conventional methods for mechanical analysis, which have been widely used so far, are insufficient because they cannot take into account for the three-dimensional microstructure. In this study, three-dimensional homogenization method is shown to be effective for the evaluations of the material constants, microscopic stresses and the strength. It has been found that the transverse stresses in the direction of lamination play an important role for the fracture of both fiber bundle and resin. Also, the effect of the mismatched lay-up on the strength has been investigated. It has well been predicted that the mismatched lay-up causes the reduction of the strength and the difference of crack initiation in the resin. These simulations give a new concept of the microstructural design of the composite materials.

  18. Cloning Nacre's 3D Interlocking Skeleton in Engineering Composites to Achieve Exceptional Mechanical Properties.

    PubMed

    Zhao, Hewei; Yue, Yonghai; Guo, Lin; Wu, Juntao; Zhang, Youwei; Li, Xiaodong; Mao, Shengcheng; Han, Xiaodong

    2016-07-01

    Ceramic/polymer composite equipped with 3D interlocking skeleton (3D IL) is developed through a simple freeze-casting method, exhibiting exceptionally light weight, high strength, toughness, and shock resistance. Long-range crack energy dissipation enabled by 3D interlocking structure is considered as the primary reinforcing mechanism for such superior properties. The smart composite design strategy should hold a place in developing future structural engineering materials. PMID:27135462

  19. Hybrid Composite Laminates Reinforced with Kevlar/Carbon/Glass Woven Fabrics for Ballistic Impact Testing

    PubMed Central

    Randjbaran, Elias; Zahari, Rizal; Abdul Jalil, Nawal Aswan; Abang Abdul Majid, Dayang Laila

    2014-01-01

    Current study reported a facile method to investigate the effects of stacking sequence layers of hybrid composite materials on ballistic energy absorption by running the ballistic test at the high velocity ballistic impact conditions. The velocity and absorbed energy were accordingly calculated as well. The specimens were fabricated from Kevlar, carbon, and glass woven fabrics and resin and were experimentally investigated under impact conditions. All the specimens possessed equal mass, shape, and density; nevertheless, the layers were ordered in different stacking sequence. After running the ballistic test at the same conditions, the final velocities of the cylindrical AISI 4340 Steel pellet showed how much energy was absorbed by the samples. The energy absorption of each sample through the ballistic impact was calculated; accordingly, the proper ballistic impact resistance materials could be found by conducting the test. This paper can be further studied in order to characterise the material properties for the different layers. PMID:24955400

  20. The influence of tensile fatigue damage on residual compressive strength of woven composites

    SciTech Connect

    Mitrovic, M.; Carman, G.P.

    1995-12-31

    The long term mechanical fatigue of a Celion G30-500/PMR-15 woven composite system is investigated to study the interrelationship between thermo-mechanical properties, namely the thermal expansion coefficient (TEC) and the compressive strength. Residual compressive strength measurements (IITRI fixture) conducted on specimens subjected to tension-tension fatigue cycling indicate that this material property is sensitive to cracks and delaminations which form during mechanical cycling. Measured compressive strength degradation are as large as 49% for this material undergoing mechanical fatigue cycling with TEC degradation as large as 61%. Experimental results show that a correlation exists between TEC measurements and compressive strength. This correlation suggests that TEC measurements may be used as a damage evaluation technique.

  1. Bending and fracture toughness of woven self-reinforced composite poly(methyl methacrylate).

    PubMed

    Wright, D D; Lautenschlager, E P; Gilbert, J L

    1997-09-15

    Loosening remains an impediment to the long-term success of total hip replacements despite numerous improvements in the materials used. In cemented prostheses, fatigue and fracture of bone cement have been implicated in the failure of these devices. A new material, self-reinforced composite poly(methyl methacrylate). (SRC-PMMA), has been developed. SRC-PMMA is formed by a novel processing method that will be described. The composite consists of high strength, highly oriented PMMA fibers embedded in a matrix of PMMA. Using a woven form of SRC-PMMA, an in vitro physical and mechanical evaluation was performed to assess the feasibility of its use in an orthopedic prosthesis. Three different weaves of SRC-PMMA were evaluated in bending and fracture toughness in air, after immersion for 30 days in 37 degrees C saline, and after gamma irradiation followed by immersion. Bending modulus and strength were decreased by gamma irradiation followed by saline immersion. The effect of saline immersion alone on bending strength and modulus was negligible. Saline immersion and gamma irradiation followed by saline immersion was shown to have little or no effect on the fracture toughness of woven SRC-PMMA. Differences in the fracture processes of the different weaves were found and can be related to the differing orientation of fibers to the fracture toughness pre-crack. Optimally incorporated SRC-PMMA absorbs the same amount of water as bone cement. Comparison to previous and current work with bone cement controls shows that SRC-PMMA is a material equal to or better than bone cement in all tests performed. It deserves further consideration as a candidate biomaterial. PMID:9294760

  2. Dynamic mechanical analysis and high strain-rate energy absorption characteristics of vertically aligned carbon nanotube reinforced woven fiber-glass composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The dynamic mechanical behavior and energy absorption characteristics of nano-enhanced functionally graded composites, consisting of 3 layers of vertically aligned carbon nanotube (VACNT) forests grown on woven fiber-glass (FG) layer and embedded within 10 layers of woven FG, with polyester (PE) and...

  3. Characterization of the as Manufactured Variability in a CVI SiC/SiC Woven Composite

    NASA Technical Reports Server (NTRS)

    Bonacuse, Peter J.; Mital, Subodh; Goldberg, Robert

    2011-01-01

    The microstructure of a 2D woven ceramic matrix composite displays significant variability and irregularity. For example, a chemical vapor infiltrated (CVI) SiC/SiC composite exhibits significant amount of porosity arranged in irregular patterns. Furthermore, the fiber tows within a ply frequently have irregular shape and spacing, and the stacked plies are often misaligned and irregularly nested within each other. The goal of an ongoing project at NASA Glenn is to investigate the effects of the complex microstructure and its variability on the properties and the durability of the material. One key requirement for this effort is the development of methods to characterize the distribution in as-fabricated ceramic matrix composite (CMC) microstructures with the objective of correlating microstructural distribution parameters with mechanical performance. An initial task in this effort was to perform quantitative image analysis of polished cross sections of CVI SiC/SiC composite specimens. This analysis provided sample distributions of various microstructural composite features, including: inter-tow pore sizes and shapes, transverse sectioned tow sizes and shapes, and within ply tow spacing. This information can then be used to quantify the effect of extreme values of these features on the local stress state with the goal of determining the likelihood of matrix cracking at a given external load.

  4. The Electrical and Thermal Conductivity of Woven Pristine and Intercalated Graphite Fiber-Polymer Composites

    NASA Technical Reports Server (NTRS)

    Gaier, James R.; Vandenburg, Yvonne Yoder; Berkebile, Steven; Stueben, Heather; Balagadde, Frederick

    2002-01-01

    A series of woven fabric laminar composite plates and narrow strips were fabricated from a variety of pitch-based pristine and bromine intercalated graphite fibers in an attempt to determine the influence of the weave on the electrical and thermal conduction. It was found generally that these materials can be treated as if they are homogeneous plates. The rule of mixtures describes the resistivity of the composite fairly well if it is realized that only the component of the fibers normal to the equipotential surface will conduct current. When the composite is narrow with respect to the fiber weave, however, there is a marked angular dependence of the resistance which was well modeled by assuming that the current follows only along the fibers (and not across them in a transverse direction), and that the contact resistance among the fibers in the composite is negligible. The thermal conductivity of composites made from less conductive fibers more closely followed the rule of mixtures than that of the high conductivity fibers, though this is thought to be an artifact of the measurement technique. Electrical and thermal anisotropy could be induced in a particular region of the structure by weaving together high and low conductivity fibers in different directions, though this must be done throughout all of the layers of the structure as interlaminar conduction precludes having only the top layer carry the anisotropy. The anisotropy in the thermal conductivity is considerably less than either that predicted by the rule of mixtures or the electrical resistivity.

  5. EFFECTS OF HETEROGENEITY ON THE STRENGTH OF 3D COMPOSITES

    SciTech Connect

    M. MAHESH; I. BEYERLEIN; S. PHOENIX

    2001-02-01

    Monte Carlo simulation interpreted with theoretical modeling is used to study the statistical failure modes in unidirectional composites consisting of a hexagonal array of elastic fibers embedded in an elastic matrix. Composite structure is idealized using the chain-of-bundles model in terms of bundles of length {delta} arranged along the fiber direction. Fibers element strengths in {delta}-bundles are taken to be Weibull distributed and Hedgepeth and Van Dyke load sharing is assumed for transverse fiber break arrays. Simulations of {delta}-bundle failure reveal two regimes. When fiber strength variability is low, the dominant failure mode is by growing clusters of fiber breaks up to instability. When this variability is high, cluster formation is suppressed by a more dispersed fiber failure mode. Corresponding to these two cases, they construct simple models that predict the strength distribution of a {delta}-bundle. Their predictions compare very favorably with simulations in the two cases.

  6. Planar Porous Graphene Woven Fabric/Epoxy Composites with Exceptional Electrical, Mechanical Properties, and Fracture Toughness.

    PubMed

    Liu, Xu; Sun, Xinying; Wang, Zhenyu; Shen, Xi; Wu, Ying; Kim, Jang-Kyo

    2015-09-30

    Planar interconnected graphene woven fabrics (GWFs) are prepared by template-based chemical vapor deposition and the GWFs are employed as multifunctional filler for epoxy-based composites. Apart from flexibility, transparency, lightweight, and high electrical conductivity, the GWFs have unique morphological features consisting of orthogonally interweaved, inherently percolated, hollow graphene tubes (GTs). The orthogonal GT structure means that the GWF/epoxy composites hold significant anisotropy in mechanical and fracture properties. The composites with 0.62 wt % graphene deliver a combination of excellent electrical and fracture properties: e.g., an electrical conductivity of ~0.18 S/cm; and fracture toughness of 1.67 and 1.78 MPa·m(1/2) when loaded along the 0° and 45° directions relative to the GT direction, respectively, equivalent to notable 57% and 67% rises compared to the solid epoxy. Unique fracture processes in GWF/epoxy composites are identified by in situ examinations, revealing crack tip blunting that occurs when the crack impinges GTs, especially those at 45° to the crack growth direction, as well as longitudinal tearing of hollow GTs as the two major toughening mechanisms. PMID:26331902

  7. Nano-hydroxyapatite/poly epsilon-caprolactone composite 3D scaffolds for mastoid obliteration

    NASA Astrophysics Data System (ADS)

    Kim, S. E.; Yun, H. S.; Hyun, Y. T.; Shin, J. W.; Song, J. J.

    2009-05-01

    The aim of this study is to evaluate the use of our nano-HA/PCL composite 3D scaffolds as graft materials for mastoid cavity obliteration in an animal model. Nano-HA particles were synthesized by chemical precipitation technique and mixed them with PCL solution to make composite paste. 3D scaffolds were fabricated by a paste extruding deposition process. The nano-HA/PCL 3D scaffolds showed good in vivo bone regeneration behaviour in a rabbit model after 4 and 8 week implantation. To characterize the 3D scaffolds as a grafting material for mastoid obliteration, mastoid cavities were introduced in rats and implanted the scaffolds. After two week implantation, histological examination showed good tissue ingrowth and new bone formation behaviour. It can be argued that our nano-HA/PCL composite 3D scaffold is a promising alternative material for mastoid obliteration.

  8. MODELING THE TRANSVERSE THERMAL CONDUCTIVITY OF 2-D SICF/SIC COMPOSITES MADE WITH WOVEN FABRIC

    SciTech Connect

    Youngblood, Gerald E; Senor, David J; Jones, Russell H

    2004-06-01

    The hierarchical two-layer (H2L) model describes the effective transverse thermal conductivity (Keff) of a 2D-SiCf/SiC composite plate made from stacked and infiltrated woven fabric layers in terms of constituent properties and microstructural and architectural variables. The H2L model includes the effects of fiber-matrix interfacial conductance, high fiber packing fractions within individual tows and the non-uniform nature of 2D fabric/matrix layers that usually include a significant amount of interlayer porosity. Previously, H2L model Keff-predictions were compared to measured values for two versions of 2D Hi-Nicalon/PyC/ICVI-SiC composite, one with a “thin” (0.11m) and the other with a “thick” (1.04m) pyrocarbon (PyC) fiber coating, and for a 2D Tyranno SA/”thin” PyC/FCVI-SIC composite. In this study, H2L model Keff-predictions were compared to measured values for a 2D-SiCf/SiC composite made using the ICVI-process with Hi-Nicalon type S fabric and a “thin” PyC fiber coating. The values of Keff determined for the latter composite were significantly greater than the Keff-values determined for the composites made with either the Hi-Nicalon or the Tyranno SA fabrics. Differences in Keff-values were expected for the different fiber types, but major differences also were due to observed microstructural and architectural variations between the composite systems, and as predicted by the H2L model.

  9. Fatigue Damage in CFRP Woven Fabric Composites through Dynamic Modulus Measurements

    SciTech Connect

    Chiaki Miyasaka; K. L. Telschow

    2004-07-01

    Advanced fiber reinforced composite materials offer substantial advantages over metallic materials for the structural applications subjected to fatigue loading. With the increasing use of these composites, it is required to understand their mechanical response to cyclic loading (1)-(4). Our major concern in this work is to macroscopically evaluate the damage development in composites during fatigue loading. For this purpose, we examine what effect the fatigue damage may have on the material properties and how they can be related mathematically to each other. In general, as the damage initiates in composite materials and grows during cyclic loading, material properties such as modulus, residual strength and strain would vary and, in many cases, they may be significantly reduced because of the progressive accumulation of cracks. Therefore, the damage can be characterized by the change in material properties, which is expected to be available for non-destructive evaluation of the fatigue damage development in composites. Here, the tension-tension fatigue tests are firstly conducted on the plain woven fabric carbon fiber composites for different loading levels. In the fatigue tests, the dynamic elastic moduli are measured on real-time, which will decrease with an increasing number of cycles due to the degradation of stiffness. Then, the damage function presenting the damage development during fatigue loading is determined from the dynamic elastic moduli thus obtained, from which the damage function is formulated in terms of a number of cycles and an applied loading level. Finally, the damage function is shown to be applied for predicting the remaining lifetime of the CFRP composites subjected to two-stress level fatigue loading.

  10. An Investigation of SiC/SiC Woven Composite Under Monotonic and Cyclic Loading

    NASA Technical Reports Server (NTRS)

    Lang, J.; Sankar, J.; Kelkar, A. D.; Bhatt, R. T.; Singh, M.; Lua, J.

    1997-01-01

    The desirable properties in ceramic matrix composites (CMCs), such as high temperature strength, corrosion resistance, high toughness, low density, or good creep resistance have led to increased use of CMCs in high-speed engine structural components and structures that operate in extreme temperature and hostile aero-thermo-chemical environments. Ceramic matrix composites have been chosen for turbine material in the design of 21 st-century civil propulsion systems to achieve high fuel economy, improved reliability, extended life, and reduced cost. Most commercial CMCs are manufactured using a chemical vapor infiltration (CVI) process. However, a lower cost fabrication known as melt-infiltration process is also providing CMCs marked for use in hot sections of high-speed civil transports. The scope of this paper is to report on the material and mechanical characterization of the CMCs subjected to this process and to predict the behavior through an analytical model. An investigation of the SiC/SiC 8-harness woven composite is ongoing and its tensile strength and fatigue behavior is being characterized for room and elevated temperatures. The investigation is being conducted at below and above the matrix cracking stress once these parameters are identified. Fractography and light microscopy results are being studied to characterize the failure modes resulting from pure uniaxial loading. A numerical model is also being developed to predict the laminate properties by using the constituent material properties and tow undulation.

  11. Investigation of Effects of Material Architecture on the Elastic Response of a Woven Ceramic Matrix Composite

    NASA Technical Reports Server (NTRS)

    Goldberg, Robert K.; Bonacuse, Peter J.; Mital, Subodh K.

    2012-01-01

    To develop methods for quantifying the effects of the microstructural variations of woven ceramic matrix composites on the effective properties and response of the material, a research program has been undertaken which is described in this paper. In order to characterize and quantify the variations in the microstructure of a five harness satin weave, CVI SiC/SiC, composite material, specimens were serially sectioned and polished to capture images that detailed the fiber tows, matrix, and porosity. Open source quantitative image analysis tools were then used to isolate the constituents and collect relevant statistics such as within ply tow spacing. This information was then used to build two dimensional finite element models that approximated the observed section geometry. With the aid of geometrical models generated by the microstructural characterization process, finite element models were generated and analyses were performed to quantify the effects of the microstructure and its variation on the effective stiffness and areas of stress concentration of the material. The results indicated that the geometry and distribution of the porosity appear to have significant effects on the through-thickness modulus. Similarly, stress concentrations on the outer surface of the composite appear to correlate to regions where the transverse tows are separated by a critical amount.

  12. Development of generalized 3-D braiding machines for composite preforms

    NASA Technical Reports Server (NTRS)

    Huey, Cecil O., Jr.; Farley, Gary L.

    1992-01-01

    The development of prototype braiding machines for the production of generalized braid patterns is described. Mechanical operating principles and control strategies are presented for two prototype machines which have been fabricated and evaluated. Both machines represent advances over current fabrication techniques for composite materials by enabling nearly ideal control of fiber orientations within preform structures. They permit optimum design of parts that might be subjected to complex loads or that have complex forms. Further, they overcome both the lack of general control of produced fiber architectures and the complexity of other weaving processes that have been proposed for the same purpose. One prototype, the Farley braider, consists of an array of turntables that can be made to oscillate in 90 degree steps. Yarn ends are transported about the surface formed by the turntables by motorized tractors which are controlled through an optical link with the turntables and powered through electrical contact with the turntables. The necessary relative motions are produced by a series of linear tractor moves combined with a series of turntable rotations. As the tractors move about, they weave the yarn ends into the desired pattern. The second device, the shuttle plate braider, consists of a braiding surface formed by an array of stationary square sections, each separated from its neighbors by a gap. A plate beneath this surface is caused to reciprocate in two perpendicular directions, first in one direction and then in the other. This movement is made possibly by openings in the plate that clear short columns supporting the surface segments. Yarn ends are moved about the surface and interwoven by shuttles which engage the reciprocating plate as needed to yield the desired movements. Power and control signals are transmitted to the shuttles through electrical contact with the braiding surface. The shuttle plate is a passively driven prime mover that supplies the power

  13. Modeling the Nonlinear, Strain Rate Dependent Deformation of Woven Ceramic Matrix Composites With Hydrostatic Stress Effects Included

    NASA Technical Reports Server (NTRS)

    Goldberg, Robert K.; Carney, Kelly S.

    2004-01-01

    An analysis method based on a deformation (as opposed to damage) approach has been developed to model the strain rate dependent, nonlinear deformation of woven ceramic matrix composites with a plain weave fiber architecture. In the developed model, the differences in the tension and compression response have also been considered. State variable based viscoplastic equations originally developed for metals have been modified to analyze the ceramic matrix composites. To account for the tension/compression asymmetry in the material, the effective stress and effective inelastic strain definitions have been modified. The equations have also been modified to account for the fact that in an orthotropic composite the in-plane shear stiffness is independent of the stiffness in the normal directions. The developed equations have been implemented into a commercially available transient dynamic finite element code, LS-DYNA, through the use of user defined subroutines (UMATs). The tensile, compressive, and shear deformation of a representative plain weave woven ceramic matrix composite are computed and compared to experimental results. The computed values correlate well to the experimental data, demonstrating the ability of the model to accurately compute the deformation response of woven ceramic matrix composites.

  14. Thermal shock behavior of two-dimensional woven fiber-reinforced ceramic composites

    SciTech Connect

    Wang, H.; Singh, R.N.; Lowden, R.A.

    1996-07-01

    The thermal shock behavior of three types of two-dimensional woven, continuous fiber-reinforced (Nextel{trademark} 312 (3M Co., St. Paul, MN) or Nicalon{trademark} (Nippon Carbon, Tokyo, Japan)) ceramic matrix (silicon carbide matrix that had been processed by chemical vapor infiltration or polymer impregnation and pyrolysis) composites was studied using the water-quench technique. Thermal-shock-induced damage was characterized by a destructive technique of four-point flexure and a nondestructive technique of Young`s modulus measurement by the dynamic resonance method. Compared with monolithic ceramics, the continuous fiber-reinforced ceramic composites were capable of preventing catastrophic failure that was caused by thermal shock. Analysis of the results that were based on the stresses that were generated by thermal shock and the mismatch of thermal expansion between fibers and matrices suggested possible mechanisms of the thermal shock damage. Preliminary results showed evidence of matrix cracking and delamination because of the thermal shock damage. The feasibility of using the nondestructive technique to detect thermal shock damage also was demonstrated.

  15. Experimental Investigation About Stamping Behaviour of 3D Warp Interlock Composite Preforms

    NASA Astrophysics Data System (ADS)

    Dufour, Clément; Wang, Peng; Boussu, François; Soulat, Damien

    2014-10-01

    Forming of continuous fibre reinforcements and thermoplastic resin commingled prepregs can be performed at room temperature due to its similar textile structure. The "cool" forming stage is better controlled and more economical. The increase of temperature and the resin consolidation phases after the forming can be carried out under the isothermal condition thanks to a closed system. It can avoid the manufacturing defects easily experienced in the non-isothermal thermoforming, in particular the wrinkling [1]. Glass/Polypropylene commingled yarns have been woven inside different three-dimensional (3D) warp interlock fabrics and then formed using a double-curved shape stamping tool. The present study investigates the in-plane and through-thickness behaviour of the 3D warp interlock fibrous reinforcements during forming with a hemispherical punch. Experimental data allow analysing the forming behaviour in the warp and weft directions and on the influence of warp interlock architectures. The results point out that the layer to layer warp interlock preform has a better stamping behaviour, in particular no forming defects and good homogeneity in thickness.

  16. Fused filament 3D printing of ionic polymer-metal composites (IPMCs)

    NASA Astrophysics Data System (ADS)

    Carrico, James D.; Traeden, Nicklaus W.; Aureli, Matteo; Leang, Kam K.

    2015-12-01

    This paper describes a new three-dimensional (3D) fused filament additive manufacturing (AM) technique in which electroactive polymer filament material is used to build soft active 3D structures, layer by layer. Specifically, the unique actuation and sensing properties of ionic polymer-metal composites (IPMCs) are exploited in 3D printing to create electroactive polymer structures for application in soft robotics and bio-inspired systems. The process begins with extruding a precursor material (non-acid Nafion precursor resin) into a thermoplastic filament for 3D printing. The filament is then used by a custom-designed 3D printer to manufacture the desired soft polymer structures, layer by layer. Since at this stage the 3D-printed samples are not yet electroactive, a chemical functionalization process follows, consisting in hydrolyzing the precursor samples in an aqueous solution of potassium hydroxide and dimethyl sulfoxide. Upon functionalization, metal electrodes are applied on the samples through an electroless plating process, which enables the 3D-printed IPMC structures to be controlled by voltage signals for actuation (or to act as sensors). This innovative AM process is described in detail and the performance of 3D printed IPMC actuators is compared to an IPMC actuator fabricated from commercially available Nafion sheet material. The experimental results show comparable performance between the two types of actuators, demonstrating the potential and feasibility of creating functional 3D-printed IPMCs.

  17. Viability of 3 D Woven Carbon Cloth and Advanced Carbon-Carbon Ribs for Adaptive Deployable Entry Placement Technology (ADEPT) for Future NASA Missions

    NASA Technical Reports Server (NTRS)

    Venkatapathy, Ethiraj; Arnold, James O.; Peterson, K. H.; Blosser, M. L.

    2013-01-01

    This paper describes aerothermodynamic and thermal structural testing that demonstrate the viability of three dimensional woven carbon cloth and advanced carbon-carbon (ACC) ribs for use in the Adaptive Deployable Entry Placement Technology (ADEPT). ADEPT is an umbrella-like entry system that is folded for stowage in the launch vehicle's shroud and deployed prior to reaching the atmeopheric interface. A key feature of the ADEPT concept is a lower ballistic coefficient for delivery of a given payload than seen with conventional, rigid body entry systems. The benefits that accrue from the lower ballistic coefficient incllude factor-of-ten reductions of deceleration forces and entry heating. The former enables consideration of new classes of scientific instruments for solar system exploration while the latter enables the design of a more efficient thermal protection system. The carbon cloth base lined for ADEPT has a dual use in that it serves as the thermal protection system and as the "skin" that transfers aerdynamic deceleration loads to its umbrella-like substructure. Arcjet testing described in this paper was conducted for some of the higher heating conditions for a future Venus mission using the ADEPT concept, thereby showing that the carbon cloth can perform in a relevant entry environment. Recently completed the thermal structural testing of the cloth attached to a representative ACC rib design is also described. Finally, this paper describes a preliminary engineering level code, based on the arcjet data, that can be used to estimate cloth thickness for future ADEPT missions and to predict carbon cloth performance in future arcjet tests.

  18. Finite Element Analysis of Thermo-Mechanical Properties of 3D Braided Composites

    NASA Astrophysics Data System (ADS)

    Jiang, Li-li; Xu, Guo-dong; Cheng, Su; Lu, Xia-mei; Zeng, Tao

    2014-04-01

    This paper presents a modified finite element model (FEM) to investigate the thermo-mechanical properties of three-dimensional (3D) braided composite. The effective coefficients of thermal expansion (CTE) and the meso-scale mechanical response of 3D braided composites are predicted. The effects of the braiding angle and fiber volume fraction on the effective CTE are evaluated. The results are compared to the experimental data available in the literature to demonstrate the accuracy and reliability of the present method. The tensile stress distributions of the representative volume element (RVE) are also outlined. It is found that the stress of the braiding yarn has a significant increase with temperature rise; on the other hand, the temperature change has an insignificant effect on the stress of the matrix. In addition, a rapid decrease in the tensile strength of 3D braided composites is observed with the increase in temperature. It is revealed that the thermal conditions have a significant effect on the strength of 3D braided composites. The present method provides an effective tool to predict the stresses of 3D braided composites under thermo-mechanical loading.

  19. Mechanical properties of 2D and 3D braided textile composites

    NASA Technical Reports Server (NTRS)

    Norman, Timothy L.

    1991-01-01

    The purpose of this research was to determine the mechanical properties of 2D and 3D braided textile composite materials. Specifically, those designed for tension or shear loading were tested under static loading to failure to investigate the effects of braiding. The overall goal of the work was to provide a structural designer with an idea of how textile composites perform under typical loading conditions. From test results for unnotched tension, it was determined that the 2D is stronger, stiffer, and has higher elongation to failure than the 3D. It was also found that the polyetherether ketone (PEEK) resin system was stronger, stiffer, and had higher elongation at failure than the resin transfer molding (RTM) epoxy. Open hole tension tests showed that PEEK resin is more notch sensitive than RTM epoxy. Of greater significance, it was found that the 3D is less notch sensitive than the 2D. Unnotched compression tests indicated, as did the tension tests, that the 2D is stronger, stiffer, and has higher elongation at failure than the RTM epoxy. The most encouraging results were from compression after impact. The 3D braided composite showed a compression after impact failure stress equal to 92 percent of the unimpacted specimen. The 2D braided composite failed at about 67 percent of the unimpacted specimen. Higher damage tolerance is observed in textiles over conventional composite materials. This is observed in the results, especially in the 3D braided materials.

  20. Effect of Ductile Agents on the Dynamic Behavior of SiC3D Network Composites

    NASA Astrophysics Data System (ADS)

    Zhu, Jingbo; Wang, Yangwei; Wang, Fuchi; Fan, Qunbo

    2016-07-01

    Co-continuous SiC ceramic composites using pure aluminum, epoxy, and polyurethane (PU) as ductile agents were developed. The dynamic mechanical behavior and failure mechanisms were investigated experimentally using the split Hopkinson pressure bar (SHPB) method and computationally by finite element (FE) simulations. The results show that the SiC3D/Al composite has the best overall performance in comparison with SiC3D/epoxy and SiC3D/PU composites. FE simulations are generally consistent with experimental data. These simulations provide valuable help in predicting mechanical strength and in interpreting the experimental results and failure mechanisms. They may be combined with micrographs for fracture characterizations of the composites. We found that interactions between the SiC phase and ductile agents under dynamic compression in the SHPB method are complex, and that interfacial condition is an important parameter that determines the mechanical response of SiC3D composites with a characteristic interlocking structure during dynamic compression. However, the effect of the mechanical properties of ductile agents on dynamic behavior of the composites is a second consideration in the production of the composites.

  1. 3D flexible NiTi-braided elastomer composites for smart structure applications

    NASA Astrophysics Data System (ADS)

    Heller, L.; Vokoun, D.; Šittner, P.; Finckh, H.

    2012-04-01

    While outstanding functional properties of thin NiTi wires are nowadays well recognized and beneficially utilized in medical NiTi devices, development of 2D/3D wire structures made out of these NiTi wires remains challenging and mostly unexplored. The research is driven by the idea of creating novel 2D/3D smart structures which inherit the functional properties of NiTi wires and actively utilize geometrical deformations within the structure to create new/improved functional properties. Generally, textile technology provides attractive processing methods for manufacturing 2D/3D smart structures made out of NiTi wires. Such structures may be beneficially combined with soft elastomers to create smart deformable composites. Following this route, we carried out experimental work focused on development of 3D flexible NiTi-braided elastomer composites involving their design, laboratory manufacture and thermomechanical testing. We describe the manufacturing technology and structural properties of these composites; and perform thermomechanical tests on the composites, focusing particularly on quasistatic tensile properties, energy absorption, damping and actuation under tensile loading. Functional thermomechanical properties of the composites are discussed with regard to the mechanical properties of the components and architecture of the composites. It is found that the composites indeed inherit all important features of the thermomechanical behavior of NiTi wires but, due to their internal architecture, outperform single NiTi wires in some features such as the magnitude of recoverable strain, superelastic damping capacity and thermally induced actuation strain.

  2. Cryogenic Interlaminar Fracture Properties of Woven Glass/Epoxy Composite Laminates Under Mixed-Mode I/III Loading Conditions

    NASA Astrophysics Data System (ADS)

    Miura, Masaya; Shindo, Yasuhide; Takeda, Tomo; Narita, Fumio

    2013-08-01

    We characterize the combined Mode I and Mode III delamination fracture behavior of woven glass fiber reinforced polymer (GFRP) composite laminates at cryogenic temperatures. The eight-point bending plate (8PBP) tests were conducted at room temperature, liquid nitrogen temperature (77 K) and liquid helium temperature (4 K) using a new test fixture. A three-dimensional finite element analysis was also performed to calculate the energy release rate distribution along the delamination front, and the delamination fracture toughnesses were evaluated for various mixed-mode I/III ratios. Furthermore, the microscopic examinations of the fracture surfaces were carried out with scanning electron microscopy (SEM), and the mixed-mode I/III delamination fracture mechanisms in the woven GFRP laminates at cryogenic temperatures were assessed. The fracture properties were then correlated with the observed characteristics.

  3. Finite Element Analysis of 2.5D Woven Composites, Part II: Damage Behavior Simulation and Strength Prediction

    NASA Astrophysics Data System (ADS)

    Song, Jian; Wen, Weidong; Cui, Haitao; Zhang, Hongjian; Xu, Ying

    2016-02-01

    In the first part of the work, a new 2.5D woven composites finite element model (2.5D WCFEM) which took into consideration the impact of face structures and can accurately predict the main elastic performances has been established. In this part, the stress-strain behavior and the damage characteristic of this material under uniaxial tension are simulated using nonlinear progressive damage analysis based on damage mechanics. Meanwhile, experimental investigation and fracture analysis are conducted to evaluate the validity of the proposed method. Finally, the influence of woven parameters on the mechanical behavior is discussed. Compared with the test results, a good agreement between the computational and experimental results has been obtained. The progressive damage characteristic and main failure modes are also revealed.

  4. Heterogeneous Differentiation of Human Mesenchymal Stem Cells in 3D Extracellular Matrix Composites

    PubMed Central

    Jung, Jangwook P.; Bache-Wiig, Meredith K.; Provenzano, Paolo P.; Ogle, Brenda M.

    2016-01-01

    Abstract Extracellular matrix (ECM) proteins are structural elements of tissue and also potent signaling molecules. Previously, our laboratory showed that ECM of 2D coatings can trigger differentiation of bone marrow-derived mesenchymal stem cells (MSCs) into mesodermal lineages in an ECM-specific manner over 14 days, in some cases comparable to chemical induction. To test whether a similar effect was possible in a 3D, tissue-like environment, we designed a synthetic-natural biomaterial composite. The composite can present whole-molecule ECM proteins to cells, even those that do not spontaneously form hydrogels ex vivo, in 3D. To this end, we entrapped collagen type I, laminin-111, or fibronectin in ECM composites with MSCs and directly compared markers of mesodermal differentiation including cardiomyogenic (ACTC1), osteogenic (SPP1), adipogenic (PPARG), and chondrogenic (SOX9) in 2D versus 3D. We found the 3D condition largely mimicked the 2D condition such that the addition of type I collagen was the most potent inducer of differentiation to all lineages tested. One notable difference between 2D and 3D was pronounced adipogenic differentiation in 3D especially in the presence of exogenous collagen type I. In particular, PPARG gene expression was significantly increased ∼16-fold relative to chemical induction, in 3D and not in 2D. Unexpectedly, 3D engagement of ECM proteins also altered immunomodulatory function of MSCs in that expression of IL-6 gene was elevated relative to basal levels in 2D. In fact, levels of IL-6 gene expression in 3D composites containing exogenously supplied collagen type I or fibronectin were statistically similar to levels attained in 2D with tumor necrosis factor-α (TNF-α) stimulation and these levels were sustained over a 2-week period. Thus, this novel biomaterial platform allowed us to compare the biochemical impact of whole-molecule ECM proteins in 2D versus 3D indicating enhanced adipogenic differentiation and IL-6 expression

  5. Heterogeneous Differentiation of Human Mesenchymal Stem Cells in 3D Extracellular Matrix Composites.

    PubMed

    Jung, Jangwook P; Bache-Wiig, Meredith K; Provenzano, Paolo P; Ogle, Brenda M

    2016-01-01

    Extracellular matrix (ECM) proteins are structural elements of tissue and also potent signaling molecules. Previously, our laboratory showed that ECM of 2D coatings can trigger differentiation of bone marrow-derived mesenchymal stem cells (MSCs) into mesodermal lineages in an ECM-specific manner over 14 days, in some cases comparable to chemical induction. To test whether a similar effect was possible in a 3D, tissue-like environment, we designed a synthetic-natural biomaterial composite. The composite can present whole-molecule ECM proteins to cells, even those that do not spontaneously form hydrogels ex vivo, in 3D. To this end, we entrapped collagen type I, laminin-111, or fibronectin in ECM composites with MSCs and directly compared markers of mesodermal differentiation including cardiomyogenic (ACTC1), osteogenic (SPP1), adipogenic (PPARG), and chondrogenic (SOX9) in 2D versus 3D. We found the 3D condition largely mimicked the 2D condition such that the addition of type I collagen was the most potent inducer of differentiation to all lineages tested. One notable difference between 2D and 3D was pronounced adipogenic differentiation in 3D especially in the presence of exogenous collagen type I. In particular, PPARG gene expression was significantly increased ∼16-fold relative to chemical induction, in 3D and not in 2D. Unexpectedly, 3D engagement of ECM proteins also altered immunomodulatory function of MSCs in that expression of IL-6 gene was elevated relative to basal levels in 2D. In fact, levels of IL-6 gene expression in 3D composites containing exogenously supplied collagen type I or fibronectin were statistically similar to levels attained in 2D with tumor necrosis factor-α (TNF-α) stimulation and these levels were sustained over a 2-week period. Thus, this novel biomaterial platform allowed us to compare the biochemical impact of whole-molecule ECM proteins in 2D versus 3D indicating enhanced adipogenic differentiation and IL-6 expression of MSC in

  6. Mechanical Behaviour of Woven Graphite/Polyimide Composites with Medium and High Modulus Graphite Fibers Subjected to Biaxial Shear Dominated Loads

    NASA Technical Reports Server (NTRS)

    Kumose, M.; Gentz, M.; Rupnowski, P.; Armentrout, D.; Kumosa, L.; Shin, E.; Sutter, J. K.

    2003-01-01

    A major limitation of woven fiber/polymer matrix composite systems is the inability of these materials to resist intralaminar and interlaminar damage initiation and propagation under shear-dominated biaxial loading conditions. There are numerous shear test methods for woven fabric composites, each with its own advantages and disadvantages. Two techniques, which show much potential, are the Iosipescu shear and +/- 45 deg tensile tests. In this paper, the application of these two tests for the room and high temperature failure analyses of woven graphite/polyimide composites is briefly evaluated. In particular, visco-elastic micro, meso, and macro-stress distributions in a woven eight harness satin (8HS) T650/PMR-15 composite subjected to these two tests are presented and their effect on the failure process of the composite is evaluated. Subsequently, the application of the Iosipescu tests to the failure analysis of woven composites with medium (T650) and high (M40J and M60J) modulus graphite fibers and PMR-15 and PMR-II-50 polyimide resins is discussed. The composites were tested as-supplied and after thermal conditioning. The effect of temperature and thermal conditioning on the initiation of intralaminar damage and the shear strength of the composites was established.

  7. Formation and properties of 3D metamaterial composites fabricated using nanometer scale laser lithography (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Prokes, Sharka M.; Perkins, Frank K.; Glembocki, Orest J.

    2015-08-01

    Metamaterials designed for the visible or near IR wavelengths require patterning on the nanometer scale. To achieve this, e-beam lithography is used, but it is extremely difficult and can only produce 2D structures. A new alternative technique to produce 2D and 3D structures involves laser fabrication using the Nanoscribe 3D laser lithography system. This is a direct laser writing technique which can form arbitrary 3D nanostructures on the nanometer scale and is based on multi-photon polymerization. We are creating 2D and 3D metamaterials via this technique, and subsequently conformally coating them using Atomic Layer Deposition of oxides and Ag. We will discuss the optical properties of these novel composite structures and their potential for dual resonant metamaterials.

  8. Two photon polymerization lithography for 3D microfabrication of single wall carbon nanotube/polymer composites

    NASA Astrophysics Data System (ADS)

    Ushiba, Shota; Shoji, Satoru; Kuray, Preeya; Masui, Kyoko; Kono, Junichiro; Kawata, Satoshi

    2013-03-01

    Two photon polymerization (TPP) lithography has been established as a powerful tool to develop 3D fine structures of polymer materials, opening up a wide range applications such as micro-electromechanical systems (MEMS). TPP lithography is also promising for 3D micro fabrication of nanocomposites embedded with nanomaterials such as metal nanoparticles. Here, we make use of TPP lithography to fabricate 3D micro structural single wall carbon nanotube (SWCNT)/polymer composites. SWCNTs exhibit remarkable mechanical, electrical, thermal and optical properties, which leads to enhance performances of polymers by loading SWCNTs. SWCNTs were uniformly dispersed in an acrylate UV-curable monomer including a few amounts of photo-initiator and photo-sensitizer. A femtosecond pulsed laser emitting at 780 nm was focused onto the resin, resulting in the photo-polymerization of a nanometric volume of the resin through TPP. By scanning the focus spot three dimensionally, arbitrary 3D structures were created. The spatial resolution of the fabrication was sub-micrometer, and SWCNTs were embedded in the sub-micro sized structures. The fabrication technique enables one to fabricate 3D micro structural SWCNT/polymer composites into desired shapes, and thus the technique should open up the further applications of SWCNT/polymer composites such as micro sized photomechanical actuators.

  9. Advanced resin systems and 3D textile preforms for low cost composite structures

    NASA Technical Reports Server (NTRS)

    Shukla, J. G.; Bayha, T. D.

    1993-01-01

    Advanced resin systems and 3D textile preforms are being evaluated at Lockheed Aeronautical Systems Company (LASC) under NASA's Advanced Composites Technology (ACT) Program. This work is aimed towards the development of low-cost, damage-tolerant composite fuselage structures. Resin systems for resin transfer molding and powder epoxy towpreg materials are being evaluated for processability, performance and cost. Three developmental epoxy resin systems for resin transfer molding (RTM) and three resin systems for powder towpregging are being investigated. Various 3D textile preform architectures using advanced weaving and braiding processes are also being evaluated. Trials are being conducted with powdered towpreg, in 2D weaving and 3D braiding processes for their textile processability and their potential for fabrication in 'net shape' fuselage structures. The progress in advanced resin screening and textile preform development is reviewed here.

  10. A simple, low-cost conductive composite material for 3D printing of electronic sensors.

    PubMed

    Leigh, Simon J; Bradley, Robert J; Purssell, Christopher P; Billson, Duncan R; Hutchins, David A

    2012-01-01

    3D printing technology can produce complex objects directly from computer aided digital designs. The technology has traditionally been used by large companies to produce fit and form concept prototypes ('rapid prototyping') before production. In recent years however there has been a move to adopt the technology as full-scale manufacturing solution. The advent of low-cost, desktop 3D printers such as the RepRap and Fab@Home has meant a wider user base are now able to have access to desktop manufacturing platforms enabling them to produce highly customised products for personal use and sale. This uptake in usage has been coupled with a demand for printing technology and materials able to print functional elements such as electronic sensors. Here we present formulation of a simple conductive thermoplastic composite we term 'carbomorph' and demonstrate how it can be used in an unmodified low-cost 3D printer to print electronic sensors able to sense mechanical flexing and capacitance changes. We show how this capability can be used to produce custom sensing devices and user interface devices along with printed objects with embedded sensing capability. This advance in low-cost 3D printing with offer a new paradigm in the 3D printing field with printed sensors and electronics embedded inside 3D printed objects in a single build process without requiring complex or expensive materials incorporating additives such as carbon nanotubes. PMID:23185319

  11. A Shell/3D Modeling Technique for the Analysis of Delaminated Composite Laminates

    NASA Technical Reports Server (NTRS)

    Krueger, Ronald; OBrien, T. Kevin

    2000-01-01

    A shell/3D modeling technique was developed for which a local solid finite element model is used only in the immediate vicinity of the delamination front. The goal was to combine the accuracy of the full three-dimensional solution with the computational efficiency of a shell finite element model. Multi-point constraints provided a kinematically compatible interface between the local 3D model and the global structural model which has been meshed with shell finite elements. Double Cantilever Beam, End Notched Flexure, and Single Leg Bending specimens were analyzed first using full 3D finite element models to obtain reference solutions. Mixed mode strain energy release rate distributions were computed using the virtual crack closure technique. The analyses were repeated using the shell/3D technique to study the feasibility for pure mode I, mode II and mixed mode I/II cases. Specimens with a unidirectional layup and with a multidirectional layup were simulated. For a local 3D model, extending to a minimum of about three specimen thicknesses on either side of the delamination front, the results were in good agreement with mixed mode strain energy release rates obtained from computations where the entire specimen had been modeled with solid elements. For large built-up composite structures the shell/3D modeling technique offers a great potential for reducing the model size, since only a relatively small section in the vicinity of the delamination front needs to be modeled with solid elements.

  12. A Simple, Low-Cost Conductive Composite Material for 3D Printing of Electronic Sensors

    PubMed Central

    Leigh, Simon J.; Bradley, Robert J.; Purssell, Christopher P.; Billson, Duncan R.; Hutchins, David A.

    2012-01-01

    3D printing technology can produce complex objects directly from computer aided digital designs. The technology has traditionally been used by large companies to produce fit and form concept prototypes (‘rapid prototyping’) before production. In recent years however there has been a move to adopt the technology as full-scale manufacturing solution. The advent of low-cost, desktop 3D printers such as the RepRap and Fab@Home has meant a wider user base are now able to have access to desktop manufacturing platforms enabling them to produce highly customised products for personal use and sale. This uptake in usage has been coupled with a demand for printing technology and materials able to print functional elements such as electronic sensors. Here we present formulation of a simple conductive thermoplastic composite we term ‘carbomorph’ and demonstrate how it can be used in an unmodified low-cost 3D printer to print electronic sensors able to sense mechanical flexing and capacitance changes. We show how this capability can be used to produce custom sensing devices and user interface devices along with printed objects with embedded sensing capability. This advance in low-cost 3D printing with offer a new paradigm in the 3D printing field with printed sensors and electronics embedded inside 3D printed objects in a single build process without requiring complex or expensive materials incorporating additives such as carbon nanotubes. PMID:23185319

  13. Development of Stitched, Braided and Woven Composite Structures in the ACT Program and at Langley Research Center

    NASA Technical Reports Server (NTRS)

    Dow, Marvin B.; Dexter, H. Benson

    1997-01-01

    Summary results are presented from the research conducted on woven, braided, knitted and stitched (textile) composites at the Langley Research Center and under the NASA Advanced Composites Technology (ACT) Program in the period from 1985 to 1997. The report also includes an annotated bibliography of 270 U.S. publications on textile composites (with their abstracts). Two major research areas are discussed: (1) the general research in textile composites performed throughout the period under the direction of the Langley Research Center and (2) the development of textile composite aircraft structures by industry under the NASA ACT Program. The annotated bibliography is organized in three subsections: (1) general textiles R&D under the auspices of Langley, (2) ACT Program development of textile structural components, and (3) textiles research by individuals and organizations not associated with the ACT Program. An author index is provided for the reports and documents.

  14. 3D scaffold alters cellular response to graphene in a polymer composite for orthopedic applications.

    PubMed

    Kumar, Sachin; Azam, Dilkash; Raj, Shammy; Kolanthai, Elayaraja; Vasu, K S; Sood, A K; Chatterjee, Kaushik

    2016-05-01

    Graphene-based polymer nanocomposites are being studied for biomedical applications. Polymer nanocomposites can be processed differently to generate planar two-dimensional (2D) substrates and porous three-dimensional (3D) scaffolds. The objective of this work was to investigate potential differences in biological response to graphene in polymer composites in the form of 2D substrates and 3D scaffolds. Polycaprolactone (PCL) nanocomposites were prepared by incorporating 1% of graphene oxide (GO) and reduced graphene oxide (RGO). GO increased modulus and strength of PCL by 44 and 22% respectively, whereas RGO increased modulus and strength by 22 and 16%, respectively. RGO increased the water contact angle of PCL from 81° to 87° whereas GO decreased it to 77°. In 2D, osteoblast proliferated 15% more on GO composites than on PCL whereas RGO composite showed 17% decrease in cell proliferation, which may be attributed to differences in water wettability. In 3D, initial cell proliferation was markedly retarded in both GO (36% lower) and RGO (55% lower) composites owing to increased roughness due to the presence of the protruding nanoparticles. Cells organized into aggregates in 3D in contrast to spread and randomly distributed cells on 2D discs due to the macro-porous architecture of the scaffolds. Increased cell-cell contact and altered cellular morphology led to significantly higher mineralization in 3D. This study demonstrates that the cellular response to nanoparticles in composites can change markedly by varying the processing route and has implications for designing orthopedic implants such as resorbable fracture fixation devices and tissue scaffolds using such nanocomposites. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 732-749, 2016. PMID:26482196

  15. A Micromechanical Unit Cell Model of 2 × 2 Twill Woven Fabric Textile Composite for Multi Scale Analysis

    NASA Astrophysics Data System (ADS)

    Dixit, A.; Mali, H. S.; Misra, R. K.

    2014-04-01

    Woven fabric based composite materials are being considered for potential structural applications in automotive and aircraft industries due to their better out of plane strength, stiffness and toughness properties than ordinary composite laminates. This paper presents the micromechanical unit cell model of 2 × 2 twill woven fabric textile composite for the estimation of in-plane elastic properties. Modelling of unit cell and its analysis for this new model is developed by using open source coded tool TexGen and finite element software, ABAQUS® respectively. The predicted values are in good agreement with the experimental results reported in literature. To ascertain the effectiveness of the developed model parametric studies have also been conducted on the predicted elastic properties in order to investigate the effects of various geometric parameters such as yarn spacing, fabric thickness, yarn width and fibre volume fraction. The scope of altering weave pattern and yarn characteristics is facilitated in this developed model. Further this model can be implemented for the multi-scale micro/macro-mechanical analysis for the calculation of strength and stiffness of laminates structure made of 2 × 2 twill composite.

  16. 3D optical printing of piezoelectric nanoparticle-polymer composite materials.

    PubMed

    Kim, Kanguk; Zhu, Wei; Qu, Xin; Aaronson, Chase; McCall, William R; Chen, Shaochen; Sirbuly, Donald J

    2014-10-28

    Here we demonstrate that efficient piezoelectric nanoparticle-polymer composite materials can be optically printed into three-dimensional (3D) microstructures using digital projection printing. Piezoelectric polymers were fabricated by incorporating barium titanate (BaTiO3, BTO) nanoparticles into photoliable polymer solutions such as polyethylene glycol diacrylate and exposing to digital optical masks that could be dynamically altered to generate user-defined 3D microstructures. To enhance the mechanical-to-electrical conversion efficiency of the composites, the BTO nanoparticles were chemically modified with acrylate surface groups, which formed direct covalent linkages with the polymer matrix under light exposure. The composites with a 10% mass loading of the chemically modified BTO nanoparticles showed piezoelectric coefficients (d(33)) of ∼ 40 pC/N, which were over 10 times larger than composites synthesized with unmodified BTO nanoparticles and over 2 times larger than composites containing unmodified BTO nanoparticles and carbon nanotubes to boost mechanical stress transfer efficiencies. These results not only provide a tool for fabricating 3D piezoelectric polymers but lay the groundwork for creating highly efficient piezoelectric polymer materials via nanointerfacial tuning. PMID:25046646

  17. Multi-shape active composites by 3D printing of digital shape memory polymers

    NASA Astrophysics Data System (ADS)

    Wu, Jiangtao; Yuan, Chao; Ding, Zhen; Isakov, Michael; Mao, Yiqi; Wang, Tiejun; Dunn, Martin L.; Qi, H. Jerry

    2016-04-01

    Recent research using 3D printing to create active structures has added an exciting new dimension to 3D printing technology. After being printed, these active, often composite, materials can change their shape over time; this has been termed as 4D printing. In this paper, we demonstrate the design and manufacture of active composites that can take multiple shapes, depending on the environmental temperature. This is achieved by 3D printing layered composite structures with multiple families of shape memory polymer (SMP) fibers – digital SMPs - with different glass transition temperatures (Tg) to control the transformation of the structure. After a simple single-step thermomechanical programming process, the fiber families can be sequentially activated to bend when the temperature is increased. By tuning the volume fraction of the fibers, bending deformation can be controlled. We develop a theoretical model to predict the deformation behavior for better understanding the phenomena and aiding the design. We also design and print several flat 2D structures that can be programmed to fold and open themselves when subjected to heat. With the advantages of an easy fabrication process and the controllable multi-shape memory effect, the printed SMP composites have a great potential in 4D printing applications.

  18. Multi-shape active composites by 3D printing of digital shape memory polymers.

    PubMed

    Wu, Jiangtao; Yuan, Chao; Ding, Zhen; Isakov, Michael; Mao, Yiqi; Wang, Tiejun; Dunn, Martin L; Qi, H Jerry

    2016-01-01

    Recent research using 3D printing to create active structures has added an exciting new dimension to 3D printing technology. After being printed, these active, often composite, materials can change their shape over time; this has been termed as 4D printing. In this paper, we demonstrate the design and manufacture of active composites that can take multiple shapes, depending on the environmental temperature. This is achieved by 3D printing layered composite structures with multiple families of shape memory polymer (SMP) fibers - digital SMPs - with different glass transition temperatures (Tg) to control the transformation of the structure. After a simple single-step thermomechanical programming process, the fiber families can be sequentially activated to bend when the temperature is increased. By tuning the volume fraction of the fibers, bending deformation can be controlled. We develop a theoretical model to predict the deformation behavior for better understanding the phenomena and aiding the design. We also design and print several flat 2D structures that can be programmed to fold and open themselves when subjected to heat. With the advantages of an easy fabrication process and the controllable multi-shape memory effect, the printed SMP composites have a great potential in 4D printing applications. PMID:27071543

  19. Multi-shape active composites by 3D printing of digital shape memory polymers

    PubMed Central

    Wu, Jiangtao; Yuan, Chao; Ding, Zhen; Isakov, Michael; Mao, Yiqi; Wang, Tiejun; Dunn, Martin L.; Qi, H. Jerry

    2016-01-01

    Recent research using 3D printing to create active structures has added an exciting new dimension to 3D printing technology. After being printed, these active, often composite, materials can change their shape over time; this has been termed as 4D printing. In this paper, we demonstrate the design and manufacture of active composites that can take multiple shapes, depending on the environmental temperature. This is achieved by 3D printing layered composite structures with multiple families of shape memory polymer (SMP) fibers – digital SMPs - with different glass transition temperatures (Tg) to control the transformation of the structure. After a simple single-step thermomechanical programming process, the fiber families can be sequentially activated to bend when the temperature is increased. By tuning the volume fraction of the fibers, bending deformation can be controlled. We develop a theoretical model to predict the deformation behavior for better understanding the phenomena and aiding the design. We also design and print several flat 2D structures that can be programmed to fold and open themselves when subjected to heat. With the advantages of an easy fabrication process and the controllable multi-shape memory effect, the printed SMP composites have a great potential in 4D printing applications. PMID:27071543

  20. A finite element analysis of a 3D auxetic textile structure for composite reinforcement

    NASA Astrophysics Data System (ADS)

    Ge, Zhaoyang; Hu, Hong; Liu, Yanping

    2013-08-01

    This paper reports the finite element analysis of an innovative 3D auxetic textile structure consisting of three yarn systems (weft, warp and stitch yarns). Different from conventional 3D textile structures, the proposed structure exhibits an auxetic behaviour under compression and can be used as a reinforcement to manufacture auxetic composites. The geometry of the structure is first described. Then a 3D finite element model is established using ANSYS software and validated by the experimental results. The deformation process of the structure at different compression strains is demonstrated, and the validated finite element model is finally used to simulate the auxetic behaviour of the structure with different structural parameters and yarn properties. The results show that the auxetic behaviour of the proposed structure increases with increasing compression strain, and all the structural parameters and yarn properties have significant effects on the auxetic behaviour of the structure. It is expected that the study could provide a better understanding of 3D auxetic textile structures and could promote their application in auxetic composites.

  1. Mechanical Performance and Parameter Sensitivity Analysis of 3D Braided Composites Joints

    PubMed Central

    Wu, Yue; Nan, Bo; Chen, Liang

    2014-01-01

    3D braided composite joints are the important components in CFRP truss, which have significant influence on the reliability and lightweight of structures. To investigate the mechanical performance of 3D braided composite joints, a numerical method based on the microscopic mechanics is put forward, the modeling technologies, including the material constants selection, element type, grid size, and the boundary conditions, are discussed in detail. Secondly, a method for determination of ultimate bearing capacity is established, which can consider the strength failure. Finally, the effect of load parameters, geometric parameters, and process parameters on the ultimate bearing capacity of joints is analyzed by the global sensitivity analysis method. The results show that the main pipe diameter thickness ratio γ, the main pipe diameter D, and the braided angle α are sensitive to the ultimate bearing capacity N. PMID:25121121

  2. Mechanical performance and parameter sensitivity analysis of 3D braided composites joints.

    PubMed

    Wu, Yue; Nan, Bo; Chen, Liang

    2014-01-01

    3D braided composite joints are the important components in CFRP truss, which have significant influence on the reliability and lightweight of structures. To investigate the mechanical performance of 3D braided composite joints, a numerical method based on the microscopic mechanics is put forward, the modeling technologies, including the material constants selection, element type, grid size, and the boundary conditions, are discussed in detail. Secondly, a method for determination of ultimate bearing capacity is established, which can consider the strength failure. Finally, the effect of load parameters, geometric parameters, and process parameters on the ultimate bearing capacity of joints is analyzed by the global sensitivity analysis method. The results show that the main pipe diameter thickness ratio γ, the main pipe diameter D, and the braided angle α are sensitive to the ultimate bearing capacity N. PMID:25121121

  3. Effect of delamination on vibration behaviour of woven Glass/Epoxy composite plate-An experimental study

    NASA Astrophysics Data System (ADS)

    Hirwani, C. K.; Sahoo, S. S.; Panda, S. K.

    2016-02-01

    We have analysed the free vibration responses of the laminated composite plate with delamination numerically and validated with subsequent experiment. In order to compute the numerical frequencies, the delaminated composite plate is modelled with two sub-laminate approaches in the commercial finite element package (ANSYS) using ANSYS parametric design language code in ANSYS environment. For the experimental analysis, the woven Glass/Epoxy composite plate is fabricated using hand layup method with the desired delamination. The natural frequencies of the delaminated plate are also computed experimentally with the help of the vibration analyser (NI-CDAQ) and validated by comparing with the simulation result. Further, the simulation model is extended for various design parameter and discussed in detail.

  4. Biomimetic staggered composites with highly enhanced energy dissipation: Modeling, 3D printing, and testing

    NASA Astrophysics Data System (ADS)

    Zhang, Pu; Heyne, Mary A.; To, Albert C.

    2015-10-01

    We investigate the damping enhancement in a class of biomimetic staggered composites via a combination of design, modeling, and experiment. In total, three kinds of staggered composites are designed by mimicking the structure of bone and nacre. These composite designs are realized by 3D printing a rigid plastic and a viscous elastomer simultaneously. Greatly-enhanced energy dissipation in the designed composites is observed from both the experimental results and theoretical prediction. The designed polymer composites have loss modulus up to ~500 MPa, higher than most of the existing polymers. In addition, their specific loss modulus (up to 0.43 km2/s2) is among the highest of damping materials. The damping enhancement is attributed to the large shear deformation of the viscous soft matrix and the large strengthening effect from the rigid inclusion phase.

  5. Pt-Free Counter Electrodes with Carbon Black and 3D Network Epoxy Polymer Composites

    PubMed Central

    Kang, Gyeongho; Choi, Jongmin; Park, Taiho

    2016-01-01

    Carbon black (CB) and a 3D network epoxy polymer composite, representing dual functions for conductive corrosion protective layer (CCPL) and catalytic layer (CL) by the control of CB weight ratio against polymer is developed. Our strategy provides a proper approach which applies high catalytic ability and chemical stability of CB in corrosive triiodide/iodide (I3−/I−) redox electrolyte system. The CB and a 3D network epoxy polymer composite coated on the stainless steel (SS) electrode to alternate counter electrodes in dye sensitized solar cells (DSSCs). A two-step spray pyrolysis process is used to apply a solution containing epoxy monomers and a polyfunctional amine hardener with 6 wt% CB to a SS substrate, which forms a CCPL. Subsequently, an 86 wt% CB is applied to form a CL. The excellent catalytic properties and corrosion protective properties of the CB and 3D network epoxy polymer composites produce efficient counter electrodes that can replace fluorine-doped tin oxide (FTO) with CCPL/SS and Pt/FTO with CL/CCPL/SS in DSSCs. This approach provides a promising approach to the development of efficient, stable, and cheap solar cells, paving the way for large-scale commercialization. PMID:26961256

  6. Pt-Free Counter Electrodes with Carbon Black and 3D Network Epoxy Polymer Composites

    NASA Astrophysics Data System (ADS)

    Kang, Gyeongho; Choi, Jongmin; Park, Taiho

    2016-03-01

    Carbon black (CB) and a 3D network epoxy polymer composite, representing dual functions for conductive corrosion protective layer (CCPL) and catalytic layer (CL) by the control of CB weight ratio against polymer is developed. Our strategy provides a proper approach which applies high catalytic ability and chemical stability of CB in corrosive triiodide/iodide (I3‑/I‑) redox electrolyte system. The CB and a 3D network epoxy polymer composite coated on the stainless steel (SS) electrode to alternate counter electrodes in dye sensitized solar cells (DSSCs). A two-step spray pyrolysis process is used to apply a solution containing epoxy monomers and a polyfunctional amine hardener with 6 wt% CB to a SS substrate, which forms a CCPL. Subsequently, an 86 wt% CB is applied to form a CL. The excellent catalytic properties and corrosion protective properties of the CB and 3D network epoxy polymer composites produce efficient counter electrodes that can replace fluorine-doped tin oxide (FTO) with CCPL/SS and Pt/FTO with CL/CCPL/SS in DSSCs. This approach provides a promising approach to the development of efficient, stable, and cheap solar cells, paving the way for large-scale commercialization.

  7. Microwave dielectric characterisation of 3D-printed BaTiO3/ABS polymer composites

    PubMed Central

    Castles, F.; Isakov, D.; Lui, A.; Lei, Q.; Dancer, C. E. J.; Wang, Y.; Janurudin, J. M.; Speller, S. C.; Grovenor, C. R. M.; Grant, P. S.

    2016-01-01

    3D printing is used extensively in product prototyping and continues to emerge as a viable option for the direct manufacture of final parts. It is known that dielectric materials with relatively high real permittivity—which are required in important technology sectors such as electronics and communications—may be 3D printed using a variety of techniques. Among these, the fused deposition of polymer composites is particularly straightforward but the range of dielectric permittivities available through commercial feedstock materials is limited. Here we report on the fabrication of a series of composites composed of various loadings of BaTiO3 microparticles in the polymer acrylonitrile butadiene styrene (ABS), which may be used with a commercial desktop 3D printer to produce printed parts containing user-defined regions with high permittivity. The microwave dielectric properties of printed parts with BaTiO3 loadings up to 70 wt% were characterised using a 15 GHz split post dielectric resonator and had real relative permittivities in the range 2.6–8.7 and loss tangents in the range 0.005–0.027. Permittivities were reproducible over the entire process, and matched those of bulk unprinted materials, to within ~1%, suggesting that the technique may be employed as a viable manufacturing process for dielectric composites. PMID:26940381

  8. Microwave dielectric characterisation of 3D-printed BaTiO3/ABS polymer composites

    NASA Astrophysics Data System (ADS)

    Castles, F.; Isakov, D.; Lui, A.; Lei, Q.; Dancer, C. E. J.; Wang, Y.; Janurudin, J. M.; Speller, S. C.; Grovenor, C. R. M.; Grant, P. S.

    2016-03-01

    3D printing is used extensively in product prototyping and continues to emerge as a viable option for the direct manufacture of final parts. It is known that dielectric materials with relatively high real permittivity—which are required in important technology sectors such as electronics and communications—may be 3D printed using a variety of techniques. Among these, the fused deposition of polymer composites is particularly straightforward but the range of dielectric permittivities available through commercial feedstock materials is limited. Here we report on the fabrication of a series of composites composed of various loadings of BaTiO3 microparticles in the polymer acrylonitrile butadiene styrene (ABS), which may be used with a commercial desktop 3D printer to produce printed parts containing user-defined regions with high permittivity. The microwave dielectric properties of printed parts with BaTiO3 loadings up to 70 wt% were characterised using a 15 GHz split post dielectric resonator and had real relative permittivities in the range 2.6–8.7 and loss tangents in the range 0.005–0.027. Permittivities were reproducible over the entire process, and matched those of bulk unprinted materials, to within ~1%, suggesting that the technique may be employed as a viable manufacturing process for dielectric composites.

  9. Pt-Free Counter Electrodes with Carbon Black and 3D Network Epoxy Polymer Composites.

    PubMed

    Kang, Gyeongho; Choi, Jongmin; Park, Taiho

    2016-01-01

    Carbon black (CB) and a 3D network epoxy polymer composite, representing dual functions for conductive corrosion protective layer (CCPL) and catalytic layer (CL) by the control of CB weight ratio against polymer is developed. Our strategy provides a proper approach which applies high catalytic ability and chemical stability of CB in corrosive triiodide/iodide (I3(-)/I(-)) redox electrolyte system. The CB and a 3D network epoxy polymer composite coated on the stainless steel (SS) electrode to alternate counter electrodes in dye sensitized solar cells (DSSCs). A two-step spray pyrolysis process is used to apply a solution containing epoxy monomers and a polyfunctional amine hardener with 6 wt% CB to a SS substrate, which forms a CCPL. Subsequently, an 86 wt% CB is applied to form a CL. The excellent catalytic properties and corrosion protective properties of the CB and 3D network epoxy polymer composites produce efficient counter electrodes that can replace fluorine-doped tin oxide (FTO) with CCPL/SS and Pt/FTO with CL/CCPL/SS in DSSCs. This approach provides a promising approach to the development of efficient, stable, and cheap solar cells, paving the way for large-scale commercialization. PMID:26961256

  10. 3D label-free prostate specific antigen (PSA) immunosensor based on graphene-gold composites.

    PubMed

    Jang, Hee Dong; Kim, Sun Kyung; Chang, Hankwon; Choi, Jeong-Woo

    2015-01-15

    Highly sensitive and label-free detection of the prostate specific antigen (PSA) remains a challenge in the diagnosis of prostate cancer. Here, a novel three-dimensional (3D) electrochemical immunosensor capable of sensitive and label-free detection of PSA is reported. This unique immunosensor is equipped with a highly conductive graphene (GR)-based gold (Au) composite modified electrode. The GR-based Au composite is prepared using aerosol spray pyrolysis and the morphology of the composite is the shape of a crumpled GR ball decorated with Au nanoparticles. Unlike the previous research, this novel 3D immunosensor functions very well over a broad linear range of 0-10 ng/mL with a low detection limit of 0.59 ng/mL; furthermore, it exhibits a significantly increased electron transfer and high sensitivity toward PSA. The highest rate of current change with respect to the PSA concentration is 5 μA/(ng/mL). Satisfactory selectivity, reproducibility, and stability of the 3D immunosensor are also exhibited. PMID:25150936

  11. Microwave dielectric characterisation of 3D-printed BaTiO3/ABS polymer composites.

    PubMed

    Castles, F; Isakov, D; Lui, A; Lei, Q; Dancer, C E J; Wang, Y; Janurudin, J M; Speller, S C; Grovenor, C R M; Grant, P S

    2016-01-01

    3D printing is used extensively in product prototyping and continues to emerge as a viable option for the direct manufacture of final parts. It is known that dielectric materials with relatively high real permittivity-which are required in important technology sectors such as electronics and communications-may be 3D printed using a variety of techniques. Among these, the fused deposition of polymer composites is particularly straightforward but the range of dielectric permittivities available through commercial feedstock materials is limited. Here we report on the fabrication of a series of composites composed of various loadings of BaTiO3 microparticles in the polymer acrylonitrile butadiene styrene (ABS), which may be used with a commercial desktop 3D printer to produce printed parts containing user-defined regions with high permittivity. The microwave dielectric properties of printed parts with BaTiO3 loadings up to 70 wt% were characterised using a 15 GHz split post dielectric resonator and had real relative permittivities in the range 2.6-8.7 and loss tangents in the range 0.005-0.027. Permittivities were reproducible over the entire process, and matched those of bulk unprinted materials, to within ~1%, suggesting that the technique may be employed as a viable manufacturing process for dielectric composites. PMID:26940381

  12. Thermal analysis of 3D composites by a new fast multipole hybrid boundary node method

    NASA Astrophysics Data System (ADS)

    Miao, Yu; Wang, Qiao; Zhu, Hongping; Li, Yinping

    2014-01-01

    This paper applies the hybrid boundary node method (Hybrid BNM) for the thermal analysis of 3D composites. A new formulation is derived for the inclusion-based composites. In the new formulation, the unknowns of the interfaces are assembled only once in the final system equation, which can reduce nearly one half of degrees of freedom (DOFs) compared with the conventional multi-domain solver when there are lots of inclusions. A new version of the fast multipole method (FMM) is also coupled with the new formulation and the technique is applied to thermal analysis of composites with many inclusions. In the new fast multipole hybrid boundary node method (FM-HBNM), a diagonal form for translation operators is used and the method presented can be applied to the computation of more than 1,000,000 DOFs on a personal computer. Numerical examples are presented to analyze the thermal behavior of composites with many inclusions.

  13. Effects of electromagnetic field frequencies on chondrocytes in 3D cell-printed composite constructs.

    PubMed

    Yi, Hee-Gyeong; Kang, Kyung Shin; Hong, Jung Min; Jang, Jinah; Park, Moon Nyeo; Jeong, Young Hun; Cho, Dong-Woo

    2016-07-01

    In cartilage tissue engineering, electromagnetic field (EMF) therapy has been reported to have a modest effect on promoting cartilage regeneration. However, these studies were conducted using different frequencies of EMF to stimulate chondrocytes. Thus, it is necessary to investigate the effect of EMF frequency on cartilage formation. In addition to the stimulation, a scaffold is required to satisfy the characteristics of cartilage such as its hydrated and dense extracellular matrix, and a mechanical resilience to applied loads. Therefore, we 3D-printed a composite construct composed of a polymeric framework and a chondrocyte-laden hydrogel. Here, we observed frequency-dependent positive and negative effects on chondrogenesis using a 3D cell-printed cartilage tissue. We found that a frequency of 45 Hz promoted gene expression and secretion of extracellular matrix molecules of chondrocytes. In contrast, a frequency of 7.5 Hz suppressed chondrogenic differentiation in vitro. Additionally, the EMF-treated composite constructs prior to implantation showed consistent results with those of in vitro, suggesting that in vitro pre-treatment with different EMF frequencies provides different capabilities for the enhancement of cartilage formation in vivo. This correlation between EMF frequency and 3D-printed chondrocytes suggests the necessity for optimization of EMF parameters when this physical stimulus is applied to engineered cartilage. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1797-1804, 2016. PMID:26991030

  14. A Shell/3D Modeling Technique for Delaminations in Composite Laminates

    NASA Technical Reports Server (NTRS)

    Krueger, Ronald

    1999-01-01

    A shell/3D modeling technique was developed for which a local solid finite element model is used only in the immediate vicinity of the delamination front. The goal was to combine the accuracy of the full three-dimensional solution with the computational efficiency of a plate or shell finite element model. Multi-point constraints provide a kinematically compatible interface between the local 3D model and the global structural model which has been meshed with plate or shell finite elements. For simple double cantilever beam (DCB), end notched flexure (ENF), and single leg bending (SLB) specimens, mixed mode energy release rate distributions were computed across the width from nonlinear finite element analyses using the virtual crack closure technique. The analyses served to test the accuracy of the shell/3D technique for the pure mode I case (DCB), mode II case (ENF) and a mixed mode I/II case (SLB). Specimens with a unidirectional layup where the delamination is located between two 0 plies, as well as a multidirectional layup where the delamination is located between two non-zero degree plies, were simulated. For a local 3D model extending to a minimum of about three specimen thicknesses in front of and behind the delamination front, the results were in good agreement with mixed mode strain energy release rates obtained from computations where the entire specimen had been modeled with solid elements. For large built-up composite structures modeled with plate elements, the shell/3D modeling technique offers a great potential, since only a relatively small section in the vicinity of the delamination front needs to be modeled with solid elements.

  15. GIA models with composite rheology and 3D viscosity: effect on GRACE mass balance in Antarctica

    NASA Astrophysics Data System (ADS)

    van der Wal, Wouter; Whitehouse, Pippa; Schrama, Ernst

    2014-05-01

    Most Glacial Isostatic Adjustment (GIA) models that have been used to correct GRACE data for the influence of GIA assume a radial stratification of viscosity in the Earth's mantle (1D viscosity). Seismic data in Antarctica indicate that there are large viscosity variations in the horizontal direction (3D viscosity). The purpose of this research is to determine the effect of 3D viscosity on GIA model output, and hence mass balance estimates in Antarctica. We use a GIA model with 3D viscosity and composite rheology in combination with ice loading histories ICE-5G and W12a. From comparisons with uplift and sea-level data in Fennoscandia and North America three preferred viscosity models are selected. For two of the 3D viscosity models the maximum gravity rate due to ICE-5G forcing is located over the Ronne-Filchner ice shelf. This is in contrast with the results obtained using a 1D model, in which the maximum gravity rate due to ICE-5G forcing is always located over the Ross ice shelf. This demonstrates that not all 3D viscosity models can be approximated with a 1D viscosity model. Using CSR release 5 GRACE data from February 2003 to June 2013 mass balance estimates for the three preferred viscosity models are -131 to -171 Gt/year for the ICE-5G model, and -48 to -57 Gt/year for the W12a model. The range due to Earth model uncertainty is larger than the error bar for GRACE (10 Gt/year), but smaller than the range resulting from the difference in ice loading histories.

  16. Stability of 3D Textile Composite Reinforcement Simulations: Solutions to Spurious Transverse Modes

    NASA Astrophysics Data System (ADS)

    Mathieu, S.; Hamila, N.; Dupé, F.; Descamps, C.; Boisse, P.

    2016-08-01

    The simulation of thick 3D composite reinforcement forming brings to light new modeling challenges. The specific anisotropic material behavior due to the possible slippage between fibers induces, among other phenomena, the development of spurious transverse modes in bending-dominated 3D simulations. To obtain coherent finite element responses, two solutions are proposed. The first one uses a simple assumed strain formulation usually prescribed to prevent volumetric locking. This solution avoids spurious transverse modes by stiffening of the hourglass modes. Nevertheless the deformation obtained by this approach still suffers from the inability of the standard continuum mechanics of Cauchy to describe fibrous material deformation. The second proposed approach is based on the introduction of a bending stiffness which both avoids the spurious transverse modes and also improves the global behavior of the element formulation by enriching the underlying continuum. To emphasize the differences between different formulations, element stiffnesses are explicitly calculated and compared.

  17. Stability of 3D Textile Composite Reinforcement Simulations: Solutions to Spurious Transverse Modes

    NASA Astrophysics Data System (ADS)

    Mathieu, S.; Hamila, N.; Dupé, F.; Descamps, C.; Boisse, P.

    2016-03-01

    The simulation of thick 3D composite reinforcement forming brings to light new modeling challenges. The specific anisotropic material behavior due to the possible slippage between fibers induces, among other phenomena, the development of spurious transverse modes in bending-dominated 3D simulations. To obtain coherent finite element responses, two solutions are proposed. The first one uses a simple assumed strain formulation usually prescribed to prevent volumetric locking. This solution avoids spurious transverse modes by stiffening of the hourglass modes. Nevertheless the deformation obtained by this approach still suffers from the inability of the standard continuum mechanics of Cauchy to describe fibrous material deformation. The second proposed approach is based on the introduction of a bending stiffness which both avoids the spurious transverse modes and also improves the global behavior of the element formulation by enriching the underlying continuum. To emphasize the differences between different formulations, element stiffnesses are explicitly calculated and compared.

  18. The toughest recorded spider egg case silks are woven into composites with tear-resistant architectures.

    PubMed

    Alam, Parvez; Otieno, Danish; Nuhamunada, Matin; Anyango, Roselyn; Odoyo, Jared; Odhiambo, John; Onyango, Kenneth

    2016-12-01

    In this communication, we report important preliminary evidence for possibly the toughest egg case silk threads recorded to date spun by the hermit spider, Nephilengys cruentata (G¯=193MJm(-3)). We further elucidate that the egg case itself is woven with a specialised repeat cross-weave that when subjected to tension, drives perpendicular-to-force threads to pile. This piling of threads constrains damage to small areas and retains the architectural integrity of the surrounding egg case material. We deduce that by having ultra-tough threads coupled to a tear resistant architecture, N. cruentata is able to protect its eggs from predators with a considerable level of effectiveness. PMID:27612704

  19. Evaluation of micro-damage accumulation in holed plain-woven CFRP composite under fatigue loading

    NASA Astrophysics Data System (ADS)

    Ying, Jia; Nishikawa, Masaaki; Hojo, Masaki

    2014-03-01

    Fluorescence method was used to detect the micro-damage caused by fatigue in a plain-woven carbon fiber reinforced polymer (CFRP). Fluorescence measurement is a method which estimates micro-damage by measuring fluorescent intensity change inside materials. The principle is, larger micro-damage means larger plastic strain, thus more space in that damaged spot which allows more fluorescent dyes coming in the material. By detecting fluorescent intensity in CFRP layer by layer using confocal laser microscopy, micro-damage can be estimated. Results show that there's a good relationship between micro-damage and fluorescent intensity gradient.

  20. Low-velocity impact behavior of woven jute/poly(lactic acid) composites

    NASA Astrophysics Data System (ADS)

    Russo, Pietro; Simeoli, Giorgio; Papa, Ilaria; Acierno, Domenico; Lopresto, Valentina; Langella, Antonio

    2016-05-01

    Biocomposite laminates based on poly(lactic acid) (PLA) and woven jute fabric were obtained by film stacking and compression molding techniques. Sample laminates were systematically characterized by impact tests with a falling dart at impact energies equal to 5, 10 and 20 J. Tests showed that, investigated PLA/jute fabric plates suffer only barely visible damages at the first two levels of impact energy while they result to be perforated at 20 J as highlighted by photographic images taken on low and back side of impacted surfaces.

  1. A Periosteum-Inspired 3D Hydrogel-Bioceramic Composite for Enhanced Bone Regeneration .

    PubMed

    Chun, Yong Yao; Wang, Jun Kit; Tan, Nguan Soon; Chan, Peggy Puk Yik; Tan, Timothy Thatt Yang; Choong, Cleo

    2016-02-01

    A 3D injectable hydrogel-bioceramic composite consisting of gelatin-3-(4-hydroxyphenyl) propionic acid (Gtn-HPA) and carboxymethyl cellulose-tyramine (CMC-Tyr), incorporated with fish scale-derived calcium phosphate (CaP), is developed for bone applications. The hydrogel-bioceramic composite has significantly improved the elastic modulus compared to the non-filled hydrogel, of which the addition of 10 w/v% CaP showed zero order fluorescein isothiocyanate (FITC)-dextran release profile and a significantly higher proliferation rate of encapsulated cells. All the samples promote the nucleation and growth of CaP minerals when exposed to 1× SBF. Overall, the hydrogel-bioceramic composite with 10 w/v% CaP can potentially be used as a periosteum-mimicking membrane to facilitate bone regeneration. PMID:26445013

  2. Fracture, failure and compression behaviour of a 3D interconnected carbon aerogel (Aerographite) epoxy composite

    DOE PAGESBeta

    Chandrasekaran, S.; Liebig, W. V.; Mecklenberg, M.; Fiedler, B.; Smazna, D.; Adelung, R.; Schulte, K.

    2015-11-04

    Aerographite (AG) is a mechanically robust, lightweight synthetic cellular material, which consists of a 3D interconnected network of tubular carbon [1]. The presence of open channels in AG aids to infiltrate them with polymer matrices, thereby yielding an electrical conducting and lightweight composite. Aerographite produced with densities in the range of 7–15 mg/cm3 was infiltrated with a low viscous epoxy resin by means of vacuum infiltration technique. Detailed morphological and structural investigations on synthesized AG and AG/epoxy composite were performed by scanning electron microscopic techniques. Our present study investigates the fracture and failure of AG/epoxy composites and its energy absorptionmore » capacity under compression. The composites displayed an extended plateau region when uni-axially compressed, which led to an increase in energy absorption of ~133% per unit volume for 1.5 wt% of AG, when compared to pure epoxy. Preliminary results on fracture toughness showed an enhancement of ~19% in KIC for AG/epoxy composites with 0.45 wt% of AG. Furthermore, our observations of fractured surfaces under scanning electron microscope gives evidence of pull-out of arms of AG tetrapod, interface and inter-graphite failure as the dominating mechanism for the toughness improvement in these composites. These observations were consistent with the results obtained from photoelasticity experiments on a thin film AG/epoxy model composite.« less

  3. Fracture, failure and compression behaviour of a 3D interconnected carbon aerogel (Aerographite) epoxy composite

    SciTech Connect

    Chandrasekaran, S.; Liebig, W. V.; Mecklenberg, M.; Fiedler, B.; Smazna, D.; Adelung, R.; Schulte, K.

    2015-11-04

    Aerographite (AG) is a mechanically robust, lightweight synthetic cellular material, which consists of a 3D interconnected network of tubular carbon [1]. The presence of open channels in AG aids to infiltrate them with polymer matrices, thereby yielding an electrical conducting and lightweight composite. Aerographite produced with densities in the range of 7–15 mg/cm3 was infiltrated with a low viscous epoxy resin by means of vacuum infiltration technique. Detailed morphological and structural investigations on synthesized AG and AG/epoxy composite were performed by scanning electron microscopic techniques. Our present study investigates the fracture and failure of AG/epoxy composites and its energy absorption capacity under compression. The composites displayed an extended plateau region when uni-axially compressed, which led to an increase in energy absorption of ~133% per unit volume for 1.5 wt% of AG, when compared to pure epoxy. Preliminary results on fracture toughness showed an enhancement of ~19% in KIC for AG/epoxy composites with 0.45 wt% of AG. Furthermore, our observations of fractured surfaces under scanning electron microscope gives evidence of pull-out of arms of AG tetrapod, interface and inter-graphite failure as the dominating mechanism for the toughness improvement in these composites. These observations were consistent with the results obtained from photoelasticity experiments on a thin film AG/epoxy model composite.

  4. Calcium phosphate/microgel composites for 3D powderbed printing of ceramic materials.

    PubMed

    Birkholz, Mandy-Nicole; Agrawal, Garima; Bergmann, Christian; Schröder, Ricarda; Lechner, Sebastian J; Pich, Andrij; Fischer, Horst

    2016-06-01

    Composites of microgels and calcium phosphates are promising as drug delivery systems and basic components for bone substitute implants. In this study, we synthesized novel composite materials consisting of pure β-tricalcium phosphate and stimuli-responsive poly(N-vinylcaprolactam-co-acetoacetoxyethyl methacrylate-co-vinylimidazole) microgels. The chemical composition, thermal properties and morphology for obtained composites were extensively characterized by Fourier transform infrared, X-ray photoelectron spectroscopy, IGAsorp moisture sorption analyzer, thermogravimetric analysis, granulometric analysis, ESEM, energy dispersive X-ray spectroscopy and TEM. Mechanical properties of the composites were evaluated by ball-on-three-balls test to determine the biaxial strength. Furthermore, initial 3D powderbed-based printing tests were conducted with spray-dried composites and diluted 2-propanol as a binder to evaluate a new binding concept for β-tricalcium phosphate-based granulates. The printed ceramic bodies were characterized before and after a sintering step by ESEM. The hypothesis that the microgels act as polymer adhesive agents by efficient chemical interactions with the β-tricalcium phosphate particles was confirmed. The obtained composites can be used for the development of new scaffolds. PMID:25870955

  5. Electromagnetic and absorbing property of CIPs/resin composite using the 3D forming process

    NASA Astrophysics Data System (ADS)

    Xu, Yonggang; Liang, Zichang; Wang, Xiaobing; Yuan, Liming; Li, Xinghao

    2016-08-01

    The absorbing composite filled with the flaky carbonyl iron particles (CIPs) were prepared using a three-dimensional (3D) forming process, in which the forming powder was fabricated using a milling process. The surface morphology was characterized by the scanning electron microscopy, the static magnetic property was evaluated on a vibrating sample magnetometer, and X-ray diffraction (XRD) patterns were done to analyze the particle crystal grain structure. The complex permittivity and permeability were measured using a vector network analyzer in the frequency range of 4-18 GHz. With the variable thickness was set, the reflection loss (RL) was simulated to analyze the absorbing property of the composite. The results showed that the forming powder was uniformly dispersed in the absorber, and the saturation magnetization and the grain structure of the CIPs in the forming powder nearly did not change in the milling process. With the same volume content CIPs added, the average permittivity and the imaginary permeability of the samples added the powder was smaller than the directly mixing sample due to the aggregation effect. The RL results showed that the absorbing composites using the 3D forming process with thickness 6 or 8 mm had an better absorbing property (minimum RL -13.58 and -21.85 dB) in 4-18 GHz.

  6. Fatigue resistance of unnotched and post impact(+/- 30 deg/0 deg) 3-D braided composites

    NASA Technical Reports Server (NTRS)

    Portanova, Marc A.

    1994-01-01

    The fatigue resistance of a multiaxial braided (3-D) graphite/expoxy composite in both unnotched and post impacted conditions has been evaluated. The material tested is a (+/- 30/0 deg) multiaxial braid constructed from AS4/12K tow graphite fibers and British Petroleum E905L epoxy resin. These materials were braided as dry preforms and the epoxy was added using a resin transfer molding process (RTM). The unnotched and post-impact specimens were tested in compression-compression fatigue at 10 Hz with a stress ratio of R=10. The unnotched tension-tension fatigue specimens were tested at S Hz with a stress ration of R=0.1. Damage initiation and growth was documented through the application of radiography and ultrasonic through transmission (C-scans). Visible inspection of surface and edge damage was also noted to describe the initiation and progression of damage in these materials. The mechanisms leading to damage initiation were established and failure modes were determined. Stiffness and strength degradation were measured as a function of applied cycles. These 3-D braided composite results were compared to strain levels currently used to design primary structure in commercial aircraft composite components made from prepreg tape and autoclave cured.

  7. Individual versus Collective Fibroblast Spreading and Migration: Regulation by Matrix Composition in 3-D Culture

    PubMed Central

    Miron-Mendoza, Miguel; Lin, Xihui; Ma, Lisha; Ririe, Peter; Petroll, W. Matthew

    2012-01-01

    Extracellular matrix (ECM) supplies both physical and chemical signals to cells and provides a substrate through which fibroblasts migrate during wound repair. To directly assess how ECM composition regulates this process, we used a nested 3D matrix model in which cell-populated collagen buttons were embedded in cell-free collagen or fibrin matrices. Time-lapse microscopy was used to record the dynamic pattern of cell migration into the outer matrices, and 3-D confocal imaging was used to assess cell connectivity and cytoskeletal organization. Corneal fibroblasts stimulated with PDGF migrated more rapidly into collagen as compared to fibrin. In addition, the pattern of fibroblast migration into fibrin and collagen ECMs was strikingly different. Corneal fibroblasts migrating into collagen matrices developed dendritic processes and moved independently, whereas cells migrating into fibrin matrices had a more fusiform morphology and formed an interconnected meshwork. A similar pattern was observed when using dermal fibroblasts, suggesting that this response in not unique to corneal cells. We next cultured corneal fibroblasts within and on top of standard collagen and fibrin matrices to assess the impact of ECM composition on the cell spreading response. Similar differences in cell morphology and connectivity were observed – cells remained separated on collagen but coalesced into clusters on fibrin. Cadherin was localized to junctions between interconnected cells, whereas fibronectin was present both between cells and at the tips of extending cell processes. Cells on fibrin matrices also developed more prominent stress fibers than those on collagen matrices. Importantly, these spreading and migration patterns were consistently observed on both rigid and compliant substrates, thus differences in ECM mechanical stiffness were not the underlying cause. Overall, these results demonstrate for the first time that ECM protein composition alone (collagen vs. fibrin) can

  8. Longitudinal compressive behaviour of 3D braided composite under various temperatures and strain rates

    NASA Astrophysics Data System (ADS)

    Pan, Zhongxiang; Gu, Bohong; Sun, Baozhong

    2015-03-01

    This paper reports the longitudinal compressive behaviour of 3D braided basalt fibre tows/epoxy composite materials under strain-rate range of 1,200-2,400 s-1 and temperature range of 23-210 °C both in experimental and finite element analyses (FEA). A split Hopkinson pressure bar system with a heating device was designed to test the longitudinal compressive behaviour of 3D braided composite materials. Testing results indicate that longitudinal compression modulus, specific energy absorption and peak stress decreased with elevated temperatures, whereas the failure strain increased with elevated temperatures. At some temperatures above the T g of epoxy resin, such as at 120 and 150 °C, strain distributions and deformations in fibre tows and epoxy resin tended to be the same. It results in relatively slighter damage status of the 3D braided composite material. The FEA results reveal that heating of the material due to the dissipative energy of the inelastic deformation and damage processes generated in resin is more than that in fibre tows. The braiding structure has a significant influence on thermomechanical failure via two aspects: distribution and accumulation of the heating leads to the development of the shear band paths along braiding angle; the buckling inflection segment rather than the straight segment generates the maximum of the heating in each fibre tows. The damage occurs at the early stage when the temperature is below T g, while at the temperature above T g, damage stage occurs at the rear of plastic deformation.

  9. Constituent Effects on the Stress-Strain Behavior of Woven Melt-Infiltrated SiC Composites

    NASA Technical Reports Server (NTRS)

    Morscher, Gregory N.; Eldridge, Jeff I.; Levine, Stanley (Technical Monitor)

    2001-01-01

    The stress-strain behavior of 2D woven SiC fiber reinforced, melt-infiltrated SiC matrix composites with BN interphases were studied for composites fabricated with different fiber tow ends per unit length, different composite thickness, and different numbers of plies. In general, the stress-strain behavior, i.e., the 'knee' in the curve and the final slope of the stress-strain curve, was controlled by the volume fraction of fibers. Some of the composites exhibited debonding and sliding in between the interphase and the matrix rather than the more common debonding and sliding interface between the fiber and the interphase. Composites that exhibited this 'outside debonding' interface, in general, had lower elastic moduli and higher ultimate strains as well as longer pull-out lengths compared to the 'inside debonding' interface composites. Stress-strain curves were modeled where matrix crack formation as a function of stress was approximated from the acoustic emission activity and the measured crack density from the failed specimens. Interfacial shear strength measurements from individual fiber push-in tests were in good agreement with the interfacial shear strength values used to model the stress-strain curves.

  10. 3D Printing of Composite Calcium Phosphate and Collagen Scaffolds for Bone Regeneration

    PubMed Central

    Inzana, Jason A.; Olvera, Diana; Fuller, Seth M.; Kelly, James P.; Graeve, Olivia A.; Schwarz, Edward M.; Kates, Stephen L.; Awad, Hani A.

    2014-01-01

    Low temperature 3D printing of calcium phosphate scaffolds holds great promise for fabricating synthetic bone graft substitutes with enhanced performance over traditional techniques. Many design parameters, such as the binder solution properties, have yet to be optimized to ensure maximal biocompatibility and osteoconductivity with sufficient mechanical properties. This study tailored the phosphoric acid-based binder solution concentration to 8.75 wt% to maximize cytocompatibility and mechanical strength, with a supplementation of Tween 80 to improve printing. To further enhance the formulation, collagen was dissolved into the binder solution to fabricate collagen-calcium phosphate composites. Reducing the viscosity and surface tension through a physiologic heat treatment and Tween 80, respectively, enabled reliable thermal inkjet printing of the collagen solutions. Supplementing the binder solution with 1–2 wt% collagen significantly improved maximum flexural strength and cell viability. To assess the bone healing performance, we implanted 3D printed scaffolds into a critically sized murine femoral defect for 9 weeks. The implants were confirmed to be osteoconductive, with new bone growth incorporating the degrading scaffold materials. In conclusion, this study demonstrates optimization of material parameters for 3D printed calcium phosphate scaffolds and enhancement of material properties by volumetric collagen incorporation via inkjet printing. PMID:24529628

  11. 3D PLLA/ibuprofen composite scaffolds obtained by a supercritical fluids assisted process.

    PubMed

    Cardea, S; Baldino, L; Scognamiglio, M; Reverchon, E

    2014-04-01

    The emerging next generation of engineered tissues is based on the development of loaded scaffolds containing bioactive molecules in order to control the cellular function or to interact on the surrounding tissues. Indeed, implantation of engineered biomaterials might cause local inflammation because of the host's immune response; thereby, the use of anti-inflammatory agents, whether steroidal or nonsteroidal is required. One of the most important stages of tissue engineering is the design and the generation of a porous 3D structure, with high porosity, high interconnectivity and homogenous morphology. Various techniques have been reported in the literature for the fabrication of biodegradable scaffolds, but they suffer several limitations. In this study, for the first time, the possibility of generating 3D polymeric scaffolds loaded with an active compound by supercritical freeze extraction process is evaluated; this innovative process combines the advantages of the thermally induced phase separation process and of the supercritical carbon dioxide drying. Poly-L-lactid acid/ibuprofen composite scaffolds characterized by a 3D geometry, micrometric cellular structures and wrinkled pores walls have been obtained; moreover, homogeneous drug distribution and controlled release of the active principle have been assured. PMID:24366467

  12. Enhanced Terahertz Imaging of Small Forced Delamination in Woven Glass Fibre-reinforced Composites with Wavelet De-noising

    NASA Astrophysics Data System (ADS)

    Dong, Junliang; Locquet, Alexandre; Citrin, D. S.

    2016-03-01

    Terahertz (THz) reflection imaging is applied to characterize a woven glass fibre-reinforced composite laminate with a small region of forced delamination. The forced delamination is created by inserting a disk of 25- μ m-thick Upilex film, which is below the THz axial resolution, resulting in one featured echo with small amplitude in the reflected THz pulses. Low-amplitude components of the temporal signal due to ambient water vapor produce features of comparable amplitude with features associated with the THz pulse reflected off the interfaces of the delamination and suppress the contrast of THz C- and B-scans. Wavelet shrinkage de-noising is performed to remove water-vapor features, leading to enhanced THz C- and B-scans to locate the delamination in three dimensions with high contrast.

  13. Notch Sensitivity of Woven Ceramic Matrix Composites Under Tensile Loading: An Experimental, Analytical, and Finite Element Study

    NASA Technical Reports Server (NTRS)

    Haque, A.; Ahmed, L.; Ware, T.; Jeelani, S.; Verrilli, Michael J. (Technical Monitor)

    2001-01-01

    The stress concentrations associated with circular notches and subjected to uniform tensile loading in woven ceramic matrix composites (CMCs) have been investigated for high-efficient turbine engine applications. The CMC's were composed of Nicalon silicon carbide woven fabric in SiNC matrix manufactured through polymer impregnation process (PIP). Several combinations of hole diameter/plate width ratios and ply orientations were considered in this study. In the first part, the stress concentrations were calculated measuring strain distributions surrounding the hole using strain gages at different locations of the specimens during the initial portion of the stress-strain curve before any microdamage developed. The stress concentration was also calculated analytically using Lekhnitskii's solution for orthotropic plates. A finite-width correction factor for anisotropic and orthotropic composite plate was considered. The stress distributions surrounding the circular hole of a CMC's plate were further studied using finite element analysis. Both solid and shell elements were considered. The experimental results were compared with both the analytical and finite element solutions. Extensive optical and scanning electron microscopic examinations were carried out for identifying the fracture behavior and failure mechanisms of both the notched and notched specimens. The stress concentration factors (SCF) determined by analytical method overpredicted the experimental results. But the numerical solution underpredicted the experimental SCF. Stress concentration factors are shown to increase with enlarged hole size and the effects of ply orientations on stress concentration factors are observed to be negligible. In all the cases, the crack initiated at the notch edge and propagated along the width towards the edge of the specimens.

  14. Production Principles and Technological Development of Novel Woven Spacer Preforms and Integrated Stiffener Structures

    NASA Astrophysics Data System (ADS)

    Torun, Ahmet R.; Mountasir, Adil; Hoffmann, Gerald; Cherif, Chokri

    2013-06-01

    3D textile preforms offer a high potential to increase mechanical properties of composites and/or decrease manufacturing costs. Within the scope of this study, production principles were developed for complex spacer preforms and integrated stiffeners. These principles were applied through technological further development of the well-known face-to-face and terry weaving techniques. Various woven preforms were produced with Glass fibre/Polypropylene (GF/PP) Commingled yarns, however, the technology is suitable for any type of reinforcement yarns. U-shaped woven spacer preform was consolidated into a sandwich composite component for lightweight applications.

  15. In-Plane Shear Testing of Medium and High Modulus Woven Graphite Fiber Reinforced/Polyimide Composites

    NASA Technical Reports Server (NTRS)

    Gentz, M.; Armentrout, D.; Rupnowski, P.; Kumosa, L.; Shin, E.; Sutter, J. K.; Kumosa, M.

    2004-01-01

    Iosipescu shear tests were performed at room temperature and at 316 C (600 F) o woven composites with either M40J or M60J graphite fibers and PMR-II-50 polyimide resin matrix. The composites were tested as supplied and after thermo-cycling, with the thermo-cycled composites being tested under dry and wet conditions. Acoustic emission (AE) was monitored during the room and high temperature Iosipescu experiments. The shear stresses at the maximum loads and the shear stresses at the significant onset of AE were determined for the composites as function of temperature and conditioning. The combined effects of thermo-cycling and moisture on the strength and stiffness properties of the composites were evaluated. It was determined that the room and high temperature shear stresses at the maximum loads were unaffected by conditioning. However, at room temperature the significant onset of AE was affected by conditioning; the thermal conditioned wet specimens showed the highest shear stress at the onset of AE followed by thermal-conditioned and then as received specimens. Also, at igh temperature the significant onset of AE occurred in some specimens after the maximum load due to the viscoelastoplastic nature of the matrix material.

  16. Modeling of chemical vapor infiltration for ceramic composites reinforced with layered, woven fabrics

    NASA Technical Reports Server (NTRS)

    Chung, Gui-Yung; Mccoy, Benjamin J.

    1991-01-01

    A homogeneous model is developed for the chemical vapor infiltration by one-dimensional diffusion into a system of layered plies consisting of woven tows containing bundles of filaments. The model predictions of the amount of deposition and the porosity of the sample as a function of time are compared with the predictions of a recent nonhomogeneous model with aligned holes formed by the weave. The nonhomogeneous model allows for diffusion through the aligned holes, into the spaces between plies, and into the gaps around filaments; i.e., three diffusion equations apply. Relative to the nonhomogeneous results, the homogeneous model underestimates the amount of deposition, since the absence of holes and spaces allows earlier occlusion of gaps around filaments and restricts the vapor infiltration.

  17. Bioactive fish collagen/polycaprolactone composite nanofibrous scaffolds fabricated by electrospinning for 3D cell culture.

    PubMed

    Choi, Da Jeong; Choi, Seung Mi; Kang, Hae Yeong; Min, Hye-Jin; Lee, Rira; Ikram, Muhammad; Subhan, Fazli; Jin, Song Wan; Jeong, Young Hun; Kwak, Jong-Young; Yoon, Sik

    2015-07-10

    One of the most challenging objectives of 3D cell culture is the development of scaffolding materials with outstanding biocompatibility and favorable mechanical strength. In this study, we fabricated a novel nanofibrous scaffold composed of fish collagen (FC) and polycaprolactone (PCL) blends by using the electrospinning method. Nanofibrous scaffolds were characterized using a scanning electron microscope (SEM), and it was revealed that the diameter of nanofibers decreased as FC content was increased in the FC/PCL composite nanofibers. The cytocompatibility of the FC/PCL scaffolds was evaluated by SEM, WST-1 assay, confocal microscopy, western blot, and RT-PCR. It was found that the scaffolds not only facilitated the adhesion, spreading, protrusions, and proliferation of thymic epithelial cells (TECs), but also stimulated the expression of genes and proteins involved in cell adhesion and T-cell development. Thus, these results suggest that the FC/PCL composite nanofibrous scaffolds will be a useful model of 3D cell culture for TECs and may have wide applicability in the future for engineering tissues or organs. PMID:25617682

  18. Modeling the transverse thermal conductivity of 3D-SICF/ SIC composites

    SciTech Connect

    Youngblood, Gerald E; Jones, Russell H; Yamada, Reiji

    2004-06-30

    Our previously developed hierarchical two-layer (H2L) model was modified to describe the effective transverse thermal conductivity (Keff) of a three-dimensional (3D) SiC/SiC composite plate made with cross-layered and Z-stitched X:Y:Z uniaxial fiber tow sub-units. As before, the model describes Keff in terms of constituent, microstructural and architectural properties that include the expected effects of fiber-matrix interfacial conductance, of high fiber packing fractions within individual tow sub-units and of the non-uniform porosity contents, shapes and orientations within these sub-units. Model predictions were obtained for two versions of a 3D-Tyranno SA/PyC/ICVI-SiC composite that had similar fiber/matrix pyrocarbon (PyC) interfaces, relatively high bulk densities (~2.88 g/cc), and an X:Y configuration with fiber content ratios 1:1. The only major difference between the two versions was their Z-stitch fiber content where the relative fiber ratios were 0.1 and 1.2 in the Z sub-units.

  19. Combining 3D optical imaging and dual energy absorptiometry to measure three compositional components

    NASA Astrophysics Data System (ADS)

    Malkov, Serghei; Shepherd, John

    2014-02-01

    We report on the design of the technique combining 3D optical imaging and dual-energy absorptiometry body scanning to estimate local body area compositions of three compartments. Dual-energy attenuation and body shape measures are used together to solve for the three compositional tissue thicknesses: water, lipid, and protein. We designed phantoms with tissue-like properties as our reference standards for calibration purposes. The calibration was created by fitting phantom values using non-linear regression of quadratic and truncated polynomials. Dual-energy measurements were performed on tissue-mimicking phantoms using a bone densitometer unit. The phantoms were made of materials shown to have similar x-ray attenuation properties of the biological compositional compartments. The components for the solid phantom were tested and their high energy/low energy attenuation ratios are in good correspondent to water, lipid, and protein for the densitometer x-ray region. The three-dimensional body shape was reconstructed from the depth maps generated by Microsoft Kinect for Windows. We used open-source Point Cloud Library and freeware software to produce dense point clouds. Accuracy and precision of compositional and thickness measures were calculated. The error contributions due to two modalities were estimated. The preliminary phantom composition and shape measurements are found to demonstrate the feasibility of the method proposed.

  20. Combining 3D optical imaging and dual energy absorptiometry to measure three compositional components

    PubMed Central

    Malkov, Serghei; Shepherd, John

    2014-01-01

    We report on the design of the technique combining 3D optical imaging and dual-energy absorptiometry body scanning to estimate local body area compositions of three compartments. Dual-energy attenuation and body shape measures are used together to solve for the three compositional tissue thicknesses: water, lipid, and protein. We designed phantoms with tissue-like properties as our reference standards for calibration purposes. The calibration was created by fitting phantom values using non-linear regression of quadratic and truncated polynomials. Dual-energy measurements were performed on tissue-mimicking phantoms using a bone densitometer unit. The phantoms were made of materials shown to have similar x-ray attenuation properties of the biological compositional compartments. The components for the solid phantom were tested and their high energy/low energy attenuation ratios are in good correspondent to water, lipid, and protein for the densitometer x-ray region. The three-dimensional body shape was reconstructed from the depth maps generated by Microsoft Kinect for Windows. We used open-source Point Cloud Library and freeware software to produce dense point clouds. Accuracy and precision of compositional and thickness measures were calculated. The error contributions due to two modalities were estimated. The preliminary phantom composition and shape measurements are found to demonstrate the feasibility of the method proposed. PMID:25083118

  1. 3D Simulation of the Growth of Alloy Semiconductor Quantum Dots Considering Morphological and Compositional Coupling

    NASA Astrophysics Data System (ADS)

    Guo, Junyan; Zhang, Yong-Wei; Narayanaswamy, Sridhar

    2012-02-01

    Fabrication of quantum dots (QDs) with high density may be realized by self-assembly via heteroepitaxial growth of thin films. Since the electronic and optoelectronic properties of QDs are sensitive to size, morphology, strain and especially composition, it is of great importance to control their composition profiles and morphology, and engineer the strain in them. Since the growth is a dynamic process, which carries out via surface diffusion driven primarily by strain relaxation and entropy change due to chemical intermixing, a strong coupling between morphological and composition evolutions during this process leads to a rather complex dynamics, which has not been fully understood. In this work, a 3-D finite element model is developed, which is capable of modeling the formation, self-assembly and coarsening of hetero-epitaxial alloy islands by considering the coupling of morphological and compositional evolution. Several interesting experimental observations, such as fast coarsening kinetics; asymmetries in composition profile and island shape; lateral motion of alloy islands have been observed in our simulations. Our model predictions have painted a rather complete picture for the entire dynamic evolution during the growth of nanoscale heteroepitaxial islands.

  2. Numerical Investigation of T-joints with 3D Four Directional Braided Composite Fillers Under Tensile Loading

    NASA Astrophysics Data System (ADS)

    Li, Xiao-kang; Liu, Zhen-guo; Hu, Long; Wang, Yi-bo; Lei, Bing; Huang, Xiang

    2016-08-01

    Numerical studied on T-joints with three-dimensional four directional (3D4D) braided composite fillers was presented in this article. Compared with conventional unidirectional prepreg fillers, the 3D braided composite fillers have excellent ability to prevent crack from penetrating trigone fillers, which constantly occurred in the conventional fillers. Meanwhile, the 3D braided composite fillers had higher fiber volume fraction and eliminated the fiber folding problem in unidirectional prepreg fillers. The braiding technology and mechanical performance of 3D4D braided fillers were studied. The numerical model of carbon fiber T-joints with 3D4D braided composite fillers was built by finite element analysis software. The damage formation, extension and failing process of T-joints with 3D4D braided fillers under tensile load were investigated. Further investigation was extended to the effect of 3D4D braided fillers with different braiding angles on mechanical behavior of the T-joints. The study results revealed that the filling area was the weakest part of the T-joints where the damage first appeared and the crack then rapidly spread to the glue film around the filling area and the interface between over-laminate and soleplate. The 3D4D braided fillers were undamaged and the braiding angle change induced a little effect on the bearing capacity of T-joints.

  3. Intermediate Temperature Stress Rupture of Woven SiC Fiber, BN Interphase, SiC Matrix Composites in Air

    NASA Technical Reports Server (NTRS)

    Morscher, Gregory N.; Levine, Stanley (Technical Monitor)

    2000-01-01

    Tensile stress-rupture experiments were performed on woven Hi-Nicalon reinforced SiC matrix composites with BN interphases in air. Modal acoustic emission (AE) was used to monitor the damage accumulation in the composites during the tests and microstructural analysis was performed to determine the amount of matrix cracking that occurred for each sample. Fiber fractograph), was also performed for individual fiber failures at the specimen fracture surface to determine the strengths at which fibers failed. The rupture strengths were significantly worse than what would have been expected front the inherent degradation of the fibers themselves when subjected to similar rupture conditions. At higher applied stresses the rate of rupture "?as larger than at lower applied stresses. It was observed that the change in rupture rate corresponded to the onset of through-thickness cracking in the composites themselves. The primary cause of the sen,ere degradation was the ease with which fibers would bond to one another at their closest separation distances, less than 100 nanometers, when exposed to the environment. The near fiber-to-fiber contact in the woven tows enabled premature fiber failure over large areas of matrix cracks due to the stress-concentrations created b), fibers bonded to one another after one or a few fibers fail. i.e. the loss of global load sharing. An@, improvement in fiber-to-fiber separation of this composite system should result in improved stress- rupture properties. A model was den,eloped in order to predict the rupture life-time for these composites based on the probabilistic nature of indin,idual fiber failure at temperature. the matrix cracking state during the rupture test, and the rate of oxidation into a matrix crack. Also incorporated into the model were estimates of the stress-concentration that would occur between the outer rim of fibers in a load-bearing bundle and the unbridged region of a matrix crack after Xia et al. For the lower stresses

  4. A High-Resolution 3D Weather Radar, MSG, and Lightning Sensor Observation Composite

    NASA Astrophysics Data System (ADS)

    Diederich, Malte; Senf, Fabian; Wapler, Kathrin; Simmer, Clemens

    2013-04-01

    Within the research group 'Object-based Analysis and SEamless prediction' (OASE) of the Hans Ertel Centre for Weather Research programme (HerZ), a data composite containing weather radar, lightning sensor, and Meteosat Second Generation observations is being developed for the use in object-based weather analysis and nowcasting. At present, a 3D merging scheme combines measurements of the Bonn and Jülich dual polarimetric weather radar systems (data provided by the TR32 and TERENO projects) into a 3-dimensional polar-stereographic volume grid, with 500 meters horizontal, and 250 meters vertical resolution. The merging takes into account and compensates for various observational error sources, such as attenuation through hydrometeors, beam blockage through topography and buildings, minimum detectable signal as a function of noise threshold, non-hydrometeor echos like insects, and interference from other radar systems. In addition to this, the effect of convection during the radar 5-minute volume scan pattern is mitigated through calculation of advection vectors from subsequent scans and their use for advection correction when projecting the measurements into space for any desired timestamp. The Meteosat Second Generation rapid scan service provides a scan in 12 spectral visual and infrared wavelengths every 5 minutes over Germany and Europe. These scans, together with the derived microphysical cloud parameters, are projected into the same polar stereographic grid used for the radar data. Lightning counts from the LINET lightning sensor network are also provided for every 2D grid pixel. The combined 3D radar and 2D MSG/LINET data is stored in a fully documented netCDF file for every 5 minute interval, and is made ready for tracking and object based weather analysis. At the moment, the 3D data only covers the Bonn and Jülich area, but the algorithms are planed to be adapted to the newly conceived DWD polarimetric C-Band 5 minute interval volume scan strategy. An

  5. 2D and 3D numerical models on compositionally buoyant diapirs in the mantle wedge

    NASA Astrophysics Data System (ADS)

    Hasenclever, Jörg; Morgan, Jason Phipps; Hort, Matthias; Rüpke, Lars H.

    2011-11-01

    We present 2D and 3D numerical model calculations that focus on the physics of compositionally buoyant diapirs rising within a mantle wedge corner flow. Compositional buoyancy is assumed to arise from slab dehydration during which water-rich volatiles enter the mantle wedge and form a wet, less dense boundary layer on top of the slab. Slab dehydration is prescribed to occur in the 80-180 km deep slab interval, and the water transport is treated as a diffusion-like process. In this study, the mantle's rheology is modeled as being isoviscous for the benefit of easier-to-interpret feedbacks between water migration and buoyant viscous flow of the mantle. We use a simple subduction geometry that does not change during the numerical calculation. In a large set of 2D calculations we have identified that five different flow regimes can form, in which the position, number, and formation time of the diapirs vary as a function of four parameters: subduction angle, subduction rate, water diffusivity (mobility), and mantle viscosity. Using the same numerical method and numerical resolution we also conducted a suite of 3D calculations for 16 selected parameter combinations. Comparing the 2D and 3D results for the same model parameters reveals that the 2D models can only give limited insights into the inherently 3D problem of mantle wedge diapirism. While often correctly predicting the position and onset time of the first diapir(s), the 2D models fail to capture the dynamics of diapir ascent as well as the formation of secondary diapirs that result from boundary layer perturbations caused by previous diapirs. Of greatest importance for physically correct results is the numerical resolution in the region where diapirs nucleate, which must be high enough to accurately capture the growth of the thin wet boundary layer on top of the slab and, subsequently, the formation, morphology, and ascent of diapirs. Here 2D models can be very useful to quantify the required resolution, which we

  6. Comparison of Elevated Temperature Tensile Properties and Fatigue Behavior of Two Variants of a Woven SiC/SiC Composite

    NASA Technical Reports Server (NTRS)

    Kalluri, Sreeramesh; Brewer, David N.; Sreeramesh, Kalluri

    2005-01-01

    Tensile properties (elastic modulus, proportional limit strength, in-plane tensile strength, and strain at failure) of two variants of a woven SiC/SiC composite, manufactured during two separate time periods (9/99 and 1/01), were determined at 1038 and 1204 C by conducting tensile tests on specimens machined from plates. Continuous cycling fatigue tests (R = 0.05) and 20 cpm) were also conducted at the same two temperatures on specimens from both composites. In this study, average tensile properties, 95% confidence intervals associated with the tensile properties, and geometric mean fatigue lives of both composite materials are compared. The observed similarities and differences in the tensile properties are highlighted and an attempt is made to understand the relationship, if any, between the tensile properties and the fatigue behaviors of the two woven composites.

  7. Correlative nanoscale 3D imaging of structure and composition in extended objects.

    PubMed

    Xu, Feng; Helfen, Lukas; Suhonen, Heikki; Elgrabli, Dan; Bayat, Sam; Reischig, Péter; Baumbach, Tilo; Cloetens, Peter

    2012-01-01

    Structure and composition at the nanoscale determine the behavior of biological systems and engineered materials. The drive to understand and control this behavior has placed strong demands on developing methods for high resolution imaging. In general, the improvement of three-dimensional (3D) resolution is accomplished by tightening constraints: reduced manageable specimen sizes, decreasing analyzable volumes, degrading contrasts, and increasing sample preparation efforts. Aiming to overcome these limitations, we present a non-destructive and multiple-contrast imaging technique, using principles of X-ray laminography, thus generalizing tomography towards laterally extended objects. We retain advantages that are usually restricted to 2D microscopic imaging, such as scanning of large areas and subsequent zooming-in towards a region of interest at the highest possible resolution. Our technique permits correlating the 3D structure and the elemental distribution yielding a high sensitivity to variations of the electron density via coherent imaging and to local trace element quantification through X-ray fluorescence. We demonstrate the method by imaging a lithographic nanostructure and an aluminum alloy. Analyzing a biological system, we visualize in lung tissue the subcellular response to toxic stress after exposure to nanotubes. We show that most of the nanotubes are trapped inside alveolar macrophages, while a small portion of the nanotubes has crossed the barrier to the cellular space of the alveolar wall. In general, our method is non-destructive and can be combined with different sample environmental or loading conditions. We therefore anticipate that correlative X-ray nano-laminography will enable a variety of in situ and in operando 3D studies. PMID:23185554

  8. Analysis of Composite Panel-Stiffener Debonding Using a Shell/3D Modeling Technique

    NASA Technical Reports Server (NTRS)

    Krueger, Ronald; Ratcliffe, James; Minguet, Pierre J.

    2007-01-01

    Interlaminar fracture mechanics has proven useful for characterizing the onset of delaminations in composites and has been used successfully primarily to investigate onset in fracture toughness specimens and laboratory size coupon type specimens. Future acceptance of the methodology by industry and certification authorities, however, requires the successful demonstration of the methodology on the structural level. For this purpose, a panel was selected that is reinforced with stiffeners. Shear loading causes the panel to buckle, and the resulting out-of-plane deformations initiate skin/stiffener separation at the location of an embedded defect. A small section of the stiffener foot, web and noodle as well as the panel skin in the vicinity of the delamination front were modeled with a local 3D solid model. Across the width of the stiffener foot, the mixedmode strain energy release rates were calculated using the virtual crack closure technique. A failure index was calculated by correlating the results with a mixed-mode failure criterion of the graphite/epoxy material. Computed failure indices were compared to corresponding results where the entire web was modeled with shell elements and only a small section of the stiffener foot and panel were modeled locally with solid elements. Including the stiffener web in the local 3D solid model increased the computed failure index. Further including the noodle and transition radius in the local 3D solid model changed the local distribution across the width. The magnitude of the failure index decreased with increasing transition radius and noodle area. For the transition radii modeled, the material properties used for the noodle area had a negligible effect on the results. The results of this study are intended to be used as a guide for conducting finite element and fracture mechanics analyses of delamination and debonding in complex structures such as integrally stiffened panels.

  9. Correlative Nanoscale 3D Imaging of Structure and Composition in Extended Objects

    PubMed Central

    Xu, Feng; Helfen, Lukas; Suhonen, Heikki; Elgrabli, Dan; Bayat, Sam; Reischig, Péter; Baumbach, Tilo; Cloetens, Peter

    2012-01-01

    Structure and composition at the nanoscale determine the behavior of biological systems and engineered materials. The drive to understand and control this behavior has placed strong demands on developing methods for high resolution imaging. In general, the improvement of three-dimensional (3D) resolution is accomplished by tightening constraints: reduced manageable specimen sizes, decreasing analyzable volumes, degrading contrasts, and increasing sample preparation efforts. Aiming to overcome these limitations, we present a non-destructive and multiple-contrast imaging technique, using principles of X-ray laminography, thus generalizing tomography towards laterally extended objects. We retain advantages that are usually restricted to 2D microscopic imaging, such as scanning of large areas and subsequent zooming-in towards a region of interest at the highest possible resolution. Our technique permits correlating the 3D structure and the elemental distribution yielding a high sensitivity to variations of the electron density via coherent imaging and to local trace element quantification through X-ray fluorescence. We demonstrate the method by imaging a lithographic nanostructure and an aluminum alloy. Analyzing a biological system, we visualize in lung tissue the subcellular response to toxic stress after exposure to nanotubes. We show that most of the nanotubes are trapped inside alveolar macrophages, while a small portion of the nanotubes has crossed the barrier to the cellular space of the alveolar wall. In general, our method is non-destructive and can be combined with different sample environmental or loading conditions. We therefore anticipate that correlative X-ray nano-laminography will enable a variety of in situ and in operando 3D studies. PMID:23185554

  10. Smart three-dimensional lightweight structure triggered from a thin composite sheet via 3D printing technique

    PubMed Central

    Zhang, Quan; Zhang, Kai; Hu, Gengkai

    2016-01-01

    Complex fabrication process and expensive materials have restricted the development of smart three-dimensional (3D) lightweight structures, which are expected to possess self-shaping, self-folding and self-unfolding performances. Here we present a simple approach to fabricate smart lightweight structures by triggering shape transformation from thin printed composite sheets. The release of the internal strain in printed polymer materials enables the printed composite sheet to keep flat under heating and transform into a designed 3D configuration when cooled down to room temperature. The 3D lightweight structure can be switched between flat and 3D configuration under appropriate thermal stimuli. Our work exploits uniform internal strain in printed materials as a controllable tool to fabricate smart 3D lightweight structures, opening an avenue for possible applications in engineering fields. PMID:26926357

  11. Smart three-dimensional lightweight structure triggered from a thin composite sheet via 3D printing technique.

    PubMed

    Zhang, Quan; Zhang, Kai; Hu, Gengkai

    2016-01-01

    Complex fabrication process and expensive materials have restricted the development of smart three-dimensional (3D) lightweight structures, which are expected to possess self-shaping, self-folding and self-unfolding performances. Here we present a simple approach to fabricate smart lightweight structures by triggering shape transformation from thin printed composite sheets. The release of the internal strain in printed polymer materials enables the printed composite sheet to keep flat under heating and transform into a designed 3D configuration when cooled down to room temperature. The 3D lightweight structure can be switched between flat and 3D configuration under appropriate thermal stimuli. Our work exploits uniform internal strain in printed materials as a controllable tool to fabricate smart 3D lightweight structures, opening an avenue for possible applications in engineering fields. PMID:26926357

  12. Smart three-dimensional lightweight structure triggered from a thin composite sheet via 3D printing technique

    NASA Astrophysics Data System (ADS)

    Zhang, Quan; Zhang, Kai; Hu, Gengkai

    2016-02-01

    Complex fabrication process and expensive materials have restricted the development of smart three-dimensional (3D) lightweight structures, which are expected to possess self-shaping, self-folding and self-unfolding performances. Here we present a simple approach to fabricate smart lightweight structures by triggering shape transformation from thin printed composite sheets. The release of the internal strain in printed polymer materials enables the printed composite sheet to keep flat under heating and transform into a designed 3D configuration when cooled down to room temperature. The 3D lightweight structure can be switched between flat and 3D configuration under appropriate thermal stimuli. Our work exploits uniform internal strain in printed materials as a controllable tool to fabricate smart 3D lightweight structures, opening an avenue for possible applications in engineering fields.

  13. Strengthening of 3D Printed Fused Deposition Manufactured Parts Using the Fill Compositing Technique

    PubMed Central

    Belter, Joseph T.; Dollar, Aaron M.

    2015-01-01

    In this paper, we present a technique for increasing the strength of thermoplastic fused deposition manufactured printed parts while retaining the benefits of the process such as ease, speed of implementation, and complex part geometries. By carefully placing voids in the printed parts and filling them with high-strength resins, we can improve the overall part strength and stiffness by up to 45% and 25%, respectively. We discuss the process parameters necessary to use this strengthening technique and the theoretically possible strength improvements to bending beam members. We then show three-point bend testing data comparing solid printed ABS samples with those strengthened through the fill compositing process, as well as examples of 3D printed parts used in real-world applications. PMID:25880807

  14. Analysis of Composite Panel-Stiffener Debonding Using a Shell/3D Modeling Technique

    NASA Technical Reports Server (NTRS)

    Krueger, Ronald; Minguet, Pierre J.

    2006-01-01

    Interlaminar fracture mechanics has proven useful for characterizing the onset of delaminations in composites and has been used with limited success primarily to investigate onset in fracture toughness specimens and laboratory size coupon type specimens. Future acceptance of the methodology by industry and certification authorities however, requires the successful demonstration of the methodology on structural level. For this purpose a panel was selected that was reinforced with stringers. Shear loading cases the panel to buckle and the resulting out-of-plane deformations initiate skin/stringer separation at the location of an embedded defect. For finite element analysis, the panel and surrounding load fixture were modeled with shell element. A small section of the stringer foot and the panel in the vicinity of the embedded defect were modeled with a local 3D solid model. A failure index was calculated by correlating computed mixed-mode failure criterion of the graphite/epoxy material.

  15. Modeling the Transverse Thermal Conductivity of 2-D SiCf/SiC Composites Made with Woven Fabric

    SciTech Connect

    Youngblood, Gerald E.; Senor, David J.; Jones, Russell H.

    2004-06-30

    The hierarchical two-layer (H2L) model was developed to describe the effective transverse thermal conductivity, Keff, of a 2D-SiCf/SiC composite made from stacked and infiltrated woven fabric layers in terms of constituent properties and microstructural and architectural variables. The H2L model includes the expected effects of fiber-matrix interfacial conductance as well as the effects of high fiber packing fractions within individual tows and the non-uniform nature of 2D-fabric layers that usually include a significant amount of interlayer porosity. Previously, H2L model predictions were compared to measured values of Keff for two versions of DuPont 2D-Hi NicalonÔ/PyC/ICVI-SiC composite, one with a “thin” (0.110 μm) and the other with a “thick” (1.040 μm) pyrocarbon (PyC) fiber coating, and for a 2D-TyrannoÔ SA/”thin” PyC/FCVI-SIC composite made by ORNL. In this study, H2L model predictions are compared to measured Keff-values for a 2D-SiCf/SiC composite made by GE Power Systems (formerly DuPont Lanxide) using the ICVI-process with Hi-NicalonÔ type S fabric. The values of Keff determined for the composite made with the Hi-NicalonÔ type S fabric were significantly greater than Keff-values determined for the composites made with either the Hi-NicalonÔor the TyrannoÔ SA fabrics. Differences in Keff-values were expected for using different fiber types, but major differences also were due to observed microstructural variations between the systems, and as predicted by the H2L model.

  16. The Effect of Temperature and Nanoclay on the Low Velocity and Ballistic Behavior of Woven Glass-Fiber Reinforced Composites

    NASA Astrophysics Data System (ADS)

    Patrin, Lauren

    The objective of this research was to study the effect of nanoclay and temperature on the behavior of woven glass-fabric reinforced epoxy composite under low velocity and ballistic impacts. The materials used in manufacturing the composite were S2 (6181) glass-fibers, epoxy resin (EPON 828), hardener (Epikure 3230), nanoclay and Heloxy 61 modifier. The nanoclay addition was 0%, 1%, 3% and 5% by weight, with respect to the resin. All specimens were manufactured at the City College facilities using vacuum infusion. Tensile tests were conducted to characterize the material and obtain the Young's modulus, ultimate stress, failure strain, Poisson's ratio, shear modulus and shear strength and their variation with nanoclay percentage and temperature. The tests were conducted at room temperature (21°C/70°F), -54°C (-65°F), -20°C (-4°F), 49°C (120°F) and 71°C (160°F). Next composite specimens with 0%, 1%, 3% and 5% nanoclay by weight, with respect to the resin, were subjected to low velocity impact at the previously specified temperatures to determine dynamic force, displacement and energy correlations. The extent of damage was studied using the ultrasound technique. Then ballistic tests were conducted on the nanoclay infused specimens at room temperature to obtain the ballistic limit (V50) and the damage behavior of the composite. The dynamic finite element analysis (FEA) software LS-DYNA was used to model and simulate the results of low velocity impact tests. Good agreement was obtained between experimental and numerical (FEA) results. Analytical analyses were undertaken to compare the results from the tensile experiments. The finite element analysis (FEA) allowed for further analytical comparison of the results. The FEA platform used was LS-DYNA due to its proficient dynamic and damage capabilities in composite materials. The FEA was used to model and simulate the low velocity impacts and compare the results to experiments.

  17. Modeling of Damage Initiation and Progression in a SiC/SiC Woven Ceramic Matrix Composite

    NASA Technical Reports Server (NTRS)

    Mital, Subodh K.; Goldberg, Robert K.; Bonacuse, Peter J.

    2012-01-01

    The goal of an ongoing project at NASA Glenn is to investigate the effects of the complex microstructure of a woven ceramic matrix composite and its variability on the effective properties and the durability of the material. Detailed analysis of these complex microstructures may provide clues for the material scientists who `design the material? or to structural analysts and designers who `design with the material? regarding damage initiation and damage propagation. A model material system, specifically a five-harness satin weave architecture CVI SiC/SiC composite composed of Sylramic-iBN fibers and a SiC matrix, has been analyzed. Specimens of the material were serially sectioned and polished to capture the detailed images of fiber tows, matrix and porosity. Open source analysis tools were used to isolate various constituents and finite elements models were then generated from simplified models of those images. Detailed finite element analyses were performed that examine how the variability in the local microstructure affected the macroscopic behavior as well as the local damage initiation and progression. Results indicate that the locations where damage initiated and propagated is linked to specific microstructural features.

  18. Multi-contrast 3D X-ray imaging of porous and composite materials

    SciTech Connect

    Sarapata, Adrian; Herzen, Julia; Ruiz-Yaniz, Maite; Zanette, Irene; Rack, Alexander; Pfeiffer, Franz

    2015-04-13

    Grating-based X-ray computed tomography allows for simultaneous and nondestructive determination of the full X-ray complex index of refraction and the scattering coefficient distribution inside an object in three dimensions. Its multi-contrast capabilities combined with a high resolution of a few micrometers make it a suitable tool for assessing multiple phases inside porous and composite materials such as concrete. Here, we present quantitative results of a proof-of-principle experiment performed on a concrete sample. Thanks to the complementarity of the contrast channels, more concrete phases could be distinguished than in conventional attenuation-based imaging. The phase-contrast reconstruction shows high contrast between the hardened cement paste and the aggregates and thus allows easy 3D segmentation. Thanks to the dark-field image, micro-cracks inside the coarse aggregates are visible. We believe that these results are extremely interesting in the field of porous and composite materials studies because of unique information provided by grating interferometry in a non-destructive way.

  19. Precise 3D printing of micro/nanostructures using highly conductive carbon nanotube-thiol-acrylate composites

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Xiong, W.; Jiang, L. J.; Zhou, Y. S.; Lu, Y. F.

    2016-04-01

    Two-photon polymerization (TPP) is of increasing interest due to its unique combination of truly three-dimensional (3D) fabrication capability and ultrahigh spatial resolution of ~40 nm. However, the stringent requirements of non-linear resins seriously limit the material functionality of 3D printing via TPP. Precise fabrication of 3D micro/nanostructures with multi-functionalities such as high electrical conductivity and mechanical strength is still a long-standing challenge. In this work, TPP fabrication of arbitrary 3D micro/nanostructures using multi-walled carbon nanotube (MWNT)-thiolacrylate (MTA) composite resins has been developed. Up to 0.2 wt% MWNTs have been incorporated into thiol-acrylate resins to form highly stable and uniform composite photoresists without obvious degradation for one week at room temperature. Various functional 3D micro/nanostructures including woodpiles, micro-coils, spiral-like photonic crystals, suspended micro-bridges, micro-gears and complex micro-cars have been successfully fabricated. The MTA composite resin offers significant enhancements in electrical conductivity and mechanical strength, and on the same time, preserving high optical transmittance and flexibility. Tightly controlled alignment of MWNTs and the strong anisotropy effect were confirmed. Microelectronic devices including capacitors and resistors made of the MTA composite polymer were demonstrated. The 3D micro/nanofabrication using the MTA composite resins enables the precise 3D printing of micro/nanostructures of high electrical conductivity and mechanical strength, which is expected to lead a wide range of device applications, including micro/nano-electromechanical systems (MEMS/NEMS), integrated photonics and 3D electronics.

  20. Enhanced photovoltaic performance of dye-sensitized solar cell using composite photoanode on 3D electrode

    NASA Astrophysics Data System (ADS)

    Lim, Chiew Keat; Huang, Hui; Tse, Man Siu; Tan, Ooi Kiang

    2013-12-01

    For dye-sensitized solar cell (DSSC), an efficient transport of electron from the dye sensitizer through the mesoporous oxide layer and to be collected by electrode is crucial for high photovoltaic conversion efficiency. In this work, two novel approaches were developed in DSSC fabrication to improve the overall photovoltaic performance. The concurrent improvement in the charge transport property and light harvesting efficiency was achieved by incorporating N-doped TiO2 in the mesoporous TiO2 layer of the photoanode. These N-doped TiO2 (TiNxOy) was formed by using the single step thermal oxidation of Titanium Nitride (TiN) nanomaterials. At the same time, the 3D electrode with SnO2 nanorods grown on the FTO glass using plasma enhanced chemical vapor deposition (PECVD) system was used to enhance the charge collection efficiency. By combining these two approaches simultaneously, the DSSC with composite TiNxOy-TiO2 photoanode on SnO2 nanorods 3D electrode was successfully fabricated and characterized. As compared to the standard DSSC, an overall increment of 28 % in the conversion efficiency was achieved. Higher incident photon-current conversion efficiency (IPCE) values were also obtained, specifically for the region 400 - 500 nm due to the cosensitization effect of N-doped TiO2. Efficient transfer of electron due to the decrease in charge transfer resistance at the mesoporous oxide/dye/electrolyte interface was observed from electrochemical impedance spectroscopy (EIS) measurement. With the use of SnO2 nanorods, the adhesion between the mesoporous TiO2/FTO was enhanced and the transit time of a photogenerated electron through the mesoporous layer before being collected at the FTO electrode was significantly reduced by 50 %.

  1. Multifunctional graphene woven fabrics

    PubMed Central

    Li, Xiao; Sun, Pengzhan; Fan, Lili; Zhu, Miao; Wang, Kunlin; Zhong, Minlin; Wei, Jinquan; Wu, Dehai; Cheng, Yao; Zhu, Hongwei

    2012-01-01

    Tailoring and assembling graphene into functional macrostructures with well-defined configuration are key for many promising applications. We report on a graphene-based woven fabric (GWF) prepared by interlacing two sets of graphene micron-ribbons where the ribbons pass each other essentially at right angles. By using a woven copper mesh as the template, the GWF grown from chemical vapour deposition retains the network configuration of the copper mesh. Embedded into polymer matrices, it has significant flexibility and strength gains compared with CVD grown graphene films. The GWFs display both good dimensional stability in both the warp and the weft directions and the combination of film transparency and conductivity could be optimized by tuning the ribbon packing density. The GWF creates a platform to integrate a large variety of applications, e.g., composites, strain sensors and solar cells, by taking advantages of the special structure and properties of graphene. PMID:22563524

  2. Intermediate Temperature Stress Rupture of a Woven Hi-Nicalon, BN-Interphase, SiC Matric Composite in Air

    NASA Technical Reports Server (NTRS)

    Morscher, Gregory N.; Hurst, Janet; Brewer, David

    1999-01-01

    Woven Hi-Nicalon (TM) reinforced melt-infiltrated SiC matrix composites were tested under tensile stress-rupture conditions in air at intermediate temperatures. A comprehensive examination of the damage state and the fiber properties at failure was performed. Modal acoustic emission analysis was used to monitor damage during the experiment. Extensive microscopy of the composite fracture surfaces and the individual fiber fracture surfaces was used to determine the mechanisms leading to ultimate failure. The rupture properties of these composites were significantly worse than expected compared to the fiber properties under similar conditions. This was due to the oxidation of the BN interphase. Oxidation occurred through the matrix cracks that intersected the surface or edge of a tensile bar. These oxidation reactions resulted in minor degradation to fiber strength and strong bonding of the fibers to one another at regions of near fiber-to-fiber contact. It was found that two regimes for rupture exist for this material: a high stress regime where rupture occurs at a fast rate and a low stress regime where rupture occurs at a slower rate. For the high stress regime, the matrix damage state consisted of through thickness cracks. The average fracture strength of fibers that were pulled-out (the final fibers to break before ultimate failure) was controlled by the slow-crack growth rupture criterion in the literature for individual Hi-Nicalon (TM) fibers. For the low stress regime, the matrix damage state consisted of microcracks which grew during the rupture test. The average fracture strength of fibers that were pulled-out in this regime was the same as the average fracture strength of individual fibers pulled out in as-produced composites tested at room temperature.

  3. Effect of Sericin on Mechanical Behavior of Composite Material Reinforced by Silk Woven Fabric

    NASA Astrophysics Data System (ADS)

    Kimura, Teruo; Ino, Haruhiro; Hanada, Koji; Katori, Sigetaka

    Recent, attention has been given to shift from glass fibers and carbon fibers to natural fibers for FRP composites for the goal of protecting the environment. This paper concerned with the application of silk fabric for composite materials. Polypropylene (PP) was used for the matrix material and the silk fabric composites were molded using a compression molding method. Especially, the effect of sericin on mechanical behaviors of composite materials was discussed. Good adhesion between silk and PP was obtained by removing the sericin existing around the fibroin. The tensile modulus of composite decreased with decreasing the sericin because of the flexibility of silk fibers without sericin. In particular, the higher Izod impact value was obtained for the composites containing the silk fibers without sericin.

  4. Continuous sensors for mode selective actuation and reception of waves for structural health monitoring of woven composite laminates

    NASA Astrophysics Data System (ADS)

    Kirikera, Goutham R.; Petculescu, Gabriela; Krishnaswamy, Sridhar; Achenbach, Jan D.

    2007-04-01

    The quantitative evaluation of damage in woven composites using mode selective excitation of Lamb waves is reported in this paper. PVDF (polyvinylidene fluoride) comb sensors are used to generate and detect a single plate mode. The top electrode is a single set of equidistant fingers connected in parallel to the same potential while the bottom electrode is kept at ground. First, a pair of such sensors is used to generate and detect a single plate mode. Group velocity changes of a wave packet traveling through the damaged area are used for quantitative damage estimation. Second, a new electrode configuration is used in order to improve the receiver signal. The proposed configuration referred to as continuous sensors, is used in structural health monitoring (SHM) for detection of growing cracks. Theoretical and experimental results are presented. In addition, an analog circuitry to actuate the structure at high frequency (~1MHz) based on energy tapped from a vibrating cantilever beam (~20Hz) is developed, towards a high-frequency energy-harvested SHM.

  5. Experimental Investigation of the Interface Behavior of Balanced and Unbalanced E-Glass/Polyester Woven Fabric Composite Laminates

    NASA Astrophysics Data System (ADS)

    Triki, E.; Zouari, B.; Jarraya, A.; Dammak, F.

    2013-12-01

    The aim of this work is to study the influence of weave structure on the crack growth behavior of thick E-glass/polyester woven fabric composites laminates. Two different types of laminates were fabricated: (i) balanced: plain weave (taffetas T)/chopped strand mat weave (M) [T/M]6 and (ii) unbalanced: 4-hardness satin weave (S)/chopped strand mat weave [S/M]7. In order to accurately predict damage criticality in such structures, mixed mode fracture toughness data is required. So, the experiments were conducted using standards delamination tests under mixed mode loading and pure mode loading. These tests were carried out in mode II using End Load Split (ELS) tests and in mixed-mode I+II by Mixed Mode Flexure (MMF) tests under static conditions. The test methodology used for the experiments will be presented. The experimental results have been expressed in terms of total strain energy release rate and R-curves. The fracture toughness results show that the T/M interface is more resistant to delamination than the S/M interface.

  6. Numerical simulating and experimental study on the woven carbon fiber-reinforced composite laminates under low-velocity impact

    NASA Astrophysics Data System (ADS)

    Liu, Hanyang; Tang, Zhanwen; Pan, Lingying; Zhao, Weidong; Sun, Baogang; Jiang, Wenge

    2016-05-01

    Impact damage has been identified as a critical form of the defects that constantly threatened the reliability of composite structures, such as those used in the aerospace structures and systems. Low energy impacts can introduce barely visible damage and cause the degradation of structural stiffness, furthermore, the flaws caused by low-velocity impact are so dangerous that they can give rise to the further extended delaminations. In order to improve the reliability and load carrying capacity of composite laminates under low-velocity impact, in this paper, the numerical simulatings and experimental studies on the woven fiber-reinforced composite laminates under low-velocity impact with impact energy 16.7J were discussed. The low velocity impact experiment was carried out through drop-weight system as the reason of inertia effect. A numerical progressive damage model was provided, in which the damages of fiber, matrix and interlamina were considered by VUMT subroutine in ABAQUS, to determine the damage modes. The Hashin failure criteria were improved to cover the failure modes of fiber failure in the directions of warp/weft and delaminations. The results of Finite Element Analysis (FEA) were compared with the experimental results of nondestructive examination including the results of ultrasonic C-scan, cross-section stereomicroscope and contact force - time history curves. It is found that the response of laminates under low-velocity impact could be divided into stages with different damage. Before the max-deformation of the laminates occurring, the matrix cracking, fiber breakage and delaminations were simulated during the impactor dropping. During the releasing and rebounding period, matrix cracking and delaminations areas kept increasing in the laminates because of the stress releasing of laminates. Finally, the simulating results showed the good agreements with the results of experiment.

  7. Analyses of Failure Mechanisms in Woven Graphite/Polyimide Composites with Medium and High Modulus Graphite Fibers Subjected to In-Plane Shear

    NASA Technical Reports Server (NTRS)

    Kumosa, M.; Armentrout, D.; Rupnowski, P.; Kumosa, L.; Shin, E.; Sutter, J. K.

    2003-01-01

    The application of the Iosipescu shear test for the room and high temperature failure analyses of the woven graphite/polyimide composites with the medium (T-650) and igh (M40J and M60J) modulus graphite fibers is discussed. The M40J/PMR-II-50 and M60J/PMR-II-50 composites were tested as supplied and after thermal conditioning. The effect of temperature and conditioning on the initiation of intralaminar damage and the shear strength of the composites was established.

  8. 3D composites based on the blends of chitosan and collagen with the addition of hyaluronic acid.

    PubMed

    Sionkowska, Alina; Kaczmarek, Beata; Lewandowska, Katarzyna; Grabska, Sylwia; Pokrywczyńska, Marta; Kloskowski, Tomasz; Drewa, Tomasz

    2016-08-01

    3D porous composites based on blends of chitosan, collagen and hyaluronic acid were obtained through the lyophilization process. Mechanical properties, swelling behavior and thermal stability of the blends were studied. Moreover, SEM images were taken and the structure of the blends was studied. Biological properties of the materials obtained were investigated by analyzing of proliferation rate of fibroblast cells incubated with biomaterial extract using MTT assay (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide). The results showed that the properties of 3D composites based on the blends of chitosan and collagen were altered after the addition 1%, 2% and 5% of hyaluronic acid. Mechanical properties and thermal stability of chitosan/collagen blends were improved in the presence of hyaluronic acid in the composite. New 3D materials based on the blends of chitosan, collagen and hyaluronic acid were non-toxic and did not significantly affect cell morphology. PMID:27151670

  9. Mechanical behavior of polyester-based woven jute/glass hybrid composites

    NASA Astrophysics Data System (ADS)

    Ahsan, Q.; Tanju, S.

    2012-06-01

    In polymer composite fabrication system, hybridization of jute fibers with synthetic fibers is one of the techniques adopted to overcome some of the limitations (poor mechanical properties and moisture resistance) that have been identified for jute fiber reinforced composites. In the present study, the effect of hybridization on mechanical properties of jute and glass mat reinforced polyester composites has been evaluated experimentally. The composites were made of glass mat, jute mat and varying layers of jute and glass mat in the polyester matrix by applying hand lay-up technique at room temperature (250C). The values of mechanical properties obtained from tensile, flexural and interlaminar shear strength (ILSS) tests show significant improvement with the increase of glass fiber content in hybrid composites. But the positive contribution from glass mat in increasing of ILSS of composite is limited to some extent and the optimum ILSS is achieved when glass-jute incorporated in composite as 50-50 weight basis. SEM images were used to study the modes of fracture, fiber-matrix adhesion, and jute-glass layer adhesion. The fracture surfaces resulted from different tests clearly show that cracks propagate throughout the polyester matrix by tearing the jute mat and delaminating the glass mat.

  10. Visualizing nanoscale 3D compositional fluctuation of lithium in advanced lithium-ion battery cathodes

    SciTech Connect

    Devaraj, Arun; Gu, Meng; Colby, Robert J.; Yan, Pengfei; Wang, Chong M.; Zheng, Jianming; Xiao, Jie; Genc, Arda; Zhang, Jiguang; Belharouak, Ilias; Wang, Dapeng; Amine, Khalil; Thevuthasan, Suntharampillai

    2015-08-14

    The distribution and concentration of lithium in Li-ion battery cathodes at different stages of cycling is a pivotal factor in determining battery performance. Non-uniform distribution of the transition metal cations has been shown to affect cathode performance; however, the Li is notoriously challenging to characterize with typical high-spatial-resolution imaging techniques. Here, for the first time, laser–assisted atom probe tomography is applied to two advanced Li-ion battery oxide cathode materials—layered Li1.2Ni0.2Mn0.6O2 and spinel LiNi0.5Mn1.5O4—to unambiguously map the three dimensional (3D) distribution of Li at sub-nanometer spatial resolution and correlate it with the distribution of the transition metal cations (M) and the oxygen. The as-fabricated layered Li1.2Ni0.2Mn0.6O2 is shown to have Li-rich Li2MO3 phase regions and Li-depleted Li(Ni0.5Mn0.5)O2 regions while in the cycled layered Li1.2Ni0.2Mn0.6O2 an overall loss of Li and presence of Ni rich regions, Mn rich regions and Li rich regions are shown in addition to providing the first direct evidence for Li loss on cycling of layered LNMO cathodes. The spinel LiNi0.5Mn1.5O4 cathode is shown to have a uniform distribution of all cations. These results were additionally validated by correlating with energy dispersive spectroscopy mapping of these nanoparticles in a scanning transmission electron microscope. Thus, we have opened the door for probing the nanoscale compositional fluctuations in crucial Li-ion battery cathode materials at an unprecedented spatial resolution of sub-nanometer scale in 3D which can provide critical information for understanding capacity decay mechanisms in these advanced cathode materials.

  11. Visualizing nanoscale 3D compositional fluctuation of lithium in advanced lithium-ion battery cathodes

    DOE PAGESBeta

    Devaraj, Arun; Gu, Meng; Colby, Robert J.; Yan, Pengfei; Wang, Chong M.; Zheng, Jianming; Xiao, Jie; Genc, Arda; Zhang, Jiguang; Belharouak, Ilias; et al

    2015-08-14

    The distribution and concentration of lithium in Li-ion battery cathodes at different stages of cycling is a pivotal factor in determining battery performance. Non-uniform distribution of the transition metal cations has been shown to affect cathode performance; however, the Li is notoriously challenging to characterize with typical high-spatial-resolution imaging techniques. Here, for the first time, laser–assisted atom probe tomography is applied to two advanced Li-ion battery oxide cathode materials—layered Li1.2Ni0.2Mn0.6O2 and spinel LiNi0.5Mn1.5O4—to unambiguously map the three dimensional (3D) distribution of Li at sub-nanometer spatial resolution and correlate it with the distribution of the transition metal cations (M) and themore » oxygen. The as-fabricated layered Li1.2Ni0.2Mn0.6O2 is shown to have Li-rich Li2MO3 phase regions and Li-depleted Li(Ni0.5Mn0.5)O2 regions while in the cycled layered Li1.2Ni0.2Mn0.6O2 an overall loss of Li and presence of Ni rich regions, Mn rich regions and Li rich regions are shown in addition to providing the first direct evidence for Li loss on cycling of layered LNMO cathodes. The spinel LiNi0.5Mn1.5O4 cathode is shown to have a uniform distribution of all cations. These results were additionally validated by correlating with energy dispersive spectroscopy mapping of these nanoparticles in a scanning transmission electron microscope. Thus, we have opened the door for probing the nanoscale compositional fluctuations in crucial Li-ion battery cathode materials at an unprecedented spatial resolution of sub-nanometer scale in 3D which can provide critical information for understanding capacity decay mechanisms in these advanced cathode materials.« less

  12. Combination of thermal extrusion printing and ultrafast laser fabrication for the manufacturing of 3D composite scaffolds

    NASA Astrophysics Data System (ADS)

    Balčiūnas, Evaldas; Lukoševičius, Laurynas; Mackevičiūtė, Dovilė; Rekštytė, Sima; Rutkūnas, Vygandas; Paipulas, Domas; Stankevičiūtė, Karolina; Baltriukienė, Daiva; Bukelskienė, Virginija; Piskarskas, Algis P.; Malinauskas, Mangirdas

    2014-03-01

    We present a novel approach to manufacturing 3D microstructured composite scaffolds for tissue engineering applications. A thermal extrusion 3D printer - a simple, low-cost tabletop device enabling rapid materialization of CAD models in plastics - was used to produce cm-scale microporous scaffolds out of polylactic acid (PLA). The fabricated objects were subsequently immersed in a photosensitive monomer solution and direct laser writing technique (DLW) was used to refine its inner structure by fabricating a fine mesh inside the previously produced scaffold. In addition, a composite material structure out of four different materials fabricated via DLW is presented. This technique, empowered by ultrafast lasers allows 3D structuring with high spatial resolution in a great variety of photosensitive materials. A composite scaffold made of distinct materials and periodicities is acquired after the development process used to wash out non-linked monomers. Another way to modify the 3D printed PLA surfaces was also demonstrated - ablation with femtosecond laser beam. Structure geometry on macro- to micro- scales could be finely tuned by combining these fabrication techniques. Such artificial 3D substrates could be used for cell growth or as biocompatible-biodegradable implants. To our best knowledge, this is the first experimental demonstration showing the creation of composite 3D scaffolds using convenient 3D printing combined with DLW. This combination of distinct material processing techniques enables rapid fabrication of diverse functional micro-featured and integrated devices. Hopefully, the proposed approach will find numerous applications in the field of tissue engineering, as well as in microelectromechanical systems, microfluidics, microoptics and others.

  13. Investigation into the effect of heat treatment on the thermal conductivity of 3-D carbon/carbon fiber composites

    SciTech Connect

    Dinwiddie, R.B.; Burchell, T.D. ); Baker, C.F. )

    1991-01-01

    The material used in this study was a carbon-carbon fiber composite manufactured from precursor yarn and petroleum based pitch through a process of repetitive densification of a woven preform. The resultant high temperature-high strength material exhibits relatively high thermal conductivity and is thus of interest to the fusion energy, plasma materials interactions (PMI) and plasma facing components (PFC) communities. Carbon-carbon fiber composite manufacture involves two distinct processes, preform weaving and component densification. In this study three samples were subjected to an additional heat treatment of 2550, 2750 or 3000{degree}C at Oak Ridge National Laboratory (ORNL) subsequent to their fourth graphitization at 2400{degree}C. It should be noted that no effort was made to optimize the composite for thermal conductivity, but rather only to provide a material with which to evaluate the effect of the final heat treatment temperature on the thermal conductivity. The fiber is the primary source of heat conduction in the composite. Consequently, increasing the fiber volume fraction, and/or the fiber thermal conductivity is expected to increase the composite thermal conductivity. 3 refs., 1 fig.

  14. Supernova Spectrum Synthesis for 3D Composition Models with the Monte Carlo Method

    NASA Astrophysics Data System (ADS)

    Thomas, Rollin

    2002-07-01

    newcommandBruteextttBrute Relying on spherical symmetry when modelling supernova spectra is clearly at best a good approximation. Recent polarization measurements, interesting features in flux spectra, and the clumpy textures of supernova remnants suggest that supernova envelopes are rife with fine structure. To account for this fine structure and create a complete picture of supernovae, new 3D explosion models will be forthcoming. To reconcile these models with observed spectra, 3D radiative transfer will be necessary. We propose a 3D Monte Carlo radiative transfer code, Brute, and improvements that will move it toward a fully self-consistent 3D transfer code. Spectroscopic HST observations of supernovae past, present and future will definitely benefit. Other 3D transfer problems of interest to HST users like AGNs will benefit from the techniques developed.

  15. Repairable Woven Carbon Fiber Composites with Full Recyclability Enabled by Malleable Polyimine Networks.

    PubMed

    Taynton, Philip; Ni, Huagang; Zhu, Chengpu; Yu, Kai; Loob, Samuel; Jin, Yinghua; Qi, H Jerry; Zhang, Wei

    2016-04-20

    Carbon-fiber reinforced composites are prepared using catalyst-free malleable polyimine networks as binders. An energy neutral closed-loop recycling process has been developed, enabling recovery of 100% of the imine components and carbon fibers in their original form. Polyimine films made using >21% recycled content exhibit no loss of mechanical performance, therefore indicating all of the thermoset composite material can be recycled and reused for the same purpose. PMID:26875745

  16. Characterization and modeling of tensile behavior of ceramic woven fabric composites

    NASA Technical Reports Server (NTRS)

    Kuo, Wen-Shyong; Chen, Wennei Y.; Parvizi-Majidi, Azar; Chou, Tsu-Wei

    1991-01-01

    This paper examines the tensile behavior of SiC/SiC fabric composites. In the characterization effort, the stress-strain relation and damage evolution are studied with a series of loading and unloading tensile test experiments. The stress-strain relation is linear in response to the initial loading and becomes nonlinear when loading exceeds the proportional limit. Transverse cracking has been observed to be a dominant damage mode governing the nonlinear deformation. The damage is initiated at the inter-tow pores where fiber yarns cross over each other. In the modeling work, the analysis is based upon a fiber bundle model, in which fiber undulation in the warp and fill directions and gaps among fiber yarns have been taken into account. Two limiting cases of fabric stacking arrangements are studied. Closed form solutions are obtained for the composite stiffness and Poisson's ratio. Transverse cracking in the composite is discussed by applying a constant failure strain criterion.

  17. Thermal expansion of laminated, woven, continuous ceramic fiber/chemical-vapor-infiltrated silicon carbide matrix composites

    NASA Technical Reports Server (NTRS)

    Eckel, Andrew J.; Bradt, Richard C.

    1990-01-01

    Thermal expansions of three two-dimensional laminate, continuous fiber/chemical-vapor-infiltrated silicon carbide matrix composites reinforced with either FP-Alumina (alumina), Nextel (mullite), or Nicalon (Si-C-O-N) fibers are reported. Experimental thermal expansion coefficients parallel to a primary fiber orientation were comparable to values calculated by the conventional rule-of-mixtures formula, except for the alumina fiber composite. Hysteresis effects were also observed during repeated thermal cycling of that composite. Those features were attributed to reoccurring fiber/matrix separation related to the micromechanical stresses generated during temperature changes and caused by the large thermal expansion mismatch between the alumina fibers and the silicon carbide matrix.

  18. Ballistic impact behaviour of woven fabric composite: Finite element analysis and experiments

    NASA Astrophysics Data System (ADS)

    Phadnis, V. A.; Pandya, K. S.; Naik, N. K.; Roy, A.; Silberschmidt, V. V.

    2013-07-01

    A mechanical behaviour of plain-weave E-glass fabric/epoxy laminate composite plate exposed to ballistic impact is studied using a finite-element (FE) code Abaqus/Explicit. A ply-level FE model is developed, where a fabric-reinforced ply is modelled as a homogeneous orthotropic elastic material with potential to sustain progressive stiffness degradation due to fiber/matrix cracking, and plastic deformation under shear loading. The model is implemented as a VUMAT user subroutine. Ballistic experiments were carried out to validate the FE model. A parametric study for varying panel thickness is performed to compare impact resistance of the studied composite.

  19. Synthesis of a 3D graphite microball using a microfluidic droplet generator and its polymer composite with core-shell structure.

    PubMed

    Han, Dong Ju; Jung, Jae Hwan; Choi, Jong Seob; Kim, Yong Tae; Seo, Tae Seok

    2013-10-21

    Spherical 3D graphite microballs (3D GMs) and their nanohybrids (3D GM-Fe3O4 nanoparticles) were synthesized by using a microfluidic droplet generator and a thermal evaporation-induced capillary compression method. Using the 3D GM-Fe3O4 nanoparticle as a support for polymerization, 3D GM-polypyrrole composites were produced with a unique core-shell structure. PMID:23921454

  20. The effect of shock wave impingement on thin, woven glass fiber reinforced, polymer composite plates

    NASA Astrophysics Data System (ADS)

    Jahnke, Douglas M.

    High-performance fiber-reinforced polymer (FRP) composites have been increasingly used in many applications over the last 30 years. Their high specific stiffness, specific strength, and energy absorption capacity have made them attractive as replacements for traditional materials. While the dynamic response of homogeneous or monolithic materials has been well documented, the response of FRP composites is still under investigation. Knowledge of the response of FRP composites under this type of loading is essential to evaluating its performance as a structural or protective material. While such information starts to be slowly available, the effects of dynamic thermomechanical extremes such as shock wave loading on the FRP composites is relatively unknown. The challenge then is to develop a consistent laboratory methodology that allows investigations of the interactions between a FRP composite and a shock wave and eventually testing of such materials for performance evaluations under shock loading. Measuring the deformation of test specimens caused by shock wave impingement of different intensities was basic to understanding the gross effects on the FRP composites. In early tests, displacement across the diameter of the test specimen was measured after the end of the test giving a static measurement of the permanent deformation. To allow meaningful comparisons between disparate materials subject to different shock wave intensities a method of weighting and normalizing the was developed. The complexity of setting up and running a shock wave test limited the number tests could be performed, so while the results aren't statically robust, the trends observed are useful in comparing or choosing among different materials. A Time-Resolved Catadioptric Stereo Digital Image Correlation (TRC-SDIC) technique was developed which provide a non-contact, full-field method of measuring deformation over the time span from the impingement of the shock wave including the maximum

  1. Characterization of E-glass/polyester woven fabric composite laminates and tubes

    SciTech Connect

    Guess, T.R.; Reedy, E.D. Jr.; Stavig, M.E.

    1995-12-01

    This report describes an experimental study that supported the LDRD program ``A General Approach for Analyzing Composite Structures``. The LDRD was a tightly coupled analytical / experimental effort to develop models for predicting post-yield progressive failure in E-glass fabric/polyester composites subjected to a variety of loading conditions. Elastic properties, fracture toughness parameters, and failure responses were measured on flat laminates, rings and tubes to support the development and validation of material and structural models. Test procedures and results are presented for laminates tested in tension, compression, flexure, short beam shear, double cantilever beam Mode I fracture toughness, and end notched flexure Mode II fracture toughness. Structural responses, including failure, of rings loaded in diametral compression and tubes tested in axial compression, are also documented.

  2. Effects of Nesting on Compression-Loaded 2-D Woven Textile Composites

    NASA Technical Reports Server (NTRS)

    Adams, Daniel OHare; Breiling, Kurtis B.; Verhulst, Mark A.

    1995-01-01

    Layer nesting was investigated in five harness satin weave textile composite laminates under static compression loading. Two carbon/epoxy material systems, AS4/3501-6 and IM7/8551-7A were considered. Laminates were fabricated with three idealized nesting cases: stacked, split-span and diagonal. Similar compression strength reductions due to the effects of idealized nesting were identified for each material. The diagonal nesting geometry produced the largest reduction in static strength when compared to the compression strength of a conventional textile composite. All three nesting cases produced reductions in strength and ultimate strain due to the effects of idealized nesting. Finite element results showed consistent strength reduction trends for the idealized nesting cases, however the magnitudes of compressive strengths were overpredicted.

  3. Experimental and Numerical Analysis of Damage in Woven GFRP Composites Under Large-deflection Bending

    NASA Astrophysics Data System (ADS)

    Ullah, Himayat; Harland, Andy R.; Silberschmidt, Vadim V.

    2012-10-01

    Textile-reinforced composites such as glass fibre-reinforced polymer (GFRP) used in sports products can be exposed to different in-service conditions such as large bending deformation and multiple impacts. Such loading conditions cause high local stresses and strains, which result in multiple modes of damage and fracture in composite laminates due to their inherent heterogeneity and non-trivial microstructure. In this paper, various damage modes in GFRP laminates are studied using experimental material characterisation, non-destructive micro-structural damage evaluation and numerical simulations. Experimental tests are carried out to characterise the behaviour of these materials under large-deflection bending. To obtain in-plane shear properties of laminates, tensile tests are performed using a full-field strain-measurement digital image correlation technique. X-ray micro computed tomography (Micro CT) is used to investigate internal material damage modes - delamination and cracking. Two-dimensional finite element (FE) models are implemented in the commercial code Abaqus to study the deformation behaviour and damage in GFRP. In these models, multiple layers of bilinear cohesive-zone elements are employed to study the onset and progression of inter-ply delamination and intra-ply fabric fracture of composite laminate, based on the X-ray Micro CT study. The developed numerical models are capable to simulate these features with their mechanisms as well as subsequent mode coupling observed in tests and Micro CT scanning. The obtained results of simulations are in agreement with experimental data.

  4. 3D palmprint and hand imaging system based on full-field composite color sinusoidal fringe projection technique.

    PubMed

    Zhang, Zonghua; Huang, Shujun; Xu, Yongjia; Chen, Chao; Zhao, Yan; Gao, Nan; Xiao, Yanjun

    2013-09-01

    Palmprint and hand shape, as two kinds of important biometric characteristics, have been widely studied and applied to human identity recognition. The existing research is based mainly on 2D images, which lose the third-dimensional information. The biological features extracted from 2D images are distorted by pressure and rolling, so the subsequent feature matching and recognition are inaccurate. This paper presents a method to acquire accurate 3D shapes of palmprint and hand by projecting full-field composite color sinusoidal fringe patterns and the corresponding color texture information. A 3D imaging system is designed to capture and process the full-field composite color fringe patterns on hand surface. Composite color fringe patterns having the optimum three fringe numbers are generated by software and projected onto the surface of human hand by a digital light processing projector. From another viewpoint, a color CCD camera captures the deformed fringe patterns and saves them for postprocessing. After compensating for the cross talk and chromatic aberration between color channels, three fringe patterns are extracted from three color channels of a captured composite color image. Wrapped phase information can be calculated from the sinusoidal fringe patterns with high precision. At the same time, the absolute phase of each pixel is determined by the optimum three-fringe selection method. After building up the relationship between absolute phase map and 3D shape data, the 3D palmprint and hand are obtained. Color texture information can be directly captured or demodulated from the captured composite fringe pattern images. Experimental results show that the proposed method and system can yield accurate 3D shape and color texture information of the palmprint and hand shape. PMID:24085070

  5. Long-Term Creep and Creep Rupture Behavior of Woven Ceramic Matrix Composites

    NASA Technical Reports Server (NTRS)

    Haque, A.; Rahman, M.; Mach, A.; Jeelani, S.; Verrilli, Michael J. (Technical Monitor)

    2001-01-01

    Tensile creep behavior of SiC/SiNC ceramic matrix composites at elevated temperatures and at various stress levels have been investigated for turbine engine applications. The objective of this research is to present creep behavior of SiC/SiCN composites at stress levels above and below the monotonic proportional limit strength and predict the life at creep rupture conditions. Tensile creep-rupture tests were performed on an Instron 8502 servohydraulic testing machine at constant load conditions up to a temperature limit of 1000 C. Individual creep curves indicate three stages such as primary, secondary, and tertiary. The creep rate increased linearly at an early stage and then gradually became exponential at higher strains. The stress exponent and activation energy were also obtained at 700 and 1000 C. The specimen lifetime was observed to be 55 hrs at 121 MPa and at 700 C. The life span reduced to 35 hrs at 143 MPa and at 1000 C. Scanning electron microscopy observations revealed significant changes in the crystalline phases and creep damage development. Creep failures were accompanied by extensive fiber pullout, matrix cracking, and debonding along with fiber fracture. The creep data was applied to Time-Temperature-Stress superposition model and the Manson-Haferd parametric model for long-time life prediction.

  6. Controlled surface topography regulates collective 3D migration by epithelial-mesenchymal composite embryonic tissues.

    PubMed

    Song, Jiho; Shawky, Joseph H; Kim, YongTae; Hazar, Melis; LeDuc, Philip R; Sitti, Metin; Davidson, Lance A

    2015-07-01

    Cells in tissues encounter a range of physical cues as they migrate. Probing single cell and collective migratory responses to physically defined three-dimensional (3D) microenvironments and the factors that modulate those responses are critical to understanding how tissue migration is regulated during development, regeneration, and cancer. One key physical factor that regulates cell migration is topography. Most studies on surface topography and cell mechanics have been carried out with single migratory cells, yet little is known about the spreading and motility response of 3D complex multi-cellular tissues to topographical cues. Here, we examine the response to complex topographical cues of microsurgically isolated tissue explants composed of epithelial and mesenchymal cell layers from naturally 3D organized embryos of the aquatic frog Xenopus laevis. We control topography using fabricated micropost arrays (MPAs) and investigate the collective 3D migration of these multi-cellular systems in these MPAs. We find that the topography regulates both collective and individual cell migration and that dense MPAs reduce but do not eliminate tissue spreading. By modulating cell size through the cell cycle inhibitor Mitomycin C or the spacing of the MPAs we uncover how 3D topographical cues disrupt collective cell migration. We find surface topography can direct both single cell motility and tissue spreading, altering tissue-scale processes that enable efficient conversion of single cell motility into collective movement. PMID:25933063

  7. Effects of Microstructural Variability on Thermo-Mechanical Properties of a Woven Ceramic Matrix Composite

    NASA Technical Reports Server (NTRS)

    Goldsmith, Marlana B.; Sankar, Bhavani V.; Haftka, Raphael T.; Goldberg, Robert K.

    2013-01-01

    The objectives of this paper include identifying important architectural parameters that describe the SiC/SiC five-harness satin weave composite and characterizing the statistical distributions and correlations of those parameters from photomicrographs of various cross sections. In addition, realistic artificial cross sections of a 2D representative volume element (RVE) are generated reflecting the variability found in the photomicrographs, which are used to determine the effects of architectural variability on the thermo-mechanical properties. Lastly, preliminary information is obtained on the sensitivity of thermo-mechanical properties to architectural variations. Finite element analysis is used in combination with a response surface and it is shown that the present method is effective in determining the effects of architectural variability on thermo-mechanical properties.

  8. An Update on Design Tools for Optimization of CMC 3D Fiber Architectures

    NASA Technical Reports Server (NTRS)

    Lang, J.; DiCarlo, J.

    2012-01-01

    Objective: Describe and up-date progress for NASA's efforts to develop 3D architectural design tools for CMC in general and for SIC/SiC composites in particular. Describe past and current sequential work efforts aimed at: Understanding key fiber and tow physical characteristics in conventional 2D and 3D woven architectures as revealed by microstructures in the literature. Developing an Excel program for down-selecting and predicting key geometric properties and resulting key fiber-controlled properties for various conventional 3D architectures. Developing a software tool for accurately visualizing all the key geometric details of conventional 3D architectures. Validating tools by visualizing and predicting the Internal geometry and key mechanical properties of a NASA SIC/SIC panel with a 3D orthogonal architecture. Applying the predictive and visualization tools toward advanced 3D orthogonal SiC/SIC composites, and combining them into a user-friendly software program.

  9. Composite lithium metal anode by melt infusion of lithium into a 3D conducting scaffold with lithiophilic coating.

    PubMed

    Liang, Zheng; Lin, Dingchang; Zhao, Jie; Lu, Zhenda; Liu, Yayuan; Liu, Chong; Lu, Yingying; Wang, Haotian; Yan, Kai; Tao, Xinyong; Cui, Yi

    2016-03-15

    Lithium metal-based battery is considered one of the best energy storage systems due to its high theoretical capacity and lowest anode potential of all. However, dendritic growth and virtually relative infinity volume change during long-term cycling often lead to severe safety hazards and catastrophic failure. Here, a stable lithium-scaffold composite electrode is developed by lithium melt infusion into a 3D porous carbon matrix with "lithiophilic" coating. Lithium is uniformly entrapped on the matrix surface and in the 3D structure. The resulting composite electrode possesses a high conductive surface area and excellent structural stability upon galvanostatic cycling. We showed stable cycling of this composite electrode with small Li plating/stripping overpotential (<90 mV) at a high current density of 3 mA/cm(2) over 80 cycles. PMID:26929378

  10. Freestanding nanocellulose-composite fibre reinforced 3D polypyrrole electrodes for energy storage applications

    NASA Astrophysics Data System (ADS)

    Wang, Zhaohui; Tammela, Petter; Zhang, Peng; Huo, Jinxing; Ericson, Fredric; Strømme, Maria; Nyholm, Leif

    2014-10-01

    It is demonstrated that 3D nanostructured polypyrrole (3D PPy) nanocomposites can be reinforced with PPy covered nanocellulose (PPy@nanocellulose) fibres to yield freestanding, mechanically strong and porosity optimised electrodes with large surface areas. Such PPy@nanocellulose reinforced 3D PPy materials can be employed as free-standing paper-like electrodes in symmetric energy storage devices exhibiting cell capacitances of 46 F g-1, corresponding to specific electrode capacitances of up to ~185 F g-1 based on the weight of the electrode, and 5.5 F cm-2 at a current density of 2 mA cm-2. After 3000 charge/discharge cycles at 30 mA cm-2, the reinforced 3D PPy electrode material also showed a cell capacitance corresponding to 92% of that initially obtained. The present findings open up new possibilities for the fabrication of high performance, low-cost and environmentally friendly energy-storage devices based on nanostructured paper-like materials.It is demonstrated that 3D nanostructured polypyrrole (3D PPy) nanocomposites can be reinforced with PPy covered nanocellulose (PPy@nanocellulose) fibres to yield freestanding, mechanically strong and porosity optimised electrodes with large surface areas. Such PPy@nanocellulose reinforced 3D PPy materials can be employed as free-standing paper-like electrodes in symmetric energy storage devices exhibiting cell capacitances of 46 F g-1, corresponding to specific electrode capacitances of up to ~185 F g-1 based on the weight of the electrode, and 5.5 F cm-2 at a current density of 2 mA cm-2. After 3000 charge/discharge cycles at 30 mA cm-2, the reinforced 3D PPy electrode material also showed a cell capacitance corresponding to 92% of that initially obtained. The present findings open up new possibilities for the fabrication of high performance, low-cost and environmentally friendly energy-storage devices based on nanostructured paper-like materials. Electronic supplementary information (ESI) available. See DOI: 10.1039/c

  11. Impact of Material and Architecture Model Parameters on the Failure of Woven Ceramic Matrix Composites (CMCs) via the Multiscale Generalized Method of Cells

    NASA Technical Reports Server (NTRS)

    Liu, Kuang C.; Arnold, Steven M.

    2011-01-01

    It is well known that failure of a material is a locally driven event. In the case of ceramic matrix composites (CMCs), significant variations in the microstructure of the composite exist and their significance on both deformation and life response need to be assessed. Examples of these variations include changes in the fiber tow shape, tow shifting/nesting and voids within and between tows. In the present work, the effects of many of these architectural parameters and material scatter of woven ceramic composite properties at the macroscale (woven RUC) will be studied to assess their sensitivity. The recently developed Multiscale Generalized Method of Cells methodology is used to determine the overall deformation response, proportional elastic limit (first matrix cracking), and failure under tensile loading conditions. The macroscale responses investigated illustrate the effect of architectural and material parameters on a single RUC representing a five harness satin weave fabric. Results shows that the most critical architectural parameter is weave void shape and content with other parameters being less in severity. Variation of the matrix material properties was also studied to illustrate the influence of the material variability on the overall features of the composite stress-strain response.

  12. Particle-Based Geometric and Mechanical Modelling of Woven Technical Textiles and Reinforcements for Composites

    NASA Astrophysics Data System (ADS)

    Samadi, Reza

    Technical textiles are increasingly being engineered and used in challenging applications, in areas such as safety, biomedical devices, architecture and others, where they must meet stringent demands including excellent and predictable load bearing capabilities. They also form the bases for one of the most widespread group of composite materials, fibre reinforced polymer-matrix composites (PMCs), which comprise materials made of stiff and strong fibres generally available in textile form and selected for their structural potential, combined with a polymer matrix that gives parts their shape. Manufacturing processes for PMCs and technical textiles, as well as parts and advanced textile structures must be engineered, ideally through simulation, and therefore diverse properties of the textiles, textile reinforcements and PMC materials must be available for predictive simulation. Knowing the detailed geometry of technical textiles is essential to predicting accurately the processing and performance properties of textiles and PMC parts. In turn, the geometry taken by a textile or a reinforcement textile is linked in an intricate manner to its constitutive behaviour. This thesis proposes, investigates and validates a general numerical tool for the integrated and comprehensive analysis of textile geometry and constitutive behaviour as required toward engineering applications featuring technical textiles and textile reinforcements. The tool shall be general with regards to the textiles modelled and the loading cases applied. Specifically, the work aims at fulfilling the following objectives: 1) developing and implementing dedicated simulation software for modelling textiles subjected to various load cases; 2) providing, through simulation, geometric descriptions for different textiles subjected to different load cases namely compaction, relaxation and shear; 3) predicting the constitutive behaviour of the textiles undergoing said load cases; 4) identifying parameters

  13. Contrast Enhancement of MicroCT Scans to Aid 3D Modelling of Carbon Fibre Fabric Composites

    NASA Astrophysics Data System (ADS)

    Djukic, Luke P.; Pearce, Garth M.; Herszberg, Israel; Bannister, Michael K.; Mollenhauer, David H.

    2013-12-01

    This paper presents a methodology for volume capture and rendering of plain weave and multi-layer fabric meso-architectures within a consolidated, cured laminate. Micro X-ray Computed Tomography (MicroCT) is an excellent tool for the non-destructive visualisation of material microstructures however the contrast between tows and resin is poor for carbon fibre composites. Firstly, this paper demonstrates techniques to improve the contrast of the microCT images by introducing higher density materials such as gold, iodine and glass into the fabric. Two approaches were demonstrated to be effective for enhancing the differentiation between the tows in the reconstructed microCT visualisations. Secondly, a method of generating three-dimensional volume models of woven composites using microCT scan data is discussed. The process of generating a model is explained from initial manufacture with the aid of an example plain weave fabric. These methods are to be used in the finite element modelling of three-dimensional fabric preforms in future work.

  14. Real-time 3-D shape measurement with composite phase-shifting fringes and multi-view system.

    PubMed

    Tao, Tianyang; Chen, Qian; Da, Jian; Feng, Shijie; Hu, Yan; Zuo, Chao

    2016-09-01

    In recent years, fringe projection has become an established and essential method for dynamic three-dimensional (3-D) shape measurement in different fields such as online inspection and real-time quality control. Numerous high-speed 3-D shape measurement methods have been developed by either employing high-speed hardware, minimizing the number of pattern projection, or both. However, dynamic 3-D shape measurement of arbitrarily-shaped objects with full sensor resolution without the necessity of additional pattern projections is still a big challenge. In this work, we introduce a high-speed 3-D shape measurement technique based on composite phase-shifting fringes and a multi-view system. The geometry constraint is adopted to search the corresponding points independently without additional images. Meanwhile, by analysing the 3-D position and the main wrapped phase of the corresponding point, pairs with an incorrect 3-D position or a considerable phase difference are effectively rejected. All of the qualified corresponding points are then corrected, and the unique one as well as the related period order is selected through the embedded triangular wave. Finally, considering that some points can only be captured by one of the cameras due to the occlusions, these points may have different fringe orders in the two views, so a left-right consistency check is employed to eliminate those erroneous period orders in this case. Several experiments on both static and dynamic scenes are performed, verifying that our method can achieve a speed of 120 frames per second (fps) with 25-period fringe patterns for fast, dense, and accurate 3-D measurement. PMID:27607632

  15. Using a magnetite/thermoplastic composite in 3D printing of direct replacements for commercially available flow sensors

    NASA Astrophysics Data System (ADS)

    Leigh, S. J.; Purssell, C. P.; Billson, D. R.; Hutchins, D. A.

    2014-09-01

    Flow sensing is an essential technique required for a wide range of application environments ranging from liquid dispensing to utility monitoring. A number of different methodologies and deployment strategies have been devised to cover the diverse range of potential application areas. The ability to easily create new bespoke sensors for new applications is therefore of natural interest. Fused deposition modelling is a 3D printing technology based upon the fabrication of 3D structures in a layer-by-layer fashion using extruded strands of molten thermoplastic. The technology was developed in the late 1980s but has only recently come to more wide-scale attention outside of specialist applications and rapid prototyping due to the advent of low-cost 3D printing platforms such as the RepRap. Due to the relatively low-cost of the printers and feedstock materials, these printers are ideal candidates for wide-scale installation as localized manufacturing platforms to quickly produce replacement parts when components fail. One of the current limitations with the technology is the availability of functional printing materials to facilitate production of complex functional 3D objects and devices beyond mere concept prototypes. This paper presents the formulation of a simple magnetite nanoparticle-loaded thermoplastic composite and its incorporation into a 3D printed flow-sensor in order to mimic the function of a commercially available flow-sensing device. Using the multi-material printing capability of the 3D printer allows a much smaller amount of functional material to be used in comparison to the commercial flow sensor by only placing the material where it is specifically required. Analysis of the printed sensor also revealed a much more linear response to increasing flow rate of water showing that 3D printed devices have the potential to at least perform as well as a conventionally produced sensor.

  16. Woven heat exchanger

    DOEpatents

    Piscitella, Roger R.

    1987-05-05

    In a woven ceramic heat exchanger using the basic tube-in-shell design, each heat exchanger consisting of tube sheets and tube, is woven separately. Individual heat exchangers are assembled in cross-flow configuration. Each heat exchanger is woven from high temperature ceramic fiber, the warp is continuous from tube to tube sheet providing a smooth transition and unitized construction.

  17. Fatigue delamination growth in woven glass/epoxy composite laminates under mixed-mode II/III loading conditions at cryogenic temperatures

    NASA Astrophysics Data System (ADS)

    Takeda, Tomo; Miura, Masaya; Shindo, Yasuhide; Narita, Fumio

    2013-12-01

    We investigate the cryogenic delamination growth behavior in woven glass fiber reinforced polymer (GFRP) composite laminates under mixed-mode II/III fatigue loading. Fatigue delamination tests were conducted with six-point bending plate (6PBP) specimens at room temperature, liquid nitrogen temperature (77 K) and liquid helium temperature (4 K), and the delamination growth rate data for various mixed-mode ratios of Modes II and III were obtained. The energy release rate was evaluated using the three-dimensional finite element method. In addition, the fatigue delamination growth mechanisms were characterized by scanning electron microscopic observations of the specimen fracture surfaces.

  18. Game Changing Technology: Woven Thermal Protection Systems

    NASA Video Gallery

    New woven composite materials are an advanced space technology that mark a major milestone toward development of the space systems that will enable extending human and robotic presence throughout t...

  19. Understanding Plasticity and Fracture in Aluminum Alloys and their Composites by 3D X-ray Synchrotron Tomography and Microdiffraction

    NASA Astrophysics Data System (ADS)

    Hruby, Peter

    Aluminum alloys and their composites are attractive materials for applications requiring high strength-to-weight ratios and reasonable cost. Many of these applications, such as those in the aerospace industry, undergo fatigue loading. An understanding of the microstructural damage that occurs in these materials is critical in assessing their fatigue resistance. Two distinct experimental studies were performed to further the understanding of fatigue damage mechanisms in aluminum alloys and their composites, specifically fracture and plasticity. Fatigue resistance of metal matrix composites (MMCs) depends on many aspects of composite microstructure. Fatigue crack growth behavior is particularly dependent on the reinforcement characteristics and matrix microstructure. The goal of this work was to obtain a fundamental understanding of fatigue crack growth behavior in SiC particle-reinforced 2080 Al alloy composites. In situ X-ray synchrotron tomography was performed on two samples at low (R=0.1) and at high (R=0.6) R-ratios. The resulting reconstructed images were used to obtain three-dimensional (3D) rendering of the particles and fatigue crack. Behaviors of the particles and crack, as well as their interaction, were analyzed and quantified. Four-dimensional (4D) visual representations were constructed to aid in the overall understanding of damage evolution. During fatigue crack growth in ductile materials, a plastic zone is created in the region surrounding the crack tip. Knowledge of the plastic zone is important for the understanding of fatigue crack formation as well as subsequent growth behavior. The goal of this work was to quantify the 3D size and shape of the plastic zone in 7075 Al alloys. X-ray synchrotron tomography and Laue microdiffraction were used to non-destructively characterize the volume surrounding a fatigue crack tip. The precise 3D crack profile was segmented from the reconstructed tomography data. Depth-resolved Laue patterns were obtained using

  20. A study on the influence of process parameters on the Mechanical Properties of 3D printed ABS composite

    NASA Astrophysics Data System (ADS)

    Jaya Christiyan, K. G.; Chandrasekhar, U.; Venkateswarlu, K.

    2016-02-01

    Additive Manufacturing (AM) technologies have been emerged as a fabrication method to obtain engineering components within a short span of time. Desktop 3D printing, also referred as additive layer manufacturing technology is one of the powerful method of rapid prototyping (RP) technique that fabricates three dimensional engineering components. In this method, 3D digital CAD data is converted directly to a product. In the present investigation, ABS + hydrous magnesium silicate composite was considered as the starting material. Mechanical properties of ABS + hydrous magnesium silicate composite material were evaluated. ASTM D638 and ASTM D760 standards were followed for carrying out tensile and flexural tests, respectively. Samples with different layer thickness and printing speed were prepared. Based on the experimental results, it is suggested that low printing speed, and low layer thickness has resulted maximum tensile and flexural strength, as compared to all the other process parameters samples.

  1. Ice-Templated Assembly Strategy to Construct 3D Boron Nitride Nanosheet Networks in Polymer Composites for Thermal Conductivity Improvement.

    PubMed

    Zeng, Xiaoliang; Yao, Yimin; Gong, Zhengyu; Wang, Fangfang; Sun, Rong; Xu, Jianbin; Wong, Ching-Ping

    2015-12-01

    Owing to the growing heat removal issue of modern electronic devices, polymer composites with high thermal conductivity have drawn much attention in the past few years. However, a traditional method to enhance the thermal conductivity of the polymers by addition of inorganic fillers usually creates composite with not only limited thermal conductivity but also other detrimental effects due to large amount of fillers required. Here, novel polymer composites are reported by first constructing 3D boron nitride nanosheets (3D-BNNS) network using ice-templated approach and then infiltrating them with epoxy matrix. The obtained polymer composites exhibit a high thermal conductivity (2.85 W m(-1) K(-1)), a low thermal expansion coefficient (24-32 ppm K(-1)), and an increased glass transition temperature (T(g)) at relatively low BNNSs loading (9.29 vol%). These results demonstrate that this approach opens a new avenue for design and preparation of polymer composites with high thermal conductivity. The polymer composites are potentially useful in advanced electronic packaging techniques, namely, thermal interface materials, underfill materials, molding compounds, and organic substrates. PMID:26479262

  2. Structure Design of the 3-D Braided Composite Based on a Hybrid Optimization Algorithm

    NASA Astrophysics Data System (ADS)

    Zhang, Ke

    Three-dimensional braided composite has the better designable characteristic. Whereas wide application of hollow-rectangular-section three-dimensional braided composite in engineering, optimization design of the three-dimensional braided composite made by 4-step method were introduced. Firstly, the stiffness and damping characteristic analysis of the composite is presented. Then, the mathematical models for structure design of the three-dimensional braided composite were established. The objective functions are based on the specific damping capacity and stiffness of the composite. The design variables are the braiding parameters of the composites and sectional geometrical size of the composite. The optimization problem is solved by using ant colony optimization (ACO), contenting the determinate restriction. The results of numeral examples show that the better damping and stiffness characteristic could be obtained. The method proposed here is useful for the structure design of the kind of member and its engineering application.

  3. Characterizing microscale aluminum composite layer properties on silicon solar cells with hybrid 3D scanning force measurements

    PubMed Central

    Bae, Sung-Kuk; Choi, Beomjoon; Chung, Haseung; Shin, Seungwon; Song, Hee-eun; Seo, Jung Hwan

    2016-01-01

    This article presents a novel technique to estimate the mechanical properties of the aluminum composite layer on silicon solar cells by using a hybrid 3-dimensional laser scanning force measurement (3-D LSFM) system. The 3-D LSFM system measures the material properties of sub-layers constituting a solar cell. This measurement is critical for realizing high-efficient ultra-thin solar cells. The screen-printed aluminum layer, which significantly affects the bowing phenomenon, is separated from the complete solar cell by removing the silicon (Si) layer with deep reactive ion etching. An elastic modulus of ~15.1 GPa and a yield strength of ~35.0 MPa for the aluminum (Al) composite layer were obtained by the 3-D LSFM system. In experiments performed for 6-inch Si solar cells, the bowing distances decreased from 12.02 to 1.18 mm while the Si layer thicknesses increased from 90 to 190 μm. These results are in excellent agreement with the theoretical predictions for ultra-thin Si thickness (90 μm) based on the obtained Al composite layer properties. PMID:26948248

  4. Characterizing microscale aluminum composite layer properties on silicon solar cells with hybrid 3D scanning force measurements

    NASA Astrophysics Data System (ADS)

    Bae, Sung-Kuk; Choi, Beomjoon; Chung, Haseung; Shin, Seungwon; Song, Hee-Eun; Seo, Jung Hwan

    2016-03-01

    This article presents a novel technique to estimate the mechanical properties of the aluminum composite layer on silicon solar cells by using a hybrid 3-dimensional laser scanning force measurement (3-D LSFM) system. The 3-D LSFM system measures the material properties of sub-layers constituting a solar cell. This measurement is critical for realizing high-efficient ultra-thin solar cells. The screen-printed aluminum layer, which significantly affects the bowing phenomenon, is separated from the complete solar cell by removing the silicon (Si) layer with deep reactive ion etching. An elastic modulus of ~15.1 GPa and a yield strength of ~35.0 MPa for the aluminum (Al) composite layer were obtained by the 3-D LSFM system. In experiments performed for 6-inch Si solar cells, the bowing distances decreased from 12.02 to 1.18 mm while the Si layer thicknesses increased from 90 to 190 μm. These results are in excellent agreement with the theoretical predictions for ultra-thin Si thickness (90 μm) based on the obtained Al composite layer properties.

  5. Characterizing microscale aluminum composite layer properties on silicon solar cells with hybrid 3D scanning force measurements.

    PubMed

    Bae, Sung-Kuk; Choi, Beomjoon; Chung, Haseung; Shin, Seungwon; Song, Hee-Eun; Seo, Jung Hwan

    2016-01-01

    This article presents a novel technique to estimate the mechanical properties of the aluminum composite layer on silicon solar cells by using a hybrid 3-dimensional laser scanning force measurement (3-D LSFM) system. The 3-D LSFM system measures the material properties of sub-layers constituting a solar cell. This measurement is critical for realizing high-efficient ultra-thin solar cells. The screen-printed aluminum layer, which significantly affects the bowing phenomenon, is separated from the complete solar cell by removing the silicon (Si) layer with deep reactive ion etching. An elastic modulus of ~15.1 GPa and a yield strength of ~35.0 MPa for the aluminum (Al) composite layer were obtained by the 3-D LSFM system. In experiments performed for 6-inch Si solar cells, the bowing distances decreased from 12.02 to 1.18 mm while the Si layer thicknesses increased from 90 to 190 μm. These results are in excellent agreement with the theoretical predictions for ultra-thin Si thickness (90 μm) based on the obtained Al composite layer properties. PMID:26948248

  6. Improved oxidation resistance of 3-d carbon/carbon composites. Final report, 1 July 1992-28 February 1993

    SciTech Connect

    Krukonis, V.; Coffey, M.P.; Anderson, S.D.

    1994-01-14

    Carbon fiber reinforced silicon carbide matrix composites (C/SiC) were made by a process termed Supercritical Fluid Infiltration. A preceramic polymer, e.g., a polycarbosilane which can pyrolyze to form SiC, is dissolved in a supercritical fluid, the solution conveyed into a tightly woven preform of carbon fiber, and the preceramic polymer caused to deposit in the interstitial volume surrounding the fibers. Subsequent pyrolysis of the polymer forms the SiC matrix and fiber coating. Supercritical propane at conditions of 140 deg C, 4000 psi dissolves polycarbosilane to a concentration level of 30% (w/w), a level that results on substantial infiltration and deposition of the polymer. The yield of SiC from the parent polymer upon pyrolysis was determined to be about 50% (w/w); the polymer was fractionated using supercritical propane (in a process termed increasing pressure profiling), and it was found that some of the low molecular weight fractions gave extremely low yields of SiC (<25%) whereas some of the high molecular weight fractions yielded over 80% SiC. When the parent polymer was used for the infiltration studies the deposited material was modular in appearance suggesting that the liquid low molecular weight portion of the polymer was predominately and adversely influencing the uniformity.

  7. Analysis of linear elasticity and non-linearity due to plasticity and material damage in woven and biaxial braided composites

    NASA Astrophysics Data System (ADS)

    Goyal, Deepak

    Textile composites have a wide variety of applications in the aerospace, sports, automobile, marine and medical industries. Due to the availability of a variety of textile architectures and numerous parameters associated with each, optimal design through extensive experimental testing is not practical. Predictive tools are needed to perform virtual experiments of various options. The focus of this research is to develop a better understanding of linear elastic response, plasticity and material damage induced nonlinear behavior and mechanics of load flow in textile composites. Textile composites exhibit multiple scales of complexity. The various textile behaviors are analyzed using a two-scale finite element modeling. A framework to allow use of a wide variety of damage initiation and growth models is proposed. Plasticity induced non-linear behavior of 2x2 braided composites is investigated using a modeling approach based on Hill's yield function for orthotropic materials. The mechanics of load flow in textile composites is demonstrated using special non-standard postprocessing techniques that not only highlight the important details, but also transform the extensive amount of output data into comprehensible modes of behavior. The investigations show that the damage models differ from each other in terms of amount of degradation as well as the properties to be degraded under a particular failure mode. When compared with experimental data, predictions of some models match well for glass/epoxy composite whereas other's match well for carbon/epoxy composites. However, all the models predicted very similar response when damage factors were made similar, which shows that the magnitude of damage factors are very important. Full 3D as well as equivalent tape laminate predictions lie within the range of the experimental data for a wide variety of braided composites with different material systems, which validated the plasticity analysis. Conclusions about the effect of

  8. Mechanism and Microstructure Transformation of 3D-Si/LG5 Composites by High Temperature Diffusion Treatment

    NASA Astrophysics Data System (ADS)

    Xiu, Ziyang; Deng, Zongquan; Wang, Xiaofeng; Wu, Gaohui

    A dense and uniform Sip/LG5 composite were fabricated by squeeze casting technology, and high temperature diffusion treatment was adapted to the composite. Microstructure observation indicated that Si transformed from irregular particles to 3D-structure. Fine dispersive precipitates Si were also observed on Si-Al interface and within Al matrix, smoothing and improving the interface. Based on the microstructure observation, three transformation stages were designated: melting, dissolution and precipitation, solidification. Thermodynamics and kinetics of the transformation can be explained by Gibbs-Thomson effect.

  9. Effect of processes and processing parameters on 3-D braided preforms for composites

    SciTech Connect

    Li, W.; Shiekh, A.E.

    1988-07-01

    A general comparison about the processes, the structures and tensile properties of two 3-D braiding techniques are presented in this paper. The yarn orientation, braid width, braider curvature at fabric surface, and yarn volume fraction of both the 4-step and 2-step braids are analytically predicted in terms of the normalized cycle length which is directly related to the machine operating conditions. The extreme values of the parameters are discussed and compared. Results of the tensile properties of the braids are presented and discussed in terms of the structure differences. 11 references, 9 figures, 1 table.

  10. Direct Determination of 3D Distribution of Elemental Composition in Single Semiconductor Nanoislands by Scanning Auger Microscopy.

    PubMed

    Ponomaryov, Semyon S; Yukhymchuk, Volodymyr O; Lytvyn, Peter M; Valakh, Mykhailo Ya

    2016-12-01

    An application of scanning Auger microscopy with ion etching technique and effective compensation of thermal drift of the surface analyzed area is proposed for direct local study of composition distribution in the bulk of single nanoislands. For GexSi1 - x-nanoislands obtained by MBE of Ge on Si-substrate gigantic interdiffusion mixing takes place both in the open and capped nanostructures. Lateral distributions of the elemental composition as well as concentration-depth profiles were recorded. 3D distribution of the elemental composition in the d-cluster bulk was obtained using the interpolation approach by lateral composition distributions in its several cross sections and concentration-depth profile. It was shown that there is a germanium core in the nanoislands of both nanostructure types, which even penetrates the substrate. In studied nanostructures maximal Ge content in the nanoislands may reach about 40 at.%. PMID:26909783

  11. Direct Determination of 3D Distribution of Elemental Composition in Single Semiconductor Nanoislands by Scanning Auger Microscopy

    NASA Astrophysics Data System (ADS)

    Ponomaryov, Semyon S.; Yukhymchuk, Volodymyr O.; Lytvyn, Peter M.; Valakh, Mykhailo Ya

    2016-02-01

    An application of scanning Auger microscopy with ion etching technique and effective compensation of thermal drift of the surface analyzed area is proposed for direct local study of composition distribution in the bulk of single nanoislands. For GexSi1 - x-nanoislands obtained by MBE of Ge on Si-substrate gigantic interdiffusion mixing takes place both in the open and capped nanostructures. Lateral distributions of the elemental composition as well as concentration-depth profiles were recorded. 3D distribution of the elemental composition in the d-cluster bulk was obtained using the interpolation approach by lateral composition distributions in its several cross sections and concentration-depth profile. It was shown that there is a germanium core in the nanoislands of both nanostructure types, which even penetrates the substrate. In studied nanostructures maximal Ge content in the nanoislands may reach about 40 at.%.

  12. Assessment of Damage Detection in Composite Structures Using 3D Vibrometry

    NASA Astrophysics Data System (ADS)

    Grigg, S.; Pearson, M.; Marks, R.; Featherston, C.; Pullin, R.

    2015-07-01

    Carbon fibre reinforced polymers (CFRP) have been used significantly more in recent years due to their increased specific strength over aluminium structures. One major area in which their use has grown is the aerospace industry where many now use CFRP in their construction. One major problem with CFRP's is their low resistance to impacts. Structural health monitoring (SHM) aims to continually monitor a structure throughout its entire life and can allow aircraft owners to identify impact damage as it occurs. This means that it can be repaired prior to growth, saving weight with the repair and the time that aircraft is grounded. Two areas of SHM being researched are Acoustic Emission (AE) monitoring and AcoustoUltrasonics (AU) both based on an understanding of the propagation of ultrasonic waves. 3D Scanning laser vibrometry was used to monitor the propagation of AU waves with the aim of gaining a better understanding their interaction with delamination in carbon fibre reinforced polymers. Three frequencies were exited with a PZT transducer and the received signal analysed by a cross correlation method. The results from this and the vibrometer scans revealed 100 kHz as the most effective propagating frequency of the three. A high resolution scan was then conducted at this frequency where it could be seen that only the out of plane component of the wave interacted with the damage, in particular the A0 mode. A 3D Fast Fourier Transform was then plotted, which identified the most effective frequency as 160 kHz.

  13. Generating virtual textile composite specimens using statistical data from micro-computed tomography: 3D tow representations

    NASA Astrophysics Data System (ADS)

    Rinaldi, Renaud G.; Blacklock, Matthew; Bale, Hrishikesh; Begley, Matthew R.; Cox, Brian N.

    2012-08-01

    Recent work presented a Monte Carlo algorithm based on Markov Chain operators for generating replicas of textile composite specimens that possess the same statistical characteristics as specimens imaged using high resolution x-ray computed tomography. That work represented the textile reinforcement by one-dimensional tow loci in three-dimensional space, suitable for use in the Binary Model of textile composites. Here analogous algorithms are used to generate solid, three-dimensional (3D) tow representations, to provide geometrical models for more detailed failure analyses. The algorithms for generating 3D models are divided into those that refer to the topology of the textile and those that deal with its geometry. The topological rules carry all the information that distinguishes textiles with different interlacing patterns (weaves, braids, etc.) and provide instructions for resolving interpenetrations or ordering errors among tows. They also simplify writing a single computer program that can accept input data for generic textile cases. The geometrical rules adjust the shape and smoothness of the generated virtual specimens to match data from imaged specimens. The virtual specimen generator is illustrated using data for an angle interlock weave, a common 3D textile architecture.

  14. Effect of braiding process on the damage tolerance of 3-D braided graphite/epoxy composites

    NASA Technical Reports Server (NTRS)

    El-Shiekh, Aly; Li, Wei; Hammad, Mohamed

    1989-01-01

    One of the key advantages of three-dimensional braided composite materials is their high impact damage tolerance comparing with laminated composites, due to their fully integrated fibrous substrates. In this paper, the effect of different processing methods on the impact damage tolerance of braided graphite/epoxy composite is experimentally assessed. The test specimens are prepared using both of the two existing three-dimensional braiding techniques (the 4-step and the 2-step processes). After the specimens are impacted under controlled impact energy, the damage introduced is studied. Then a compression test is conducted to evaluate the compression strength of the specimens after impact.

  15. A full 3D plane-wave-expansion model for 1-3 piezoelectric composite structures.

    PubMed

    Wilm, Mikaël; Ballandras, Sylvain; Laude, Vincent; Pastureaud, Thomas

    2002-09-01

    The plane-wave-expansion (PWE) approach dedicated to the simulation of periodic devices has been extended to 1-3 connectivity piezoelectric composite structures. The case of simple but actual piezoelectric composite structures is addressed, taking piezoelectricity, acoustic losses, and electrical excitation conditions rigorously into account. The material distribution is represented by using a bidimensional Fourier series and the electromechanical response is simulated using a Bloch-Floquet expansion together with the Fahmy-Adler formulation of the Christoffel problem. Application of the model to 1-3 connectivity piezoelectric composites is reported and compared to previously published analyses of this problem. PMID:12243182

  16. Woven TPS Mechanical Property Evaluation

    NASA Technical Reports Server (NTRS)

    Gonzales, Gregory Lewis; Kao, David Jan-Woei; Stackpoole, Margaret M.

    2013-01-01

    Woven Thermal Protection Systems (WTPS) is a relatively new program funded by the Office of the Chief Technologist (OCT). The WTPS approach to producing TPS architectures uses precisely engineered 3-D weaving techniques that allow tailoring material characteristics needed to meet specific mission requirements. A series of mechanical tests were performed to evaluate performance of different weave types, and get a better understanding of failure modes expected in these three-dimensional architectures. These properties will aid in material down selection and guide selection of the appropriate WTPS for a potential mission.

  17. Probabilistic Modeling of High-Temperature Material Properties of a 5-Harness 0/90 Sylramic Fiber/ CVI-SiC/ MI-SiC Woven Composite

    NASA Technical Reports Server (NTRS)

    Nagpal, Vinod K.; Tong, Michael; Murthy, P. L. N.; Mital, Subodh

    1998-01-01

    An integrated probabilistic approach has been developed to assess composites for high temperature applications. This approach was used to determine thermal and mechanical properties and their probabilistic distributions of a 5-harness 0/90 Sylramic fiber/CVI-SiC/Mi-SiC woven Ceramic Matrix Composite (CMC) at high temperatures. The purpose of developing this approach was to generate quantitative probabilistic information on this CMC to help complete the evaluation for its potential application for HSCT combustor liner. This approach quantified the influences of uncertainties inherent in constituent properties called primitive variables on selected key response variables of the CMC at 2200 F. The quantitative information is presented in the form of Cumulative Density Functions (CDFs). Probability Density Functions (PDFS) and primitive variable sensitivities on response. Results indicate that the scatters in response variables were reduced by 30-50% when the uncertainties in the primitive variables, which showed the most influence, were reduced by 50%.

  18. Multi-scale Characterisation of the 3D Microstructure of a Thermally-Shocked Bulk Metallic Glass Matrix Composite.

    PubMed

    Zhang, Wei; Bodey, Andrew J; Sui, Tan; Kockelmann, Winfried; Rau, Christoph; Korsunsky, Alexander M; Mi, Jiawei

    2016-01-01

    Bulk metallic glass matrix composites (BMGMCs) are a new class of metal alloys which have significantly increased ductility and impact toughness, resulting from the ductile crystalline phases distributed uniformly within the amorphous matrix. However, the 3D structures and their morphologies of such composite at nano and micrometre scale have never been reported before. We have used high density electric currents to thermally shock a Zr-Ti based BMGMC to different temperatures, and used X-ray microtomography, FIB-SEM nanotomography and neutron diffraction to reveal the morphologies, compositions, volume fractions and thermal stabilities of the nano and microstructures. Understanding of these is essential for optimizing the design of BMGMCs and developing viable manufacturing methods. PMID:26725519

  19. Multi-scale Characterisation of the 3D Microstructure of a Thermally-Shocked Bulk Metallic Glass Matrix Composite

    PubMed Central

    Zhang, Wei; Bodey, Andrew J.; Sui, Tan; Kockelmann, Winfried; Rau, Christoph; Korsunsky, Alexander M.; Mi, Jiawei

    2016-01-01

    Bulk metallic glass matrix composites (BMGMCs) are a new class of metal alloys which have significantly increased ductility and impact toughness, resulting from the ductile crystalline phases distributed uniformly within the amorphous matrix. However, the 3D structures and their morphologies of such composite at nano and micrometre scale have never been reported before. We have used high density electric currents to thermally shock a Zr-Ti based BMGMC to different temperatures, and used X-ray microtomography, FIB-SEM nanotomography and neutron diffraction to reveal the morphologies, compositions, volume fractions and thermal stabilities of the nano and microstructures. Understanding of these is essential for optimizing the design of BMGMCs and developing viable manufacturing methods. PMID:26725519

  20. Influence of locational states of submicron fibers added into matrix on mechanical properties of plain-woven Carbon Fiber Composite

    NASA Astrophysics Data System (ADS)

    Kumamoto, Soichiro; Okubo, Kazuya; Fujii, Toru

    2016-01-01

    The aim of this study was to show the influence of locational states of submicron fibers added into epoxy matrix on mechanical properties of modified plane-woven carbon fiber reinforced plastic (CFRP). To change the locational states of submicron fibers, two kinds of fabrication processes were applied in preparing specimen by hand lay-up method. Submicron fibers were simply added into epoxy resin with ethanol after they were stirred by a dispersion process using homogenizer to be located far from the interface between reinforcement and matrix. In contrast, submicron fibers were attached onto the carbon fibers by injecting from a spray nozzle accompanying with ethanol to be located near the interface, after they were tentatively contained in ethanol. The plain-woven CFRP plates were fabricated by hand lay-up method and cured at 80 degree-C for 1 hour and then at 150 degree-C for 3 hours. After curing, the plain-woven CFRP plates were cut into the dimension of specimen. Tensile shear strength and Mode-II fracture toughness of CFRP were determined by tensile lap-shear test and End-notched flexure(ENF) test, respectively. When submicron fibers were located far from the interface between carbon fibers and epoxy resin, tensile shear strength and Mode-II fracture toughness of CFRP were improved 30% and 18% compared with those of unmodified case. The improvement ratio in modified case was rather low (about few percentages) in the case where submicron fibers were located near the interface. The result suggested that crack propagation should be prevented when submicron fibers were existed far from the interface due to the effective stress state around the crack tip.

  1. Woven heat exchanger

    DOEpatents

    Piscitella, R.R.

    1984-07-16

    This invention relates to a heat exchanger for waste heat recovery from high temperature industrial exhaust streams. In a woven ceramic heat exchanger using the basic tube-in-shell design, each heat exchanger consisting of tube sheets and tube, is woven separately. Individual heat exchangers are assembled in cross-flow configuration. Each heat exchanger is woven from high temperature ceramic fiber, the warp is continuous from tube to tube sheet providing a smooth transition and unitized construction.

  2. Thermal Conductivity of 3D CNT-Polymer Composites with Controlled Dispersion

    NASA Astrophysics Data System (ADS)

    Klittich, Mena; Wang, Xue; Dhinojwala, Ali

    The high thermal conductivity of isolated carbon nanotubes (CNTs) has inspired its use as a thermal filler for insulative polymers. However, the performance of these composites has consistently been sub par. Extensive analyses of these complex systems have resulted in the conclusion that resistance at the CNT/polymer interface due to phonon mismatch and poor physical binding, as well as the weakly bonded tube-tube interactions restrict the effectiveness of CNTs in practice. Experimental comparisons of CNT treatments, coatings, functionalization, and interactions with various polymers have proved challenging, due to the interconnected nature of the composite properties. Here, we have reversed the paradigm and used a constant CNT structure that is then modified post-growth to allow for direct comparisons of polymer composites.

  3. 3D finite element modelling of guided wave scattering at delaminations in composites

    NASA Astrophysics Data System (ADS)

    Murat, Bibi Intan Suraya; Fromme, Paul

    2016-02-01

    Carbon fiber laminate composites are increasingly used for aerospace structures as they offer a number of advantages including a good strength to weight ratio. However, impact during the operation and servicing of the aircraft can lead to barely visible and difficult to detect damage. Depending on the severity of the impact, delaminations can occur, reducing the load carrying capacity of the structure. Efficient nondestructive testing of composite panels can be achieved using guided ultrasonic waves propagating along the structure. The guided wave (A0 Lamb wave mode) scattering at delaminations was modeled using full three-dimensional Finite Element (FE) simulations. The influence of the delamination size was systematically investigated from a parameter study. A significant influence of the delamination width on the guided wave scattering was found, especially on the angular dependency of the scattered guided wave amplitude. The sensitivity of guided ultrasonic waves for the detection of delamination damage in composite panels is discussed.

  4. LiFePO4 - 3D carbon nanofiber composites as cathode materials for Li-ions batteries

    NASA Astrophysics Data System (ADS)

    Dimesso, L.; Spanheimer, C.; Jaegermann, W.; Zhang, Y.; Yarin, A. L.

    2012-03-01

    The characterization of carbon nanofiber 3D nonwovens, prepared by electrospinning process, coated with olivine structured lithium iron phosphate is reported. The LiFePO4 as cathode material for lithium ion batteries was prepared by a Pechini-assisted reversed polyol process. The coating has been successfully performed on carbon nanofiber 3D nonwovens by soaking in aqueous solution containing lithium, iron salts and phosphates at 70 °C for 2-4 h. After drying-out, the composites were annealed at 600 °C for 5 h under nitrogen. The surface investigation of the prepared composites showed a uniform coating of the carbon nonwoven nanofibers as well as the formation of cauliflower-like crystalline structures which are uniformly distributed all over the surface area of the carbon nanofibers. The electrochemical measurements on the composites showed good performances delivering a discharge specific capacity of 156 mAhg- 1 at a discharging rate of C/25 and 152 mAhg- 1 at a discharging rate of C/10 at room temperature.

  5. Tri-color composite volume H-PDLC grating and its application to 3D color autostereoscopic display.

    PubMed

    Wang, Kangni; Zheng, Jihong; Gao, Hui; Lu, Feiyue; Sun, Lijia; Yin, Stuart; Zhuang, Songlin

    2015-11-30

    A tri-color composite volume holographic polymer dispersed liquid crystal (H-PDLC) grating and its application to 3-dimensional (3D) color autostereoscopic display are reported in this paper. The composite volume H-PDLC grating consists of three different period volume H-PDLC sub-gratings. The longer period diffracts red light, the medium period diffracts the green light, and the shorter period diffracts the blue light. To record three different period gratings simultaneously, two photoinitiators are employed. The first initiator consists of methylene blue and p-toluenesulfonic acid and the second initiator is composed of Rose Bengal and N-phenyglycine. In this case, the holographic recording medium is sensitive to entire visible wavelengths, including red, green, and blue so that the tri-color composite grating can be written simultaneously by harnessing three different color laser beams. In the experiment, the red beam comes from a He-Ne laser with an output wavelength of 632.8 nm, the green beam comes from a Verdi solid state laser with an output wavelength of 532 nm, and the blue beam comes from a He-Cd laser with an output wavelength of 441.6 nm. The experimental results show that diffraction efficiencies corresponding to red, green, and blue colors are 57%, 75% and 33%, respectively. Although this diffraction efficiency is not perfect, it is high enough to demonstrate the effect of 3D color autostereoscopic display. PMID:26698768

  6. Failure models for textile composites

    NASA Technical Reports Server (NTRS)

    Cox, Brian

    1995-01-01

    The goals of this investigation were to: (1) identify mechanisms of failure and determine how the architecture of reinforcing fibers in 3D woven composites controlled stiffness, strength, strain to failure, work of fracture, notch sensitivity, and fatigue life; and (2) to model composite stiffness, strength, and fatigue life. A total of 11 different angle and orthogonal interlock woven composites were examined. Composite properties depended on the weave architecture, the tow size, and the spatial distributions and strength of geometrical flaws. Simple models were developed for elastic properties, strength, and fatigue life. A more complicated stochastic model, called the 'Binary Model,' was developed for damage tolerance and ultimate failure. These 3D woven composites possessed an extraordinary combination of strength, damage tolerance, and notch insensitivity.

  7. Recipe for High Moment Materials with Rare-earth and 3d Transition Metal Composites

    PubMed Central

    Autieri, Carmine; Kumar, P. Anil; Walecki, Dirk; Webers, Samira; Gubbins, Mark A.; Wende, Heiko; Sanyal, Biplab

    2016-01-01

    Materials with high volume magnetization are perpetually needed for the generation of sufficiently large magnetic fields by writer pole of magnetic hard disks, especially for achieving increased areal density in storage media. In search of suitable materials combinations for this purpose, we have employed density functional theory to predict the magnetic coupling between iron and gadolinium layers separated by one to several monolayers of 3d transition metals (Sc-Zn). We demonstrate that it is possible to find ferromagnetic coupling for many of them and in particular for the early transition metals giving rise to high moment. Cr and Mn are the only elements able to produce a significant ferromagnetic coupling for thicker spacer layers. We also present experimental results on two trilayer systems Fe/Sc/Gd and Fe/Mn/Gd. From the experiments, we confirm a ferromagnetic coupling between Fe and Gd across a 3 monolayers Sc spacer or a Mn spacer thicker than 1 monolayer. In addition, we observe a peculiar dependence of Fe/Gd magnetic coupling on the Mn spacer thickness. PMID:27381456

  8. Recipe for High Moment Materials with Rare-earth and 3d Transition Metal Composites

    NASA Astrophysics Data System (ADS)

    Autieri, Carmine; Kumar, P. Anil; Walecki, Dirk; Webers, Samira; Gubbins, Mark A.; Wende, Heiko; Sanyal, Biplab

    2016-07-01

    Materials with high volume magnetization are perpetually needed for the generation of sufficiently large magnetic fields by writer pole of magnetic hard disks, especially for achieving increased areal density in storage media. In search of suitable materials combinations for this purpose, we have employed density functional theory to predict the magnetic coupling between iron and gadolinium layers separated by one to several monolayers of 3d transition metals (Sc-Zn). We demonstrate that it is possible to find ferromagnetic coupling for many of them and in particular for the early transition metals giving rise to high moment. Cr and Mn are the only elements able to produce a significant ferromagnetic coupling for thicker spacer layers. We also present experimental results on two trilayer systems Fe/Sc/Gd and Fe/Mn/Gd. From the experiments, we confirm a ferromagnetic coupling between Fe and Gd across a 3 monolayers Sc spacer or a Mn spacer thicker than 1 monolayer. In addition, we observe a peculiar dependence of Fe/Gd magnetic coupling on the Mn spacer thickness.

  9. Recipe for High Moment Materials with Rare-earth and 3d Transition Metal Composites.

    PubMed

    Autieri, Carmine; Kumar, P Anil; Walecki, Dirk; Webers, Samira; Gubbins, Mark A; Wende, Heiko; Sanyal, Biplab

    2016-01-01

    Materials with high volume magnetization are perpetually needed for the generation of sufficiently large magnetic fields by writer pole of magnetic hard disks, especially for achieving increased areal density in storage media. In search of suitable materials combinations for this purpose, we have employed density functional theory to predict the magnetic coupling between iron and gadolinium layers separated by one to several monolayers of 3d transition metals (Sc-Zn). We demonstrate that it is possible to find ferromagnetic coupling for many of them and in particular for the early transition metals giving rise to high moment. Cr and Mn are the only elements able to produce a significant ferromagnetic coupling for thicker spacer layers. We also present experimental results on two trilayer systems Fe/Sc/Gd and Fe/Mn/Gd. From the experiments, we confirm a ferromagnetic coupling between Fe and Gd across a 3 monolayers Sc spacer or a Mn spacer thicker than 1 monolayer. In addition, we observe a peculiar dependence of Fe/Gd magnetic coupling on the Mn spacer thickness. PMID:27381456

  10. On topological mapping of yarn structures in 3-D braided composite preforms

    SciTech Connect

    Wang, Y.Q.; Wang, A.S.D.

    1994-12-31

    Previous studies have established that the internal yarn structure in a 3-D braided preform possesses a certain topological character which is determined by the braiding method alone, regardless of the preform shape or the yarn size used. This unique geometric property provides the possibility that yarn structures in preforms of different shapes may be mathematically connected from one to another, as long as the preforms are produced by the same braiding procedure. Exploring this possibility, the present paper discusses a geometric mapping method for the determination of the internal yarn structures in preforms of complex shapes. The idea is to obtain the desired mapping between two preform shapes, the mapping being able to also link analytically the respective yarn structures. Thus, if the yarn structure in one shape (simple) is known, the yarn structure in the other shape (complex) can be determined by the mapping. Illustrative examples using preforms braided by the 4-step 1x1 method are presented in detail. In general, determination of the desired mapping between two preforms of complex shapes requires a numerical and iterative procedure; between two preforms of relatively simple shapes, closed form mapping functions can be obtained.

  11. Microstructure of 3D-Printed Polymer Composites Investigated by Small-Angle Neutron Scattering

    NASA Astrophysics Data System (ADS)

    Kang, Tae Hui; Compton, Brett G.; Heller, William T.; Urban, Voker S.; Duty, Chad E.; Do, Changwoo

    Polymer composites printed from the large scale printer at Manufacturing Demonstration Facility at Oak Ridge National Laboratory have been investigated by small-angle neutron scattering (SANS). For the Acrylonitrile Butadiene Styrene (ABS)/Carbon Fiber (CF) composites, the microstructure of polymer domains and the alignment of CF have been characterized across the layer from the printed piece. CF shows strong anisotropic alignment along the printing direction due to the flow of polymer melt at the nozzle. Order parameter of the anisotropy which ranges from -0.11 to -0.06 exhibits strong correlation with the position within the layer: stronger alignment near the layer interface. It is also confirmed that the existence of CF reduces the polymer domain correlation length significantly and reinforces the mechanical strength of the polymer composites. For the Epoxy/nano-clay platelet composites, the effect of processing condition, nozzle size, and the addition of the another filler, Silicon Carbide (SC), have been investigated by SANS. Nano-clay platelet shows strong anisotropic alignment along the printing direction as well. Order parameter of the anisotropy varies according to nozzle size and presence of the SC, and difference disappears at high Q region. Scientific User Facilities Division and Materials Sciences and Energy Division, Office of Basic Energy Sciences, U.S. Department of Energy.

  12. Characterization of New PEEK/HA Composites with 3D HA Network Fabricated by Extrusion Freeforming.

    PubMed

    Vaezi, Mohammad; Black, Cameron; Gibbs, David M R; Oreffo, Richard O C; Brady, Mark; Moshrefi-Torbati, Mohamed; Yang, Shoufeng

    2016-01-01

    Addition of bioactive materials such as calcium phosphates or Bioglass, and incorporation of porosity into polyetheretherketone (PEEK) has been identified as an effective approach to improve bone-implant interfaces and osseointegration of PEEK-based devices. In this paper, a novel production technique based on the extrusion freeforming method is proposed that yields a bioactive PEEK/hydroxyapatite (PEEK/HA) composite with a unique configuration in which the bioactive phase (i.e., HA) distribution is computer-controlled within a PEEK matrix. The 100% interconnectivity of the HA network in the biocomposite confers an advantage over alternative forms of other microstructural configurations. Moreover, the technique can be employed to produce porous PEEK structures with controlled pore size and distribution, facilitating greater cellular infiltration and biological integration of PEEK composites within patient tissue. The results of unconfined, uniaxial compressive tests on these new PEEK/HA biocomposites with 40% HA under both static and cyclic mode were promising, showing the composites possess yield and compressive strength within the range of human cortical bone suitable for load bearing applications. In addition, preliminary evidence supporting initial biological safety of the new technique developed is demonstrated in this paper. Sufficient cell attachment, sustained viability in contact with the sample over a seven-day period, evidence of cell bridging and matrix deposition all confirmed excellent biocompatibility. PMID:27240326

  13. A mapping of an ensemble of mitochondrial sequences for various organisms into 3D space based on the word composition.

    PubMed

    Aita, Takuyo; Nishigaki, Koichi

    2012-11-01

    To visualize a bird's-eye view of an ensemble of mitochondrial genome sequences for various species, we recently developed a novel method of mapping a biological sequence ensemble into Three-Dimensional (3D) vector space. First, we represented a biological sequence of a species s by a word-composition vector x(s), where its length [absolute value]x(s)[absolute value] represents the sequence length, and its unit vector x(s)/[absolute value]x(s)[absolute value] represents the relative composition of the K-tuple words through the sequence and the size of the dimension, N=4(K), is the number of all possible words with the length of K. Second, we mapped the vector x(s) to the 3D position vector y(s), based on the two following simple principles: (1) [absolute value]y(s)[absolute value]=[absolute value]x(s)[absolute value] and (2) the angle between y(s) and y(t) maximally correlates with the angle between x(s) and x(t). The mitochondrial genome sequences for 311 species, including 177 Animalia, 85 Fungi and 49 Green plants, were mapped into 3D space by using K=7. The mapping was successful because the angles between vectors before and after the mapping highly correlated with each other (correlation coefficients were 0.92-0.97). Interestingly, the Animalia kingdom is distributed along a single arc belt (just like the Milky Way on a Celestial Globe), and the Fungi and Green plant kingdoms are distributed in a similar arc belt. These two arc belts intersect at their respective middle regions and form a cross structure just like a jet aircraft fuselage and its wings. This new mapping method will allow researchers to intuitively interpret the visual information presented in the maps in a highly effective manner. PMID:22776549

  14. Measurement and analysis of flow in 3D preforms for aerospace composites

    NASA Astrophysics Data System (ADS)

    Stewart, Andrew Lawrence

    Composite materials have become viable alternatives to traditional engineering materials for many different product categories. Liquid transfer moulding (LTM) processes, specifically resin transfer moulding (RTM), is a cost-effective manufacturing technique for creating high performance composite parts. These parts can be tailor-made to their specific application by optimizing the properties of the textile preform. Preforms which require little or no further assembly work and are close to the shape of the final part are critical to obtaining high quality parts while simultaneously reducing labour and costs associated with other composite manufacturing techniques. One type of fabric which is well suited for near-net- shape preforms is stitched non-crimp fabrics. These fabrics offer very high in-plane strength and stiffness while also having increased resistance to delamination. Manufacturing parts from these dry preforms typically involves long-scale fluid flow through both open channels and porous fibre bundles. This thesis documents and analyzes the flow of fluid through preforms manufactured from non-crimp fabrics featuring through-thickness stitches. The objective of this research is to determine the effect of this type of stitch on the RTM injection process. All of the tests used preforms with fibre volume fractions representative of primary and secondary structural parts. A series of trials was conducted using different fibre materials, flow rates, fibre volumes fractions, and degrees of fibre consolidation. All of the trials were conducted for cases similar to RTM. Consolidation of the fibres showed improvements to both the thoroughness of the filling and to the fibre volume fraction. Experimentally determined permeability data was shown to trend well with simple models and precision of the permeability data was comparable to values presented by other authors who studied fabrics which did not feature the through-thickness stitches.

  15. A Review of 3D imaging techniques for visualisation of the structure of energetic composites

    NASA Astrophysics Data System (ADS)

    Carmichael, A. E.; Williamson, D. M.; Govier, R.

    2011-06-01

    A review of imaging techniques which can be used to acquire three dimensional data on the structure of polymer composite materials is presented. The techniques chosen utilise a variety of mechanisms for forming contrast, and include x-ray tomography (XCT), nuclear magnetic resonance (NMR), and optical & electron microscopy. Discussion is illustrated with reference to a particular HMX based UK PBX. The achievable contrast and spatial resolutions are considered, along with arguments relating to the destructive and non-destructive methods of acquiring data. Particular emphasis is given to the safety concerns and the added experimental complications which arise when studying energetic materials.

  16. Glacial isostatic adjustment model with composite 3-D Earth rheology for Fennoscandia

    NASA Astrophysics Data System (ADS)

    van der Wal, Wouter; Barnhoorn, Auke; Stocchi, Paolo; Gradmann, Sofie; Wu, Patrick; Drury, Martyn; Vermeersen, Bert

    2013-07-01

    Models for glacial isostatic adjustment (GIA) can provide constraints on rheology of the mantle if past ice thickness variations are assumed to be known. The Pleistocene ice loading histories that are used to obtain such constraints are based on an a priori 1-D mantle viscosity profile that assumes a single deformation mechanism for mantle rocks. Such a simplified viscosity profile makes it hard to compare the inferred mantle rheology to inferences from seismology and laboratory experiments. It is unknown what constraints GIA observations can provide on more realistic mantle rheology with an ice history that is not based on an a priori mantle viscosity profile. This paper investigates a model for GIA with a new ice history for Fennoscandia that is constrained by palaeoclimate proxies and glacial sediments. Diffusion and dislocation creep flow law data are taken from a compilation of laboratory measurements on olivine. Upper-mantle temperature data sets down to 400 km depth are derived from surface heatflow measurements, a petrochemical model for Fennoscandia and seismic velocity anomalies. Creep parameters below 400 km are taken from an earlier study and are only varying with depth. The olivine grain size and water content (a wet state, or a dry state) are used as free parameters. The solid Earth response is computed with a global spherical 3-D finite-element model for an incompressible, self-gravitating Earth. We compare predictions to sea level data and GPS uplift rates in Fennoscandia. The objective is to see if the mantle rheology and the ice model is consistent with GIA observations. We also test if the inclusion of dislocation creep gives any improvements over predictions with diffusion creep only, and whether the laterally varying temperatures result in an improved fit compared to a widely used 1-D viscosity profile (VM2). We find that sea level data can be explained with our ice model and with information on mantle rheology from laboratory experiments

  17. Efficient parallel seismic simulations including topography and 3-D material heterogeneities on locally refined composite grids

    NASA Astrophysics Data System (ADS)

    Petersson, Anders; Rodgers, Arthur

    2010-05-01

    The finite difference method on a uniform Cartesian grid is a highly efficient and easy to implement technique for solving the elastic wave equation in seismic applications. However, the spacing in a uniform Cartesian grid is fixed throughout the computational domain, whereas the resolution requirements in realistic seismic simulations usually are higher near the surface than at depth. This can be seen from the well-known formula h ≤ L-P which relates the grid spacing h to the wave length L, and the required number of grid points per wavelength P for obtaining an accurate solution. The compressional and shear wave lengths in the earth generally increase with depth and are often a factor of ten larger below the Moho discontinuity (at about 30 km depth), than in sedimentary basins near the surface. A uniform grid must have a grid spacing based on the small wave lengths near the surface, which results in over-resolving the solution at depth. As a result, the number of points in a uniform grid is unnecessarily large. In the wave propagation project (WPP) code, we address the over-resolution-at-depth issue by generalizing our previously developed single grid finite difference scheme to work on a composite grid consisting of a set of structured rectangular grids of different spacings, with hanging nodes on the grid refinement interfaces. The computational domain in a regional seismic simulation often extends to depth 40-50 km. Hence, using a refinement ratio of two, we need about three grid refinements from the bottom of the computational domain to the surface, to keep the local grid size in approximate parity with the local wave lengths. The challenge of the composite grid approach is to find a stable and accurate method for coupling the solution across the grid refinement interface. Of particular importance is the treatment of the solution at the hanging nodes, i.e., the fine grid points which are located in between coarse grid points. WPP implements a new, energy

  18. The lithosphere-asthenosphere system beneath Ireland from integrated geophysical-petrological modeling II: 3D thermal and compositional structure

    NASA Astrophysics Data System (ADS)

    Fullea, J.; Muller, M. R.; Jones, A. G.; Afonso, J. C.

    2014-02-01

    The lithosphere-asthenosphere boundary (LAB) depth represents a fundamental parameter in any quantitative lithospheric model, controlling to a large extent the temperature distribution within the crust and the uppermost mantle. The tectonic history of Ireland includes early Paleozoic closure of the Iapetus Ocean across the Iapetus Suture Zone (ISZ), and in northeastern Ireland late Paleozoic to early Mesozoic crustal extension, during which thick Permo-Triassic sedimentary successions were deposited, followed by early Cenozoic extrusion of large scale flood basalts. Although the crustal structure in Ireland and neighboring offshore areas is fairly well constrained, with the notable exception of the crust beneath Northern Ireland, the Irish uppermost mantle remains to date relatively unknown. In particular, the nature and extent of a hypothetical interaction between a putative proto Icelandic mantle plume and the Irish and Scottish lithosphere during the Tertiary opening of the North Atlantic has long been discussed in the literature with diverging conclusions. In this work, the present-day thermal and compositional structure of the lithosphere in Ireland is modeled based on a geophysical-petrological approach (LitMod3D) that combines comprehensively a large variety of data (namely elevation, surface heat flow, potential fields, xenoliths and seismic tomography models), reducing the inherent uncertainties and trade-offs associated with classical modeling of those individual data sets. The preferred 3D lithospheric models show moderate lateral density variations in Ireland characterized by a slightly thickened lithosphere along the SW-NE trending ISZ, and a progressive lithospheric thinning from southern Ireland towards the north. The mantle composition in the southern half of Ireland (East Avalonia) is relatively and uniformly fertile (i.e., typical Phanerozoic mantle), whereas the lithospheric composition in the northern half of Ireland (Laurentia) seems to vary

  19. Pushing the Limits: 3D Layer-by-Layer-Assembled Composites for Cathodes with 160 C Discharge Rates.

    PubMed

    Mo, Runwei; Tung, Siu On; Lei, Zhengyu; Zhao, Guangyu; Sun, Kening; Kotov, Nicholas A

    2015-05-26

    Deficiencies of cathode materials severely limit cycling performance and discharge rates of Li batteries. The key problem is that cathode materials must combine multiple properties: high lithium ion intercalation capacity, electrical/ionic conductivity, porosity, and mechanical toughness. Some materials revealed promising characteristics in a subset of these properties, but attaining the entire set of often contrarian characteristics requires new methods of materials engineering. In this paper, we report high surface area 3D composite from reduced graphene oxide loaded with LiFePO4 (LFP) nanoparticles made by layer-by-layer assembly (LBL). High electrical conductivity of the LBL composite is combined with high ionic conductivity, toughness, and low impedance. As a result of such materials properties, reversible lithium storage capacity and Coulombic efficiency were as high as 148 mA h g(-1) and 99%, respectively, after 100 cycles at 1 C. Moreover, these composites enabled unusually high reversible charge-discharge rates up to 160 C with a storage capacity of 56 mA h g(-1), exceeding those of known LFP-based cathodes, some of them by several times while retaining high content of active cathode material. The study demonstrates that LBL-assembled composites enable resolution of difficult materials engineering tasks. PMID:25910177

  20. Stress analysis of a rectangular implant in laminated composites using 2-D and 3-D finite elements

    NASA Technical Reports Server (NTRS)

    Chow, Wai T.; Graves, Michael J.

    1992-01-01

    An analysis method using the FEM based on the Hellinger-Reissner variation principle has been developed to determine the 3-D stresses and displacements near a rectangular implant inside a laminated composite material. Three-dimensional elements are employed in regions where the interlaminar stress is considered to be significant; 2-D elements are used in other areas. Uniaxially loaded graphite-epoxy laminates have been analyzed; the implant was modeled as four plies of 3501/6 epoxy located in the middle of the laminate. It is shown that the interlaminar stresses are an order of magnitude lower than the stress representing the applied far-field load. The stress concentration factors of both the interlaminar and in-plane stresses depend on the stacking sequence of the laminate.

  1. Composite Scaffolds Containing Silk Fibroin, Gelatin, and Hydroxyapatite for Bone Tissue Regeneration and 3D Cell Culturing

    PubMed Central

    Moisenovich, M. M.; Arkhipova, A. Yu.; Orlova, A. A.; Drutskaya, M. S; Volkova, S. V.; Zacharov, S. E.; Agapov, I. I.; Kirpichnikov, M. P.

    2014-01-01

    Three-dimensional (3D) silk fibroin scaffolds were modified with one of the major bone tissue derivatives (nano-hydroxyapatite) and/or a collagen derivative (gelatin). Adhesion and proliferation of mouse embryonic fibroblasts (MEF) within the scaffold were increased after modification with either nano-hydroxyapatite or gelatin. However, a significant increase in MEF adhesion and proliferation was observed when both additives were introduced into the scaffold. Such modified composite scaffolds provide a new and better platform to study wound healing, bone and other tissue regeneration, as well as artificial organ bioengineering. This system can further be applied to establish experimental models to study cell-substrate interactions, cell migration and other complex processes, which may be difficult to address using the conventional two-dimensional culture systems. PMID:24772332

  2. Modeling Three-Phase Compositional Flow on Complex 3D Unstructured Grids with Higher-Order Finite Element Methods

    NASA Astrophysics Data System (ADS)

    Moortgat, J.; Firoozabadi, A.

    2013-12-01

    Most problems of interest in hydrogeology and subsurface energy resources involve complex heterogeneous geological formations. Such domains are most naturally represented in numerical reservoir simulations by unstructured computational grids. Finite element methods are a natural choice to describe fluid flow on unstructured meshes, because the governing equations can be readily discretized for any grid-element geometry. In this work, we consider the challenging problem of fully compositional three-phase flow in 3D unstructured grids, discretized by tetrahedra, prisms, or hexahedra, and compare to simulations on 3D structured grids. We employ a combination of mixed hybrid finite element methods to solve for the pressure and flux fields in a fractional flow formulation, and higher-order discontinuous Galerkin methods for the mass transport equations. These methods are well suited to simulate flow in heterogeneous and fractured reservoirs, because they provide a globally continuous pressure and flux field, while allowing for sharp discontinuities in the phase properties, such as compositions and saturations. The increased accuracy from using higher-order methods improves the modeling of highly non-linear flow, such as gravitational and viscous fingering. We present several numerical examples to study convergence rates and the (lack of) sensitivity to gridding/mesh orientation, and mesh quality. These examples consider gravity depletion, water and gas injection in oil saturated subsurface reservoirs with species exchange between up to three fluid phases. The examples demonstrate the wide applicability of our chosen finite element methods in the study of challenging multiphase flow problems in porous, geometrically complex, subsurface media.

  3. Guided-wave-based damage detection in a composite T-joint using 3D scanning laser Doppler vibrometer

    NASA Astrophysics Data System (ADS)

    Kolappan Geetha, Ganesh; Roy Mahapatra, D.; Srinivasan, Gopalakrishnan

    2012-04-01

    Composite T-joints are commonly used in modern composite airframe, pressure vessels and piping structures, mainly to increase the bending strength of the joint and prevents buckling of plates and shells, and in multi-cell thin-walled structures. Here we report a detailed study on the propagation of guided ultrasonic wave modes in a composite T-joint and their interactions with delamination in the co-cured co-bonded flange. A well designed guiding path is employed wherein the waves undergo a two step mode conversion process, one is due to the web and joint filler on the back face of the flange and the other is due to the delamination edges close to underneath the accessible surface of the flange. A 3D Laser Doppler Vibrometer is used to obtain the three components of surface displacements/velocities of the accessible face of the flange of the T-joint. The waves are launched by a piezo ceramic wafer bonded on to the back surface of the flange. What is novel in the proposed method is that the location of any change in material/geometric properties can be traced by computing a frequency domain power flow along a scan line. The scan line can be chosen over a grid either during scan or during post-processing of the scan data off-line. The proposed technique eliminates the necessity of baseline data and disassembly of structure for structural interrogation.

  4. Cutter for Woven Materials

    NASA Technical Reports Server (NTRS)

    Hammons, J. M.; Keir, A. R.

    1983-01-01

    Simple tool makes accurate square cuts through strips of woven or felted materials, such as high temperature aramid fabric. Pressing handle on Guillotine Cutter forces razor blade through strip of material in slot, cutting strip off squarely.

  5. Bioconductive 3D nano-composite constructs with tunable elasticity to initiate stem cell growth and induce bone mineralization.

    PubMed

    Sagar, Nitin; Khanna, Kunal; Sardesai, Varda S; Singh, Atul K; Temgire, Mayur; Kalita, Mridula Phukan; Kadam, Sachin S; Soni, Vivek P; Bhartiya, Deepa; Bellare, Jayesh R

    2016-12-01

    Bioactive 3D composites play an important role in advanced biomaterial design to provide molecular coupling and improve integrity with the cellular environment of the native bone. In the present study, a hybrid lyophilized polymer composite blend of anionic charged sodium salt of carboxymethyl chitin and gelatin (CMChNa-GEL) reinforced with nano-rod agglomerated hydroxyapatite (nHA) has been developed with enhanced biocompatibility and tunable elasticity. The scaffolds have an open, uniform and interconnected porous structure with an average pore diameter of 157±30μm and 89.47+0.03% with four dimensional X-ray. The aspect ratio of ellipsoidal pores decrease from 4.4 to 1.2 with increase in gelatin concentration; and from 2.14 to 1.93 with decrease in gelling temperature. The samples were resilient with elastic stain at 1.2MPa of stress also decreased from 0.33 to 0.23 with increase in gelatin concentration. The crosslinker HMDI (hexamethylene diisocyanate) yielded more resilient samples at 1.2MPa in comparison to glutaraldehyde. Increased crosslinking time from 2 to 4h in continuous compression cycle show no improvement in maximum elastic stain of 1.2MPa stress. This surface elasticity of the scaffold enables the capacity of these materials for adherent self renewal and cultivation of the NTERA-2 cL.D1 (NT2/D1), pluripotent embryonal carcinoma cell with biomechanical surface, as is shown here. Proliferation with MG-63, ALP activity and Alizarin red mineralization assay on optimized scaffold demonstrated ***p<0.001 between different time points thus showing its potential for bone healing. In pre-clinical study histological bone response of the scaffold construct displayed improved activity of bone regeneration in comparison to self healing of control groups (sham) up to week 07 after implantation in rabbit tibia critical-size defect. Therefore, this nHA-CMChNa-GEL scaffold composite exhibits inherent and efficient physicochemical, mechanical and biological

  6. Mixed-hybrid and vertex-discontinuous-Galerkin finite element modeling of multiphase compositional flow on 3D unstructured grids

    NASA Astrophysics Data System (ADS)

    Moortgat, Joachim; Firoozabadi, Abbas

    2016-06-01

    Problems of interest in hydrogeology and hydrocarbon resources involve complex heterogeneous geological formations. Such domains are most accurately represented in reservoir simulations by unstructured computational grids. Finite element methods accurately describe flow on unstructured meshes with complex geometries, and their flexible formulation allows implementation on different grid types. In this work, we consider for the first time the challenging problem of fully compositional three-phase flow in 3D unstructured grids, discretized by any combination of tetrahedra, prisms, and hexahedra. We employ a mass conserving mixed hybrid finite element (MHFE) method to solve for the pressure and flux fields. The transport equations are approximated with a higher-order vertex-based discontinuous Galerkin (DG) discretization. We show that this approach outperforms a face-based implementation of the same polynomial order. These methods are well suited for heterogeneous and fractured reservoirs, because they provide globally continuous pressure and flux fields, while allowing for sharp discontinuities in compositions and saturations. The higher-order accuracy improves the modeling of strongly non-linear flow, such as gravitational and viscous fingering. We review the literature on unstructured reservoir simulation models, and present many examples that consider gravity depletion, water flooding, and gas injection in oil saturated reservoirs. We study convergence rates, mesh sensitivity, and demonstrate the wide applicability of our chosen finite element methods for challenging multiphase flow problems in geometrically complex subsurface media.

  7. Extracellular matrix composition and rigidity regulate invasive behavior and response to PDT in 3D pancreatic tumor models

    NASA Astrophysics Data System (ADS)

    Cramer, Gwendolyn; El-Hamidi, Hamid; Jafari, Seyedehrojin; Jones, Dustin P.; Celli, Jonathan P.

    2016-03-01

    The composition and mechanical compliance of the extracellular matrix (ECM) have been shown to serve as regulators of tumor growth and invasive behavior. These effects may be particularly relevant in tumors of the pancreas, noted for a profound desmoplastic reaction and an abundance of stroma rich in ECM. In view of recent progress in the clinical implementation of photodynamic therapy (PDT) for pancreatic tumors, in this report we examine how ECM composition and rheological properties impact upon invasive behavior and response to PDT in 3D multicellular pancreatic tumor spheroids in ECM environments with characterized rheological properties. Tumor spheroids were cultured initially in attachment-free conditions to form millimeter-sized spheroids that were transplanted into reconstituted ECM microenvironments (Matrigel and Type I Collagen) that were characterized using bulk oscillatory shear rheology. Analysis of growth behavior shows that the soft collagen ECM promoted growth and extensive invasion and this microenvironment was used in subsequent assessment of PDT and chemotherapy response. Evaluation of treatment response revealed that primary tumor nodule growth is inhibited more effectively with PDT, while verteporfin PDT response is significantly enhanced in the ECM-infiltrating populations that are non-responsive to oxaliplatin chemotherapy. This finding is potentially significant, suggesting the potential for PDT to target these clinically problematic invasive populations that are associated with aggressive metastatic progression and chemoresistance. Experiments to further validate and identify the mechanistic basis of this observation are ongoing.

  8. Modeling of Nonlinear Mechanical Behavior for 3D Needled C/C-SiC Composites Under Tensile Load

    NASA Astrophysics Data System (ADS)

    Xie, Junbo; Fang, Guodong; Chen, Zhen; Liang, Jun

    2016-04-01

    This paper established a macroscopic constitutive model to describe the nonlinear stress-strain behavior of 3D needled C/C-SiC composites under tensile load. Extensive on- and off-axis tensile tests were performed to investigate the macroscopic mechanical behavior and damage characteristics of the composites. The nonlinear mechanical behavior of the material was mainly induced by matrix tensile cracking and fiber/matrix debonding. Permanent deformations and secant modulus degradation were observed in cyclic loading-unloading tests. The nonlinear stress-strain relationship of the material could be described macroscopically by plasticity deformation and stiffness degradation. In the proposed model, we employed a plasticity theory with associated plastic flow rule to describe the evolution of plastic strains. A novel damage variable was also introduced to characterize the stiffness degradation of the material. The damage evolution law was derived from the statistical distribution of material strength. Parameters of the proposed model can be determined from off-axis tensile tests. Stress-strain curves predicted by this model showed reasonable agreement with experimental results.

  9. Modeling of Nonlinear Mechanical Behavior for 3D Needled C/C-SiC Composites Under Tensile Load

    NASA Astrophysics Data System (ADS)

    Xie, Junbo; Fang, Guodong; Chen, Zhen; Liang, Jun

    2016-08-01

    This paper established a macroscopic constitutive model to describe the nonlinear stress-strain behavior of 3D needled C/C-SiC composites under tensile load. Extensive on- and off-axis tensile tests were performed to investigate the macroscopic mechanical behavior and damage characteristics of the composites. The nonlinear mechanical behavior of the material was mainly induced by matrix tensile cracking and fiber/matrix debonding. Permanent deformations and secant modulus degradation were observed in cyclic loading-unloading tests. The nonlinear stress-strain relationship of the material could be described macroscopically by plasticity deformation and stiffness degradation. In the proposed model, we employed a plasticity theory with associated plastic flow rule to describe the evolution of plastic strains. A novel damage variable was also introduced to characterize the stiffness degradation of the material. The damage evolution law was derived from the statistical distribution of material strength. Parameters of the proposed model can be determined from off-axis tensile tests. Stress-strain curves predicted by this model showed reasonable agreement with experimental results.

  10. Mesomechanical analysis of the ELASTO-PLASTIC behavior of a 3D composite-structure under tension

    NASA Astrophysics Data System (ADS)

    Romanova, V. A.; Soppa, E.; Schmauder, S.; Balokhonov, R. R.

    2005-11-01

    In this contribution, a mesomechanical approach to simulate the mechanical behavior with explicit consideration of the three-dimensional structure is applied to study the elasto-plastic response of a metal matrix composite material under tension. A procedure of a step-by-step packing (SSP) of a finite volume with structural elements has been used to design the composite structure consisting of an Al(6061)-matrix with Al2O3-inclusions. A three-dimensional mechanical problem of the structure behavior under tension has been solved numerically, using both an implicit finite-element method and an explicit finite-difference code. Special attention is given to the comparison of quasistatic and dynamic calculations. Evolution of plastic deformation in the matrix during tensile loading has been investigated. Qualitative and quantitative analysis of different components of stress and strain tensors is provided on the basis of mesomechanical concepts. Basing on the 3D-analysis, some conclusions regarding an applicability of a 2D approximation when considering deformation behavior on meso and macro scale levels have been done.

  11. PEG-diacrylate/hyaluronic acid semi-interpenetrating network compositions for 3D cell spreading and migration

    PubMed Central

    Lee, Ho-Joon; Sen, Atanu; Bae, Sooneon; Lee, Jeoung Soo; Webb, Ken

    2015-01-01

    To serve as artificial matrices for therapeutic cell transplantation, synthetic hydrogels must incorporate mechanisms enabling localized, cell-mediated degradation that allows cell spreading and migration. Previously, we have shown that hybrid semi-interpenetrating polymer networks (semi-IPNs) composed of hydrolytically degradable PEG-diacrylates (PEGdA), acrylate-PEG-GRGDS, and native hyaluronic acid (HA) support increased cell spreading relative to fully synthetic networks that is dependent on cellular hyaluronidase activity. This study systematically investigated the effects of PEGdA/HA semi-IPN network composition on 3D spreading of encapsulated fibroblasts, the underlying changes in gel structure responsible for this activity, and the ability of optimized gel formulations to support long-term cell survival and migration. Fibroblast spreading exhibited a biphasic response to HA concentration, required a minimum HA molecular weight, decreased with increasing PEGdA concentration, and was independent of hydrolytic degradation at early time points. Increased gel turbidity was observed in semi-IPNs, but not in copolymerized hydrogels containing methacrylated HA that did not support cell spreading; suggesting an underlying mechanism of polymerization-induced phase separation resulting in HA-enriched defects within the network structure. PEGdA/HA semi-IPNs were also able to support cell spreading at relatively high levels of mechanical properties (~10 kPa elastic modulus) compared to alternative hybrid hydrogels. In order to support long-term cellular remodeling, the degradation rate of the PEGdA component was optimized by preparing blends of three different PEGdA macromers with varying susceptibility to hydrolytic degradation. Optimized semi-IPN formulations supported long-term survival of encapsulated fibroblasts and sustained migration in a gel-within-gel encapsulation model. These results demonstrate that PEGdA/HA semi-IPNs provide dynamic microenvironments that

  12. 3D Non-destructive Imaging of Punctures in Polyethylene Composite Armor by THz Time Domain Spectroscopy

    NASA Astrophysics Data System (ADS)

    Palka, N.; Panowicz, R.; Ospald, F.; Beigang, R.

    2015-08-01

    An ultra-high molecular weight polyethylene composite sample totally punctured by a projectile was examined by THz TDS raster scanning method in reflection configuration. The scanning results correctly match the distribution of delaminations inside the sample, which was proven with cross-sectional and frontal views after waterjet cutting. For further analysis, a signal-processing algorithm based on the deconvolution method was developed and the modified reference signal was used to reduce disturbances. The complex refractive index of the sample was determined by transmission TDS technique and was later used for the simulation of pulse propagation by the finite difference time domain method. These simulations verified the correctness of the proposed method and showed its constraints. Using the proposed algorithm, the ambiguous raw THz image was converted into a binary 3D image of the sample, which consists only of two areas: sample—polyethylene and delamination—air. As a result, a clear image of the distribution of delaminations with their spatial extent was obtained which can be used for further comparative analysis. The limitation of the proposed method is that parts of the central area of the puncture cannot be analyzed because tilted layers deflect the incident signal.

  13. Optimization of composition, structure and mechanical strength of bioactive 3-D glass-ceramic scaffolds for bone substitution.

    PubMed

    Baino, Francesco; Ferraris, Monica; Bretcanu, Oana; Verné, Enrica; Vitale-Brovarone, Chiara

    2013-03-01

    Fabrication of 3-D highly porous, bioactive, and mechanically competent scaffolds represents a significant challenge of bone tissue engineering. In this work, Bioglass®-derived glass-ceramic scaffolds actually fulfilling this complex set of requirements were successfully produced through the sponge replication method. Scaffold processing parameters and sintering treatment were carefully designed in order to obtain final porous bodies with pore content (porosity above 70 %vol), trabecular architecture and mechanical properties (compressive strength up to 3 MPa) analogous to those of the cancellous bone. Influence of the Bioglass® particles size on the structural and mechanical features of the sintered scaffolds was considered and discussed. Relationship between porosity and mechanical strength was investigated and modeled. Three-dimensional architecture, porosity, mechanical strength and in vitro bioactivity of the optimized Bioglass®-derived scaffolds were also compared to those of CEL2-based glass-ceramic scaffolds (CEL2 is an experimental bioactive glass originally developed by the authors at Politecnico di Torino) fabricated by the same processing technique, in an attempt at understanding the role of different bioactive glass composition on the major features of scaffolds prepared by the same method. PMID:22207602

  14. Effect of a glaze/composite sealant on the 3-D surface roughness of esthetic restorative materials.

    PubMed

    Perez, Cesar dos Reis; Hirata, Raphael Júnior; da Silva, Antonio Henrique Monteiro da Fonseca Thomé; Sampaio, Eduardo Martins; de Miranda, Mauro Sayão

    2009-01-01

    The main goal of the current study was to evaluate the surface roughness of tooth-colored restorative materials after different finishing/polishing protocols, including a liquid polisher (BisCover, BISCO, Schaumburg, IL, USA). The restorative materials tested included two nanofilled resin composites (Filtek Supreme, 3M Dental Products, St Paul, MN, USA and Grandio, Voco, Cuxhaven, Germany), one resin-modified glass ionomer cement (Vitremer, 3M Dental Products) and one conventional glass ionomer cement (Meron Molar ART, Voco). The finishing/polishing methods were divided into five groups: G1 (compression with Mylar matrix), G2 (finishing with diamond burs), G3 (Sof-Lex, 3M Dental Products), G4 (BisCover, BISCO, after diamond burs) and G5 (BisCover after Sof-Lex). Five cylindrical specimens of each material were prepared for each group according to the manufacturer's instructions. The finishing/polishing methods were performed by a single operator in one direction to avoid variations at low speed (15,000 RPM). The surface roughness was evaluated using a 3-D scanning instrument with two parameters considered (Ra and Rz). The data was analyzed using one-way ANOVA followed by a multiple comparison Tukey's test. The results showed that BisCover (BISCO) was capable of reducing surface roughness and provided polished surfaces for all materials, enhancing smoothness over already polished surfaces (Sof-Lex, 3M Dental Products) and achieving polishing after finishing with diamond burs. PMID:19953776

  15. 3D compositional characterization of Si/SiO2 vertical interface structure by atom probe tomography

    NASA Astrophysics Data System (ADS)

    Lee, J. H.; Kim, Y. T.; Kim, J. J.; Lee, S. Y.; Park, C. G.

    2013-11-01

    Precise interpretation of three-dimensional atom probe tomography (3D-APT) data is necessary to reconstruct semiconductor-device structures. In particular, it is difficult to reconstruct the hetero-structure of conductors and insulators using APT analysis, due to the preferential evaporation of low-evaporation field-material. In this paper, shallow-trench isolation (STI) structure, consisting of a Si column and a SiO2 region, is analyzed using APT. The dimensional artifact known as the local-magnification-effect occurring as a result of the geometric deviation from the ideal hemisphere was successfully calibrated by `high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) tomography' and Electron Energy Loss Spectroscopy (EELS). In the direction of the width, the Si layer was compressed by 50%, and the interface was expanded by 250% with respect to the reference data obtained for the same sample. A 5-nm-thick transition layer was observed at the interface between Si and SiO2. The composition of the transition layer follows the well-developed sequence Si-Si2O-SiO-SiO2 from the Si area to the SiO2 area. Atoms at the interface were likely to evaporate with a bit wider angle than atoms in the Si area due to the preferentially evaporated Si layer, which caused the interface area to appear locally magnified.

  16. 3D Progressive Damage Modeling for Laminated Composite Based on Crack Band Theory and Continuum Damage Mechanics

    NASA Technical Reports Server (NTRS)

    Wang, John T.; Pineda, Evan J.; Ranatunga, Vipul; Smeltzer, Stanley S.

    2015-01-01

    A simple continuum damage mechanics (CDM) based 3D progressive damage analysis (PDA) tool for laminated composites was developed and implemented as a user defined material subroutine to link with a commercially available explicit finite element code. This PDA tool uses linear lamina properties from standard tests, predicts damage initiation with an easy-to-implement Hashin-Rotem failure criteria, and in the damage evolution phase, evaluates the degradation of material properties based on the crack band theory and traction-separation cohesive laws. It follows Matzenmiller et al.'s formulation to incorporate the degrading material properties into the damaged stiffness matrix. Since nonlinear shear and matrix stress-strain relations are not implemented, correction factors are used for slowing the reduction of the damaged shear stiffness terms to reflect the effect of these nonlinearities on the laminate strength predictions. This CDM based PDA tool is implemented as a user defined material (VUMAT) to link with the Abaqus/Explicit code. Strength predictions obtained, using this VUMAT, are correlated with test data for a set of notched specimens under tension and compression loads.

  17. Acoustic Emission and Damage Accumulation for Various Woven C/SiC Composites Tested in Tension at Room Temperature

    NASA Technical Reports Server (NTRS)

    Morscher, Gregory N.; Petko, Jeanne; Kiser, James D.; Gray, Hugh R. (Technical Monitor)

    2002-01-01

    Modal acoustic emission (AE) has proven to be an excellent technique to monitor damage accumulation in ceramic matrix composites. In this study, AE was used to monitor tensile load-unload-reload hysteresis tests for a variety of C fiber reinforced, SiC matrix composites. C/SiC composites were reinforced with T300 and IM7 fibers, had C, multilayer, or pseudo-porous C interphases, and had chemical vapor infiltrated SiC or melt-infiltrated SiC matrices. All of the composites exhibited considerable AE during testing. The extent and nature of the AE activity will be analyzed and discussed in light of matrix cracking and the variety of composite constituents. It is hoped that understanding the nature of stress dependent damage accumulation in these materials can be of use in life modeling for these types of composites.

  18. Acoustic Emission and Damage Accumulation for Various Woven C/SiC Composites Tested in Tension at Room Temperature

    NASA Technical Reports Server (NTRS)

    Morscher, Gregory; Petko, Jeanne; Kiser, James D.

    2002-01-01

    Modal acoustic emission (AE) has proven to be an excellent technique to monitor damage accumulation in ceramic matrix composites. In this study, AE was used to monitor tensile load-unload-reload hysteresis tests for a variety of C fiber reinforced, Sic matrix composites. C/SiC composites were reinforced with T-300 and IM7 fibers, had C, multilayer, or pseudo-porous C interphases, and had chemical vapor infiltrated Sic or melt-infiltrated SiC matrices. All of the composites exhibited considerable AE during testing. The extent and nature of the AE activity will be analyzed and discussed in light of matrix cracking and the variety of composite constituents. It is hoped that understanding the nature of stress-dependent damage accumulation in these materials can be of use in life-modeling for these types of composites.

  19. Feasibility Study for Ballet E-Learning: Automatic Composition System for Ballet "Enchainement" with Online 3D Motion Data Archive

    ERIC Educational Resources Information Center

    Umino, Bin; Longstaff, Jeffrey Scott; Soga, Asako

    2009-01-01

    This paper reports on "Web3D dance composer" for ballet e-learning. Elementary "petit allegro" ballet steps were enumerated in collaboration with ballet teachers, digitally acquired through 3D motion capture systems, and categorised into families and sub-families. Digital data was manipulated into virtual reality modelling language (VRML) and fit…

  20. Influence of resin system on the energy absorption capability and morphological properties of plain woven kenaf composites

    NASA Astrophysics Data System (ADS)

    Salman, S. D.; Leman, Z.; Sultan, M. T. H.; Ishak, M. R.; Cardona, F.

    2015-12-01

    Due to both environmental and technical advantages, natural fibers are being used as reinforcement of polymeric composite in many industries. The flexibility of the most natural fibers is one of the important technical characteristic which allows them to resist impact forces. An investigation was carried out to compare the energy absorption capability of kenaf/PVB film and kenaf/epoxy composites. The hot and cold press techniques were used to fabricate the specimens with 35% kenaf fibre weight fraction. The charpy impact test was performed on forty notched specimens using a pendulum impact tester with different hammer energy. The results showed that the kenaf/PVB film composite has the highest energy absorption, strength and toughness compared with the epoxy composite. At high energy levels, the impact strength and toughness of the kenaf/PVB film was six times of kenaf/epoxy composite. In addition, the scanning electron microscopy was assessed to demonstrate the different failure in fracture surfaces. It was found that the kenaf/PVB film composite failed by fibre fracture while kenaf/epoxy composite failed by a combination of fibre pull-out and fibre fracture as well as crack propagations through the matrix.

  1. CMAS 3D, a new program to visualize and project major elements compositions in the CMAS system

    NASA Astrophysics Data System (ADS)

    France, L.; Ouillon, N.; Chazot, G.; Kornprobst, J.; Boivin, P.

    2009-06-01

    CMAS 3D, developed in MATLAB ®, is a program to support visualization of major element chemical data in three dimensions. Such projections are used to discuss correlations, metamorphic reactions and the chemical evolution of rocks, melts or minerals. It can also project data into 2D plots. The CMAS 3D interface makes it easy to use, and does not require any knowledge of Matlab ® programming. CMAS 3D uses data compiled in a Microsoft Excel™ spreadsheet. Although useful for scientific research, the program is also a powerful tool for teaching.

  2. Temperature Dependence of Electrical Resistance of Woven Melt-Infiltrated SiCf/SiC Ceramic Matrix Composites

    NASA Technical Reports Server (NTRS)

    Appleby, Matthew P.; Morscher, Gregory N.; Zhu, Dongming

    2016-01-01

    Recent studies have successfully shown the use of electrical resistance (ER)measurements to monitor room temperature damage accumulation in SiC fiber reinforced SiC matrix composites (SiCf/SiC) Ceramic Matrix Composites (CMCs). In order to determine the feasibility of resistance monitoring at elevated temperatures, the present work investigates the temperature dependent electrical response of various MI (Melt Infiltrated)-CVI (Chemical Vapor Infiltrated) SiC/SiC composites containing Hi-Nicalon Type S, Tyranno ZMI and SA reinforcing fibers. Test were conducted using a commercially available isothermal testing apparatus as well as a novel, laser-based heating approach developed to more accurately simulate thermomechanical testing of CMCs. Secondly, a post-test inspection technique is demonstrated to show the effect of high-temperature exposure on electrical properties. Analysis was performed to determine the respective contribution of the fiber and matrix to the overall composite conductivity at elevated temperatures. It was concluded that because the silicon-rich matrix material dominates the electrical response at high temperature, ER monitoring would continue to be a feasible method for monitoring stress dependent matrix cracking of melt-infiltrated SiC/SiC composites under high temperature mechanical testing conditions. Finally, the effect of thermal gradients generated during localized heating of tensile coupons on overall electrical response of the composite is determined.

  3. Synthesis and Application of Novel 3D Magnetic Chlorogenic Acid Imprinted Polymers Based on a Graphene-Carbon Nanotube Composite.

    PubMed

    Yan, Liang; Yin, Yuli; Lv, Piaopiao; Zhang, Zhaohui; Wang, Jing; Long, Fang

    2016-04-20

    A novel three-dimensional (3D) magnetic chlorogenic acid (CGA) imprinted polymer (MMIP) was prepared with novel carbon hybrid nanocomposite as the carrier, chlorogenic acid as the template molecule, and methacrylic acid as the functional monomer. The 3D MMIPs were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, vibrating sample magnetometer, and UV spectrometry in detail. The results showed that the imprinted layer was attached successfully on the surface of a 3D magnetic carbon hybrid nanocomposite. The adsorption performance of the 3D MMIPs was investigated, and the results showed that the 3D MMIPs exhibited high adsorption capacity and fast adsorption rate toward CGA with a maximum adsorption capacity of 10.88 mg g(-1). The extraction conditions involving washing solvent, the pH of eluent solvent, elution volume, and desorption time were also investigated in detail. Combined with high-performance liquid chromatography, the 3D MMIPs have been applied to successfully extract CGA from Eucommia leaf extract samples. PMID:27049929

  4. Effects of carbon fiber surface treatment on the tribological properties of 2D woven carbon fabric/polyimide composites

    NASA Astrophysics Data System (ADS)

    Zhang, Xinrui; Pei, Xianqiang; Jia, Qian; Wang, Qihua

    2009-06-01

    Polyacrylonitrile (PAN)-based carbon fabric (CF) was modified with strong HNO3 oxidation and then introduced into polyimide (PI) composites. The friction and wear properties of the carbon fabric reinforced polyimide composites (CFRP), sliding against GCr15 stainless steel rings, were investigated on an M-2000 model ring-on-block test rig under dry sliding. Experimental results revealed that the carbon fiber surface treatment largely reduced the friction and wear of the CFRP. Compared with the untreated ones, the surface-modified CF can enhance the tribological properties of CFRP efficiently due to the improved adhesion between the CF and the PI matrix. Scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) study of the carbon fiber surface showed that the fiber surface became rougher and the oxygen concentration increased greatly after surface treatment, which improved the adhesion between the fiber and the PI matrix and improved the friction-reduction and anti-wear properties of the CFRP.

  5. Editorial on the original article entitled “3D printing of composite calcium phosphate and collagen scaffolds for bone regeneration” published in the Biomaterials on February 14, 2014

    PubMed Central

    Li, Lan

    2015-01-01

    The paper entitled “3D printing of composite calcium phosphate and collagen scaffolds for bone regeneration” published in the Biomaterials recently illuminated the way to make particular scaffolds with calcium phosphate (CaP) powder, phosphoric acid, type I collagen and Tween 80 in low temperature. After the optimal concentration of each component was determined, the scaffolds were evaluated in a critically sized murine femoral defect model and exhibited good material properties. We made some related introduction of materials applied in 3D printing for bone tissue engineering based on this article to demonstrate the current progress in this field of study. PMID:26046065

  6. Composite System of Graphene Oxide and Polypeptide Thermogel As an Injectable 3D Scaffold for Adipogenic Differentiation of Tonsil-Derived Mesenchymal Stem Cells.

    PubMed

    Patel, Madhumita; Moon, Hyo Jung; Ko, Du Young; Jeong, Byeongmoon

    2016-03-01

    As two-dimensional (2D) nanomaterials, graphene (G) and graphene oxide (GO) have evolved into new platforms for biomedical research as biosensors, imaging agents, and drug delivery carriers. In particular, the unique surface properties of GO can be an important tool in modulating cellular behavior and various biological sequences. Here, we report that a composite system of graphene oxide/polypeptide thermogel (GO/P), prepared by temperature-sensitive sol-to-gel transition of a GO-suspended poly(ethylene glycol)-poly(l-alanine) (PEG-PA) aqueous solution significantly enhances the expression of adipogenic biomarkers, including PPAR-γ, CEBP-α, LPL, AP2, ELOVL3, and HSL, compared to both a pure hydrogel system and a composite system of G/P, graphene-incorporated hydrogel. We prove that insulin, an adipogenic differentiation factor, preferentially adhered to GO, is supplied to the incorporated stem cells in a sustained manner over the three-dimensional (3D) cell culture period. On the other hand, insulin is partially denatured in the presence of G and interferes with the adipogenic differentiation of the stem cells. The study suggests that a 2D/3D composite system is a promising platform as a 3D cell culture matrix, where the surface properties of 2D materials in modulating the fates of the stem cells are effectively transcribed in a 3D culture system. PMID:26844684

  7. Synergetic adsorption and photocatalytic degradation of pollutants over 3D TiO2-graphene aerogel composites synthesized via a facile one-pot route.

    PubMed

    Zhang, Jing-Jie; Wu, Yu-Hui; Mei, Jin-Ya; Zheng, Guang-Ping; Yan, Ting-Ting; Zheng, Xiu-Cheng; Liu, Pu; Guan, Xin-Xin

    2016-08-01

    A series of composites consisting of anatase TiO2 nanocrystals and three-dimensional (3D) graphene aerogel (TiO2-GA) were self-assembled directly from tetrabutyl titanate and graphene oxides via a one-pot hydrothermal process. TiO2 was found to uniformly distribute inside the 3D network of GA in the resulting composites with large surface areas (SBET > 125 m(2) g(-1)) and high pore volumes (Vp > 0.22 cm(3) g(-1)). In comparison with GA and TiO2, the composites possessed much higher adsorption capacities and visible light photocatalytic activity in the degradation of rhodamine B (RhB). With an initial concentration of 20.0 mg L(-1) of RhB, the adsorptive decolourization of RhB was as high as 95.1% and the total decolourization value reached up to 98.7% under visible light irradiation over 5.0 mg of the resulting composites. It was elucidated that the physical and chemical properties of the TiO2-GA composites could be ascribed to their unique 3D nanoporous structure with high surface areas and the synergetic activities of graphene nanosheets and TiO2 nanoparticles. PMID:27417708

  8. Testing and simulation of a polypropylene-glass fibre reinforced woven composite on a wide range of strain-rates

    NASA Astrophysics Data System (ADS)

    Martin, A.; Othman, R.; Rozycki, P.

    2012-08-01

    Medium costs composites materials are good candidates to develop lightweight and economical shock absorber for the next generation of cars. In this context we are interested in characterising and modelling of Twintex a long glass fiber reinforced polypropylene. Testing will be carried with a standard tensile rig and an original layout using a crossbow/Hopkinson rig. A special attention is made to compression behaviour identification, often neglected but critical for crash absorber behaviour. The model will be checked on the testing specimen and its validity will be discussed.

  9. Effect of Interface Control on Mode I Interlaminar Fracture Toughness of Woven C/C Composite Laminates

    NASA Astrophysics Data System (ADS)

    Hojo, Masaki; Yamao, Taketoshi; Tanaka, Mototsugu; Ochiai, Shojiro; Iwashita, Norio; Sawada, Yoshihiro

    Effects of fiber/matrix interface and matrix microstructure on the mode I interlaminar fracture toughness of C/C composite materials were investigated by coating bismaleimide-triazine co-polymer (BT-resin) on the surface of carbon fiber and changing the heat-treatment temperature (HTT). For the case of laminates with HTT of 1600°C (carbonized C/C composites), the initial fracture toughness, GIC, was insensitive to BT-resin coating. Moreover, the fracture toughness during crack propagation, GIR, increased by coating BT-resin. On the other hand, both GIC and GIR decreased with BT-resin coating for the laminates with HTT of 2500°C. While both GIC and GIR are insensitive to HTT for laminates without BT-resin coating, they both decreased by increasing HTT for laminates with BT-resin coating. The difference of the effects of interface control and HTT was discussed on the basis of microscopic mechanism consideration. Comparison between in-plane and interlaminar strength indicated the possibility to optimize the interface control.

  10. A model for calculating the errors of 2D bulk analysis relative to the true 3D bulk composition of an object, with application to chondrules

    NASA Astrophysics Data System (ADS)

    Hezel, Dominik C.

    2007-09-01

    Certain problems in Geosciences require knowledge of the chemical bulk composition of objects, such as, for example, minerals or lithic clasts. This 3D bulk chemical composition (bcc) is often difficult to obtain, but if the object is prepared as a thin or thick polished section a 2D bcc can be easily determined using, for example, an electron microprobe. The 2D bcc contains an error relative to the true 3D bcc that is unknown. Here I present a computer program that calculates this error, which is represented as the standard deviation of the 2D bcc relative to the real 3D bcc. A requirement for such calculations is an approximate structure of the 3D object. In petrological applications, the known fabrics of rocks facilitate modeling. The size of the standard deviation depends on (1) the modal abundance of the phases, (2) the element concentration differences between phases and (3) the distribution of the phases, i.e. the homogeneity/heterogeneity of the object considered. A newly introduced parameter " τ" is used as a measure of this homogeneity/heterogeneity. Accessory phases, which do not necessarily appear in 2D thin sections, are a second source of error, in particular if they contain high concentrations of specific elements. An abundance of only 1 vol% of an accessory phase may raise the 3D bcc of an element by up to a factor of ˜8. The code can be queried as to whether broad beam, point, line or area analysis technique is best for obtaining 2D bcc. No general conclusion can be deduced, as the error rates of these techniques depend on the specific structure of the object considered. As an example chondrules—rapidly solidified melt droplets of chondritic meteorites—are used. It is demonstrated that 2D bcc may be used to reveal trends in the chemistry of 3D objects.

  11. SU-C-213-05: Evaluation of a Composite Copper-Plastic Material for a 3D Printed Radiation Therapy Bolus

    SciTech Connect

    Vitzthum, L; Ehler, E; Sterling, D; Reynolds, T; Higgins, P; Dusenbery, K

    2015-06-15

    Purpose: To evaluate a novel 3D printed bolus fabricated from a copper-plastic composite as a thin flexible, custom fitting device that can replicate doses achieved with conventional bolus techniques. Methods: Two models of bolus were created on a 3D printer using a composite copper-PLA/PHA. Firstly, boluses were constructed at thicknesses of 0.4, 0.6 and 0.8 mm. Relative dose measurements were performed under the bolus with an Attix Chamber as well as with radiochromic film. Results were compared to superficial Attix Chamber measurements in a water equivalent material to determine the dosimetric water equivalence of the copper-PLA/PHA plastic. Secondly, CT images of a RANDO phantom were used to create a custom fitting bolus across the anterolateral scalp. Surface dose with the bolus placed on the RANDO phantom was measured with radiochromic film at tangential angles with 6, 10, 10 flattening filter free (FFF) and 18 MV photon beams. Results: Mean surface doses for 6, 10, 10FFF and 18 MV were measured as a percent of Dmax for the flat bolus devices of each thickness. The 0.4 mm thickness bolus was determined to be near equivalent to 2.5 mm depth in water for all four energies. Surface doses ranged from 59–63% without bolus and 85–90% with the custom 0.4 mm copper-plastic bolus relative to the prescribed dose for an oblique tangential beam arrangement on the RANDO phantom. Conclusion: Sub-millimeter thickness, 3D printed composite copper-PLA/PHA bolus can provide a build-up effect equivalent to conventional bolus. At this thickness, the 3D printed bolus allows a level of flexure that may provide more patient comfort than current 3D printing materials used in bolus fabrication while still retaining the CT based custom patient shape. Funding provided by an intra-department grant of the University of Minnesota Department of Radiation Oncology.

  12. Effect of interfacial characteristics on mode I fracture behavior of glass woven fabric composites under static and fatigue loading

    SciTech Connect

    Hamada, Hiroyuki; Kotaki, Masaya; Lowe, A.

    1997-12-31

    The influence of fiber surface treatment on the mode I delamination characteristics of a glass fabric/vinyl ester composite was studied. Five treatments were used: solutions containing 0.01 wt%, 0.4 wt % and 1.0 wt% of {gamma}-methacryloxy-propyltrimethoxysilane (MS); 0.4 wt% of MS subsequently washed in methanol; and 0.4 wt% of {gamma}-glycidoxypropyltrimethoxysilane (ES). Static mode I tests were performed on specimens oriented in both the wasp and weft fiber directions. The tests revealed that stable crack propagation was only observed with the ES-treated specimens and with the most dilute MS treatment. Invariably, fracture toughnesses were higher in the weft oriented specimens. The degree of unstable fracture observed under fatigue loading was generally significantly lower than under static loading. The specimens treated with the highest concentrations of MS possessed the highest fatigue resistance and had threshold toughness values in excess of the static toughness values. Fractographic examination was performed on both static and fatigue fracture surfaces, revealing markedly different fracture morphologies in relation to the degree of interfacial failure observed.

  13. Effect of GIA models with 3D composite mantle viscosity on GRACE mass balance estimates for Antarctica

    NASA Astrophysics Data System (ADS)

    van der Wal, Wouter; Whitehouse, Pippa L.; Schrama, Ernst J. O.

    2015-03-01

    Seismic data indicate that there are large viscosity variations in the mantle beneath Antarctica. Consideration of such variations would affect predictions of models of Glacial Isostatic Adjustment (GIA), which are used to correct satellite measurements of ice mass change. However, most GIA models used for that purpose have assumed the mantle to be uniformly stratified in terms of viscosity. The goal of this study is to estimate the effect of lateral variations in viscosity on Antarctic mass balance estimates derived from the Gravity Recovery and Climate Experiment (GRACE) data. To this end, recently-developed global GIA models based on lateral variations in mantle temperature are tuned to fit constraints in the northern hemisphere and then compared to GPS-derived uplift rates in Antarctica. We find that these models can provide a better fit to GPS uplift rates in Antarctica than existing GIA models with a radially-varying (1D) rheology. When 3D viscosity models in combination with specific ice loading histories are used to correct GRACE measurements, mass loss in Antarctica is smaller than previously found for the same ice loading histories and their preferred 1D viscosity profiles. The variation in mass balance estimates arising from using different plausible realizations of 3D viscosity amounts to 20 Gt/yr for the ICE-5G ice model and 16 Gt/yr for the W12a ice model; these values are larger than the GRACE measurement error, but smaller than the variation arising from unknown ice history. While there exist 1D Earth models that can reproduce the total mass balance estimates derived using 3D Earth models, the spatial pattern of gravity rates can be significantly affected by 3D viscosity in a way that cannot be reproduced by GIA models with 1D viscosity. As an example, models with 1D viscosity always predict maximum gravity rates in the Ross Sea for the ICE-5G ice model, however, for one of the three preferred 3D models the maximum (for the same ice model) is found

  14. Analysis of Composite Skin-Stiffener Debond Specimens Using a Shell/3D Modeling Technique and Submodeling

    NASA Technical Reports Server (NTRS)

    OBrien, T. Kevin (Technical Monitor); Krueger, Ronald; Minguet, Pierre J.

    2004-01-01

    The application of a shell/3D modeling technique for the simulation of skin/stringer debond in a specimen subjected to tension and three-point bending was studied. The global structure was modeled with shell elements. A local three-dimensional model, extending to about three specimen thicknesses on either side of the delamination front was used to model the details of the damaged section. Computed total strain energy release rates and mixed-mode ratios obtained from shell/3D simulations were in good agreement with results obtained from full solid models. The good correlation of the results demonstrated the effectiveness of the shell/3D modeling technique for the investigation of skin/stiffener separation due to delamination in the adherents. In addition, the application of the submodeling technique for the simulation of skin/stringer debond was also studied. Global models made of shell elements and solid elements were studied. Solid elements were used for local submodels, which extended between three and six specimen thicknesses on either side of the delamination front to model the details of the damaged section. Computed total strain energy release rates and mixed-mode ratios obtained from the simulations using the submodeling technique were not in agreement with results obtained from full solid models.

  15. Mechanical, Electromagnetic, and X-ray Shielding Characterization of a 3D Printable Tungsten-Polycarbonate Polymer Matrix Composite for Space-Based Applications

    NASA Astrophysics Data System (ADS)

    Shemelya, Corey M.; Rivera, Armando; Perez, Angel Torrado; Rocha, Carmen; Liang, Min; Yu, Xiaoju; Kief, Craig; Alexander, David; Stegeman, James; Xin, Hao; Wicker, Ryan B.; MacDonald, Eric; Roberson, David A.

    2015-08-01

    Material-extrusion three-dimensional (3D) printing has recently attracted much interest because of its process flexibility, rapid response to design alterations, and ability to create structures "on-the-go". For this reason, 3D printing has possible applications in rapid creation of space-based devices, for example cube satellites (CubeSat). This work focused on fabrication and characterization of tungsten-doped polycarbonate polymer matrix composites specifically designed for x-ray radiation-shielding applications. The polycarbonate-tungsten polymer composite obtained intentionally utilizes low loading levels to provide x-ray shielding while limiting effects on other properties of the material, for example weight, electromagnetic functionality, and mechanical strength. The fabrication process, from tungsten functionalization to filament extrusion and material characterization, is described, including printability, determination of x-ray attenuation, tensile strength, impact resistance, and gigahertz permittivity, and failure analysis. The proposed materials are uniquely advantageous when implemented in 3D printed structures, because even a small volume fraction of tungsten has been shown to substantially alter the properties of the resulting composite.

  16. Analysis of Composite Skin-Stiffener Debond Specimens Using Volume Elements and a Shell/3D Modeling Technique

    NASA Technical Reports Server (NTRS)

    Krueger, Ronald; Minguet, Pierre J.; Bushnell, Dennis M. (Technical Monitor)

    2002-01-01

    The debonding of a skin/stringer specimen subjected to tension was studied using three-dimensional volume element modeling and computational fracture mechanics. Mixed mode strain energy release rates were calculated from finite element results using the virtual crack closure technique. The simulations revealed an increase in total energy release rate in the immediate vicinity of the free edges of the specimen. Correlation of the computed mixed-mode strain energy release rates along the delamination front contour with a two-dimensional mixed-mode interlaminar fracture criterion suggested that in spite of peak total energy release rates at the free edge the delamination would not advance at the edges first. The qualitative prediction of the shape of the delamination front was confirmed by X-ray photographs of a specimen taken during testing. The good correlation between prediction based on analysis and experiment demonstrated the efficiency of a mixed-mode failure analysis for the investigation of skin/stiffener separation due to delamination in the adherents. The application of a shell/3D modeling technique for the simulation of skin/stringer debond in a specimen subjected to three-point bending is also demonstrated. The global structure was modeled with shell elements. A local three-dimensional model, extending to about three specimen thicknesses on either side of the delamination front was used to capture the details of the damaged section. Computed total strain energy release rates and mixed-mode ratios obtained from shell/3D simulations were in good agreement with results obtained from full solid models. The good correlations of the results demonstrated the effectiveness of the shell/3D modeling technique for the investigation of skin/stiffener separation due to delamination in the adherents.

  17. Li2S@C composite incorporated into 3D reduced graphene oxide as a cathode material for lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Wang, D. H.; Xie, D.; Yang, T.; Zhong, Y.; Wang, X. L.; Xia, X. H.; Gu, C. D.; Tu, J. P.

    2016-05-01

    Surface conductive engineering on Li2S is critical for construction of advanced cathodes of lithium-sulfur batteries. Herein, we construct a high-performance Li2S-based composite cathode with the help of three-dimensional reduced graphene oxide (3D-rGO) network and outer carbon coating. Typically, the Li2S@C particles are uniformly embedded into 3D-rGO to form a binder-free 3D-rGO-Li2S@C cathode by the combination of a liquid solution-evaporation coating and PVP (Polyvinyl Pyrrolidone) carbonization. The 3D-rGO-Li2S@C cathode exhibits a high initial discharge capacity of 856 mAh g-1 at 0.1C, superior cycling stability with a capacity of 388.4 mAh g-1 after 200 cycles at 1C, corresponding to a low capacity fading rate. It is demonstrated that the outer conductive coating is effective and necessary for electrochemical enhancement of Li2S cathodes by improving electrical conductivity and prohibiting polysulfide from shuttling during cycling.

  18. Synthesis of 3D graphite oxide-exfoliated carbon nanotube carbon composite and its application as catalyst support for fuel cells

    NASA Astrophysics Data System (ADS)

    Wang, Hailin; Kakade, Bhalchandra A.; Tamaki, Takanori; Yamaguchi, Takeo

    2014-08-01

    The restacking of graphene or reduced graphite oxide (r-GO) is commonly regarded as a severe obstacle for potential applications. We propose the application of exfoliated carbon nanotube (e-CNT) as an effective carbon spacer for fabricating a sandwich-like three-dimensional (3D) carbon composite with GO. The 3D carbon combination of GO + e-CNT is successfully prepared via homogenously mixing of GO and e-CNT in an aqueous dispersion in which carbon spacers are homogenously intercalated with graphene layers. With the addition of a carbon spacer, the BET surface area of 3D carbon (51.6 m2 g-1) is enhanced by a factor of three compared with r-GO (17.2 m2 g-1) after thermal reduction. In addition, the 3D GO + e-CNT supported PtPd catalyst (PtPd-GO + e-CNT) shows homogenous distribution of PtPd nanoparticles of 3.9 ± 0.6 nm in size, with an enlarged electrochemical active surface area (ECSA) value of 164 m2 g-1 and a mass activity of 690 mA mg-1 toward the methanol oxidation reaction (MOR), which is the typical anode reaction for direct methanol fuel cells (DMFC).

  19. Woven TPS - A New Approach to TPS Design and Manufacturing

    NASA Technical Reports Server (NTRS)

    Feldman, Jay; Stackpoole, Mairead; Venkatapathy, Ethiraj

    2012-01-01

    NASA's Office of the Chief Technologist (OCT) Game Changing Division recently funded an effort to advance a Woven TPS (WTPS) concept. WTPS is a new approach to producing TPS materials that uses precisely engineered 3D weaving techniques to customize material characteristics needed to meet specific missions requirements for protecting space vehicles from the intense heating generated during atmospheric entry. Using WTPS, sustainable, scalable, mission-optimized TPS solutions can be achieved with relatively low life cycle costs compared with the high costs and long development schedules currently associated with material development and certification. WTPS leverages the mature state-of-the-art weaving technology that has evolved from the textile industry to design TPS materials with tailorable performance by varying material composition and properties via the controlled placement of fibers within a woven structure. The resulting material can be designed to perform optimally for a wide range of entry conditions encompassing NASAs current and future mission needs. WTPS enables these optimized TPS designs to be translated precisely into mission-specific, manufactured materials that can substantially increase the efficiency, utility, and robustness of heat shield materials compared to the current state-of-the-art material options. By delivering improved heat shield performance and affordability, this technology will impact all future exploration missions, from the robotic in-situ science missions to Mars, Venus and Saturn to the next generation of human missions. WTPS can change the way NASA develops, certifies, and integrates TPS into mission life cycles - instead of being a mission constraint, TPS will become a mission enabler. It is anticipated that WTPS will have direct impact on SMD, HEOMD and OCT and will be of interest for DoD and COTS applications. This presentation will overview the WTPS concept and present some results from initial testing completed.

  20. The Effects of 3D-Representation Instruction on Composite-Solid Surface-Area Learning for Elementary School Students

    ERIC Educational Resources Information Center

    Sung, Yao-Ting; Shih, Pao-Chen; Chang, Kuo-En

    2015-01-01

    Providing instruction on spatial geometry, specifically how to calculate the surface areas of composite solids, challenges many elementary school teachers. Determining the surface areas of composite solids involves complex calculations and advanced spatial concepts. The goals of this study were to build on students' learning processes for…

  1. Synthesis of SiO2/3D porous carbon composite as anode material with enhanced lithium storage performance

    NASA Astrophysics Data System (ADS)

    Yuan, Zhinan; Zhao, Naiqin; Shi, Chunsheng; Liu, Enzuo; He, Chunnian; He, Fang

    2016-05-01

    A SiO2/porous carbon nanocomposite was synthesized by a facile combined heat and acid treatments method. The nanocomposite featured a 3D porous carbon structure with amorphous SiO2 nanoparticles embedded in the wall of the pores. The microstructure improved the electrical conductivity, shortened the diffusion distance of lithium ions, and alleviated the volume expansion of SiO2 during Li intercalation. Accordingly, the SiO2/porous carbon nanocomposite displayed excellent cyclic performance with a high reversible capacity of 434 mAh g-1 after 50 cycles at 0.1 A g-1 and rate capability delivering a capacity of 187.4 mAh g-1 even at 5 A g-1.

  2. Mechanical and in vitro performance of apatite-wollastonite glass ceramic reinforced hydroxyapatite composite fabricated by 3D-printing.

    PubMed

    Suwanprateeb, J; Sanngam, R; Suvannapruk, W; Panyathanmaporn, T

    2009-06-01

    In situ hydroxyapatite/apatite-wollastonite glass ceramic composite was fabricated by a three dimensional printing (3DP) technique and characterized. It was found that the as-fabricated mean green strength of the composite was 1.27 MPa which was sufficient for general handling. After varying sintering temperatures (1050-1300 degrees C) and times (1-10 h), it was found that sintering at 1300 degrees C for 3 h gave the greatest flexural modulus and strength, 34.10 GPa and 76.82 MPa respectively. This was associated with a decrease in porosity and increase in densification ability of the composite resulting from liquid phase sintering. Bioactivity tested by soaking in simulated body fluid (SBF) and In Vitro toxicity studies showed that 3DP hydroxyapatite/A-W glass ceramic composite was non-toxic and bioactive. A new calcium phosphate layer was observed on the surface of the composite after soaking in SBF for only 1 day while osteoblast cells were able to attach and attain normal morphology on the surface of the composite. PMID:19225870

  3. Microstructure and tribological properties of 3D needle-punched C/C-SiC brake composites

    NASA Astrophysics Data System (ADS)

    Xiao, Peng; Li, Zhuan; Xiong, Xiang

    2010-04-01

    Carbon fibre reinforced carbon and silicon carbide dual matrix composites (C/C-SiC) show excellent tribological properties and are promising candidates for advanced friction materials. A pressure infiltration/carbonization combined with liquid silicon infiltration was developed for fabricating C/C-SiC composites. The carbon fabric preform was fabricated with the three-dimensional needling method. In the pressure infiltration process, the carbon fibre reinforced plastic was prepared by infiltration of the fabric preform with the furan resin. Then the carbon fibre reinforced plastic was carbonized which was pyrolysed to form a porous carbon/carbon composites. Finally, the porous carbon/carbon was infiltrated with molten silicon to obtain C/C-SiC composites. The composites exhibit excellent friction behavior, including a good stability of brake, and the average dynamic μ is 0.38 and static μ is 0.50, in combination with the linear wear rate of about 5.6 μm cycle -1. Moreover, the friction surface was covered with friction film which is about 10 μm in thickness. These results show that the C/C-SiC brake composites are promising candidates for advanced brake and clutch systems.

  4. Test methods for textile composites

    NASA Technical Reports Server (NTRS)

    Minguet, Pierre J.; Fedro, Mark J.; Gunther, Christian K.

    1994-01-01

    Various test methods commonly used for measuring properties of tape laminate composites were evaluated to determine their suitability for the testing of textile composites. Three different types of textile composites were utilized in this investigation: two-dimensional (2-D) triaxial braids, stitched uniweave fabric, and three-dimensional (3-D) interlock woven fabric. Four 2-D braid architectures, five stitched laminates, and six 3-D woven architectures were tested. All preforms used AS4 fibers and were resin-transfer-molded with Shell RSL-1895 epoxy resin. Ten categories of material properties were investigated: tension, open-hole tension, compression, open-hole compression, in-plane shear, filled-hole tension, bolt bearing, interlaminar tension, interlaminar shear, and interlaminar fracture toughness. Different test methods and specimen sizes were considered for each category of test. Strength and stiffness properties obtained with each of these methods are documented in this report for all the material systems mentioned above.

  5. Research Summary of an Additive Manufacturing Technology for the Fabrication of 3D Composites with Tailored Internal Structure

    NASA Astrophysics Data System (ADS)

    Holmes, Larry R.; Riddick, Jaret C.

    2014-01-01

    A novel additive manufacturing technology is used to create micro-composites, which can be tailored for specific end-use applications. The Field-Aided Laminar Composite (FALCom) process uses specifically focused electric fields to align nano- to micro-sized particles into chain-like structures, which are referred to as pseudo-fibers. These pseudo-fibers are then immediately frozen into place by incident ultraviolet radiation on the photopolymer matrix. The pseudo-fibers are arranged by design, and they are used to create three-dimensional composite structures. Multiple filler materials have been evaluated for use in the FALCom system; however, this report describes aluminum micro-particles that are aligned and oriented in an acrylic photopolymer matrix. A description of the technology and a review of experimental processing are shown, and conclusions, as well as, future work are discussed.

  6. 3D-finite element analyses of cusp movements in a human upper premolar, restored with adhesive resin-based composites.

    PubMed

    Ausiello, P; Apicella, A; Davidson, C L; Rengo, S

    2001-10-01

    The combination of diverse materials and complex geometry makes stress distribution analysis in teeth very complicated. Simulation in a computerized model might enable a study of the simultaneous interaction of the many variables. A 3D solid model of a human maxillary premolar was prepared and exported into a 3D-finite element model (FEM). Additionally, a generic class II MOD cavity preparation and restoration was simulated in the FEM model by a proper choice of the mesh volumes. A validation procedure of the FEM model was executed based on a comparison of theoretical calculations and experimental data. Different rigidities were assigned to the adhesive system and restorative materials. Two different stress conditions were simulated: (a) stresses arising from the polymerization shrinkage and (b) stresses resulting from shrinkage stress in combination with vertical occlusal loading. Three different cases were analyzed: a sound tooth, a tooth with a class II MOD cavity, adhesively restored with a high (25 GPa) and one with a low (12.5GPa) elastic modulus composite. The cusp movements induced by polymerization stress and (over)-functional occlusal loading were evaluated. While cusp displacement was higher for the more rigid composites due to the pre-stressing from polymerization shrinkage, cusp movements turned out to be lower for the more flexible composites in case the restored tooth which was stressed by the occlusal loading. This preliminary study by 3D FEA on adhesively restored teeth with a class II MOD cavity indicated that Young's modulus values of the restorative materials play an essential role in the success of the restoration. Premature failure due to stresses arising from polymerization shrinkage and occlusal loading can be prevented by proper selection and combination of materials. PMID:11522306

  7. Analysis of Ablative Performance of C/C Composite Throat Containing Defects Based on X-ray 3D Reconstruction in a Solid Rocket Motor

    NASA Astrophysics Data System (ADS)

    Hui, Wei-Hua; Bao, Fu-Ting; Wei, Xiang-Geng; Liu, Yang

    2015-12-01

    In this paper, a new measuring method of ablation rate was proposed based on X-ray three-dimensional (3D) reconstruction. The ablation of 4-direction carbon/carbon composite nozzles was investigated in the combustion environment of a solid rocket motor, and the macroscopic ablation and linear recession rate were studied through the X-ray 3D reconstruction method. The results showed that the maximum relative error of the X-ray 3D reconstruction was 0.0576%, which met the minimum accuracy of the ablation analysis; along the nozzle axial direction, from convergence segment, throat to expansion segment, the ablation gradually weakened; in terms of defect ablation, the middle ablation was weak, while the ablation in both sides was more serious. In a word, the proposed reconstruction method based on X-ray about C/C nozzle ablation can construct a clear model of ablative nozzle which characterizes the details about micro-cracks, deposition, pores and surface to analyze ablation, so that this method can create the ablation curve in any surface clearly.

  8. Matrix Cracking in 3D Orthogonal Melt-Infiltrated SiC/SiC Composites with Various Z-Fiber Types

    NASA Technical Reports Server (NTRS)

    Morscher, Gregory N.; Yun, Hee Mann; DiCarlo, James A.

    2003-01-01

    The occurrence of matrix cracks in melt-infiltrated SiC/SiC composites with a 3D orthogonal architecture was determined at room temperature for specimens tested in tension oriented in the X-direction (parallel to Z-bundle weave direction) and Y-direction (perpendicular to Z-bundle weave direction) and Y-direction (perpendicular to Z-bundle weave direction). The fiber-types were Sylramic and Sylramic-IBN in the X and Y-directions and lower modulus ZMI, T300, and rayon in the Z-direction. Acoustic emission (AE) was used to monitor the matrix cracking activity. For Y-direction composites, the AE data was used to determine the exact (+/- 0.25 mm) location where matrix cracks occurred in the 3D orthogonal architecture. This enabled the determination of the stress-dependent matrix crack distributions for small but repeatable matrix rich 'unidirectional' and the matrix poor 'cross-ply' regions within the architecture. It was found that matrix cracking initiated at very low stresses (approx. 40 MPa) in the 'unidirectional' regions for the largest z-direction fiber tow composites. Decreasing the size of the z-fiber bundle, increased the stress for matrix cracking in the 'unidirectional' regions. Matrix cracking in the 'cross-ply' regions always occurred at higher stresses than in 'unidirectional' regions, and the stress-dependent matrix crack distribution of the 'cross-ply' regions was always over a wider stress-range than the 'unidirectional' regions. For composites tested in the X-direction, a lower elastic modulus and a narrower and lower stress-range for matrix cracking were observed compared to composites tested in the Y-direction.

  9. Reducing Uncertainty in the Distribution of Hydrogeologic Units within Volcanic Composite Units of Pahute Mesa Using High-Resolution 3-D Resistivity Methods, Nevada Test Site, Nevada

    USGS Publications Warehouse

    Rodriguez, Brian D.; Sweetkind, Don; Burton, Bethany L.

    2010-01-01

    The U.S. Department of Energy (DOE) and the National Nuclear Security Administration (NNSA) at their Nevada Site Office (NSO) are addressing groundwater contamination resulting from historical underground nuclear testing through the Environmental Management program and, in particular, the Underground Test Area (UGTA) project. From 1951 to 1992, 828 underground nuclear tests were conducted at the Nevada Test Site (NTS) northwest of Las Vegas (DOE UGTA, 2003). Most of these tests were conducted hundreds of feet above the groundwater table; however, more than 200 of the tests were near, or within, the water table. This underground testing was limited to specific areas of the NTS including Pahute Mesa, Rainier Mesa/Shoshone Mountain, Frenchman Flat, and Yucca Flat. Volcanic composite units make up much of the area within the Pahute Mesa Corrective Action Unit (CAU) at the NTS, Nevada. The extent of many of these volcanic composite units extends throughout and south of the primary areas of past underground testing at Pahute and Rainier Mesas. As situated, these units likely influence the rate and direction of groundwater flow and radionuclide transport. Currently, these units are poorly resolved in terms of their hydrologic properties introducing large uncertainties into current CAU-scale flow and transport models. In 2007, the U.S. Geological Survey (USGS), in cooperation with DOE and NNSA-NSO acquired three-dimensional (3-D) tensor magnetotelluric data at the NTS in Area 20 of Pahute Mesa CAU. A total of 20 magnetotelluric recording stations were established at about 600-m spacing on a 3-D array and were tied to ER20-6 well and other nearby well control (fig. 1). The purpose of this survey was to determine if closely spaced 3-D resistivity measurements can be used to characterize the distribution of shallow (600- to 1,500-m-depth range) devitrified rhyolite lava-flow aquifers (LFA) and zeolitic tuff confining units (TCU) in areas of limited drill hole control on

  10. High velocity impact on different hybrid architectures of 2D laminated and 3D warp interlock fabric composite

    NASA Astrophysics Data System (ADS)

    Provost, B.; Boussu, F.; Coutellier, D.; Vallee, D.; Rondot, F.

    2012-08-01

    For decades, conventional amour shield is mainly oriented on metallic materials which are today well-known. Since the use of non conventional threats as IEDs, performances of those protections are required to be upgraded. The expected improvements that manufacturers are looking for are mainly oriented to the weight reduction which is the key parameter to reduce the fuel consumption, increase the payload, and offer more manoeuvrability to vehicles [1]. However, the difficulty is to reduce as cautiously as possible the total mass of the protection solution while ensuring the safety of the vehicle. One of the possible solutions is to use new combinations of materials, able to be more efficient against new threats and lighter than the traditional steel armour. It is in this context that the combination between some well-known ballistic alloys and textile composite material appear as a high potential solution for armour plated protection. Indeed, used as a backing, textile composite material present some interesting properties such as a very low density compared with steel and good behaviour in term of ballistic efficiency. This study proposes to test and compare the behaviour and efficiency of three different textile composite backings.

  11. Woven Thermal Protection System (Woven TPS) for Extreme Entry Environments

    NASA Video Gallery

    The Woven Thermal Protection System (WTPS) project explores an innovative way to design, develop and manufacture a family of ablative TPS materials using weaving technology and testing them in the ...

  12. Dielectric investigation of some woven fabrics

    NASA Astrophysics Data System (ADS)

    Cerovic, Dragana D.; Dojcilovic, Jablan R.; Asanovic, Koviljka A.; Mihajlidi, Tatjana A.

    2009-10-01

    In this paper, we have investigated the temperature dependence of dielectric properties (relative dielectric permeabilities and dielectric tangents of losses) for woven fabrics of hemp, jute, flax, cotton, polyester (PES), cotton-PES mixture, and wool. The measurements have been carried out at a temperature range from -50 to 50 °C in the electric periodic field at a frequency 1 MHz in vacuum. For the same specimens, the values of the dielectric properties have also been measured at an air temperature of 21 °C and at relative humidities of 40%, 60%, and 80%. At different frequencies from 80 kHz to 5 MHz, the dielectric properties have been measured at a relative humidity of 40% and at a temperature of 21 °C. An investigation of the dielectric properties of woven fabrics can provide a better understanding of the relation between the dielectric properties of woven fabrics and the different raw material compositions, temperatures, relative air humidities, and frequencies for specimens. Hence, this investigation helps to improve textile material properties.

  13. Morphology-controlled MnO2-graphene oxide-diatomaceous earth 3-dimensional (3D) composites for high-performance supercapacitors.

    PubMed

    Wen, Zhong Quan; Li, Min; Li, Fei; Zhu, Shi Jin; Liu, Xiao Ying; Zhang, Yu Xin; Kumeria, Tushar; Losic, Dusan; Gao, Yang; Zhang, Wei; He, Shi Xuan

    2016-01-21

    3-Dimensional (3D) composites based on a unique combination of MnO2-nanostructures, graphene oxide nanosheets and porous Diatomaceous Earth (DE) microparticles (GO-DE@MnO2) were synthesized and explored for application in high-performance supercapacitors. To explore the influence of the structural properties of MnO2 nanostructures on supercapacitor performances, several MnO2 structures with nanosheet and nanowire morphologies were synthesized and characterized. The prepared GO-DE@MnO2 composites with MnO2 nanosheets due to their higher conductivity and higher surface area showed a larger specific capacitance of 152.5 F g(-1) and a relatively better cycle stability (83.3% capacitance retention after 2000 cycles at a scan rate of 2 A g(-1)), indicating great potential for application in supercapacitors. PMID:26645931

  14. 3D-architectured nickel-cobalt-manganese layered double hydroxide/reduced graphene oxide composite for high-performance supercapacitor

    NASA Astrophysics Data System (ADS)

    Li, M.; Cheng, J. P.; Liu, F.; Zhang, X. B.

    2015-11-01

    Pure flower-like NiCoMn layered double hydroxide (LDH) and 3D-architectured NiCoMn LDH/reduced graphene oxide (rGO) composite are fabricated by a solution method. The NiCoMn hydroxide nanoflakes are tightly deposited on the surface of rGO. Electrochemical measurements prove that rGO can greatly improve its capacitive performances, compared with the pure counterpart. A high-specific capacitance of 912 F g-1, high-rate capability and long cycle life are achieved for the composite. A NiCoMn LDH/rGO//activated carbon hybrid capacitor is also fabricated. It possesses a high-specific capacitance of 206 F g-1 and an energy density of 92.8 W h kg-1 in 1.8 V.

  15. Cartilage Repair and Subchondral Bone Migration Using 3D Printing Osteochondral Composites: A One-Year-Period Study in Rabbit Trochlea

    PubMed Central

    Li, Dichen; Wang, Kunzheng; Hao, Dingjun; Bian, Weiguo; He, Jiankang; Jin, Zhongmin

    2014-01-01

    Increasing evidences show that subchondral bone may play a significant role in the repair or progression of cartilage damage in situ. However, the exact change of subchondral bone during osteochondral repair is still poorly understood. In this paper, biphasic osteochondral composite scaffolds were fabricated by 3D printing technology using PEG hydrogel and β-TCP ceramic and then implanted in rabbit trochlea within a critical size defect model. Animals were euthanized at 1, 2, 4, 8, 16, 24, and 52 weeks after implantation. Histological results showed that hyaline-like cartilage formed along with white smooth surface and invisible margin at 24 weeks postoperatively, typical tidemark formation at 52 weeks. The repaired subchondral bone formed from 16 to 52 weeks in a “flow like” manner from surrounding bone to the defect center gradually. Statistical analysis illustrated that both subchondral bone volume and migration area percentage were highly correlated with the gross appearance Wayne score of repaired cartilage. Therefore, subchondral bone migration is related to cartilage repair for critical size osteochondral defects. Furthermore, the subchondral bone remodeling proceeds in a “flow like” manner and repaired cartilage with tidemark implies that the biphasic PEG/β-TCP composites fabricated by 3D printing provides a feasible strategy for osteochondral tissue engineering application. PMID:25177697

  16. Fabrication of Compositionally and Topographically Complex Robust Tissue Forms by 3D-Electrochemical Compaction of Collagen

    PubMed Central

    Younesi, Mousa; Islam, Anowarul; Kishore, Vipuil; Panit, Stefi; Akkus, Ozan

    2015-01-01

    Collagen solutions are phase-transformed to mechanically robust shell structures with curviplanar topographies using electrochemically induced pH gradients. The process enables rapid layer-by-layer deposition of collagen-rich mixtures over the entire field simultaneously to obtain compositionally diverse multilayered structures. In-plane tensile strength and modulus of the electrocompacted collagen sheet samples were 5200 -fold and 2300 -fold greater than that of uncompacted collagen samples. Out of plane compression tests showed 27 -fold and fold increase in compressive stress and 46 -fold increase in compressive modulus compared to uncompacted collagen sheets. Cells proliferated 4.9 times faster, and cellular area spread was 2.7 times greater on compacted collagen sheets. Electrocompaction also resulted in 2.9 times greater focal adhesion area than on regular collagen hydrogel. The reported improvements in the cell-matrix interactions with electrocompaction would serve to expedite the population of electrocompacted collagen scaffolds by cells. The capacity of the method to fabricate nonlinear curved topographies with compositional heterogeneous layers is demonstrated by sequential deposition of collagenhydroxyapatite layer over a collagen layer. The complex curved topography of the nasal structure is replicated by the electrochemical compaction method. The presented electrochemical compaction process is an enabling modality which holds significant promise for reconstruction of a wide spectrum of topographically complex systems such as joint surfaces, craniofacial defects, ears, nose or urogenital forms. PMID:26069162

  17. 3D-stacked carbon composites employing networked electrical intra-pathways for direct-printable, extremely stretchable conductors.

    PubMed

    Chae, Changju; Seo, Yeong-Hui; Jo, Yejin; Kim, Ki Woong; Song, Wooseok; An, Ki-Seok; Choi, Sungho; Choi, Youngmin; Lee, Sun Sook; Jeong, Sunho

    2015-02-25

    The newly designed materials for stretchable conductors meeting the demands for both electrical and mechanical stability upon morphological elongation have recently been of paramount interest in the applications of stretchable, wearable electronics. To date, carbon nanotube-elastomeric polymer mixtures have been mainly developed; however, the method of preparing such CNT-polymer mixtures as stretchable conductors has been limited to an ionic liquid-mediated approach. In this study, we suggest a simple wet-chemical method for producing newly designed, three-dimensionally stacked carbon composite materials that facilitate the stable morphological elongation up to a strain of 300% with normalized conductivity variation of only 0.34 under a strain of 300%. Through a comparative study with other control samples, it is demonstrated that the intraconnected electrical pathways in hierarchically structured composite materials enable the generation of highly stretchable conductors. Their direct patternability is also evaluated by printing on demand using a programmable disperser without the use of prepatterned masks. PMID:25647807

  18. Effects of microstructure on the fatigue crack propagation resistance in composite microstructure by 3D fabric modeling for energy transport

    SciTech Connect

    Ishihara, T.; Kim, J.K.; Kobayashi, Y.

    1995-10-01

    In this study, martensite-ferrite dual phase steel composed of martensite in hard phase and ferrite in soft phase is made 3 dimensions fabric composite for energy transport and the difference in fatigue crack propagation behavior resulting from the structural size is investigated by fracture mechanics and microstructural method. The main results obtained are as follows: (1) the fatigue crack propagation rate is influenced by the ferrite grain size, in other words, in the low {Delta}K region the fatigue crack propagation rate is decreased with decreasing of the grain size but the difference of propagation rate resulted from the structural size is decreased as {Delta}K is increased; (2) the above results are explained by the degree of crack arrest effect of the martensite phase for the fatigue crack propagation depending on the ratio of reversed plastic zone size to the ferrite grain size.

  19. What lies beneath: Unveiling the fine-scale 3D compositional and thermal structure of the lithosphere and upper mantle

    NASA Astrophysics Data System (ADS)

    Afonso, Juan Carlos

    2013-04-01

    The lithosphere and sublithospheric upper mantle (above 410d) are highly heterogeneous in their chemistry, thermal structure and physical properties. Since most of the upper mantle is inaccessible to direct observation, we must rely on indirect methods to estimate its thermochemical structure. Lateral discontinuities (i.e. sharp changes in the thermal and/or compositional structure) in these regions are known to correlate with the location of seismically active zones, oil producing basins, foci of magma intrusion/production, and giant ore deposits. Understanding the fine-scale thermochemical structure of the lithosphere and sublithospheric upper mantle is therefore one of the most important goals in Geosciences. A detailed knowledge of the thermal and compositional structure of the upper mantle is also an essential prerequisite to understanding the formation, deformation and destruction of continents, the physical and chemical interactions between the lithosphere and the convective sublithospheric upper mantle, the long-term stability of ancient lithosphere, and the evolution of surface topography. Unfortunately, with current geophysical methods, such a holistic and detailed characterisation remains a technically and conceptually challenging problem. In this talk, I will discuss recent advancements in thermodynamically-constrained multi-observable probabilistic inversions, which have the potential to overcome the problems affecting other inversions schemes and provide realistic estimates of the present-day thermochemical structure of the lithosphere and upper mantle. I will present results for both synthetic and real case studies, which serve to highlight the advantages and limitations of our approach compared to others. I will also discuss future work towards the incorporation of such an approach into global thermo-mechanical simulations/inversions to study the intricate connections between the thermochemical structure of the upper mantle and the evolution of

  20. Ultrasound - A new approach for non-woven scaffolds investigation

    NASA Astrophysics Data System (ADS)

    Khramtsova, E. A.; Morokov, E. S.; Lukanina, K. I.; Grigoriev, T. E.; Petronyuk, Y. S.; Levin, V. M.

    2016-05-01

    In this study we verified the method of impulse acoustic microscopy as a tool for scaffold evaluation in tissue engineering investigation. Cellulose diacetate (CDA) non-woven 3D scaffold was used as a model object. Scanning electron microscopy and optical microscopy were used as reference methods in order to realize feasibility of acoustic microscopy method in a regenerative medicine field. Direct comparison of the different methods was carried out.

  1. 3-D multiobservable probabilistic inversion for the compositional and thermal structure of the lithosphere and upper mantle. I: a priori petrological information and geophysical observables

    NASA Astrophysics Data System (ADS)

    Afonso, J. C.; Fullea, J.; Griffin, W. L.; Yang, Y.; Jones, A. G.; D. Connolly, J. A.; O'Reilly, S. Y.

    2013-05-01

    of natural mantle samples collected from different tectonic settings (xenoliths, abyssal peridotites, ophiolite samples, etc.). This strategy relaxes more typical and restrictive assumptions such as the use of local/limited xenolith data or compositional regionalizations based on age-composition relations. We demonstrate that the combination of our ρ(m) with a L(m) that exploits the differential sensitivities of specific geophysical observables provides a general and robust inference platform to address the thermochemical structure of the lithosphere and sublithospheric upper mantle. An accompanying paper deals with the integration of these two functions into a general 3-D multiobservable Bayesian inversion method and its computational implementation.

  2. Nanostructured exchange coupled hard/soft composites: From the local magnetization profile to an extended 3d simple model

    NASA Astrophysics Data System (ADS)

    Russier, V.; Younsi, K.; Bessais, L.

    2012-03-01

    In nanocomposite magnetic materials the exchange coupling between phases plays a central role in the determination of the extrinsic magnetic properties of the material: coercive field,remanence magnetization. Exchange coupling is therefore of crucial importance in composite systems made of magnetically hard and soft grains or in partially crystallized media including nanosized crystallites in a soft matrix. It has been shown also to be a key point in the control of stratified hard/soft media coercive field in the research for optimized recording media. A signature of the exchange coupling due to the nanostructure is generally obtained on the magnetization curve M(H) with a plateau characteristic of the domain wall compression at the hard/soft interface ending at the depinning of the wall inside the hard phase. This compression/depinning behavior is clearly evidenced through one dimensional description of the interface, which is rigorously possible only in stratified media. Starting from a local description of the hard/soft interface in a model for nanocomposite system we show that one can extend this kind of behavior for system of hard crystallites embedded in a soft matrix.

  3. Recent developments in multi-layer flat knitting technology for waste free production of complex shaped 3D-reinforcing structures for composites

    NASA Astrophysics Data System (ADS)

    Trümper, W.; Lin, H.; Callin, T.; Bollengier, Q.; Cherif, C.; Krzywinski, S.

    2016-07-01

    Constantly increasing prices for raw materials and energy as well as the current discourse on the reduction of CO2-emissions places a special emphasis on the advantages of lightweight constructions and its resource conserving production methods. Fibre-reinforced composites are already seeing a number of applications in automobile, energy and mechanical engineering. Future applications within the named areas require greater material and energy efficiency and therefore manufacturing methods for textile preforms and lightweight constructions enabling an optimal arrangement of the reinforcing fibres while in the same time limiting waste to a minimum. One manufacturing method for textile reinforced preforms fulfilling quite many of the named requirements is the multilayer weft knitting technology. Multilayer weft knitted fabrics containing straight reinforcing yarns at least in two directions. The arrangement of these yarns is fixed by the loop yarn. Used yarn material in each knitting row is adaptable e. g. according to the load requirements or for the local integration of sensors. Draping properties of these fabrics can be varied within a great range and through this enabling draping of very complex shaped 3D-preforms without wrinkles from just one uncut fabric. The latest developments at ITM are concentrating on the development of a full production chain considering the 3D-CAD geometry, the load analysis, the generation of machine control programs as well as the development of technology and machines to enable the manufacturing of innovative net shape 3D-multilayer weft knitted fabrics such as complex shaped spacer fabrics and tubular fabrics with biaxial reinforcement.

  4. 3D nanospherical CdxZn1-xS/reduced graphene oxide composites with superior photocatalytic activity and photocorrosion resistance

    NASA Astrophysics Data System (ADS)

    Huang, Meina; Yu, Jianhua; Deng, Changshun; Huang, Yingheng; Fan, Minguang; Li, Bin; Tong, Zhangfa; Zhang, Feiyue; Dong, Lihui

    2016-03-01

    Herein, a series of CdxZn1-xS and sulfide/graphene photocatalysts with 3D nanospherical framework have been successfully fabricated by one-pot solvothermal method for the first time. The morphology and structure of samples were confirmed by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray (EDX) spectrometry, N2 adsorption, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS). The as-prepared samples exhibit excellent photocatalytic activities and photocorrosion resistance in the degradation of dyes under visible light. The Cd0.5Zn0.5S/rGO sample shows the most efficient in the photodegradation of methyl orange (MO). It takes about 30 min for degradation completely. The enhanced photocatalytic activity is mainly attributed to the slow photon enhancement of the 3D structure, and the heterojunction between the 3D nanospherical Cd0.5Zn0.5S solid solutions and a high quality 2D rGO support, which can greatly promote the separation of light-induced electrons and holes. Moreover, the large SBET and extended light absorption range also play an important role for improving the photocatalytic activity. The high photocatalytic stability is due to the successful inhibition of the photocorrosion of Cd0.5Zn0.5S/rGO by forming heterojunction between CdS and ZnS, and transferring the photogenerated electrons of Cd0.5Zn0.5S to rGO. The present work can provide rational design of graphene-based photocatalysts with large contact interface and strong interaction between the composites for other application.

  5. In-Plane Cracking Behavior and Ultimate Strength for 2D Woven and Braided Melt-Infiltrated SiC/SiC Composites Tensile Loaded in Off-Axis Fiber Directions

    NASA Technical Reports Server (NTRS)

    Morscher, Gregory N.; Yun, Hee Mann; DiCarlo, James A.

    2007-01-01

    The tensile mechanical properties of ceramic matrix composites (CMC) in directions off the primary axes of the reinforcing fibers are important for architectural design of CMC components that are subjected to multi-axial stress states. In this study, 2D-woven melt-infiltrated (MI) SiC/SiC composite panels with balanced fiber content in the 0 degree and 90 degree directions were tensile loaded in-plane in the 0 degree direction and at 45 degree to this direction. In addition, a 2D triaxially-braided MI composite panel with balanced fiber content in the plus or minus 67 degree bias directions and reduced fiber content in the axial direction was tensile loaded perpendicular to the axial direction tows (i.e., 23 degrees from the bias fibers). Stress-strain behavior, acoustic emission, and optical microscopy were used to quantify stress-dependent matrix cracking and ultimate strength in the panels. It was observed that both off-axis loaded panels displayed higher composite onset stresses for through-thickness matrix cracking than the 2D-woven 0/90 panels loaded in the primary 0 degree direction. These improvements for off-axis cracking strength can in part be attributed to higher effective fiber fractions in the loading direction, which in turn reduces internal stresses on critical matrix flaws for a given composite stress. Also for the 0/90 panel loaded in the 45 degree direction, an improved distribution of matrix flaws existed due to the absence of fiber tows perpendicular to the loading direction. In addition, for the +67/0/-67 braided panel, the axial tows perpendicular to the loading direction were not only low in volume fraction, but were also were well separated from one another. Both off-axis oriented panels also showed relatively good ultimate tensile strength when compared to other off-axis oriented composites in the literature, both on an absolute strength basis as well as when normalized by the average fiber strength within the composites. Initial

  6. Europeana and 3D

    NASA Astrophysics Data System (ADS)

    Pletinckx, D.

    2011-09-01

    The current 3D hype creates a lot of interest in 3D. People go to 3D movies, but are we ready to use 3D in our homes, in our offices, in our communication? Are we ready to deliver real 3D to a general public and use interactive 3D in a meaningful way to enjoy, learn, communicate? The CARARE project is realising this for the moment in the domain of monuments and archaeology, so that real 3D of archaeological sites and European monuments will be available to the general public by 2012. There are several aspects to this endeavour. First of all is the technical aspect of flawlessly delivering 3D content over all platforms and operating systems, without installing software. We have currently a working solution in PDF, but HTML5 will probably be the future. Secondly, there is still little knowledge on how to create 3D learning objects, 3D tourist information or 3D scholarly communication. We are still in a prototype phase when it comes to integrate 3D objects in physical or virtual museums. Nevertheless, Europeana has a tremendous potential as a multi-facetted virtual museum. Finally, 3D has a large potential to act as a hub of information, linking to related 2D imagery, texts, video, sound. We describe how to create such rich, explorable 3D objects that can be used intuitively by the generic Europeana user and what metadata is needed to support the semantic linking.

  7. Method of making carbon-carbon composites

    DOEpatents

    Engle, Glen B.

    1993-01-01

    A process for making 2D and 3D carbon-carbon composites having a combined high crystallinity, high strength, high modulus and high thermal and electrical conductivity. High-modulus/high-strength mesophase derived carbon fibers are woven into a suitable cloth. Layers of this easily graphitizible woven cloth are infiltrated with carbon material to form green composites. The carbonized composite is then impregnated several times with pitch by covering the composite with hot pitch under pressure. The composites are given a heat treatment between each impregnant step to crack up the infiltrated carbon and allow additional pitch to enter the microstructure during the next impregnation cycle. The impregnated composites are then given a final heat treatment in the range 2500.degree. to 3100.degree. C. to fully graphitize the fibers and the matrix carbon. The composites are then infiltrated with pyrolytic carbon by chemical vapor deposition in the range 1000.degree. C. to 1300.degree. C. at a reduced. pressure.

  8. High Energy Density Asymmetric Supercapacitor Based on NiOOH/Ni3S2/3D Graphene and Fe3O4/Graphene Composite Electrodes

    PubMed Central

    Lin, Tsung-Wu; Dai, Chao-Shuan; Hung, Kuan-Chung

    2014-01-01

    The application of the composite of Ni3S2 nanoparticles and 3D graphene as a novel cathode material for supercapacitors is systematically investigated in this study. It is found that the electrode capacitance increases by up to 111% after the composite electrode is activated by the consecutive cyclic voltammetry scanning in 1 M KOH. Due to the synergistic effect, the capacitance and the diffusion coefficient of electrolyte ions of the activated composite electrode are ca. 3.7 and 6.5 times higher than those of the Ni3S2 electrode, respectively. Furthermore, the activated composite electrode exhibits an ultrahigh specific capacitance of 3296 F/g and great cycling stability at a current density of 16 A/g. To obtain the reasonable matching of cathode/anode electrodes, the composite of Fe3O4 nanoparticles and chemically reduced graphene oxide (Fe3O4/rGO) is synthesized as the anode material. The Fe3O4/rGO electrode exhibits the specific capacitance of 661 F/g at 1 A/g and excellent rate capability. More importantly, an asymmetric supercapacitor fabricated by two different composite electrodes can be operated reversibly between 0 and 1.6 V and obtain a high specific capacitance of 233 F/g at 5 mV/s, which delivers a maximum energy density of 82.5 Wh/kg at a power density of 930 W/kg. PMID:25449978

  9. Compositional Density Structure of the Upper Mantle from Constrained 3-D Inversion of Gravity Anomaly: A Case Study of Southeast Asia

    NASA Astrophysics Data System (ADS)

    Liang, Q.; Chen, C.; Kaban, M. K.; Thomas, M.

    2014-12-01

    Mantle density structure is a key for tectonics. The density variations in the upper mantle are affected by temperature and composition. Seismic tomography method has been widely applied to obtain the P- and S-wave velocity structure in the mantle, which is then used to calculate the density perturbation. However, the velocity model is mainly due to the thermal effects but not the compositional effects. A method of 3-D inversion of gravity anomaly developed in spherical coordinates is used to image the large-scale density structure of upper mantle in Southeast Asia. The mantle gravity anomalies used in inversion are calculated by removing the crustal effects from the observed gravity. With constraints of thermal density model from seismic tomography, the integrative density structure is estimated from gravity inversion. Consequently, we obtain the compositional density by subtracting the thermal density from the integrative structure. The result of inversion shows the anisotropic composition of subduction zones, Cratons and plates boundary in Southeast Asia. In the shallow depth, the compositional density anomalies of large scales present uniform features in oceanic and continental mantle. In depth of 75-175 km, there are differences between the thermal and the compositional variations. The density anomalies at these depths are both affected by temperature and composition of the upper mantle. Below 175-km depth, the density anomalies are dominated by the compositional variations. Furthermore, comparing with high seismicity occurred at moderate-depth (50-300 km), we found that the compositional density variations is one of the factor that inducing earthquakes. The constrained inversion of mantle gravity anomaly has possibility to reveal the subduction which is not clearly seen from low-resolution tomography data, and may reveal the relation of seismicity and composition in the upper mantle. This study is supported by the Program of International Science and

  10. Thermal and Structural Performance of Woven Carbon Cloth For Adaptive Deployable Entry and Placement Technology

    NASA Technical Reports Server (NTRS)

    Arnold, James O.; Peterson, Keith H.; Yount, Bryan C.; Schneider, Nigel; Chavez-Garcia, Jose

    2013-01-01

    Arcjet testing and analysis of a three-dimensional (3D) woven carbon fabric has shown that it can be used as a thermal protection system and as a load bearing structural component for a low ballistic coefficient hypersonic decelerator called ADEPT (Adaptive Deployable Entry and Placement Technology). Results of arcjet tests proved that the 3D woven carbon fabric can withstand flight-like heating while under flight-like biaxial mechanical loads representative of those encountered during shallow entry flight path angles into the atmosphere of Venus. Importantly, the arcjet test results have been used to extend a preliminary material thermal response model based on previous testing of the same 3D woven carbon fabric under uni-axial mechanical loading.

  11. Stochastic Nonlinear Response of Woven CMCs

    NASA Technical Reports Server (NTRS)

    Kuang, C. Liu; Arnold, Steven M.

    2013-01-01

    It is well known that failure of a material is a locally driven event. In the case of ceramic matrix composites (CMCs), significant variations in the microstructure of the composite exist and their significance on both deformation and life response need to be assessed. Examples of these variations include changes in the fiber tow shape, tow shifting/nesting and voids within and between tows. In the present work, the influence of scale specific architectural features of woven ceramic composite are examined stochastically at both the macroscale (woven repeating unit cell (RUC)) and structural scale (idealized using multiple RUCs). The recently developed MultiScale Generalized Method of Cells methodology is used to determine the overall deformation response, proportional elastic limit (first matrix cracking), and failure under tensile loading conditions and associated probability distribution functions. Prior results showed that the most critical architectural parameter to account for is weave void shape and content with other parameters being less in severity. Current results show that statistically only the post-elastic limit region (secondary hardening modulus and ultimate tensile strength) is impacted by local uncertainties both at the macro and structural level.

  12. 3d-3d correspondence revisited

    NASA Astrophysics Data System (ADS)

    Chung, Hee-Joong; Dimofte, Tudor; Gukov, Sergei; Sułkowski, Piotr

    2016-04-01

    In fivebrane compactifications on 3-manifolds, we point out the importance of all flat connections in the proper definition of the effective 3d {N}=2 theory. The Lagrangians of some theories with the desired properties can be constructed with the help of homological knot invariants that categorify colored Jones polynomials. Higgsing the full 3d theories constructed this way recovers theories found previously by Dimofte-Gaiotto-Gukov. We also consider the cutting and gluing of 3-manifolds along smooth boundaries and the role played by all flat connections in this operation.

  13. Development of test methods for textile composites

    NASA Technical Reports Server (NTRS)

    Masters, John E.; Ifju, Peter G.; Fedro, Mark J.

    1993-01-01

    NASA's Advanced Composite Technology (ACT) Program was initiated in 1990 with the purpose of developing less costly composite aircraft structures. A number of innovative materials and processes were evaluated as a part of this effort. Chief among them are composite materials reinforced with textile preforms. These new forms of composite materials bring with them potential testing problems. Methods currently in practice were developed over the years for composite materials made from prepreg tape or simple 2-D woven fabrics. A wide variety of 2-D and 3-D braided, woven, stitched, and knit preforms were suggested for application in the ACT program. The applicability of existing test methods to the wide range of emerging materials bears investigation. The overriding concern is that the values measured are accurate representations of the true material response. The ultimate objective of this work is to establish a set of test methods to evaluate the textile composites developed for the ACT Program.

  14. 75 FR 53711 - Narrow Woven Ribbons With Woven Selvedge From China and Taiwan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-01

    ..., and by publishing the notice in the Federal Register on March 12, 2010 (75 FR 11908). The hearing was... COMMISSION Narrow Woven Ribbons With Woven Selvedge From China and Taiwan Determinations On the basis of the... reason of imports of narrow woven ribbons with woven selvedge from Taiwan, primarily provided for...

  15. Application of Three Unit-Cells Models on Mechanical Analysis of 3D Five-Directional and Full Five-Directional Braided Composites

    NASA Astrophysics Data System (ADS)

    Zhang, Chao; Xu, Xiwu; Chen, Kang

    2013-10-01

    As new lightweight textile material, 3D five directional and full five directional braided composites (5DBC and F5DBC) have tremendous potential applications in the aerospace industry. Before they are used in primary loading-bearing structures, a rational characterization of their mechanical properties is essential. In this paper, three types of unit-cell models corresponding to the interior, surface and corner regions of 5DBC and F5DBC are proposed. By introducing the reasonable boundary conditions, the effective stiffness properties of these two materials are predicted and compared by the three unit-cells models. The detailed mechanical response characteristic of the three unit-cell models is presented and analyzed in various loading cases. Numerical results show good agreement with experiment data, thus validates the proposed simulation method. Moreover, a parametric study is carried out for analyzing the effects of braiding angle and fiber volume fraction on the elastic properties of 5DBC and F5DBC. The obtained results can help designers to optimize the braided composite structures.

  16. Deployable robotic woven wire structures and joints for space applications

    NASA Technical Reports Server (NTRS)

    Shahinpoor, MO; Smith, Bradford

    1991-01-01

    Deployable robotic structures are basically expandable and contractable structures that may be transported or launched to space in a compact form. These structures may then be intelligently deployed by suitable actuators. The deployment may also be done by means of either airbag or spring-loaded typed mechanisms. The actuators may be pneumatic, hydraulic, ball-screw type, or electromagnetic. The means to trigger actuation may be on-board EPROMS, programmable logic controllers (PLCs) that trigger actuation based on some input caused by the placement of the structure in the space environment. The actuation may also be performed remotely by suitable remote triggering devices. Several deployable woven wire structures are examined. These woven wire structures possess a unique form of joint, the woven wire joint, which is capable of moving and changing its position and orientation with respect to the structure itself. Due to the highly dynamic and articulate nature of these joints the 3-D structures built using them are uniquely and highly expandable, deployable, and dynamic. The 3-D structure naturally gives rise to a new generation of deployable three-dimensional spatial structures.

  17. 3D and Education

    NASA Astrophysics Data System (ADS)

    Meulien Ohlmann, Odile

    2013-02-01

    Today the industry offers a chain of 3D products. Learning to "read" and to "create in 3D" becomes an issue of education of primary importance. 25 years professional experience in France, the United States and Germany, Odile Meulien set up a personal method of initiation to 3D creation that entails the spatial/temporal experience of the holographic visual. She will present some different tools and techniques used for this learning, their advantages and disadvantages, programs and issues of educational policies, constraints and expectations related to the development of new techniques for 3D imaging. Although the creation of display holograms is very much reduced compared to the creation of the 90ies, the holographic concept is spreading in all scientific, social, and artistic activities of our present time. She will also raise many questions: What means 3D? Is it communication? Is it perception? How the seeing and none seeing is interferes? What else has to be taken in consideration to communicate in 3D? How to handle the non visible relations of moving objects with subjects? Does this transform our model of exchange with others? What kind of interaction this has with our everyday life? Then come more practical questions: How to learn creating 3D visualization, to learn 3D grammar, 3D language, 3D thinking? What for? At what level? In which matter? for whom?

  18. 3D Imaging.

    ERIC Educational Resources Information Center

    Hastings, S. K.

    2002-01-01

    Discusses 3 D imaging as it relates to digital representations in virtual library collections. Highlights include X-ray computed tomography (X-ray CT); the National Science Foundation (NSF) Digital Library Initiatives; output peripherals; image retrieval systems, including metadata; and applications of 3 D imaging for libraries and museums. (LRW)

  19. Electrochemical and bio-sensing platform based on a novel 3D Cu nano-flowers/layered MoS₂ composite.

    PubMed

    Lin, Xiaoyun; Ni, Yongnian; Kokot, Serge

    2016-05-15

    A novel 3D nano-flower-like Cu/multi-layer molybdenum disulfide composite (CuNFs/MoS2) modified glassy carbon electrode (GCE) has been successfully constructed. It was a highly sensitive and selective non-enzymatic hydrogen peroxide (H2O2) and glucose biosensor. The morphology of the obtained CuNFs-MoS2 nano-particles was investigated with the use of a scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS). The physicochemical properties of the modified electrode were characterized at each of the construction stages with the use of an electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques. The new sensor combined the advantages of MoS2 and CuNFs, and exhibited high electro-catalytic activity toward H2O2 and glucose. Quantitative analysis of H2O2 and glucose was carried out with the use of the amperometric i-t method. Linear ranges were obtained between 0.04-1.88 μM and 1.88-35.6 μM for H2O2 and 1-20 μM and 20-70 μM for glucose, and their corresponding limits of detection (LOD) were 0.021 μM and 0.32 μM. This novel sensor was successfully applied for the quantitative analysis of H2O2 in tap water and glucose in human serum samples. PMID:26773372

  20. TRACE 3-D documentation

    SciTech Connect

    Crandall, K.R.

    1987-08-01

    TRACE 3-D is an interactive beam-dynamics program that calculates the envelopes of a bunched beam, including linear space-charge forces, through a user-defined transport system. TRACE 3-D provides an immediate graphics display of the envelopes and the phase-space ellipses and allows nine types of beam-matching options. This report describes the beam-dynamics calculations and gives detailed instruction for using the code. Several examples are described in detail.

  1. Woven-Yarn Thermoelectric Textiles.

    PubMed

    Lee, Jae Ah; Aliev, Ali E; Bykova, Julia S; de Andrade, Mônica Jung; Kim, Daeyoung; Sim, Hyeon Jun; Lepró, Xavier; Zakhidov, Anvar A; Lee, Jeong-Bong; Spinks, Geoffrey M; Roth, Siegmar; Kim, Seon Jeong; Baughman, Ray H

    2016-07-01

    The fabrication and characterization of highly flexible textiles are reported. These textiles can harvest thermal energy from temperature gradients in the desirable through-thickness direction. The tiger yarns containing n- and p-type segments are woven to provide textiles containing n-p junctions. A high power output of up to 8.6 W m(-2) is obtained for a temperature difference of 200 °C. PMID:27110905

  2. Stress-Dependent Matrix Cracking in 2D Woven SiC-Fiber Reinforced Melt-Infiltrated SiC Matrix Composites

    NASA Technical Reports Server (NTRS)

    Morscher, Gregory N.

    2003-01-01

    The matrix cracking of a variety of SiC/SiC composites has been characterized for a wide range of constituent variation. These composites were fabricated by the 2-dimensional lay-up of 0/90 five-harness satin fabric consisting of Sylramic fiber tows that were then chemical vapor infiltrated (CVI) with BN, CVI with SiC, slurry infiltrated with SiC particles followed by molten infiltration of Si. The composites varied in number of plies, the number of tows per length, thickness, and the size of the tows. This resulted in composites with a fiber volume fraction in the loading direction that ranged from 0.12 to 0.20. Matrix cracking was monitored with modal acoustic emission in order to estimate the stress-dependent distribution of matrix cracks. It was found that the general matrix crack properties of this system could be fairly well characterized by assuming that no matrix cracks originated in the load-bearing fiber, interphase, chemical vapor infiltrated Sic tow-minicomposites, i.e., all matrix cracks originate in the 90 degree tow-minicomposites or the large unreinforced Sic-Si matrix regions. Also, it was determined that the larger tow size composites had a much narrower stress range for matrix cracking compared to the standard tow size composites.

  3. Coated woven materials and method of preparation

    DOEpatents

    McCreary, W.J.; Carroll, D.W.

    Coating of woven materials so that not only the outer surfaces are coated has been a problem. Now, a solution to that problem is by coating with materials, with metals or with pyrolytic carbon. Materials are deposited in Chemical Vapor Deposition (CND) reactions using a fluidized bed so that the porosity of the woven materials is retained and the tiny filaments which make up the strands which are woven (including inner as well as outer filaments) are substantially uniformly coated.

  4. Coated woven materials and method of preparation

    DOEpatents

    McCreary, William J.; Carroll, David W.

    1981-01-01

    Coating of woven materials so that not only the outer surfaces are coated has been a problem. Now, a solution to that problem is the following: Woven materials are coated with materials, for example with metals or with pyrolytic carbon, which materials are deposited in Chemical Vapor Deposition (CVD) reactions using a fluidized bed so that the porosity of the woven material is retained and so that the tiny filaments which make up the strands which are woven (including inner as well as outer filaments) are substantially uniformly coated.

  5. 77 FR 32938 - Narrow Woven Ribbons With Woven Selvedge From Taiwan: Preliminary Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-04

    ...The Department of Commerce (Department) is conducting the first administrative review of the antidumping duty order on narrow woven ribbons with woven selvedge (narrow woven ribbons) from Taiwan. The sole mandatory respondent in this administrative review, Hubschercorp, did not respond to the Department's questionnaire. As a result, we have preliminarily assigned Hubschercorp a margin based on......

  6. Radiochromic 3D Detectors

    NASA Astrophysics Data System (ADS)

    Oldham, Mark

    2015-01-01

    Radiochromic materials exhibit a colour change when exposed to ionising radiation. Radiochromic film has been used for clinical dosimetry for many years and increasingly so recently, as films of higher sensitivities have become available. The two principle advantages of radiochromic dosimetry include greater tissue equivalence (radiologically) and the lack of requirement for development of the colour change. In a radiochromic material, the colour change arises direct from ionising interactions affecting dye molecules, without requiring any latent chemical, optical or thermal development, with important implications for increased accuracy and convenience. It is only relatively recently however, that 3D radiochromic dosimetry has become possible. In this article we review recent developments and the current state-of-the-art of 3D radiochromic dosimetry, and the potential for a more comprehensive solution for the verification of complex radiation therapy treatments, and 3D dose measurement in general.

  7. Bootstrapping 3D fermions

    NASA Astrophysics Data System (ADS)

    Iliesiu, Luca; Kos, Filip; Poland, David; Pufu, Silviu S.; Simmons-Duffin, David; Yacoby, Ran

    2016-03-01

    We study the conformal bootstrap for a 4-point function of fermions < ψψψψ> in 3D. We first introduce an embedding formalism for 3D spinors and compute the conformal blocks appearing in fermion 4-point functions. Using these results, we find general bounds on the dimensions of operators appearing in the ψ × ψ OPE, and also on the central charge C T . We observe features in our bounds that coincide with scaling dimensions in the GrossNeveu models at large N . We also speculate that other features could coincide with a fermionic CFT containing no relevant scalar operators.

  8. SRM nozzle design breakthroughs with advanced composite materials

    NASA Astrophysics Data System (ADS)

    Berdoyes, Michel

    1993-06-01

    The weight reduction-related performance and cost of the Space Shuttle's Solid Rocket Motor (SRM) units' critical nozzle components are undergoing revolutionary improvements through the use of 3D-woven carbon/carbon and carbon/alumina composite materials. These can be used to fabricate the SRM's nozzle throat nondegradable insulators, thermostructural insulator, and exit cones. Additional developments are noted among nozzle-related structural components for additional rocket propulsion systems, including a three-piece extendible nozzle.

  9. Fabrication and physical testing of graphite composite panels utilizing woven graphite fabric with current and advanced state-of-the-art resin systems

    NASA Technical Reports Server (NTRS)

    Lee, S. C. S.

    1979-01-01

    Three weaves were evaluated; a balanced plain weave, a balanced 8-harness satin weave, and a semiunidirectional crowfoot satin weave. The current state-of-the-art resin system selected was Fiberite's 934 Epoxy; the advanced resin systems evaluated were Phenolic, Phenolic/Novolac, Benzyl and Bismaleimide. The panels were fabricated for testing on NASA/Ames Research Center's Composites Modification Program. Room temperature mechanical tests only were performed by Hitco; the results are presented.

  10. A Study of Strength Transfer from tow to Textile Composite Using Different Reinforcement Architectures

    NASA Astrophysics Data System (ADS)

    Cristian, Irina; Nauman, Saad; Boussu, Francois; Koncar, Vladan

    2012-06-01

    The paper proposes an experimental and analytical approach of designing composites with the predetermined ultimate strength, reinforced with warp interlock fabrics. In order to better understand the phenomena of transfer of tensile properties from a tow to the composite, intermediate phases of composite manufacturing have also been taken into account and tensile properties of tows taken from the loom and the woven reinforcements have also been tested. Process of transfer of mechanical properties of raw materials to the final product (composite) depends on various structural factors. Here the influence of weave structure, which ultimately influences crimp has been studied. A strength transfer coefficient has been proposed which helps in estimating the influence of architectural parameters on 3D woven composites. 3 woven interlock reinforcements were woven to form composites. The coefficients of strength transfer were calculated for these three variants. The structural parameters were kept the same for these three reinforcements except for the weave structure. In was found that the phenomenon of strength transfer from tow to composite is negatively influenced by the crimp. In general the strength transfer coefficients have higher values for dry reinforcements and afterwards due to resin impregnation the values drop.

  11. 3D microscope

    NASA Astrophysics Data System (ADS)

    Iizuka, Keigo

    2008-02-01

    In order to circumvent the fact that only one observer can view the image from a stereoscopic microscope, an attachment was devised for displaying the 3D microscopic image on a large LCD monitor for viewing by multiple observers in real time. The principle of operation, design, fabrication, and performance are presented, along with tolerance measurements relating to the properties of the cellophane half-wave plate used in the design.

  12. Meshing Preprocessor for the Mesoscopic 3D Finite Element Simulation of 2D and Interlock Fabric Deformation

    NASA Astrophysics Data System (ADS)

    Wendling, A.; Daniel, J. L.; Hivet, G.; Vidal-Sallé, E.; Boisse, P.

    2015-12-01

    Numerical simulation is a powerful tool to predict the mechanical behavior and the feasibility of composite parts. Among the available numerical approaches, as far as woven reinforced composites are concerned, 3D finite element simulation at the mesoscopic scale leads to a good compromise between realism and complexity. At this scale, the fibrous reinforcement is modeled by an interlacement of yarns assumed to be homogeneous that have to be accurately represented. Among the numerous issues induced by these simulations, the first one consists in providing a representative meshed geometrical model of the unit cell at the mesoscopic scale. The second one consists in enabling a fast data input in the finite element software (contacts definition, boundary conditions, elements reorientation, etc.) so as to obtain results within reasonable time. Based on parameterized 3D CAD modeling tool of unit-cells of dry fabrics already developed, this paper presents an efficient strategy which permits an automated meshing of the models with 3D hexahedral elements and to accelerate of several orders of magnitude the simulation data input. Finally, the overall modeling strategy is illustrated by examples of finite element simulation of the mechanical behavior of fabrics.

  13. 3D hierarchical MnO2 nanorod/welded Ag-nanowire-network composites for high-performance supercapacitor electrodes.

    PubMed

    Qiao, Zhensong; Yang, Xiaopeng; Yang, Shuhua; Zhang, Liqiang; Cao, Bingqiang

    2016-06-28

    3D MnO2 nanorod/welded Ag-nanowire-network supercapacitor electrodes were prepared. Welding treatment of the Ag nanowire-network leads to low resistance and long lifetime. Galvanostatic charge/discharge (GCD) induces an ever-lasting morphology changing from flower-like to honeycomb-like for MnO2, which manifests as increasing specific capacitance to 663.4 F g(-1) after 7000 GCD cycles. PMID:27263832

  14. Multiviewer 3D monitor

    NASA Astrophysics Data System (ADS)

    Kostrzewski, Andrew A.; Aye, Tin M.; Kim, Dai Hyun; Esterkin, Vladimir; Savant, Gajendra D.

    1998-09-01

    Physical Optics Corporation has developed an advanced 3-D virtual reality system for use with simulation tools for training technical and military personnel. This system avoids such drawbacks of other virtual reality (VR) systems as eye fatigue, headaches, and alignment for each viewer, all of which are due to the need to wear special VR goggles. The new system is based on direct viewing of an interactive environment. This innovative holographic multiplexed screen technology makes it unnecessary for the viewer to wear special goggles.

  15. 3D Audio System

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Ames Research Center research into virtual reality led to the development of the Convolvotron, a high speed digital audio processing system that delivers three-dimensional sound over headphones. It consists of a two-card set designed for use with a personal computer. The Convolvotron's primary application is presentation of 3D audio signals over headphones. Four independent sound sources are filtered with large time-varying filters that compensate for motion. The perceived location of the sound remains constant. Possible applications are in air traffic control towers or airplane cockpits, hearing and perception research and virtual reality development.

  16. An aerial 3D printing test mission

    NASA Astrophysics Data System (ADS)

    Hirsch, Michael; McGuire, Thomas; Parsons, Michael; Leake, Skye; Straub, Jeremy

    2016-05-01

    This paper provides an overview of an aerial 3D printing technology, its development and its testing. This technology is potentially useful in its own right. In addition, this work advances the development of a related in-space 3D printing technology. A series of aerial 3D printing test missions, used to test the aerial printing technology, are discussed. Through completing these test missions, the design for an in-space 3D printer may be advanced. The current design for the in-space 3D printer involves focusing thermal energy to heat an extrusion head and allow for the extrusion of molten print material. Plastics can be used as well as composites including metal, allowing for the extrusion of conductive material. A variety of experiments will be used to test this initial 3D printer design. High altitude balloons will be used to test the effects of microgravity on 3D printing, as well as parabolic flight tests. Zero pressure balloons can be used to test the effect of long 3D printing missions subjected to low temperatures. Vacuum chambers will be used to test 3D printing in a vacuum environment. The results will be used to adapt a current prototype of an in-space 3D printer. Then, a small scale prototype can be sent into low-Earth orbit as a 3-U cube satellite. With the ability to 3D print in space demonstrated, future missions can launch production hardware through which the sustainability and durability of structures in space will be greatly improved.

  17. 3D Surgical Simulation

    PubMed Central

    Cevidanes, Lucia; Tucker, Scott; Styner, Martin; Kim, Hyungmin; Chapuis, Jonas; Reyes, Mauricio; Proffit, William; Turvey, Timothy; Jaskolka, Michael

    2009-01-01

    This paper discusses the development of methods for computer-aided jaw surgery. Computer-aided jaw surgery allows us to incorporate the high level of precision necessary for transferring virtual plans into the operating room. We also present a complete computer-aided surgery (CAS) system developed in close collaboration with surgeons. Surgery planning and simulation include construction of 3D surface models from Cone-beam CT (CBCT), dynamic cephalometry, semi-automatic mirroring, interactive cutting of bone and bony segment repositioning. A virtual setup can be used to manufacture positioning splints for intra-operative guidance. The system provides further intra-operative assistance with the help of a computer display showing jaw positions and 3D positioning guides updated in real-time during the surgical procedure. The CAS system aids in dealing with complex cases with benefits for the patient, with surgical practice, and for orthodontic finishing. Advanced software tools for diagnosis and treatment planning allow preparation of detailed operative plans, osteotomy repositioning, bone reconstructions, surgical resident training and assessing the difficulties of the surgical procedures prior to the surgery. CAS has the potential to make the elaboration of the surgical plan a more flexible process, increase the level of detail and accuracy of the plan, yield higher operative precision and control, and enhance documentation of cases. Supported by NIDCR DE017727, and DE018962 PMID:20816308

  18. Explicit 3-D Hydrodynamic FEM Program

    2000-11-07

    DYNA3D is a nonlinear explicit finite element code for analyzing 3-D structures and solid continuum. The code is vectorized and available on several computer platforms. The element library includes continuum, shell, beam, truss and spring/damper elements to allow maximum flexibility in modeling physical problems. Many materials are available to represent a wide range of material behavior, including elasticity, plasticity, composites, thermal effects and rate dependence. In addition, DYNA3D has a sophisticated contact interface capability, includingmore » frictional sliding, single surface contact and automatic contact generation.« less

  19. Explicit 3-D Hydrodynamic FEM Program

    SciTech Connect

    2000-11-07

    DYNA3D is a nonlinear explicit finite element code for analyzing 3-D structures and solid continuum. The code is vectorized and available on several computer platforms. The element library includes continuum, shell, beam, truss and spring/damper elements to allow maximum flexibility in modeling physical problems. Many materials are available to represent a wide range of material behavior, including elasticity, plasticity, composites, thermal effects and rate dependence. In addition, DYNA3D has a sophisticated contact interface capability, including frictional sliding, single surface contact and automatic contact generation.

  20. Manufacture and analysis of multilayer woven preforms

    SciTech Connect

    Bannister, M.K.; Herszberg, I.; Coman, F.; Raper, H.; Curiskis, J.

    1994-12-31

    Multilayer woven preforms were manufactured from high-tenacity, continuous multifilament polyester yarn and HTA carbon yarn. Orthogonal fiber architectures were constructed with a variety of binder thread configurations and yarn densities. The effect of the binder thread arrangement upon the as-woven preform architecture was examined. The preforms were then consolidated using liquid moulding techniques and the effect of the consolidation pressure upon the fiber architecture was investigated. Modeling of the preform architecture in its as-woven state is progressing and preliminary results are presented in this paper.

  1. Computational modeling and impact analysis of textile composite structures

    NASA Astrophysics Data System (ADS)

    Hur, Hae-Kyu

    This study is devoted to the development of an integrated numerical modeling enabling one to investigate the static and the dynamic behaviors and failures of 2-D textile composite as well as 3-D orthogonal woven composite structures weakened by cracks and subjected to static-, impact- and ballistic-type loads. As more complicated modeling about textile composite structures is introduced, some of homogenization schemes, geometrical modeling and crack propagations become more difficult problems to solve. To overcome these problems, this study presents effective mesh-generation schemes, homogenization modeling based on a repeating unit cell and sinusoidal functions, and also a cohesive element to study micro-crack shapes. This proposed research has two: (1) studying behavior of textile composites under static loads, (2) studying dynamic responses of these textile composite structures subjected to the transient/ballistic loading. In the first part, efficient homogenization schemes are suggested to show the influence of textile architectures on mechanical characteristics considering the micro modeling of repeating unit cell. Furthermore, the structures of multi-layered or multi-phase composites combined with different laminar such as a sub-laminate, are considered to find the mechanical characteristics. A simple progressive failure mechanism for the textile composites is also presented. In the second part, this study focuses on three main phenomena to solve the dynamic problems: micro-crack shapes, textile architectures and textile effective moduli. To obtain a good solutions of the dynamic problems, this research attempts to use four approaches: (I) determination of governing equations via a three-level hierarchy: micro-mechanical unit cell analysis, layer-wise analysis accounting for transverse strains and stresses, and structural analysis based on anisotropic plate layers, (II) development of an efficient computational approach enabling one to perform transient

  2. 3D polarimetric purity

    NASA Astrophysics Data System (ADS)

    Gil, José J.; San José, Ignacio

    2010-11-01

    From our previous definition of the indices of polarimetric purity for 3D light beams [J.J. Gil, J.M. Correas, P.A. Melero and C. Ferreira, Monogr. Semin. Mat. G. de Galdeano 31, 161 (2004)], an analysis of their geometric and physical interpretation is presented. It is found that, in agreement with previous results, the first parameter is a measure of the degree of polarization, whereas the second parameter (called the degree of directionality) is a measure of the mean angular aperture of the direction of propagation of the corresponding light beam. This pair of invariant, non-dimensional, indices of polarimetric purity contains complete information about the polarimetric purity of a light beam. The overall degree of polarimetric purity is obtained as a weighted quadratic average of the degree of polarization and the degree of directionality.

  3. 3D field harmonics

    SciTech Connect

    Caspi, S.; Helm, M.; Laslett, L.J.

    1991-03-30

    We have developed an harmonic representation for the three dimensional field components within the windings of accelerator magnets. The form by which the field is presented is suitable for interfacing with other codes that make use of the 3D field components (particle tracking and stability). The field components can be calculated with high precision and reduced cup time at any location (r,{theta},z) inside the magnet bore. The same conductor geometry which is used to simulate line currents is also used in CAD with modifications more readily available. It is our hope that the format used here for magnetic fields can be used not only as a means of delivering fields but also as a way by which beam dynamics can suggest correction to the conductor geometry. 5 refs., 70 figs.

  4. 'Bonneville' in 3-D!

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The Mars Exploration Rover Spirit took this 3-D navigation camera mosaic of the crater called 'Bonneville' after driving approximately 13 meters (42.7 feet) to get a better vantage point. Spirit's current position is close enough to the edge to see the interior of the crater, but high enough and far enough back to get a view of all of the walls. Because scientists and rover controllers are so pleased with this location, they will stay here for at least two more martian days, or sols, to take high resolution panoramic camera images of 'Bonneville' in its entirety. Just above the far crater rim, on the left side, is the rover's heatshield, which is visible as a tiny reflective speck.

  5. In-plane response and mode II fracture response of Z-pin woven laminates

    NASA Astrophysics Data System (ADS)

    Huang, Hseng-Ji

    Textile composites are proven to be an attractive choice over traditional pre-preg based composites because of reduced manufacturing costs and improved transverse mechanical properties. However, similar to traditional pre-preg composites, 2D laminates consisting of multiple layers of laminae still suffer from delamination under impact or transverse loads. Z-pin (carbon fiber of small diameter inserted in the thickness direction-z) composites are a means to provide higher through-thethickness stiffness and strength that 2D woven composites lack. In this thesis, The influences of Z-pin density and Z-pin diameter on the response of Z-pin under in-plane loads (compression) and transverse loads (mode II fracture) are examined. Both experiments and numerical simulations were performed to address the problems. Compression tests were conducted first and failure mechanism in each loading scenario was identified, through optical and mechanical measurements, during and after the tests. This was followed by the development of different numerical models of varying degree of sophistication, which include in-plane 2D models, (used to study fiber distortion and damage due to Z-pin insertion), multi-layer 2D models, (used to provide an inexpensive multi-layer model to study the effect of phase difference due to stacking consolidation), and multi-layer-multi-cell models (used to provide a full 3D multi-layer and multi-representative unit cell description). The second part of this thesis investigates the mode II fracture response under static and dynamic loading. Discrete Cohesive Zone Model (DCZM) was adopted to obtain the fracture toughness in conjunction with experimental data. In dynamic test, a crack advance gage (CAG) was designed to capture the exact time when the crack begins to propagate. By use of these CAGs, the corresponding crack propagation speed between different CAGs can be computed accordingly. These observations are supplemented through high speed optical images

  6. Personnel occupied woven envelope robot power

    NASA Technical Reports Server (NTRS)

    Wessling, F. C.

    1988-01-01

    The Personnel Occupied Woven Envelope Robot (POWER) concept has evolved over the course of the study. The goal of the project was the development of methods and algorithms for solid modeling for the flexible robot arm.

  7. Advances in Composites Technology

    NASA Technical Reports Server (NTRS)

    Tenney, D. R.; Dexter, H. B.

    1985-01-01

    A significant level of research is currently focused on the development of tough resins and high strain fibers in an effort to gain improved damage tolerance. Moderate success has been achieved with the development of new resins such as PEEK and additional improvements look promising with new thermoplastic resins. Development of innovative material forms such as 2-D and 3-D woven fabrics and braided structural subelements is also expected to improve damage tolerance and durability of composite hardware. The new thrust in composites is to develop low cost manufacturing and design concepts to lower the cost of composite hardware. Processes being examined include automated material placement, filament winding, pultrusion, and thermoforming. The factory of the future will likely incorporate extensive automation in all aspects of manufacturing composite components.

  8. Formable woven preforms based on in situ reinforced thermoplastic fibers

    SciTech Connect

    Robertson, C.G.; Souza, J.P. de; Baird, D.G.

    1995-12-01

    Blends of Vectra B950 (VB) and polypropylene (PP) were spun into fibers utilizing a dual extrusion process for use in formable fabric prepregs. Fibers of 50/50 weight composition were processed up to fiber draw ratios of 106. The tensile modulus of these fibers showed positive deviation from the rule of mixtures for draw ratios greater than 40, and the tensile modulus and strength properties did not level off within the range of draw ratios investigated. The fibers, pre-wetted with polypropylene, were woven into fabrics that were subsequently impregnated with polypropylene sheet to form composites. The tensile mechanical properties of these composites were nearly equivalent to those of long glass fiber reinforced polypropylene. At temperatures between 240 and 280{degrees}C, composites of 6.3 wt.% VB proved formable with elongation to break values in excess of 20%. Impregnated fabric composites were successfully thermoformed without noticeable fiber damage, and a combined fabric impregnation / thermoforming process was developed.

  9. Prominent rocks - 3D

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Many prominent rocks near the Sagan Memorial Station are featured in this image, taken in stereo by the Imager for Mars Pathfinder (IMP) on Sol 3. 3D glasses are necessary to identify surface detail. Wedge is at lower left; Shark, Half-Dome, and Pumpkin are at center. Flat Top, about four inches high, is at lower right. The horizon in the distance is one to two kilometers away.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

    Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right

  10. 'Diamond' in 3-D

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This 3-D, microscopic imager mosaic of a target area on a rock called 'Diamond Jenness' was taken after NASA's Mars Exploration Rover Opportunity ground into the surface with its rock abrasion tool for a second time.

    Opportunity has bored nearly a dozen holes into the inner walls of 'Endurance Crater.' On sols 177 and 178 (July 23 and July 24, 2004), the rover worked double-duty on Diamond Jenness. Surface debris and the bumpy shape of the rock resulted in a shallow and irregular hole, only about 2 millimeters (0.08 inch) deep. The final depth was not enough to remove all the bumps and leave a neat hole with a smooth floor. This extremely shallow depression was then examined by the rover's alpha particle X-ray spectrometer.

    On Sol 178, Opportunity's 'robotic rodent' dined on Diamond Jenness once again, grinding almost an additional 5 millimeters (about 0.2 inch). The rover then applied its Moessbauer spectrometer to the deepened hole. This double dose of Diamond Jenness enabled the science team to examine the rock at varying layers. Results from those grindings are currently being analyzed.

    The image mosaic is about 6 centimeters (2.4 inches) across.

  11. Polyaniline-modified 3D-flower-like molybdenum disulfide composite for efficient adsorption/photocatalytic reduction of Cr(VI).

    PubMed

    Gao, Yang; Chen, Changlun; Tan, Xiaoli; Xu, Huan; Zhu, Kairuo

    2016-08-15

    Polyaniline (PANI) was modified onto 3D flower-like molybdenum disulfide (MoS2) to prepare a novel organic-inorganic hybrid material, PANI@MoS2. PANI@MoS2 was characterized by scanning and transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and thermogravimetric analysis. The results indicate that PANI was modified onto MoS2. PANI@MoS2 was applied as an adsorbent to remove Cr(VI) from aqueous solutions, and the adsorption isotherms fit well to the Langmuir model; the maximum removal capacity of Cr(VI) by PANI@MoS2 was 526.3 and 623.2mg/g at pH 3.0 and 1.5, respectively. PANI@MoS2 exhibited an enhanced removal capacity of Cr(VI) in comparison with bare MoS2 and other adsorbents. The adsorption of Cr(VI) on PANI@MoS2 might be attributed to the complexation between the amine and imine groups on the surface of PANI@MoS2 with Cr(VI). This study implies that the hybrid material PANI@MoS2 is a potential adsorbent for Cr(VI) removal from large volumes of aqueous solutions. PMID:27209391

  12. 3D coral-like nitrogen-sulfur co-doped carbon-sulfur composite for high performance lithium-sulfur batteries.

    PubMed

    Wu, Feng; Li, Jian; Tian, Yafen; Su, Yuefeng; Wang, Jing; Yang, Wen; Li, Ning; Chen, Shi; Bao, Liying

    2015-01-01

    3D coral-like, nitrogen and sulfur co-doped mesoporous carbon has been synthesized by a facile hydrothermal-nanocasting method to house sulfur for Li-S batteries. The primary doped species (pyridinic-N, pyrrolic-N, thiophenic-S and sulfonic-S) enable this carbon matrix to suppress the diffusion of polysulfides, while the interconnected mesoporous carbon network is favourable for rapid transport of both electrons and lithium ions. Based on the synergistic effect of N, S co-doping and the mesoporous conductive pathway, the as-fabricated C/S cathodes yield excellent cycling stability at a current rate of 4 C (1 C = 1675 mA g(-1)) with only 0.085% capacity decay per cycle for over 250 cycles and ultra-high rate capability (693 mAh g(-1) at 10 C rate). These capabilities have rarely been reported before for Li-S batteries. PMID:26288961

  13. Conversion of uniform graphene oxide/polypyrrole composites into functionalized 3D carbon nanosheet frameworks with superior supercapacitive and sodium-ion storage properties

    NASA Astrophysics Data System (ADS)

    Wang, Huanwen; Zhang, Yu; Sun, Wenping; Tan, Hui Teng; Franklin, Joseph B.; Guo, Yuanyuan; Fan, Haosen; Ulaganathan, Mani; Wu, Xing-Long; Luo, Zhong-Zhen; Madhavi, Srinivasan; Yan, Qingyu

    2016-03-01

    Two-dimensional (2D) graphene oxide/polypyrrole (GO/PPy) hybrid materials derived from in-situ polymerization are used as precursors for constructing functionalized three-dimensional (3D) porous nitrogen-doped carbon nanosheet frameworks (FT-PNCNFs) through a one-step activation strategy. In the formation process of FT-PNCNFs, PPY is directly converted into hierarchical porous nitrogen-doped carbon layers, while GO is simultaneously reduced to become electrically conductive. The complementary functions of individual components endow the FT-PNCNFs with excellent properties for both supercapacitors (SCs) and sodium ion batteries (SIBs) applications. When tested in symmetrical SC, the FT-PNCNFs demonstrate superior energy storage behaviour. At an extremely high scan rate of 3000 mV s-1, the cyclic voltammetry (CV) curve retains an inspiring quasi-rectangle shape in KOH solution. Meanwhile, high capacitances (∼247 F g-1 at 10 mV s-1; ∼146 F g-1 at 3000 mV s-1) and good cycling stability (∼95% retention after 8000 cycles) are achieved. In addition, an attractive SIB anode performance could be achieved. The FT-PNCNFs electrode delivers a reversible capacity of 187 mAh g-1 during 160th cycle at 100 mA g-1. Its reversible capacity retains 144 mAh g-1 after extending the number of cycles to 500 at 500 mA g-1.

  14. 3D coral-like nitrogen-sulfur co-doped carbon-sulfur composite for high performance lithium-sulfur batteries

    PubMed Central

    Wu, Feng; Li, Jian; Tian, Yafen; Su, Yuefeng; Wang, Jing; Yang, Wen; Li, Ning; Chen, Shi; Bao, Liying

    2015-01-01

    3D coral-like, nitrogen and sulfur co-doped mesoporous carbon has been synthesized by a facile hydrothermal-nanocasting method to house sulfur for Li–S batteries. The primary doped species (pyridinic-N, pyrrolic-N, thiophenic-S and sulfonic-S) enable this carbon matrix to suppress the diffusion of polysulfides, while the interconnected mesoporous carbon network is favourable for rapid transport of both electrons and lithium ions. Based on the synergistic effect of N, S co-doping and the mesoporous conductive pathway, the as-fabricated C/S cathodes yield excellent cycling stability at a current rate of 4 C (1 C = 1675 mA g−1) with only 0.085% capacity decay per cycle for over 250 cycles and ultra-high rate capability (693 mAh g−1 at 10 C rate). These capabilities have rarely been reported before for Li-S batteries. PMID:26288961

  15. High hardness BaCb-(BxOy/BN) composites with 3D mesh-like fine grain-boundary structure by reactive spark plasma sintering.

    PubMed

    Vasylkiv, Oleg; Borodianska, Hanna; Badica, Petre; Grasso, Salvatore; Sakka, Yoshio; Tok, Alfred; Su, Liap Tat; Bosman, Michael; Ma, Jan

    2012-02-01

    Boron carbide B4C powders were subject to reactive spark plasma sintering (also known as field assisted sintering, pulsed current sintering or plasma assisted sintering) under nitrogen atmosphere. For an optimum hexagonal BN (h-BN) content estimated from X-ray diffraction measurements at approximately 0.4 wt%, the as-prepared BaCb-(BxOy/BN) ceramic shows values of Berkovich and Vickers hardness of 56.7 +/- 3.1 GPa and 39.3 +/- 7.6 GPa, respectively. These values are higher than for the vacuum SPS processed B4C pristine sample and the h-BN -mechanically-added samples. XRD and electronic microscopy data suggest that in the samples produced by reactive SPS in N2 atmosphere, and containing an estimated amount of 0.3-1.5% h-BN, the crystallite size of the boron carbide grains is decreasing with the increasing amount of N2, while for the newly formed lamellar h-BN the crystallite size is almost constant (approximately 30-50 nm). BN is located at the grain boundaries between the boron carbide grains and it is wrapped and intercalated by a thin layer of boron oxide. BxOy/BN forms a fine and continuous 3D mesh-like structure that is a possible reason for good mechanical properties. PMID:22629879

  16. 3D coral-like nitrogen-sulfur co-doped carbon-sulfur composite for high performance lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Wu, Feng; Li, Jian; Tian, Yafen; Su, Yuefeng; Wang, Jing; Yang, Wen; Li, Ning; Chen, Shi; Bao, Liying

    2015-08-01

    3D coral-like, nitrogen and sulfur co-doped mesoporous carbon has been synthesized by a facile hydrothermal-nanocasting method to house sulfur for Li-S batteries. The primary doped species (pyridinic-N, pyrrolic-N, thiophenic-S and sulfonic-S) enable this carbon matrix to suppress the diffusion of polysulfides, while the interconnected mesoporous carbon network is favourable for rapid transport of both electrons and lithium ions. Based on the synergistic effect of N, S co-doping and the mesoporous conductive pathway, the as-fabricated C/S cathodes yield excellent cycling stability at a current rate of 4 C (1 C = 1675 mA g-1) with only 0.085% capacity decay per cycle for over 250 cycles and ultra-high rate capability (693 mAh g-1 at 10 C rate). These capabilities have rarely been reported before for Li-S batteries.

  17. Exact geometry solid-shell element based on a sampling surfaces technique for 3D stress analysis of doubly-curved composite shells

    NASA Astrophysics Data System (ADS)

    Kulikov, G. M.; Mamontov, A. A.; Plotnikova, S. V.; Mamontov, S. A.

    2015-11-01

    A hybrid-mixed ANS four-node shell element by using the sampling surfaces (SaS) technique is developed. The SaS formulation is based on choosing inside the nth layer In not equally spaced SaS parallel to the middle surface of the shell in order to introduce the displacements of these surfaces as basic shell variables. Such choice of unknowns with the consequent use of Lagrange polynomials of degree In - 1 in the thickness direction for each layer permits the presentation of the layered shell formulation in a very compact form. The SaS are located inside each layer at Chebyshev polynomial nodes that allows one to minimize uniformly the error due to the Lagrange interpolation. To implement the efficient analytical integration throughout the element, the enhanced ANS method is employed. The proposed hybrid-mixed four-node shell element is based on the Hu-Washizu variational equation and exhibits a superior performance in the case of coarse meshes. It could be useful for the 3D stress analysis of thick and thin doubly-curved shells since the SaS formulation gives the possibility to obtain numerical solutions with a prescribed accuracy, which asymptotically approach the exact solutions of elasticity as the number of SaS tends to infinity.

  18. 78 FR 29703 - Narrow Woven Ribbons With Woven Selvedge From Taiwan: Preliminary Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-21

    ... Determination of Sales at Less than Fair Value: Narrow Woven Ribbons with Woven Selvedge from Taiwan, 75 FR... questionnaire. As a result, we have preliminarily assigned these companies a margin based on adverse facts... preliminary results, we have relied on facts available and, because the respondents did not act to the best...

  19. Personnel occupied woven envelope robot

    NASA Technical Reports Server (NTRS)

    Wessling, Francis; Teoh, William; Ziemke, M. Carl

    1988-01-01

    The Personnel Occupied Woven Envelope Robot (POWER) provides an alternative to extravehicular activity (EVA) of space suited astronauts and/or use of long slender manipulator arms such as are used in the Shuttle Remote Manipulator System. POWER provides the capability for a shirt sleeved astronaut to perform such work by entering a control pod through air locks at both ends of an inflated flexible bellows (access tunnel). The exoskeleton of the tunnel is a series of six degrees of freedom (Six-DOF) articulated links compressible to 1/6 of their fully extended length. The operator can maneuver the control pod to almost any location within about 50 m of the base attachment to the space station. POWER can be envisioned as a series of hollow Six-DOF manipulator segments or arms wherein each arm grasps the shoulder of the next arm. Inside the hollow arms ia a bellow-type access tunnel. The control pod is the fist of the series of linked hollow arms. The fingers of the fist are conventional manipulator arms under direct visual control of the nearby operator in the pod. The applications and progress to date of the POWER system is given.

  20. Regoliths in 3-D

    NASA Technical Reports Server (NTRS)

    Grant, John; Cheng, Andrew; Delamere, Allen; Gorevan, Steven; Korotev, Randy; McKay, David; Schmitt, Harrison; Zarnecki, John

    1996-01-01

    A planetary regolith is any layer of fragments, unconsolidated material that may or may not be textually or compositionally altered relative to underlying substrate and occurs on the outer surface of a solar system body. This includes fragmented material from volcanic, sedimentary, and meteoritic infall sources, and derived by any process (e.g. impact and all other endogenic or exogenic processes). Many measurements that can be made from orbit or from Earth-based observations provide information only about the uppermost portions of a regolith and not the underlying substrate(s). Thus an understanding of the formation processes, physical properties, composition, and evolution of planetary regoliths is essential in answering scientific questions posed by the Committee on Planetary and Lunar Exploration (COMPLEX). This paper provides examples of measurements required to answer these critical science questions.

  1. Microstructural characterization of fiber-reinforced composites

    SciTech Connect

    Summerscales, J.

    1998-12-31

    In the past 50 years, great progress has been made in developing artificial fiber-reinforced composite materials, generally using filaments with microscopic diameters. An array of reinforcement forms can be used in commercial applications--with the microstructure being a critical factor in realizing the required properties in a material. This book comprehensively examines the application of advanced microstructural characterization techniques to fiber-reinforced composites. Its contents include: (1) flexible textile composite microstructure; (2) 3-D confocal microscopy of glass fiber-reinforced composites; (3) geometric modeling of yarn and fiber assemblies; (4) characterization of yarn shape in woven fabric composites; (5) quantitative microstructural analysis for continuous fiber composites; (6) electron microscopy of polymer composites; (7) micromechanics of reinforcement using laser raman spectroscopy; and (8) acoustic microscopy of ceramic fiber composites.

  2. One-pot solvothermal synthesis of three-dimensional (3D) BiOI/BiOCl composites with enhanced visible-light photocatalytic activities for the degradation of bisphenol-A.

    PubMed

    Xiao, Xin; Hao, Rong; Liang, Min; Zuo, Xiaoxi; Nan, Junmin; Li, Laisheng; Zhang, Weide

    2012-09-30

    Three-dimensional (3D) BiOI/BiOCl composite microspheres with enhanced visible-light photodegradation activity of bisphenol-A (BPA) are synthesized by a simple, one-pot, template-free, solvothermal method using BiI(3) and BiCl(3) as precursors. These 3D hierarchical microspheres with heterojunction structures are composed of 2D nanosheets and have composition-dependent absorption properties in the ultraviolet and visible light regions. The photocatalytic oxidation of BPA over BiOI/BiOCl composites followed pseudo first-order kinetics according to the Langmuir-Hinshelwood model. The highest photodegradation efficiency of BPA, i.e., nearly 100%, was observed with the BiOI/BiOCl composite (containing 90% BiOI) using a catalyst dosage of 1 g L(-1) in the BPA solution (C(0)=20 mg L(-1), pH=7.0) under visible light irradiation for 60 min. Under these conditions, the reaction rate constant was more than 4 and 20 times greater than that of pure BiOI and the commercially available Degussa P25, respectively. The superior photocatalytic activity of this composite catalyst is attributed to the suitable band gap energies and the low recombination rate of the photogenerated electron-hole pairs due to the presence of BiOI/BiOCl heterostructures. Only one intermediate at m/z 151 was observed in the photodegradation process of BPA by liquid chromatography combined with mass spectrometry (LC-MS) analysis, and a simple and hole-predominated photodegradation pathway of BPA was subsequently proposed. Furthermore, this photocatalyst exhibited a high mineralization ratio, high stability and easy separation for recycling use, suggesting that it is a promising photocatalyst for the removal of BPA pollutants. PMID:22818177

  3. Possible Applications of 3D Printing Technology on Textile Substrates

    NASA Astrophysics Data System (ADS)

    Korger, M.; Bergschneider, J.; Lutz, M.; Mahltig, B.; Finsterbusch, K.; Rabe, M.

    2016-07-01

    3D printing is a rapidly emerging additive manufacturing technology which can offer cost efficiency and flexibility in product development and production. In textile production 3D printing can also serve as an add-on process to apply 3D structures on textiles. In this study the low-cost fused deposition modeling (FDM) technique was applied using different thermoplastic printing materials available on the market with focus on flexible filaments such as thermoplastic elastomers (TPE) or Soft PLA. Since a good adhesion and stability of the 3D printed structures on textiles are essential, separation force and abrasion resistance tests were conducted with different kinds of printed woven fabrics demonstrating that a sufficient adhesion can be achieved. The main influencing factor can be attributed to the topography of the textile surface affected by the weave, roughness and hairiness offering formlocking connections followed by the wettability of the textile surface by the molten polymer, which depends on the textile surface energy and can be specifically controlled by washing (desizing), finishing or plasma treatment of the textile before the print. These basic adhesion mechanisms can also be considered crucial for 3D printing on knitwear.

  4. Higher-order compositional modeling of three-phase flow in 3D fractured porous media based on cross-flow equilibrium

    SciTech Connect

    Moortgat, Joachim Firoozabadi, Abbas

    2013-10-01

    Numerical simulation of multiphase compositional flow in fractured porous media, when all the species can transfer between the phases, is a real challenge. Despite the broad applications in hydrocarbon reservoir engineering and hydrology, a compositional numerical simulator for three-phase flow in fractured media has not appeared in the literature, to the best of our knowledge. In this work, we present a three-phase fully compositional simulator for fractured media, based on higher-order finite element methods. To achieve computational efficiency, we invoke the cross-flow equilibrium (CFE) concept between discrete fractures and a small neighborhood in the matrix blocks. We adopt the mixed hybrid finite element (MHFE) method to approximate convective Darcy fluxes and the pressure equation. This approach is the most natural choice for flow in fractured media. The mass balance equations are discretized by the discontinuous Galerkin (DG) method, which is perhaps the most efficient approach to capture physical discontinuities in phase properties at the matrix-fracture interfaces and at phase boundaries. In this work, we account for gravity and Fickian diffusion. The modeling of capillary effects is discussed in a separate paper. We present the mathematical framework, using the implicit-pressure-explicit-composition (IMPEC) scheme, which facilitates rigorous thermodynamic stability analyses and the computation of phase behavior effects to account for transfer of species between the phases. A deceptively simple CFL condition is implemented to improve numerical stability and accuracy. We provide six numerical examples at both small and larger scales and in two and three dimensions, to demonstrate powerful features of the formulation.

  5. Design of Stable and Powerful Nanobiocatalysts, Based on Enzyme Laccase Immobilized on Self-Assembled 3D Graphene/Polymer Composite Hydrogels.

    PubMed

    Ormategui, Nerea; Veloso, Antonio; Leal, Gracia Patricia; Rodriguez-Couto, Susana; Tomovska, Radmila

    2015-07-01

    Graphene-based materials appear as a suitable answer to the demand for novel nanostructured materials for effective nanobiocatalytic systems design. In this work, a design of stable and efficient nanobiocatalysts made of enzyme laccase immobilized on composite hydrogels [reduced graphene oxide (rGO)/polymer] is presented. The composite hydrogel supports were synthesized by self-assembly of graphene oxide nanoplatelets in the frame of a polymer latex matrix, where the polymer nanoparticles were adsorbed onto the GO surface, creating hybrid nanoplatelets. These hybrids self-assembled when ascorbic acid was added as a GO reducing agent and formed three-dimensional porous structures, greatly swollen with water, e.g., the composite hydrogels. The hydrogels were used as a support for covalent immobilization of the laccase. The performance of the nanobiocatalysts was tested in the oxidative degradation of the recalcitrant synthetic dye Remazol Brilliant Blue R in aqueous solutions. The biocatalysts showed strong dye discoloration ability and high stability as they preserved their catalytic action in four successive batches of dye degradation. The presented biocatalysts offer possibilities for overcoming the main disadvantages of the enzyme catalysts (fragile nature, high cost, and high loading of the enzyme), which would lead to a step forward toward their industrial application. PMID:26075472

  6. Chondrogenesis and Mineralization During In Vitro Culture of Human Mesenchymal Stem Cells on Three-Dimensional Woven Scaffolds

    PubMed Central

    Abrahamsson, Christoffer K.; Yang, Fan; Park, Hyoungshin; Brunger, Jonathan M.; Valonen, Piia K.; Langer, Robert; Welter, Jean F.; Caplan, Arnold I.; Guilak, Farshid

    2010-01-01

    Human mesenchymal stem cells (hMSCs) and three-dimensional (3D) woven poly(ɛ-caprolactone) (PCL) scaffolds are promising tools for skeletal tissue engineering. We hypothesized that in vitro culture duration and medium additives can individually and interactively influence the structure, composition, mechanical, and molecular properties of engineered tissues based on hMSCs and 3D poly(ɛ-caprolactone). Bone marrow hMSCs were suspended in collagen gel, seeded on scaffolds, and cultured for 1, 21, or 45 days under chondrogenic and/or osteogenic conditions. Structure, composition, biomechanics, and gene expression were analyzed. In chondrogenic medium, cartilaginous tissue formed by day 21, and hypertrophic mineralization was observed in the newly formed extracellular matrix at the interface with underlying scaffold by day 45. Glycosaminoglycan, hydroxyproline, and calcium contents, and alkaline phosphatase activity depended on culture duration and medium additives, with significant interactive effects (all p < 0.0001). The 45-day constructs exhibited mechanical properties on the order of magnitude of native articular cartilage (aggregate, Young's, and shear moduli of 0.15, 0.12, and 0.033 MPa, respectively). Gene expression was characteristic of chondrogenesis and endochondral bone formation, with sequential regulation of Sox-9, collagen type II, aggrecan, core binding factor alpha 1 (Cbfα1)/Runx2, bone sialoprotein, bone morphogenetic protein-2, and osteocalcin. In contrast, osteogenic medium produced limited osteogenesis. Long-term culture of hMSC on 3D scaffolds resulted in chondrogenesis and regional mineralization at the interface between soft, newly formed engineered cartilage, and stiffer underlying scaffold. These findings merit consideration when developing grafts for osteochondral defect repair. PMID:20673022

  7. Biomechanical comparison of implant retained fixed partial dentures with fiber reinforced composite versus conventional metal frameworks: a 3D FEA study.

    PubMed

    Erkmen, Erkan; Meriç, Gökçe; Kurt, Ahmet; Tunç, Yahya; Eser, Atılım

    2011-01-01

    Fiber reinforced composite (FRC) materials have been successfully used in a variety of commercial applications. These materials have also been widely used in dentistry. The use of fiber composite technology in implant prostheses has been previously presented, since they may solve many problems associated with metal alloy frameworks such as corrosion, complexity of fabrication and high cost. The hypothesis of this study was that an FRC framework with lower flexural modulus provides more even stress distribution throughout the implant retained fixed partial dentures (FPDs) than a metal framework does. A 3-dimensional finite element analysis was conducted to evaluate the stress distribution in bone, implant-abutment complex and prosthetic structures. Hence, two distinctly different models of implant retained 3-unit fixed partial dentures, composed of Cr-Co and porcelain (M-FPD model) or FRC and particulate composite (FRC-FPD model) were utilized. In separate load cases, 300 N vertical, 150 N oblique and 60 N horizontal forces were simulated. When the FRC-FPD and M-FPD models were compared, it was found that all investigated stress values in the M-FPD model were higher than the values in the FRC-FPD model except for the stress values in the implant-abutment complex. It can be concluded that the implant supported FRC-FPD could eliminate the excessive stresses in the bone-implant interface and maintain normal physiological loading of the surrounding bone, therefore minimizing the risk of peri-implant bone loss due to stress-shielding. PMID:21094484

  8. Acousto-Ultrasonic analysis of failure in ceramic matrix composite tensile specimens

    NASA Technical Reports Server (NTRS)

    Kautz, Harold E.; Chulya, Abhisak

    1993-01-01

    Three types of acousto-ultrasonic (AU) measurements, stress-wave factor (SWF), lowest antisymmetric plate mode group velocity (VS), and lowest symmetric plate mode group velocity (VL), were performed on specimens before and after tensile failure. Three different Nicalon fiber architectures with ceramic matrices were tested. These composites were categorized as 1D (unidirectional fiber orientation) SiC/CAS glass ceramic, and 2D and 3D woven SiC/SiC ceramic matrix materials. SWF was found to be degraded after tensile failure in all three material categories. VS was found to be degraded only in the 1D SiC/CAS. VL was difficult to determine on the irregular specimen surfaces but appeared unchanged on all failed specimens. 3D woven specimens with heat-treatment at high temperature exhibited degradation only in SWF.

  9. A multiple-shape memory polymer-metal composite actuator capable of programmable control, creating complex 3D motion of bending, twisting, and oscillation

    PubMed Central

    Shen, Qi; Trabia, Sarah; Stalbaum, Tyler; Palmre, Viljar; Kim, Kwang; Oh, Il-Kwon

    2016-01-01

    Development of biomimetic actuators has been an essential motivation in the study of smart materials. However, few materials are capable of controlling complex twisting and bending deformations simultaneously or separately using a dynamic control system. Here, we report an ionic polymer-metal composite actuator having multiple-shape memory effect, and is able to perform complex motion by two external inputs, electrical and thermal. Prior to the development of this type of actuator, this capability only could be realized with existing actuator technologies by using multiple actuators or another robotic system. This paper introduces a soft multiple-shape-memory polymer-metal composite (MSMPMC) actuator having multiple degrees-of-freedom that demonstrates high maneuverability when controlled by two external inputs, electrical and thermal. These multiple inputs allow for complex motions that are routine in nature, but that would be otherwise difficult to obtain with a single actuator. To the best of the authors’ knowledge, this MSMPMC actuator is the first solitary actuator capable of multiple-input control and the resulting deformability and maneuverability. PMID:27080134

  10. A multiple-shape memory polymer-metal composite actuator capable of programmable control, creating complex 3D motion of bending, twisting, and oscillation.

    PubMed

    Shen, Qi; Trabia, Sarah; Stalbaum, Tyler; Palmre, Viljar; Kim, Kwang; Oh, Il-Kwon

    2016-01-01

    Development of biomimetic actuators has been an essential motivation in the study of smart materials. However, few materials are capable of controlling complex twisting and bending deformations simultaneously or separately using a dynamic control system. Here, we report an ionic polymer-metal composite actuator having multiple-shape memory effect, and is able to perform complex motion by two external inputs, electrical and thermal. Prior to the development of this type of actuator, this capability only could be realized with existing actuator technologies by using multiple actuators or another robotic system. This paper introduces a soft multiple-shape-memory polymer-metal composite (MSMPMC) actuator having multiple degrees-of-freedom that demonstrates high maneuverability when controlled by two external inputs, electrical and thermal. These multiple inputs allow for complex motions that are routine in nature, but that would be otherwise difficult to obtain with a single actuator. To the best of the authors' knowledge, this MSMPMC actuator is the first solitary actuator capable of multiple-input control and the resulting deformability and maneuverability. PMID:27080134

  11. A multiple-shape memory polymer-metal composite actuator capable of programmable control, creating complex 3D motion of bending, twisting, and oscillation

    NASA Astrophysics Data System (ADS)

    Shen, Qi; Trabia, Sarah; Stalbaum, Tyler; Palmre, Viljar; Kim, Kwang; Oh, Il-Kwon

    2016-04-01

    Development of biomimetic actuators has been an essential motivation in the study of smart materials. However, few materials are capable of controlling complex twisting and bending deformations simultaneously or separately using a dynamic control system. Here, we report an ionic polymer-metal composite actuator having multiple-shape memory effect, and is able to perform complex motion by two external inputs, electrical and thermal. Prior to the development of this type of actuator, this capability only could be realized with existing actuator technologies by using multiple actuators or another robotic system. This paper introduces a soft multiple-shape-memory polymer-metal composite (MSMPMC) actuator having multiple degrees-of-freedom that demonstrates high maneuverability when controlled by two external inputs, electrical and thermal. These multiple inputs allow for complex motions that are routine in nature, but that would be otherwise difficult to obtain with a single actuator. To the best of the authors’ knowledge, this MSMPMC actuator is the first solitary actuator capable of multiple-input control and the resulting deformability and maneuverability.

  12. Bacterial inhibition potential of 3D rapid-prototyped magnesium-based porous composite scaffolds–an in vitro efficacy study

    PubMed Central

    Ma, Rui; Lai, Yu-xiao; Li, Long; Tan, Hong-lue; Wang, Jia-li; Li, Ye; Tang, Ting-ting; Qin, Ling

    2015-01-01

    Bone infections are common in trauma-induced open fractures with bone defects. Therefore, developing anti-infection scaffolds for repairing bone defects is desirable. This study develoepd novel Mg-based porous composite scaffolds with a basal matrix composed of poly(lactic-co-glycolicacid) (PLGA) and tricalcium phosphate (TCP). A unique low-temperature rapid prototyping technology was used to fabricate the scaffolds, including PLGA/TCP (PT), PLGA/TCP/5%Mg (PT5M), PLGA/TCP/10%Mg (PT10M), and PLGA/TCP/15%Mg (PT15M). The bacterial adhesion and biofilm formation of Staphylococcus aureus were evaluated. The results indicated that the Mg-based scaffolds significantly inhibited bacterial adhesion and biofilm formation compared to PT, and the PT10M and PT15M exhibited significantly stronger anti-biofilm ability than PT5M. In vitro degratation tests revealed that the degradation of the Mg-based scaffolds caused an increase of pH, Mg2+ concentration and osmolality, and the increased pH may be one of the major contributing factors to the antibacterial function of the Mg-based scaffolds. Additionally, the PT15M exhibited an inhibitory effect on cell adhesion and proliferation of MC3T3-E1 cells. In conclusion, the PLGA/TCP/Mg scaffolds could inhibit bacterial adhesion and biofilm formation, and the PT10M scaffold was considered to be an effective composition with considerable antibacterial ability and good cytocompatibility. PMID:26346217

  13. Solar Energetic Particle spectral and compositional invariance in the 3-D Heliosphere: Ulysses and ACE/WIND comparisons in late 2001

    NASA Astrophysics Data System (ADS)

    Malandraki, Olga; Tylka, Allan J.; Ng, Chee K.; Marsden, Richard G.; Tranquille, Cecil; Patterson, Doug; Armstrong, Thomas P.; Lanzerotti, Louis J.

    2013-04-01

    We carry out the first detailed examination and comparison of elemental spectra and composition in the late decay phase of two Solar Energetic Particle (SEP) events in the so-called 'reservoir' regions, between spacecraft widely separated in latitude, as well as in longitude and radial distance in the Heliosphere. Energetic particle data from instruments onboard the Ulysses spacecraft located at a high heliospheric latitude of about 70 deg N and at a heliocentric distance of about 2.5 AU and from spacecraft at L1 are used in this work. Particle intensities over time are observed to be in close agreement following the shock passage over the widely separated spacecraft. Electron measurements were used to identify the extent of the particle reservoir. In this update on reservoir composition studies, we extend our previous work to sub-MeV/nucleon energies, using measurements from HI-SCALE on Ulysses and EPAM on ACE. Implications of the observations for models of SEP transport are also discussed. Acknowledgments: The presented work has received funding from the European Union FP7 project COMESEP (263252) and has also been supported by NASA under grants NNH09AK79I and NNX09AU98G (AJT).

  14. 3D Spectroscopy in Astronomy

    NASA Astrophysics Data System (ADS)

    Mediavilla, Evencio; Arribas, Santiago; Roth, Martin; Cepa-Nogué, Jordi; Sánchez, Francisco

    2011-09-01

    Preface; Acknowledgements; 1. Introductory review and technical approaches Martin M. Roth; 2. Observational procedures and data reduction James E. H. Turner; 3. 3D Spectroscopy instrumentation M. A. Bershady; 4. Analysis of 3D data Pierre Ferruit; 5. Science motivation for IFS and galactic studies F. Eisenhauer; 6. Extragalactic studies and future IFS science Luis Colina; 7. Tutorials: how to handle 3D spectroscopy data Sebastian F. Sánchez, Begona García-Lorenzo and Arlette Pécontal-Rousset.

  15. 3D Elevation Program—Virtual USA in 3D

    USGS Publications Warehouse

    Lukas, Vicki; Stoker, J.M.

    2016-01-01

    The U.S. Geological Survey (USGS) 3D Elevation Program (3DEP) uses a laser system called ‘lidar’ (light detection and ranging) to create a virtual reality map of the Nation that is very accurate. 3D maps have many uses with new uses being discovered all the time.  

  16. Energetic particle spectral and compositional invariance in the 3-D Heliosphere: Comparison between Ulysses and ACE/WIND in late 2001

    NASA Astrophysics Data System (ADS)

    Malandraki, O. E.; Tylka, A. J.; Ng, C. K.; Marsden, R. G.; Tranquille, C.; Patterson, D.; Armstrong, T. P.; Lanzerotti, L. J.; Dorrian, G.

    2012-04-01

    Basic research on Space Weather carried out at the Institute of Astronomy and Astrophysics of the National Observatory of Athens within the framework of COMESEP, a collaborative project funded by the Seventh Framework Programme of the European Union is presented in this work. We carry out the first detailed examination and comparison of elemental spectra and composition in the late decay phase of two Solar Energetic Particle (SEP) events in the so-called 'reservoir' regions, between spacecraft widely separated in latitude, as well as in longitude and radial distance in the Heliosphere. Energetic particle data from instruments onboard the Ulysses spacecraft located at a high heliospheric latitude of ~70° N and at a heliocentric distance of ~2.5 AU and from spacecraft at L1 are used in this work. Particle intensities over time are observed to be in close agreement following the shock passage over the widely separated spacecraft. Electron measurements were used to identify the extent of the particle reservoir. Implications of the observations for models of SEP transport are also discussed. Acknowledgments: The presented work has received funding from the European Union FP7 project COMESEP (263252) and has also been supported by NASA under grants NNH09AK79I and NNX09AU98G (AJT).

  17. 49 CFR 178.518 - Standards for woven plastic bags.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Standards for woven plastic bags. 178.518 Section... PACKAGINGS Non-bulk Performance-Oriented Packaging Standards § 178.518 Standards for woven plastic bags. (a) The following are identification codes for woven plastic bags: (1) 5H1 for an unlined or...

  18. 49 CFR 178.518 - Standards for woven plastic bags.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Standards for woven plastic bags. 178.518 Section...-bulk Performance-Oriented Packaging Standards § 178.518 Standards for woven plastic bags. (a) The following are identification codes for woven plastic bags: (1) 5H1 for an unlined or non-coated...

  19. 49 CFR 178.518 - Standards for woven plastic bags.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Standards for woven plastic bags. 178.518 Section...-bulk Performance-Oriented Packaging Standards § 178.518 Standards for woven plastic bags. (a) The following are identification codes for woven plastic bags: (1) 5H1 for an unlined or non-coated...

  20. 49 CFR 178.518 - Standards for woven plastic bags.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Standards for woven plastic bags. 178.518 Section...-bulk Performance-Oriented Packaging Standards § 178.518 Standards for woven plastic bags. (a) The following are identification codes for woven plastic bags: (1) 5H1 for an unlined or non-coated...

  1. 49 CFR 178.518 - Standards for woven plastic bags.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Standards for woven plastic bags. 178.518 Section...-bulk Performance-Oriented Packaging Standards § 178.518 Standards for woven plastic bags. (a) The following are identification codes for woven plastic bags: (1) 5H1 for an unlined or non-coated...

  2. Thermal Testing of Woven TPS Materials in Extreme Entry Environments

    NASA Astrophysics Data System (ADS)

    Gonzales, G.

    2014-06-01

    Some recent thermal tests of woven TPS have been used to help develop and qualify the capabilities of the NASA's IHF and AEDC's H3 arcjet facilities and this woven material. These tests have benefited both the facilities and woven teams.

  3. Fine Aerosol Bulk Composition Measured on WP-3D Research Aircraft in Vicinity of the Northeastern United States - Results from NEAQS

    NASA Technical Reports Server (NTRS)

    Peltier, R. E.; Sullivan, A. P.; Weber, R. J.; Brock, C. A.; Wollny, A. G.; Holloway, J. S.; deGouw, J. A.; Warneke, C.

    2007-01-01

    During the New England Air Quality Study (NEAQS) in the summer of 2004, airborne measurements were made of the major inorganic ions and the water-soluble organic carbon (WSOC) of the submicron (PM(sub 1.0)) aerosol. These and ancillary data are used to describe the overall aerosol chemical characteristics encountered during the study. Fine particle mass was estimated from particle volume and a calculated density based on measured particle composition. Fine particle organic matter (OM) was estimated from WSOC and a mass balance analysis. The aerosol over the northeastern United States (U.S.) and Canada was predominantly sulfate and associated ammonium, and organic components, although in unique plumes additional ionic components were also periodically above detection limits. In power generation regions, and especially in the Ohio River Valley region, the aerosol tended to be predominantly sulfate (approximately 60% micro gram /micro gram) and apparently acidic, based on an excess of measured anions compared to cations. In all other regions where sulfate concentrations were lower and a smaller fraction of overall mass, the cations and anions were balanced suggesting a more neutral aerosol. In contrast, the WSOC and estimated OM were more spatially uniform and the fraction of OM relative to PM mass was largely influenced by sources of sulfate. The study median OM mass fraction was 40%. Throughout the study region, sulfate and organic aerosol mass were highest near the surface and decreased rapidly with increasing altitude. The relative fraction of organic mass to sulfate was similar throughout all altitudes within the boundary layer (altitude less than 2.5 km), but was significantly higher at altitude layers in the free troposphere (above 2.5 km). A number of distinct biomass burning plumes from fires in Alaska and the Yukon were periodically intercepted, mostly at altitudes between 3 and 4 km. These plumes were associated with highest aerosol concentrations of the

  4. Holographic Interferometry based on photorefractive crystal to measure 3D thermo-elastic distortion of composite structures and comparison with finite element models

    NASA Astrophysics Data System (ADS)

    Thizy, C.; Eliot, F.; Ballhause, D.; Olympio, K. R.; Kluge, R.; Shannon, A.; Laduree, G.; Logut, D.; Georges, M. P.

    2013-04-01

    Thermo-elastic distortions of composite structures have been measured by a holographic camera using a BSO photorefractive crystal as the recording medium. The first test campaign (Phase 1) was performed on CFRP struts with titanium end-fittings glued to the tips of the strut. The samples were placed in a vacuum chamber. The holographic camera was located outside the chamber and configured with two illuminations to measure the relative out-of-plane and in-plane (in one direction) displacements. The second test campaign (Phase 2) was performed on a structure composed of a large Silicon Carbide base plate supported by 3 GFRP struts with glued Titanium end-fittings. Thermo-elastic distortions have been measured with the same holographic camera used in phase 1, but four illuminations, instead of two, have been used to provide the three components of displacement. This technique was specially developed and validated during the phase 2 in CSL laboratory. The system has been designed to measure an object size of typically 250x250 mm2; the measurement range is such that the sum of the largest relative displacements in the three measurement directions is maximum 20 μm. The validation of the four-illuminations technique led to measurement uncertainties of 120 nm for the relative in-plane and out-of-plane displacements, 230 nm for the absolute in-plane displacement and 400 nm for the absolute out-of-plane displacement. For both campaigns, the test results have been compared to the predictions obtained by finite element analyses and the correlation of these results was good.

  5. Tropospheric gas composition of Jupiter's north equatorial belt (NH/sub 3/, PH/sub 3/, CH/sub 3/D, GeH/sub 4/, H/sub 2/O) and the Jovian D/H isotopic ratio

    SciTech Connect

    Kunde, V.; Hanel, R.; Maguire, W.; Gautier, D.; Baluteau, J.P.; Marten, A.; Chedin, A.; Husson, N.; Scott, N.

    1982-12-01

    The gas composition of the troposphere of Jupiter in the clearest regions of the North Equatorial Belt (NEB) was derived from the Voyager 1 IRIS data. The infrared spectrum for this homogeneous ''cloud-free'' region was modeled to infer altitude profiles for NH/sub 3/, PH/sub 3/, CH/sub 3/D, GeH/sub 4/, and H/sub 2/O. The profiles for NH/sub 3/ and PH/sub 3/ were found to be depleted in the upper troposphere but otherwise in agreement with their solar values at the 1 bar level. The mole fraction for CH/sub 3/D was determined to be 3.5/sup +1.0//sub -1.3/ x 10/sup -7/. The GeH/sub 4/ mole fraction of 7 +- 2 x 10/sup -10/ at the 2-5 bar level is a factor of 10 lower than the solar value. The H/sub 2/O mole fraction is approx.1 x 10/sup -6/ at the 2.5 bar level and is increasing to approx.3 x 10/sup -5/ at 4 bars where it is a factor of 30 lower than solar. Using IRIS inferred values for the mole fractions of CH/sub 3/D and CH/sub 4/ a value of D/H = 3.6/sup +1.0//sub -1.4/ x 10/sup -5/ is derived. Assuming this Jovian D/H ratio is representative of the protosolar nebula, and correcting for chemical galactic evolution, yields a value of 5.5--9.0 x 10/sup -5/ for the primordial D/H ratio and an upper limit of 1.8--2.4 x 10/sup -31/ g cm/sup -3/ for the present-day baryon density.

  6. Modular 3-D Transport model

    EPA Science Inventory

    MT3D was first developed by Chunmiao Zheng in 1990 at S.S. Papadopulos & Associates, Inc. with partial support from the U.S. Environmental Protection Agency (USEPA). Starting in 1990, MT3D was released as a pubic domain code from the USEPA. Commercial versions with enhanced capab...

  7. Market study: 3-D eyetracker

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A market study of a proposed version of a 3-D eyetracker for initial use at NASA's Ames Research Center was made. The commercialization potential of a simplified, less expensive 3-D eyetracker was ascertained. Primary focus on present and potential users of eyetrackers, as well as present and potential manufacturers has provided an effective means of analyzing the prospects for commercialization.

  8. LLNL-Earth3D

    2013-10-01

    Earth3D is a computer code designed to allow fast calculation of seismic rays and travel times through a 3D model of the Earth. LLNL is using this for earthquake location and global tomography efforts and such codes are of great interest to the Earth Science community.

  9. [3-D ultrasound in gastroenterology].

    PubMed

    Zoller, W G; Liess, H

    1994-06-01

    Three-dimensional (3D) sonography represents a development of noninvasive diagnostic imaging by real-time two-dimensional (2D) sonography. The use of transparent rotating scans, comparable to a block of glass, generates a 3D effect. The objective of the present study was to optimate 3D presentation of abdominal findings. Additional investigations were made with a new volumetric program to determine the volume of selected findings of the liver. The results were compared with the estimated volumes of 2D sonography and 2D computer tomography (CT). For the processing of 3D images, typical parameter constellations were found for the different findings, which facilitated processing of 3D images. In more than 75% of the cases examined we found an optimal 3D presentation of sonographic findings with respect to the evaluation criteria developed by us for the 3D imaging of processed data. Great differences were found for the estimated volumes of the findings of the liver concerning the three different techniques applied. 3D ultrasound represents a valuable method to judge morphological appearance in abdominal findings. The possibility of volumetric measurements enlarges its potential diagnostic significance. Further clinical investigations are necessary to find out if definite differentiation between benign and malign findings is possible. PMID:7919882

  10. 3D World Building System

    SciTech Connect

    2013-10-30

    This video provides an overview of the Sandia National Laboratories developed 3-D World Model Building capability that provides users with an immersive, texture rich 3-D model of their environment in minutes using a laptop and color and depth camera.

  11. 3D World Building System

    ScienceCinema

    None

    2014-02-26

    This video provides an overview of the Sandia National Laboratories developed 3-D World Model Building capability that provides users with an immersive, texture rich 3-D model of their environment in minutes using a laptop and color and depth camera.

  12. Handbook of Analytical Methods for Textile Composites

    NASA Technical Reports Server (NTRS)

    Cox, Brian N.; Flanagan, Gerry

    1997-01-01

    The purpose of this handbook is to introduce models and computer codes for predicting the properties of textile composites. The handbook includes several models for predicting the stress-strain response all the way to ultimate failure; methods for assessing work of fracture and notch sensitivity; and design rules for avoiding certain critical mechanisms of failure, such as delamination, by proper textile design. The following textiles received some treatment: 2D woven, braided, and knitted/stitched laminates and 3D interlock weaves, and braids.

  13. Magnetic Properties of 3D Printed Toroids

    NASA Astrophysics Data System (ADS)

    Bollig, Lindsey; Otto, Austin; Hilpisch, Peter; Mowry, Greg; Nelson-Cheeseman, Brittany; Renewable Energy; Alternatives Lab (REAL) Team

    Transformers are ubiquitous in electronics today. Although toroidal geometries perform most efficiently, transformers are traditionally made with rectangular cross-sections due to the lower manufacturing costs. Additive manufacturing techniques (3D printing) can easily achieve toroidal geometries by building up a part through a series of 2D layers. To get strong magnetic properties in a 3D printed transformer, a composite filament is used containing Fe dispersed in a polymer matrix. How the resulting 3D printed toroid responds to a magnetic field depends on two structural factors of the printed 2D layers: fill factor (planar density) and fill pattern. In this work, we investigate how the fill factor and fill pattern affect the magnetic properties of 3D printed toroids. The magnetic properties of the printed toroids are measured by a custom circuit that produces a hysteresis loop for each toroid. Toroids with various fill factors and fill patterns are compared to determine how these two factors can affect the magnetic field the toroid can produce. These 3D printed toroids can be used for numerous applications in order to increase the efficiency of transformers by making it possible for manufacturers to make a toroidal geometry.

  14. Euro3D Science Conference

    NASA Astrophysics Data System (ADS)

    Walsh, J. R.

    2004-02-01

    The Euro3D RTN is an EU funded Research Training Network to foster the exploitation of 3D spectroscopy in Europe. 3D spectroscopy is a general term for spectroscopy of an area of the sky and derives its name from its two spatial + one spectral dimensions. There are an increasing number of instruments which use integral field devices to achieve spectroscopy of an area of the sky, either using lens arrays, optical fibres or image slicers, to pack spectra of multiple pixels on the sky (``spaxels'') onto a 2D detector. On account of the large volume of data and the special methods required to reduce and analyse 3D data, there are only a few centres of expertise and these are mostly involved with instrument developments. There is a perceived lack of expertise in 3D spectroscopy spread though the astronomical community and its use in the armoury of the observational astronomer is viewed as being highly specialised. For precisely this reason the Euro3D RTN was proposed to train young researchers in this area and develop user tools to widen the experience with this particular type of data in Europe. The Euro3D RTN is coordinated by Martin M. Roth (Astrophysikalisches Institut Potsdam) and has been running since July 2002. The first Euro3D science conference was held in Cambridge, UK from 22 to 23 May 2003. The main emphasis of the conference was, in keeping with the RTN, to expose the work of the young post-docs who are funded by the RTN. In addition the team members from the eleven European institutes involved in Euro3D also presented instrumental and observational developments. The conference was organized by Andy Bunker and held at the Institute of Astronomy. There were over thirty participants and 26 talks covered the whole range of application of 3D techniques. The science ranged from Galactic planetary nebulae and globular clusters to kinematics of nearby galaxies out to objects at high redshift. Several talks were devoted to reporting recent observations with newly

  15. PLOT3D user's manual

    NASA Technical Reports Server (NTRS)

    Walatka, Pamela P.; Buning, Pieter G.; Pierce, Larry; Elson, Patricia A.

    1990-01-01

    PLOT3D is a computer graphics program designed to visualize the grids and solutions of computational fluid dynamics. Seventy-four functions are available. Versions are available for many systems. PLOT3D can handle multiple grids with a million or more grid points, and can produce varieties of model renderings, such as wireframe or flat shaded. Output from PLOT3D can be used in animation programs. The first part of this manual is a tutorial that takes the reader, keystroke by keystroke, through a PLOT3D session. The second part of the manual contains reference chapters, including the helpfile, data file formats, advice on changing PLOT3D, and sample command files.

  16. 3D printing in dentistry.

    PubMed

    Dawood, A; Marti Marti, B; Sauret-Jackson, V; Darwood, A

    2015-12-01

    3D printing has been hailed as a disruptive technology which will change manufacturing. Used in aerospace, defence, art and design, 3D printing is becoming a subject of great interest in surgery. The technology has a particular resonance with dentistry, and with advances in 3D imaging and modelling technologies such as cone beam computed tomography and intraoral scanning, and with the relatively long history of the use of CAD CAM technologies in dentistry, it will become of increasing importance. Uses of 3D printing include the production of drill guides for dental implants, the production of physical models for prosthodontics, orthodontics and surgery, the manufacture of dental, craniomaxillofacial and orthopaedic implants, and the fabrication of copings and frameworks for implant and dental restorations. This paper reviews the types of 3D printing technologies available and their various applications in dentistry and in maxillofacial surgery. PMID:26657435

  17. Sol-gel synthesis, phase composition, morphological and structural characterization of Ca10(PO4)6(OH)2: XRD, FTIR, SEM, 3D SEM and solid-state NMR studies

    NASA Astrophysics Data System (ADS)

    Kareiva, Simonas; Klimavicius, Vytautas; Momot, Aleksandr; Kausteklis, Jonas; Prichodko, Aleksandra; Dagys, Laurynas; Ivanauskas, Feliksas; Sakirzanovas, Simas; Balevicius, Vytautas; Kareiva, Aivaras

    2016-09-01

    Aqueous sol-gel chemistry route based on ammonium-hydrogen phosphate as the phosphorus precursor, calcium acetate monohydrate as source of calcium ions, and 1,2-ethylendiaminetetraacetic acid (EDTA), or 1,2-diaminocyclohexanetetracetic acid (DCTA), or tartaric acid (TA), or ethylene glycol (EG), or glycerol (GL) as complexing agents have been used to prepare calcium hydroxyapatite (Ca10(PO4)6(OH)2, CHAp). The phase transformations, composition, and structural changes in the polycrystalline samples were studied by infrared spectroscopy (FTIR), X-ray powder diffraction analysis (XRD), and scanning electron microscopy (SEM). The local short-range (nano- and mezo-) scale effects in CHAp were studied using solid-state NMR spectroscopy. The spatial 3D data from the SEM images of CHAp samples obtained by TA, EG and GL sol-gel routes were recovered for the first time to our knowledge.

  18. PLOT3D/AMES, APOLLO UNIX VERSION USING GMR3D (WITH TURB3D)

    NASA Technical Reports Server (NTRS)

    Buning, P.

    1994-01-01

    PLOT3D is an interactive graphics program designed to help scientists visualize computational fluid dynamics (CFD) grids and solutions. Today, supercomputers and CFD algorithms can provide scientists with simulations of such highly complex phenomena that obtaining an understanding of the simulations has become a major problem. Tools which help the scientist visualize the simulations can be of tremendous aid. PLOT3D/AMES offers more functions and features, and has been adapted for more types of computers than any other CFD graphics program. Version 3.6b+ is supported for five computers and graphic libraries. Using PLOT3D, CFD physicists can view their computational models from any angle, observing the physics of problems and the quality of solutions. As an aid in designing aircraft, for example, PLOT3D's interactive computer graphics can show vortices, temperature, reverse flow, pressure, and dozens of other characteristics of air flow during flight. As critical areas become obvious, they can easily be studied more closely using a finer grid. PLOT3D is part of a computational fluid dynamics software cycle. First, a program such as 3DGRAPE (ARC-12620) helps the scientist generate computational grids to model an object and its surrounding space. Once the grids have been designed and parameters such as the angle of attack, Mach number, and Reynolds number have been specified, a "flow-solver" program such as INS3D (ARC-11794 or COS-10019) solves the system of equations governing fluid flow, usually on a supercomputer. Grids sometimes have as many as two million points, and the "flow-solver" produces a solution file which contains density, x- y- and z-momentum, and stagnation energy for each grid point. With such a solution file and a grid file containing up to 50 grids as input, PLOT3D can calculate and graphically display any one of 74 functions, including shock waves, surface pressure, velocity vectors, and particle traces. PLOT3D's 74 functions are organized into

  19. PLOT3D/AMES, APOLLO UNIX VERSION USING GMR3D (WITHOUT TURB3D)

    NASA Technical Reports Server (NTRS)

    Buning, P.

    1994-01-01

    PLOT3D is an interactive graphics program designed to help scientists visualize computational fluid dynamics (CFD) grids and solutions. Today, supercomputers and CFD algorithms can provide scientists with simulations of such highly complex phenomena that obtaining an understanding of the simulations has become a major problem. Tools which help the scientist visualize the simulations can be of tremendous aid. PLOT3D/AMES offers more functions and features, and has been adapted for more types of computers than any other CFD graphics program. Version 3.6b+ is supported for five computers and graphic libraries. Using PLOT3D, CFD physicists can view their computational models from any angle, observing the physics of problems and the quality of solutions. As an aid in designing aircraft, for example, PLOT3D's interactive computer graphics can show vortices, temperature, reverse flow, pressure, and dozens of other characteristics of air flow during flight. As critical areas become obvious, they can easily be studied more closely using a finer grid. PLOT3D is part of a computational fluid dynamics software cycle. First, a program such as 3DGRAPE (ARC-12620) helps the scientist generate computational grids to model an object and its surrounding space. Once the grids have been designed and parameters such as the angle of attack, Mach number, and Reynolds number have been specified, a "flow-solver" program such as INS3D (ARC-11794 or COS-10019) solves the system of equations governing fluid flow, usually on a supercomputer. Grids sometimes have as many as two million points, and the "flow-solver" produces a solution file which contains density, x- y- and z-momentum, and stagnation energy for each grid point. With such a solution file and a grid file containing up to 50 grids as input, PLOT3D can calculate and graphically display any one of 74 functions, including shock waves, surface pressure, velocity vectors, and particle traces. PLOT3D's 74 functions are organized into

  20. A two-storey structured photoanode of a 3D Cu2ZnSnS4/CdS/ZnO@steel composite nanostructure for efficient photoelectrochemical hydrogen generation.

    PubMed

    Choi, Youngwoo; Baek, Minki; Zhang, Zhuo; Dao, Van-Duong; Choi, Ho-Suk; Yong, Kijung

    2015-10-01

    A two-storey structured photoanode of a 3D Cu2ZnSnS4(CZTS)/CdS/ZnO@steel composite nanostructure has been fabricated by using the solution method and demonstrated highly efficient photoelectrochemical hydrogen generation due to its contraption in the structure for sufficient light absorption as well as the three step-down band alignments for efficient charge separation and transport. This composite structure is composed of two storeys: the upper storey is the CZTS/CdS/ZnO hetero-nanorods (NRs) covered on the stainless steel mesh; the bottom storey is the CZTS/CdS/ZnO hetero-NRs grown on the FTO glass. The CZTS/CdS/ZnO hetero-NRs have cascade band gaps decreasing from 3.15 to 1.82 eV, which gives them efficient charge transfer and broad photoresponse in the UV to near-IR region, resulting in 47% IPCE in a wide light region from 400 to 500 nm; and the stainless steel mesh serves not only as a conductor for charge transport, but also as a skeleton of the grid structure for absorbing more light. The related mechanism has been investigated, which demonstrates that the two-storey CZTS/CdS/ZnO@steel composite nanostructure would have great potential as a promising photoelectrode with high efficiency and low cost for PEC hydrogen generation. PMID:26327311

  1. Facile aqueous synthesis and electromagnetic properties of novel 3D urchin-like glass/Ni-Ni(3)P/Co(2)P(2)O(7) core/shell/shell composite hollow structures.

    PubMed

    An, Zhenguo; Zhang, Jingjie; Pan, Shunlong

    2010-04-14

    Novel 3D urchin-like glass/Ni-Ni(3)P/Co(2)P(2)O(7) core/shell/shell composite hollow structures are fabricated for the first time by controlled stepwise assembly of granular Ni-Ni(3)P alloy and ribbon-like Co(2)P(2)O(7) nanocrystals on hollow glass spheres in aqueous solutions at mild conditions. It is found that the shell structure and the overall morphology of the products can be tailored by properly tuning the annealing temperature. The as-obtained composite core/shell/shell products possess low density (ca. 1.18 g cm(-3)) and shape-dependent magnetic and microwave absorbing properties, and thus may have some promising applications in the fields of low-density magnetic materials, microwave absorbers, etc. Based on a series of contrast experiments, the probable formation mechanism of the core/shell/shell hierarchical structures is proposed. This work provides an additional strategy to prepare core/shell composite spheres with tailored shell morphology and electromagnetic properties. PMID:20379530

  2. Bioprinting of 3D hydrogels.

    PubMed

    Stanton, M M; Samitier, J; Sánchez, S

    2015-08-01

    Three-dimensional (3D) bioprinting has recently emerged as an extension of 3D material printing, by using biocompatible or cellular components to build structures in an additive, layer-by-layer methodology for encapsulation and culture of cells. These 3D systems allow for cell culture in a suspension for formation of highly organized tissue or controlled spatial orientation of cell environments. The in vitro 3D cellular environments simulate the complexity of an in vivo environment and natural extracellular matrices (ECM). This paper will focus on bioprinting utilizing hydrogels as 3D scaffolds. Hydrogels are advantageous for cell culture as they are highly permeable to cell culture media, nutrients, and waste products generated during metabolic cell processes. They have the ability to be fabricated in customized shapes with various material properties with dimensions at the micron scale. 3D hydrogels are a reliable method for biocompatible 3D printing and have applications in tissue engineering, drug screening, and organ on a chip models. PMID:26066320

  3. Unassisted 3D camera calibration

    NASA Astrophysics Data System (ADS)

    Atanassov, Kalin; Ramachandra, Vikas; Nash, James; Goma, Sergio R.

    2012-03-01

    With the rapid growth of 3D technology, 3D image capture has become a critical part of the 3D feature set on mobile phones. 3D image quality is affected by the scene geometry as well as on-the-device processing. An automatic 3D system usually assumes known camera poses accomplished by factory calibration using a special chart. In real life settings, pose parameters estimated by factory calibration can be negatively impacted by movements of the lens barrel due to shaking, focusing, or camera drop. If any of these factors displaces the optical axes of either or both cameras, vertical disparity might exceed the maximum tolerable margin and the 3D user may experience eye strain or headaches. To make 3D capture more practical, one needs to consider unassisted (on arbitrary scenes) calibration. In this paper, we propose an algorithm that relies on detection and matching of keypoints between left and right images. Frames containing erroneous matches, along with frames with insufficiently rich keypoint constellations, are detected and discarded. Roll, pitch yaw , and scale differences between left and right frames are then estimated. The algorithm performance is evaluated in terms of the remaining vertical disparity as compared to the maximum tolerable vertical disparity.

  4. Arena3D: visualization of biological networks in 3D

    PubMed Central

    Pavlopoulos, Georgios A; O'Donoghue, Seán I; Satagopam, Venkata P; Soldatos, Theodoros G; Pafilis, Evangelos; Schneider, Reinhard

    2008-01-01

    Background Complexity is a key problem when visualizing biological networks; as the number of entities increases, most graphical views become incomprehensible. Our goal is to enable many thousands of entities to be visualized meaningfully and with high performance. Results We present a new visualization tool, Arena3D, which introduces a new concept of staggered layers in 3D space. Related data – such as proteins, chemicals, or pathways – can be grouped onto separate layers and arranged via layout algorithms, such as Fruchterman-Reingold, distance geometry, and a novel hierarchical layout. Data on a layer can be clustered via k-means, affinity propagation, Markov clustering, neighbor joining, tree clustering, or UPGMA ('unweighted pair-group method with arithmetic mean'). A simple input format defines the name and URL for each node, and defines connections or similarity scores between pairs of nodes. The use of Arena3D is illustrated with datasets related to Huntington's disease. Conclusion Arena3D is a user friendly visualization tool that is able to visualize biological or any other network in 3D space. It is free for academic use and runs on any platform. It can be downloaded or lunched directly from . Java3D library and Java 1.5 need to be pre-installed for the software to run. PMID:19040715

  5. 3D Multifunctional Ablative Thermal Protection System

    NASA Technical Reports Server (NTRS)

    Feldman, Jay; Venkatapathy, Ethiraj; Wilkinson, Curt; Mercer, Ken

    2015-01-01

    NASA is developing the Orion spacecraft to carry astronauts farther into the solar system than ever before, with human exploration of Mars as its ultimate goal. One of the technologies required to enable this advanced, Apollo-shaped capsule is a 3-dimensional quartz fiber composite for the vehicle's compression pad. During its mission, the compression pad serves first as a structural component and later as an ablative heat shield, partially consumed on Earth re-entry. This presentation will summarize the development of a new 3D quartz cyanate ester composite material, 3-Dimensional Multifunctional Ablative Thermal Protection System (3D-MAT), designed to meet the mission requirements for the Orion compression pad. Manufacturing development, aerothermal (arc-jet) testing, structural performance, and the overall status of material development for the 2018 EM-1 flight test will be discussed.

  6. Fdf in US3D

    NASA Astrophysics Data System (ADS)

    Otis, Collin; Ferrero, Pietro; Candler, Graham; Givi, Peyman

    2013-11-01

    The scalar filtered mass density function (SFMDF) methodology is implemented into the computer code US3D. This is an unstructured Eulerian finite volume hydrodynamic solver and has proven very effective for simulation of compressible turbulent flows. The resulting SFMDF-US3D code is employed for large eddy simulation (LES) on unstructured meshes. Simulations are conducted of subsonic and supersonic flows under non-reacting and reacting conditions. The consistency and the accuracy of the simulated results are assessed along with appraisal of the overall performance of the methodology. The SFMDF-US3D is now capable of simulating high speed flows in complex configurations.

  7. Unit cell geometry of 3-D braided structures

    NASA Technical Reports Server (NTRS)

    Du, Guang-Wu; Ko, Frank K.

    1993-01-01

    The traditional approach used in modeling of composites reinforced by three-dimensional (3-D) braids is to assume a simple unit cell geometry of a 3-D braided structure with known fiber volume fraction and orientation. In this article, we first examine 3-D braiding methods in the light of braid structures, followed by the development of geometric models for 3-D braids using a unit cell approach. The unit cell geometry of 3-D braids is identified and the relationship of structural parameters such as yarn orientation angle and fiber volume fraction with the key processing parameters established. The limiting geometry has been computed by establishing the point at which yarns jam against each other. Using this factor makes it possible to identify the complete range of allowable geometric arrangements for 3-D braided preforms. This identified unit cell geometry can be translated to mechanical models which relate the geometrical properties of fabric preforms to the mechanical responses of composite systems.

  8. Wavefront construction in 3-D

    SciTech Connect

    Chilcoat, S.R. Hildebrand, S.T.

    1995-12-31

    Travel time computation in inhomogeneous media is essential for pre-stack Kirchhoff imaging in areas such as the sub-salt province in the Gulf of Mexico. The 2D algorithm published by Vinje, et al, has been extended to 3D to compute wavefronts in complicated inhomogeneous media. The 3D wavefront construction algorithm provides many advantages over conventional ray tracing and other methods of computing travel times in 3D. The algorithm dynamically maintains a reasonably consistent ray density without making a priori guesses at the number of rays to shoot. The determination of caustics in 3D is a straight forward geometric procedure. The wavefront algorithm also enables the computation of multi-valued travel time surfaces.

  9. Heterodyne 3D ghost imaging

    NASA Astrophysics Data System (ADS)

    Yang, Xu; Zhang, Yong; Yang, Chenghua; Xu, Lu; Wang, Qiang; Zhao, Yuan

    2016-06-01

    Conventional three dimensional (3D) ghost imaging measures range of target based on pulse fight time measurement method. Due to the limit of data acquisition system sampling rate, range resolution of the conventional 3D ghost imaging is usually low. In order to take off the effect of sampling rate to range resolution of 3D ghost imaging, a heterodyne 3D ghost imaging (HGI) system is presented in this study. The source of HGI is a continuous wave laser instead of pulse laser. Temporal correlation and spatial correlation of light are both utilized to obtain the range image of target. Through theory analysis and numerical simulations, it is demonstrated that HGI can obtain high range resolution image with low sampling rate.

  10. Combinatorial 3D Mechanical Metamaterials

    NASA Astrophysics Data System (ADS)

    Coulais, Corentin; Teomy, Eial; de Reus, Koen; Shokef, Yair; van Hecke, Martin

    2015-03-01

    We present a class of elastic structures which exhibit 3D-folding motion. Our structures consist of cubic lattices of anisotropic unit cells that can be tiled in a complex combinatorial fashion. We design and 3d-print this complex ordered mechanism, in which we combine elastic hinges and defects to tailor the mechanics of the material. Finally, we use this large design space to encode smart functionalities such as surface patterning and multistability.

  11. Effect of Frictions on the Ballistic Performance of a 3D Warp Interlock Fabric: Numerical Analysis

    NASA Astrophysics Data System (ADS)

    Ha-Minh, Cuong; Boussu, François; Kanit, Toufik; Crépin, David; Imad, Abdellatif

    2012-06-01

    3D interlock woven fabrics are promising materials to replace the 2D structures in the field of ballistic protection. The structural complexity of this material caused many difficulties in numerical modeling. This paper presents a new tool that permits to generate a geometry model of any woven fabric, then, mesh this model in shell or solid elements, and apply the mechanical properties of yarns to them. The tool shows many advantages over existing software. It is very handy in use with an organization of the functions in menu and using a graphic interface. It can describe correctly the geometry of all textile woven fabrics. With this tool, the orientation of the local axes of finite elements following the yarn direction facilitates defining the yarn mechanical properties in a numerical model. This tool can be largely applied because it is compatible with popular finite element codes such as Abaqus, Ansys, Radioss etc. Thanks to this tool, a finite element model was carried out to describe a ballistic impact on a 3D warp interlock Kevlar KM2® fabric. This work focuses on studying the effect of friction onto the ballistic impact behavior of this textile interlock structure. Results showed that the friction among yarns affects considerably on the impact behavior of this fabric. The effect of the friction between projectile and yarn is less important. The friction plays an important role in keeping the fabric structural stability during the impact event. This phenomenon explained why the projectile is easier to penetrate this 3D warp interlock fabric in the no-friction case. This result also indicates that the ballistic performance of the interlock woven fabrics can be improved by using fibers with great friction coefficients.

  12. The tropospheric gas composition of Jupiter's north equatorial belt (NH3, PH3, CH3D, GeH4, H2O) and the Jovian D/H isotropic ratio

    NASA Technical Reports Server (NTRS)

    Kunde, V.; Hanel, R.; Maguire, W.; Gautier, D.; Baluteau, J. P.; Marten, A.; Chedin, A.; Husson, N.; Scott, N.

    1982-01-01

    The gas composition of the troposphere of Jupiter in the clearest regions of the North Equatorial Belt (NEB) was derived from the Voyager 1 IRIS data. The infrared spectrum for this homogeneous cloud free region was modeled to infer altitude profiles for NH3, PH3, GeH4 and H2O. The Profiles for NH3 and PH3 were found to be depleted in the upper troposphere but otherwise in agreement with their solar values at the 1 bar level. The mole fraction for CH3D was determined to be 3.5(+1.0 or -1.3) x 10 to the minus 7th power. The GeH4 mole fraction of 7+ or -2 x 10 to the minus 10th power at the 2 to 3 bar level is a factor of 10 lower than the solar value. The H2O mole fraction is approximately 1 x 0.00001 at the 2.5 bar level and is increasing to approximately 3 x 0.00001 at 4 bars where it is a factor of 30 lower than solar. Using IRIS infrared values for the mole fractions of CH3D and CH4 a value of D/H = 3.6(+1.0 or -1.4)x 0.00001 is derived. Assuming this Jovian D/H ratio is representative of the protosolar nebula, and correcting for chemical galactic evolution, yields a value of 5.5 - 9.0 x 0.00001 for the primordial D/H ratio and an upper limit of 1.8 to 2.4 x 10 to the minus 31st power cu cm for the present day baryon density.

  13. From 3D view to 3D print

    NASA Astrophysics Data System (ADS)

    Dima, M.; Farisato, G.; Bergomi, M.; Viotto, V.; Magrin, D.; Greggio, D.; Farinato, J.; Marafatto, L.; Ragazzoni, R.; Piazza, D.

    2014-08-01

    In the last few years 3D printing is getting more and more popular and used in many fields going from manufacturing to industrial design, architecture, medical support and aerospace. 3D printing is an evolution of bi-dimensional printing, which allows to obtain a solid object from a 3D model, realized with a 3D modelling software. The final product is obtained using an additive process, in which successive layers of material are laid down one over the other. A 3D printer allows to realize, in a simple way, very complex shapes, which would be quite difficult to be produced with dedicated conventional facilities. Thanks to the fact that the 3D printing is obtained superposing one layer to the others, it doesn't need any particular work flow and it is sufficient to simply draw the model and send it to print. Many different kinds of 3D printers exist based on the technology and material used for layer deposition. A common material used by the toner is ABS plastics, which is a light and rigid thermoplastic polymer, whose peculiar mechanical properties make it diffusely used in several fields, like pipes production and cars interiors manufacturing. I used this technology to create a 1:1 scale model of the telescope which is the hardware core of the space small mission CHEOPS (CHaracterising ExOPlanets Satellite) by ESA, which aims to characterize EXOplanets via transits observations. The telescope has a Ritchey-Chrétien configuration with a 30cm aperture and the launch is foreseen in 2017. In this paper, I present the different phases for the realization of such a model, focusing onto pros and cons of this kind of technology. For example, because of the finite printable volume (10×10×12 inches in the x, y and z directions respectively), it has been necessary to split the largest parts of the instrument in smaller components to be then reassembled and post-processed. A further issue is the resolution of the printed material, which is expressed in terms of layers

  14. A two-storey structured photoanode of a 3D Cu2ZnSnS4/CdS/ZnO@steel composite nanostructure for efficient photoelectrochemical hydrogen generation

    NASA Astrophysics Data System (ADS)

    Choi, Youngwoo; Baek, Minki; Zhang, Zhuo; Dao, Van-Duong; Choi, Ho-Suk; Yong, Kijung

    2015-09-01

    A two-storey structured photoanode of a 3D Cu2ZnSnS4(CZTS)/CdS/ZnO@steel composite nanostructure has been fabricated by using the solution method and demonstrated highly efficient photoelectrochemical hydrogen generation due to its contraption in the structure for sufficient light absorption as well as the three step-down band alignments for efficient charge separation and transport. This composite structure is composed of two storeys: the upper storey is the CZTS/CdS/ZnO hetero-nanorods (NRs) covered on the stainless steel mesh; the bottom storey is the CZTS/CdS/ZnO hetero-NRs grown on the FTO glass. The CZTS/CdS/ZnO hetero-NRs have cascade band gaps decreasing from 3.15 to 1.82 eV, which gives them efficient charge transfer and broad photoresponse in the UV to near-IR region, resulting in 47% IPCE in a wide light region from 400 to 500 nm; and the stainless steel mesh serves not only as a conductor for charge transport, but also as a skeleton of the grid structure for absorbing more light. The related mechanism has been investigated, which demonstrates that the two-storey CZTS/CdS/ZnO@steel composite nanostructure would have great potential as a promising photoelectrode with high efficiency and low cost for PEC hydrogen generation.A two-storey structured photoanode of a 3D Cu2ZnSnS4(CZTS)/CdS/ZnO@steel composite nanostructure has been fabricated by using the solution method and demonstrated highly efficient photoelectrochemical hydrogen generation due to its contraption in the structure for sufficient light absorption as well as the three step-down band alignments for efficient charge separation and transport. This composite structure is composed of two storeys: the upper storey is the CZTS/CdS/ZnO hetero-nanorods (NRs) covered on the stainless steel mesh; the bottom storey is the CZTS/CdS/ZnO hetero-NRs grown on the FTO glass. The CZTS/CdS/ZnO hetero-NRs have cascade band gaps decreasing from 3.15 to 1.82 eV, which gives them efficient charge transfer and broad

  15. YouDash3D: exploring stereoscopic 3D gaming for 3D movie theaters

    NASA Astrophysics Data System (ADS)

    Schild, Jonas; Seele, Sven; Masuch, Maic

    2012-03-01

    Along with the success of the digitally revived stereoscopic cinema, events beyond 3D movies become attractive for movie theater operators, i.e. interactive 3D games. In this paper, we present a case that explores possible challenges and solutions for interactive 3D games to be played by a movie theater audience. We analyze the setting and showcase current issues related to lighting and interaction. Our second focus is to provide gameplay mechanics that make special use of stereoscopy, especially depth-based game design. Based on these results, we present YouDash3D, a game prototype that explores public stereoscopic gameplay in a reduced kiosk setup. It features live 3D HD video stream of a professional stereo camera rig rendered in a real-time game scene. We use the effect to place the stereoscopic effigies of players into the digital game. The game showcases how stereoscopic vision can provide for a novel depth-based game mechanic. Projected trigger zones and distributed clusters of the audience video allow for easy adaptation to larger audiences and 3D movie theater gaming.

  16. Remote 3D Medical Consultation

    NASA Astrophysics Data System (ADS)

    Welch, Greg; Sonnenwald, Diane H.; Fuchs, Henry; Cairns, Bruce; Mayer-Patel, Ketan; Yang, Ruigang; State, Andrei; Towles, Herman; Ilie, Adrian; Krishnan, Srinivas; Söderholm, Hanna M.

    Two-dimensional (2D) video-based telemedical consultation has been explored widely in the past 15-20 years. Two issues that seem to arise in most relevant case studies are the difficulty associated with obtaining the desired 2D camera views, and poor depth perception. To address these problems we are exploring the use of a small array of cameras to synthesize a spatially continuous range of dynamic three-dimensional (3D) views of a remote environment and events. The 3D views can be sent across wired or wireless networks to remote viewers with fixed displays or mobile devices such as a personal digital assistant (PDA). The viewpoints could be specified manually or automatically via user head or PDA tracking, giving the remote viewer virtual head- or hand-slaved (PDA-based) remote cameras for mono or stereo viewing. We call this idea remote 3D medical consultation (3DMC). In this article we motivate and explain the vision for 3D medical consultation; we describe the relevant computer vision/graphics, display, and networking research; we present a proof-of-concept prototype system; and we present some early experimental results supporting the general hypothesis that 3D remote medical consultation could offer benefits over conventional 2D televideo.

  17. Speaking Volumes About 3-D

    NASA Technical Reports Server (NTRS)

    2002-01-01

    In 1999, Genex submitted a proposal to Stennis Space Center for a volumetric 3-D display technique that would provide multiple users with a 360-degree perspective to simultaneously view and analyze 3-D data. The futuristic capabilities of the VolumeViewer(R) have offered tremendous benefits to commercial users in the fields of medicine and surgery, air traffic control, pilot training and education, computer-aided design/computer-aided manufacturing, and military/battlefield management. The technology has also helped NASA to better analyze and assess the various data collected by its satellite and spacecraft sensors. Genex capitalized on its success with Stennis by introducing two separate products to the commercial market that incorporate key elements of the 3-D display technology designed under an SBIR contract. The company Rainbow 3D(R) imaging camera is a novel, three-dimensional surface profile measurement system that can obtain a full-frame 3-D image in less than 1 second. The third product is the 360-degree OmniEye(R) video system. Ideal for intrusion detection, surveillance, and situation management, this unique camera system offers a continuous, panoramic view of a scene in real time.

  18. The elastic properties of woven polymeric fabric

    SciTech Connect

    Warren, W.E. )

    1989-01-01

    The in-plane linear elastic constants of woven fabric are determined in terms of the specific fabric microstructure. The fabric is assumed to be a spatially periodic interlaced network of orthogonal yarns and the individual yarns are modeled as extensible elastica. These results indicate that a significant coupling of bending and stretching effects occurs during deformation. Results of this theoretical analysis compare favorable with measured in-plane elastic constants for Vincel yarn fabrics. 17 refs., 2 figs., 1 tab.

  19. 3D-Printed Microfluidics.

    PubMed

    Au, Anthony K; Huynh, Wilson; Horowitz, Lisa F; Folch, Albert

    2016-03-14

    The advent of soft lithography allowed for an unprecedented expansion in the field of microfluidics. However, the vast majority of PDMS microfluidic devices are still made with extensive manual labor, are tethered to bulky control systems, and have cumbersome user interfaces, which all render commercialization difficult. On the other hand, 3D printing has begun to embrace the range of sizes and materials that appeal to the developers of microfluidic devices. Prior to fabrication, a design is digitally built as a detailed 3D CAD file. The design can be assembled in modules by remotely collaborating teams, and its mechanical and fluidic behavior can be simulated using finite-element modeling. As structures are created by adding materials without the need for etching or dissolution, processing is environmentally friendly and economically efficient. We predict that in the next few years, 3D printing will replace most PDMS and plastic molding techniques in academia. PMID:26854878

  20. Woven silk fabric-reinforced silk nanofibrous scaffolds for regenerating load-bearing soft tissues.

    PubMed

    Han, F; Liu, S; Liu, X; Pei, Y; Bai, S; Zhao, H; Lu, Q; Ma, F; Kaplan, D L; Zhu, H

    2014-02-01

    Although three-dimensional (3-D) porous regenerated silk scaffolds with outstanding biocompatibility, biodegradability and low inflammatory reactions have promising application in different tissue regeneration, the mechanical properties of regenerated scaffolds, especially suture retention strength, must be further improved to satisfy the requirements of clinical applications. This study presents woven silk fabric-reinforced silk nanofibrous scaffolds aimed at dermal tissue engineering. To improve the mechanical properties, silk scaffolds prepared by lyophilization were reinforced with degummed woven silk fabrics. The ultimate tensile strength, elongation at break and suture retention strength of the scaffolds were significantly improved, providing suitable mechanical properties strong enough for clinical applications. The stiffness and degradation behaviors were then further regulated by different after-treatment processes, making the scaffolds more suitable for dermal tissue regeneration. The in vitro cell culture results indicated that these scaffolds maintained their excellent biocompatibility after being reinforced with woven silk fabrics. Without sacrifice of porous structure and biocompatibility, the fabric-reinforced scaffolds with better mechanical properties could facilitate future clinical applications of silk as matrices in skin repair. PMID:24090985

  1. 3D Computations and Experiments

    SciTech Connect

    Couch, R; Faux, D; Goto, D; Nikkel, D

    2004-04-05

    This project consists of two activities. Task A, Simulations and Measurements, combines all the material model development and associated numerical work with the materials-oriented experimental activities. The goal of this effort is to provide an improved understanding of dynamic material properties and to provide accurate numerical representations of those properties for use in analysis codes. Task B, ALE3D Development, involves general development activities in the ALE3D code with the focus of improving simulation capabilities for problems of mutual interest to DoD and DOE. Emphasis is on problems involving multi-phase flow, blast loading of structures and system safety/vulnerability studies.

  2. 3D Computations and Experiments

    SciTech Connect

    Couch, R; Faux, D; Goto, D; Nikkel, D

    2003-05-12

    This project is in its first full year after the combining of two previously funded projects: ''3D Code Development'' and ''Dynamic Material Properties''. The motivation behind this move was to emphasize and strengthen the ties between the experimental work and the computational model development in the materials area. The next year's activities will indicate the merging of the two efforts. The current activity is structured in two tasks. Task A, ''Simulations and Measurements'', combines all the material model development and associated numerical work with the materials-oriented experimental activities. Task B, ''ALE3D Development'', is a continuation of the non-materials related activities from the previous project.

  3. Elastic-plastic behavior of non-woven fibrous mats

    NASA Astrophysics Data System (ADS)

    Silberstein, Meredith N.; Pai, Chia-Ling; Rutledge, Gregory C.; Boyce, Mary C.

    2012-02-01

    Electrospinning is a novel method for creating non-woven polymer mats that have high surface area and high porosity. These attributes make them ideal candidates for multifunctional composites. Understanding the mechanical properties as a function of fiber properties and mat microstructure can aid in designing these composites. Further, a constitutive model which captures the membrane stress-strain behavior as a function of fiber properties and the geometry of the fibrous network would be a powerful design tool. Here, mats electrospun from amorphous polyamide are used as a model system. The elastic-plastic behavior of single fibers are obtained in tensile tests. Uniaxial monotonic and cyclic tensile tests are conducted on non-woven mats. The mat exhibits elastic-plastic stress-strain behavior. The transverse strain behavior provides important complementary data, showing a negligible initial Poisson's ratio followed by a transverse:axial strain ratio greater than -1:1 after an axial strain of 0.02. A triangulated framework has been developed to emulate the fibrous network structure of the mat. The micromechanically based model incorporates the elastic-plastic behavior of single fibers into a macroscopic membrane model of the mat. This representative volume element based model is shown to capture the uniaxial elastic-plastic response of the mat under monotonic and cyclic loading. The initial modulus and yield stress of the mat are governed by the fiber properties, the network geometry, and the network density. The transverse strain behavior is linked to discrete deformation mechanisms of the fibrous mat structure including fiber alignment, fiber bending, and network consolidation. The model is further validated in comparison to experiments under different constrained axial loading conditions and found to capture the constraint effect on stiffness, yield, post-yield hardening, and post-yield transverse strain behavior. Due to the direct connection between

  4. Advanced textile structural composites -- status and outlook

    SciTech Connect

    Arendts, F.J.; Drechsler, K.; Brandt, J.

    1993-12-31

    Composites with 3D woven, braided or knitted fiber reinforcement offer a high potential for the cost-effective manufacturing of structures featuring an interesting mechanical performance, for example with regard to damage tolerance or energy absorption capability. In this paper, the properties of various textile structural composites with regard to stiffness, strength, damage tolerance, energy absorption capability as well as the respective manufacturing processes (RTM or thermoplastic hybrid-yarn technique) are presented in comparison to conventional ud tape based composites. The influence of the fiber architecture on the mechanical performance (tensile stiffness and strength, compression strength, interlaminar shear strength, compression strength after impact, fracture mechanical properties, through-penetration resistance) of monolithic and composite sandwich structures has been evaluated in an experimental study. It has been shown that composites involving new 3D weavings with minimum fiber crimp can compete with tape-based laminates as far as stiffness and strength are concerned. Using knittings makes it possible to manufacture composites having superior through-penetration resistance. The specific feature of the 3D braiding process is the ability to produce complex shaped structures having a high degree of freedom with regard to fiber geometry. Finally, the application of various textile structural composites will be presented on the basis of three demonstrator components (automotive engine mount, aircraft leading edge and motor cycle helmet), and the potential for further developments will be discussed.

  5. SNL3dFace

    2007-07-20

    This software distribution contains MATLAB and C++ code to enable identity verification using 3D images that may or may not contain a texture component. The code is organized to support system performance testing and system capability demonstration through the proper configuration of the available user interface. Using specific algorithm parameters the face recognition system has been demonstrated to achieve a 96.6% verification rate (Pd) at 0.001 false alarm rate. The system computes robust facial featuresmore » of a 3D normalized face using Principal Component Analysis (PCA) and Fisher Linear Discriminant Analysis (FLDA). A 3D normalized face is obtained by alighning each face, represented by a set of XYZ coordinated, to a scaled reference face using the Iterative Closest Point (ICP) algorithm. The scaled reference face is then deformed to the input face using an iterative framework with parameters that control the deformed surface regulation an rate of deformation. A variety of options are available to control the information that is encoded by the PCA. Such options include the XYZ coordinates, the difference of each XYZ coordinates from the reference, the Z coordinate, the intensity/texture values, etc. In addition to PCA/FLDA feature projection this software supports feature matching to obtain similarity matrices for performance analysis. In addition, this software supports visualization of the STL, MRD, 2D normalized, and PCA synthetic representations in a 3D environment.« less

  6. Making Inexpensive 3-D Models

    ERIC Educational Resources Information Center

    Manos, Harry

    2016-01-01

    Visual aids are important to student learning, and they help make the teacher's job easier. Keeping with the "TPT" theme of "The Art, Craft, and Science of Physics Teaching," the purpose of this article is to show how teachers, lacking equipment and funds, can construct a durable 3-D model reference frame and a model gravity…

  7. SNL3dFace

    SciTech Connect

    Russ, Trina; Koch, Mark; Koudelka, Melissa; Peters, Ralph; Little, Charles; Boehnen, Chris; Peters, Tanya

    2007-07-20

    This software distribution contains MATLAB and C++ code to enable identity verification using 3D images that may or may not contain a texture component. The code is organized to support system performance testing and system capability demonstration through the proper configuration of the available user interface. Using specific algorithm parameters the face recognition system has been demonstrated to achieve a 96.6% verification rate (Pd) at 0.001 false alarm rate. The system computes robust facial features of a 3D normalized face using Principal Component Analysis (PCA) and Fisher Linear Discriminant Analysis (FLDA). A 3D normalized face is obtained by alighning each face, represented by a set of XYZ coordinated, to a scaled reference face using the Iterative Closest Point (ICP) algorithm. The scaled reference face is then deformed to the input face using an iterative framework with parameters that control the deformed surface regulation an rate of deformation. A variety of options are available to control the information that is encoded by the PCA. Such options include the XYZ coordinates, the difference of each XYZ coordinates from the reference, the Z coordinate, the intensity/texture values, etc. In addition to PCA/FLDA feature projection this software supports feature matching to obtain similarity matrices for performance analysis. In addition, this software supports visualization of the STL, MRD, 2D normalized, and PCA synthetic representations in a 3D environment.

  8. 3D Printing: Exploring Capabilities

    ERIC Educational Resources Information Center

    Samuels, Kyle; Flowers, Jim

    2015-01-01

    As 3D printers become more affordable, schools are using them in increasing numbers. They fit well with the emphasis on product design in technology and engineering education, allowing students to create high-fidelity physical models to see and test different iterations in their product designs. They may also help students to "think in three…

  9. 75 FR 7236 - Narrow Woven Ribbons with Woven Selvedge from Taiwan: Preliminary Determination of Sales at Less...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-18

    ...The Department of Commerce (the Department) preliminarily determines that narrow woven ribbons with woven selvedge (narrow woven ribbons) from Taiwan are being, or are likely to be, sold in the United States at less than fair value (LTFV), as provided in section 733(b) of the Tariff Act of 1930, as amended (the Act). The estimated dumping margins are listed in the ``Suspension of Liquidation''......

  10. TACO3D. 3-D Finite Element Heat Transfer Code

    SciTech Connect

    Mason, W.E.

    1992-03-04

    TACO3D is a three-dimensional, finite-element program for heat transfer analysis. An extension of the two-dimensional TACO program, it can perform linear and nonlinear analyses and can be used to solve either transient or steady-state problems. The program accepts time-dependent or temperature-dependent material properties, and materials may be isotropic or orthotropic. A variety of time-dependent and temperature-dependent boundary conditions and loadings are available including temperature, flux, convection, and radiation boundary conditions and internal heat generation. Additional specialized features treat enclosure radiation, bulk nodes, and master/slave internal surface conditions (e.g., contact resistance). Data input via a free-field format is provided. A user subprogram feature allows for any type of functional representation of any independent variable. A profile (bandwidth) minimization option is available. The code is limited to implicit time integration for transient solutions. TACO3D has no general mesh generation capability. Rows of evenly-spaced nodes and rows of sequential elements may be generated, but the program relies on separate mesh generators for complex zoning. TACO3D does not have the ability to calculate view factors internally. Graphical representation of data in the form of time history and spatial plots is provided through links to the POSTACO and GRAPE postprocessor codes.

  11. Compression Testing of Textile Composite Materials

    NASA Technical Reports Server (NTRS)

    Masters, John E.

    1996-01-01

    The applicability of existing test methods, which were developed primarily for laminates made of unidirectional prepreg tape, to textile composites is an area of concern. The issue is whether the values measured for the 2-D and 3-D braided, woven, stitched, and knit materials are accurate representations of the true material response. This report provides a review of efforts to establish a compression test method for textile reinforced composite materials. Experimental data have been gathered from several sources and evaluated to assess the effectiveness of a variety of test methods. The effectiveness of the individual test methods to measure the material's modulus and strength is determined. Data are presented for 2-D triaxial braided, 3-D woven, and stitched graphite/epoxy material. However, the determination of a recommended test method and specimen dimensions is based, primarily, on experimental results obtained by the Boeing Defense and Space Group for 2-D triaxially braided materials. They evaluated seven test methods: NASA Short Block, Modified IITRI, Boeing Open Hole Compression, Zabora Compression, Boeing Compression after Impact, NASA ST-4, and a Sandwich Column Test.

  12. Damage in woven CFRP laminates subjected to low velocity impacts

    NASA Astrophysics Data System (ADS)

    Ullah, H.; Abdel-Wahab, A. A.; Harland, A. R.; Silberschmidt, V. V.

    2012-08-01

    Carbon fabric-reinforced polymer (CFRP) composites used in sports products can be exposed to different in-service conditions such as large dynamic bending deformations caused by impact loading. Composite materials subjected to such loads demonstrate various damage modes such as matrix cracking, delamination and, ultimately, fabric fracture. Damage evolution in these materials affects both their in-service properties and performance that can deteriorate with time. These processes need adequate means of analysis and investigation, the major approaches being experimental characterisation and non-destructive examination of internal damage in composite laminates. This research deals with a deformation behaviour and damage in woven composite laminates due to low-velocity dynamic out-of-plane bending. Experimental tests are carried out to characterise the behaviour of such laminates under large-deflection dynamic bending in un-notched specimens in Izod tests using a Resil Impactor. A series of low-velocity impact tests is carried out at various levels of impact energy to assess the energy absorbed and force-time response of CFRP laminates. X-ray micro computed tomography (micro-CT) is used to investigate material damage modes in the impacted specimens. X-ray tomographs revealed that through-thickness matrix cracking, inter-ply delamination and intra-ply delamination, such as tow debonding and fabric fracture, were the prominent damage modes.

  13. A 3-D chimera grid embedding technique

    NASA Technical Reports Server (NTRS)

    Benek, J. A.; Buning, P. G.; Steger, J. L.

    1985-01-01

    A three-dimensional (3-D) chimera grid-embedding technique is described. The technique simplifies the construction of computational grids about complex geometries. The method subdivides the physical domain into regions which can accommodate easily generated grids. Communication among the grids is accomplished by interpolation of the dependent variables at grid boundaries. The procedures for constructing the composite mesh and the associated data structures are described. The method is demonstrated by solution of the Euler equations for the transonic flow about a wing/body, wing/body/tail, and a configuration of three ellipsoidal bodies.

  14. 3D printing of versatile reactionware for chemical synthesis.

    PubMed

    Kitson, Philip J; Glatzel, Stefan; Chen, Wei; Lin, Chang-Gen; Song, Yu-Fei; Cronin, Leroy

    2016-05-01

    In recent decades, 3D printing (also known as additive manufacturing) techniques have moved beyond their traditional applications in the fields of industrial manufacturing and prototyping to increasingly find roles in scientific research contexts, such as synthetic chemistry. We present a general approach for the production of bespoke chemical reactors, termed reactionware, using two different approaches to extrusion-based 3D printing. This protocol describes the printing of an inert polypropylene (PP) architecture with the concurrent printing of soft material catalyst composites, using two different 3D printer setups. The steps of the PROCEDURE describe the design and preparation of a 3D digital model of the desired reactionware device and the preparation of this model for use with fused deposition modeling (FDM) type 3D printers. The protocol then further describes the preparation of composite catalyst-silicone materials for incorporation into the 3D-printed device and the steps required to fabricate a reactionware device. This combined approach allows versatility in the design and use of reactionware based on the specific needs of the experimental user. To illustrate this, we present a detailed procedure for the production of one such reactionware device that will result in the production of a sealed reactor capable of effecting a multistep organic synthesis. Depending on the design time of the 3D model, and including time for curing and drying of materials, this procedure can be completed in ∼3 d. PMID:27077333

  15. Optoplasmonics: hybridization in 3D

    NASA Astrophysics Data System (ADS)

    Rosa, L.; Gervinskas, G.; Žukauskas, A.; Malinauskas, M.; Brasselet, E.; Juodkazis, S.

    2013-12-01

    Femtosecond laser fabrication has been used to make hybrid refractive and di ractive micro-optical elements in photo-polymer SZ2080. For applications in micro- uidics, axicon lenses were fabricated (both single and arrays), for generation of light intensity patterns extending through the entire depth of a typically tens-of-micrometers deep channel. Further hybridisation of an axicon with a plasmonic slot is fabricated and demonstrated nu- merically. Spiralling chiral grooves were inscribed into a 100-nm-thick gold coating sputtered over polymerized micro-axicon lenses, using a focused ion beam. This demonstrates possibility of hybridisation between optical and plasmonic 3D micro-optical elements. Numerical modelling of optical performance by 3D-FDTD method is presented.

  16. 3-D Relativistic MHD Simulations

    NASA Astrophysics Data System (ADS)

    Nishikawa, K.-I.; Frank, J.; Koide, S.; Sakai, J.-I.; Christodoulou, D. M.; Sol, H.; Mutel, R. L.

    1998-12-01

    We present 3-D numerical simulations of moderately hot, supersonic jets propagating initially along or obliquely to the field lines of a denser magnetized background medium with Lorentz factors of W = 4.56 and evolving in a four-dimensional spacetime. The new results are understood as follows: Relativistic simulations have consistently shown that these jets are effectively heavy and so they do not suffer substantial momentum losses and are not decelerated as efficiently as their nonrelativistic counterparts. In addition, the ambient magnetic field, however strong, can be pushed aside with relative ease by the beam, provided that the degrees of freedom associated with all three spatial dimensions are followed self-consistently in the simulations. This effect is analogous to pushing Japanese ``noren'' or vertical Venetian blinds out of the way while the slats are allowed to bend in 3-D space rather than as a 2-D slab structure.

  17. Forensic 3D Scene Reconstruction

    SciTech Connect

    LITTLE,CHARLES Q.; PETERS,RALPH R.; RIGDON,J. BRIAN; SMALL,DANIEL E.

    1999-10-12

    Traditionally law enforcement agencies have relied on basic measurement and imaging tools, such as tape measures and cameras, in recording a crime scene. A disadvantage of these methods is that they are slow and cumbersome. The development of a portable system that can rapidly record a crime scene with current camera imaging, 3D geometric surface maps, and contribute quantitative measurements such as accurate relative positioning of crime scene objects, would be an asset to law enforcement agents in collecting and recording significant forensic data. The purpose of this project is to develop a feasible prototype of a fast, accurate, 3D measurement and imaging system that would support law enforcement agents to quickly document and accurately record a crime scene.

  18. Forensic 3D scene reconstruction

    NASA Astrophysics Data System (ADS)

    Little, Charles Q.; Small, Daniel E.; Peters, Ralph R.; Rigdon, J. B.

    2000-05-01

    Traditionally law enforcement agencies have relied on basic measurement and imaging tools, such as tape measures and cameras, in recording a crime scene. A disadvantage of these methods is that they are slow and cumbersome. The development of a portable system that can rapidly record a crime scene with current camera imaging, 3D geometric surface maps, and contribute quantitative measurements such as accurate relative positioning of crime scene objects, would be an asset to law enforcement agents in collecting and recording significant forensic data. The purpose of this project is to develop a fieldable prototype of a fast, accurate, 3D measurement and imaging system that would support law enforcement agents to quickly document and accurately record a crime scene.

  19. 360-degree 3D profilometry

    NASA Astrophysics Data System (ADS)

    Song, Yuanhe; Zhao, Hong; Chen, Wenyi; Tan, Yushan

    1997-12-01

    A new method of 360 degree turning 3D shape measurement in which light sectioning and phase shifting techniques are both used is presented in this paper. A sine light field is applied in the projected light stripe, meanwhile phase shifting technique is used to calculate phases of the light slit. Thereafter wrapped phase distribution of the slit is formed and the unwrapping process is made by means of the height information based on the light sectioning method. Therefore phase measuring results with better precision can be obtained. At last the target 3D shape data can be produced according to geometric relationships between phases and the object heights. The principles of this method are discussed in detail and experimental results are shown in this paper.

  20. 3D Printed Robotic Hand

    NASA Technical Reports Server (NTRS)

    Pizarro, Yaritzmar Rosario; Schuler, Jason M.; Lippitt, Thomas C.

    2013-01-01

    Dexterous robotic hands are changing the way robots and humans interact and use common tools. Unfortunately, the complexity of the joints and actuations drive up the manufacturing cost. Some cutting edge and commercially available rapid prototyping machines now have the ability to print multiple materials and even combine these materials in the same job. A 3D model of a robotic hand was designed using Creo Parametric 2.0. Combining "hard" and "soft" materials, the model was printed on the Object Connex350 3D printer with the purpose of resembling as much as possible the human appearance and mobility of a real hand while needing no assembly. After printing the prototype, strings where installed as actuators to test mobility. Based on printing materials, the manufacturing cost of the hand was $167, significantly lower than other robotic hands without the actuators since they have more complex assembly processes.