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Sample records for fiber reinforced polyester

  1. Fiber Reinforced Polyester Resins Polymerized by Microwave Source

    NASA Astrophysics Data System (ADS)

    Visco, A. M.; Calabrese, L.; Cianciafara, P.; Bonaccorsi, L.; Proverbio, E.

    2007-12-01

    Polyester resin based composite materials are widely used in the manufacture of fiberglass boats. Production time of fiberglass laminate components could be strongly reduced by using an intense energy source as well as microwaves. In this work a polyester resin was used with 2% by weight of catalyst and reinforced with chopped or woven glass fabric. Pure resin and composite samples were cured by microwaves exposition for different radiation times. A three point bending test was performed on all the cured samples by using an universal testing machine and the resulting fracture surfaces were observed by means of scanning electron microscopy (SEM). The results of mechanical and microscopy analyses evidenced that microwave activation lowers curing time of the composite while good mechanical properties were retained. Microwaves exposition time is crucial for mechanical performance of the composite. It was evidenced that short exposition times suffice for resin activation while long exposure times cause fast cross linking and premature matrix fracture. Furthermore high-radiation times induce bubbles growth or defects nucleation within the sample, decreasing composite performance. On the basis of such results microwave curing activation of polyester resin based composites could be proposed as a valid alternative method for faster processing of laminated materials employed for large-scale applications.

  2. The Effect of Oil Palm Fibers as Reinforcement on Tribological Performance of Polyester Composite

    NASA Astrophysics Data System (ADS)

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

    In the present work, the effect of oil palm fibers on tribological performance of polyester composite against a polished stainless steel counterface is investigated using a pin-on-disc machine. Wear and friction characteristics of oil palm fiber reinforced polyester (OPRP) composite and neat polyester were tested at different sliding distances (0-5 km), sliding velocities (1.7-3.9 m/s), and applied loads (30-70 N) under dry contact condition. SEM observations were performed on the worn surfaces to examine the damage features. The results showed that the test parameters significantly influenced the tribo-performance of OPRP composite and neat polyester. The presence of oil palm fiber in the polyester enhanced the wear property by about three to four times compared to neat polyester. In addition, the friction coefficient of OPRP composite was less by about 23% than that of the neat polyester. Wear mechanisms of OPRP composite were categorized by debonding, bending and tear of fibers, and high deformation in resinous region.

  3. Dimensionally stable PET fibers for tire reinforcement. [Polyethylene terephthalate (POLYESTERS)

    SciTech Connect

    Rim, P.B.; Nelson, C.J.

    1991-05-01

    High-modulus, high-tenacity polyethylene terephthalate (PET) fibers have gained wide acceptance in reinforcement for rubber products such as tires and hoses; in geotextiles, and in ropes and cordage. Accordingly, a great deal of fundamental research has been conducted on how the processing and resulting morphology of these thermoplastic fibers affect their physical properties. The translation of these starting fiber properties to those in the final end-use product has received much less attention. This article compares the structure-property relationships of recently-developed PET yarns possessing high dimensional stability (i.e., high modulus and low shrinkage) with conventional PET tire yarn. Interest in these materials is stimulated by their ability to improve tire uniformity and, for some tire manufacturers, eliminate the need for post-cure inflation during tire manufacturing. Where possible, cause and effect relationships will be developed.

  4. A comparison of tensile properties of polyester composites reinforced with pineapple leaf fiber and pineapple peduncle fiber

    NASA Astrophysics Data System (ADS)

    Juraidi, J. M.; Shuhairul, N.; Syed Azuan, S. A.; Intan Saffinaz Anuar, Noor

    2013-12-01

    Pineapple fiber which is rich in cellulose, relatively inexpensive, and abundantly available has the potential for polymer reinforcement. This research presents a study of the tensile properties of pineapple leaf fiber and pineapple peduncle fiber reinforced polyester composites. Composites were fabricated using leaf fiber and peduncle fiber with varying fiber length and fiber loading. Both fibers were mixed with polyester composites the various fiber volume fractions of 4, 8 and 12% and with three different fiber lengths of 10, 20 and 30 mm. The composites panels were fabricated using hand lay-out technique. The tensile test was carried out in accordance to ASTM D638. The result showed that pineapple peduncle fiber with 4% fiber volume fraction and fiber length of 30 mm give highest tensile properties. From the overall results, pineapple peduncle fiber shown the higher tensile properties compared to pineapple leaf fiber. It is found that by increasing the fiber volume fraction the tensile properties has significantly decreased but by increasing the fiber length, the tensile properties will be increased proportionally. Minitab software is used to perform the two-way ANOVA analysis to measure the significant. From the analysis done, there is a significant effect of fiber volume fraction and fiber length on the tensile properties.

  5. Effect of polyester fiber reinforcement on the mechanical properties of interim fixed partial dentures

    PubMed Central

    Gopichander, N.; Halini Kumarai, K.V.; Vasanthakumar, M.

    2015-01-01

    Background Different reinforcements currently available for interim fixed partial denture (FPD) materials do not provide the ideal strength for long-term use. Therefore, the aim of this investigation was to develop a more ideal provisional material for long-term use with better mechanical properties. This study evaluated the effectiveness of polyester fiber reinforcement on different interim FPD materials. Methods Thirty resin-bonded FPDs were constructed from three provisional interim FPD materials. Specimens were tested with a universal testing machine (UTM). The modulus of elasticity and flexural strength were recorded in MPa. The compressive strength and degree of deflection were calculated from the obtained values, and a two-way analysis of variance (ANOVA) was used to determine the significance. Results The polyester fiber reinforcement increased the mechanical properties. The modulus of elasticity for heat-polymerized polymethyl methacrylate (PMMA) was 624 MPa, compared to 700.2 MPa for the reinforced heat-cured sample. The flexural strengths of the bis-acrylic and cold-polymerized reinforced samples increased significantly to 2807 MPa and 979.86 MPa, respectively, compared to the nonreinforced samples. The mean compressive strength of the reinforced cold-polymerized PMMA samples was 439.17 MPa; and for the reinforced heat-polymerized PMMA samples, it was 1117.41 MPa. The degree of deflection was significantly greater (P < 0.05) in the reinforced bis-acrylic sample (5.03 MPa), compared with the nonreinforced bis-acrylic sample (2.95 MPa). Conclusion Within the limitations of this study, polyester fiber reinforcements improved the mechanical properties of heat-polymerized PMMA, cold-polymerized PMMA, and bis-acrylic provisional FPD materials. PMID:26644754

  6. Reinforcement mechanism of polyester-fiber-reinforced rubber--a model study

    SciTech Connect

    Xue, G.; Koenig, J.L.; Wheeler, D.D.; Ishida, H.

    1983-08-01

    The reinforcement mechanism of polyester tire cord was studied by Fourier-transform infrared spectroscopy using various model compounds. Three model compounds representing the main chain of polyester and the terminal groups, namely carboxylic acid and hydroxyl groups, were used. Chemical reactions between these polyester models and an epoxy functional silane coupling agent were studied qualitatively as well as quantitatively. Among the many possible reactions, the reaction between the carboxylic acid and epoxy group was found to proceed readily. Kinetic studies of the major reactions also show quantitative differences in their activation energies as well as the rate constants. Based on the quantitative studies, we have estimated the expected rate of interfacial reaction at the heat treating temperature of polyester tire cord.

  7. Hemp-Fiber-Reinforced Unsaturated Polyester Composites: Optimization of Processing and Improvement of Interfacial Adhesion

    SciTech Connect

    Qui, Renhui; Ren, Xiaofeng; Fifield, Leonard S.; Simmons, Kevin L.; Li, Kaichang

    2011-02-25

    The processing variables for making hemp-fiber-reinforced unsaturated polyester (UPE) composites were optimized through orthogonal experiments. It was found that the usage of initiator, methyl ethyl ketone peroxide, had the most significant effect on the tensile strength of the composites. The treatment of hemp fibers with a combination of 1, 6-diisocyanatohexane (DIH) and 2-hydroxylethyl acrylate (HEA) significantly increased tensile strength, flexural modulus of rupture and flexural modulus of elasticity, and water resistance of the resulting hemp-UPE composites. FTIR spectra revealed that DIH and HEA were covalently bonded to hemp fibers. Scanning electronic microscopy graphs of the fractured hemp-UPE composites demonstrated that treatment of hemp fibers with a combination of DIH and HEA greatly improved the interfacial adhesion between hemp fibers and UPE. The mechanism of improving the interfacial adhesion is proposed.

  8. Kenaf-glass fiber reinforced unsaturated polyester hybrid composites: Tensile properties

    NASA Astrophysics Data System (ADS)

    Zhafer, S. F.; Rozyanty, A. R.; Shahnaz, S. B. S.; Musa, L.; Zuliahani, A.

    2016-07-01

    The use of natural fibers in composite is rising in recent years due their lightweight, non-abrasive, combustible, non-toxic, low cost and biodegradable properties. However, in comparison with synthetic fibers, the mechanical properties of natural fibers are lower. Therefore, the inclusion of synthetic fibers could improve the mechanical performance of natural fiber based composites. In this study, kenaf bast fiber and glass fiber at different weight percentage loading were used as reinforcement to produce hybrid composites. Unsaturated polyester (UP) resin was used as matrix and hand lay-up process was performed to apply the UP resin on the hybrid kenaf bast/glass fiber composite. Effect of different fiber loading on tensile strength, tensile modulus and elongation at break of the hybrid composite was studied. It has been found that the highest value of tensile strength and modulus was achieved at 10 wt.% kenaf/10 wt.% glass fiber loading. It was concluded that addition of glass fiber has improved the tensile properties of kenaf bast fiber based UP composites.

  9. Development and Evaluation of Novel Coupling Agents for Kenaf-Fiber-Reinforced Unsaturated Polyester Composites

    NASA Astrophysics Data System (ADS)

    Ren, Xiaofeng

    Natural fibers are gaining popularity as reinforcement materials for thermoset resins over the last two decades. Natural fibers are inexpensive, abundant, renewable and environmentally friendly. Kenaf fibers are one of the natural fibers that can potentially be used for reinforcing unsaturated polyester (UPE). As a polymer matrix, UPE enjoys a 40% market share of all the thermoset composites. This widespread application is due to many favorable characteristics including low cost, ease of cure at room temperature, ease of molding, a good balance of mechanical, electrical and chemical properties. One of the barriers for the full utilization of the kenaf fiber reinforced UPE composites, however, is the poor interfacial adhesion between the natural fibers and the UPE resins. The good interfacial adhesion between kenaf fibers and UPE matrix is essential for generating the desired properties of kenaf-UPE composites for most of the end applications. Use of a coupling agent is one of the most effective ways of improving the interfacial adhesion. In this study, six novel effective coupling agents were developed and investigated for kenaf-UPE composites: DIH-HEA, MFA, NMA, AESO-DIH, AESO-MDI, and AESO-PMDI. All the coupling agents were able to improve the interfacial adhesion between kanaf and UPE resins. The coupling agents were found to significantly enhance the flexural properties and water resistance of the kenaf-UPE composites. Fourier transform infrared spectroscopy (FTIR) confirmed all the coupling agents were covalently bonded onto kenaf fibers. Scanning electron microscopy (SEM) images of the composites revealed the improved interfacial adhesion between kanaf fibers and UPE resins.

  10. Chemical and physical degradation of glass fiber reinforced cross-linked polyester immersed in hot water

    SciTech Connect

    Hamada, H.; Maekawa, Z.I.; Ikuta, N.; Kiyosumi, K.; Tanimoto, T.; Morii, T.

    1994-12-31

    This study deals with chemical and physical degradation behavior of randomly oriented E-glass fiber continuous strand mat reinforced cross-linked polyester immersed in hot water at 80 and 95 C. The specimens were immersed in hot water for 3, 10, 30, 100, 300, 1000, 3000 and 4000h. Weight change measurement, three-point bending and infrared measurement were performed for the specimens after the immersion. Changes of the weight gain indicated the Fickian diffusion at early immersion time, and after that, it indicated the non-Fickian diffusion with a gradual progress of debonding between fiber and matrix. This degradation of the interface caused a remarkable increase of the weight loss, which was never observed in neat resin. The bending modulus decreased with increase of the weight gain at early immersion time, however, it kept constant at longer immersion time both at 80 C and at 95 C. The constant modulus level at 80C was higher than that at 95 C. At longer immersion time at 80 C, the modulus decreased again to the same level at 95C. The results of infrared measurement suggested the difference of degradation mechanism between early immersion time and longer immersion time. At early immersion time, the resin changed physically by swelling and extraction of polymer with water penetration. Such differences of degradation affected the reduction of modulus. Moreover, the effect of the debonding at the interface on the modulus was discussed by the finite element analysis by introducing the damage mechanics.

  11. Erosive wear characteristics of multi-fiber reinforced polyester under different operating conditions

    NASA Astrophysics Data System (ADS)

    Debnath, U. K.; Chowdhury, M. A.; Nuruzzaman, D. M.

    2016-02-01

    Composite materials are used in a wide range of applications. The erosion properties of combination of glass, jute and carbon fiber-reinforced polyester were analyzed in this study. Randomly-shaped silica (SiO2) particles of various sizes (300-355μm, 355-500μm, and 500- 600μm) were selected as the erosive element. Impingement angles between 15-90°, impingement velocities between 30-50 m/sec, and stand-off distances of 15-25 mm at ambient temperature were selected. During experiment, the maximum erosion of the tested composite occurred at 60° impingement angle, indicating a semi-ductile nature of the test material. Erosion increased with impact velocity and decreased with stand-off distance. In a dimensional analysis, erosion efficiency (η) and the relationship between friction and erosion were established. Test results were evaluated using Taguchi's concept to minimize the observations needed, and ANOVA was used to identify interactions between tested parameters and to identify the most significant parameters. The S/N ratio indicates that there is only percentage of deviation between the predicted and experimental results. In further, sophisticated analyses and GMDH methods were employed, and surface damage was examined using scanning electron microscopy (SEM) to examine the nature of the wear behaviour.

  12. Effects of Surface Treatments on Mechanical Properties and Water Resistance of Kenaf Fiber-Reinforced Unsaturated Polyester Composites

    SciTech Connect

    Ren, Xiaofeng; Qui, Renhui; Fifield, Leonard S.; Simmons, Kevin L.; li, Kaichang

    2012-05-17

    Effects of surface treatments on the strength and water resistance of kenaf fiber-reinforced unsaturated polyester (UPE) composites were investigated. A new coupling agent that consists of 1,6-diisocyanato-hexane (DIH) and 2-hydroxylethyl acrylate (HEA) was investigated for surface treatments of kenaf fibers. The surface treatments were found to significantly enhance the tensile strength, modulus of rupture, modulus of elasticity, and water resistance of the resulting kenaf UPE composites. Fourier transform infrared spectroscopy (FTIR) confirmed that DIH-HEA was covalently bonded onto kenaf fibers. Scanning electron microscopy (SEM) images of the composites revealed that chemical treatment of kenaf fibers with a combination of DIH and HEA improved the interfacial adhesion between kenaf fibers and UPE resin in the DIHHEA-treated kenafUPE composites. The mechanisms by which the chemical treatment of kenaf fiber surfaces improved strength and water resistance of the resulting kenaf UPE composites were discussed.

  13. Tensile properties and translaminar fracture toughness of glass fiber reinforced unsaturated polyester resin composites aged in distilled and salt water

    NASA Astrophysics Data System (ADS)

    Sugiman, Gozali, M. Hulaifi; Setyawan, Paryanto Dwi

    2016-03-01

    Glass fiber reinforced polymer has been widely used in chemical industry and transportation due to lightweight and cost effective manufacturing. However due to the ability to absorb water from the environment, the durability issue is of interest for up to days. This paper investigated the water uptake and the effect of absorbed water on the tensile properties and the translaminar fracture toughness of glass fiber reinforced unsaturated polyester composites (GFRP) aged in distilled and salt water up to 30 days at a temperature of 50°C. It has been shown that GFRP absorbed more water in distilled water than in salt water. In distilled water, the tensile strength of GFRP tends to decrease steeply at 7 days and then slightly recovered for further immersion time. In salt water, the tensile strength tends to decrease continually up to 30 days immersion. The translaminar fracture toughness of GFRP aged in both distilled and salt-water shows the similar behavior. The translaminar fracture toughness increases after 7 days immersion and then tends to decrease beyond that immersion time. In the existence of ionics content in salt water, it causes more detrimental effect on the mechanical properties of fiberglass/unsaturated polyester composites compared to that of distilled water.

  14. Depolymerization of unsaturated polyesters and waste fiber-reinforced plastics by using ionic liquids: the use of microwaves to accelerate the reaction rate.

    PubMed

    Kamimura, Akio; Yamamoto, Shigehiro; Yamada, Kazuo

    2011-05-23

    Waste fiber-reinforced plastics (FRP) and unsaturated polyesters were readily depolymerized by subjecting them to a treatment with ionic liquids under heating conditions. The use of microwaves for heating effectively progressed depolymerization, whereas the conventional heating method was ineffective for this purpose. We isolated the monomeric material, phthalic anhydride, by direct distillation from the reaction pot under reduced pressure with yields of more than 90%. We recovered the glass fibers in a pure form and achieved the effective removal of polystyrene, the linker unit of FRP. Ionic liquids were useful for several iterations of the reaction, and purification of the used ionic liquids was also possible. Thus, we developed a new use of ionic liquids for chemical recycling of waste plastics. PMID:21557493

  15. Rheological behaviour of nanocellulose reinforced unsaturated polyester nanocomposites.

    PubMed

    Chirayil, Cintil Jose; Mathew, Lovely; Hassan, P A; Mozetic, Miran; Thomas, Sabu

    2014-08-01

    Nanocellulose (NC) reinforced unsaturated polyester (UPR) composites were prepared by mechanical mixing process. Effect of isora nanocellulose on the properties of polyester composites has been studied in detail. Rheological properties of unsaturated polyester resin suspensions containing various amounts (0.5, 1 and 3wt%) of nanocellulose were investigated by oscillatory rheometer with parallel plate geometry. Analysis of curing revealed that the time required for gelation in NC filled UPR is lower than neat resin, which describe the catalytic action of NC on cure reaction. NC reinforced polyester suspensions showed shear thinning behaviour initially and at higher shear rates they showed Newtonian behaviour. Tensile and impact properties showed superior behaviour revealing improved interfacial bonding between nanofiller and the polymer matrix. With respect to the neat polyester the percentage increase in tensile strength of 0.5wt% NC reinforced composite is 57%. Optical and atomic force microscopic studies confirmed that the dispersion state of NC within the polyester matrix was adequate. Maximum glass transition temperature is obtained for 0.5wt% NC reinforced composite, which showed an increase of 10°C than neat resin. PMID:24877644

  16. Ceramic fiber reinforced filter

    DOEpatents

    Stinton, David P.; McLaughlin, Jerry C.; Lowden, Richard A.

    1991-01-01

    A filter for removing particulate matter from high temperature flowing fluids, and in particular gases, that is reinforced with ceramic fibers. The filter has a ceramic base fiber material in the form of a fabric, felt, paper of the like, with the refractory fibers thereof coated with a thin layer of a protective and bonding refractory applied by chemical vapor deposition techniques. This coating causes each fiber to be physically joined to adjoining fibers so as to prevent movement of the fibers during use and to increase the strength and toughness of the composite filter. Further, the coating can be selected to minimize any reactions between the constituents of the fluids and the fibers. A description is given of the formation of a composite filter using a felt preform of commercial silicon carbide fibers together with the coating of these fibers with pure silicon carbide. Filter efficiency approaching 100% has been demonstrated with these filters. The fiber base material is alternately made from aluminosilicate fibers, zirconia fibers and alumina fibers. Coating with Al.sub.2 O.sub.3 is also described. Advanced configurations for the composite filter are suggested.

  17. Fiber-reinforced glass

    SciTech Connect

    Beier, W.; Markman, S.

    1997-12-01

    Fiber-reinforced glass composites are glass or glass ceramic matrices reinforced with long fibers of carbon or silicon carbide. These composites are lighter than steel but just as strong as many steel grades, and can resist higher temperatures. They also have outstanding resistance to impact, thermal shock, and wear, and can be formulated to control thermal and electrical conductivity. With proper tooling, operations such as drilling, grinding, and turning can be completed in half the time required for non-reinforced glass. Currently, fiber-reinforced glass components are primarily used for handling hot glass or molten aluminum during manufacturing operations. But FRG is also under test as an engineering material in a variety of markets, including the aerospace, automotive, and semiconductor industries. Toward this end, research is being carried out to increase the size of components that can be delivered on a production basis, to develop economical methods of achieving complex near-net shapes, and to reduce the cycle time for production of specific shapes. This article focuses on the properties and applications of fiber-reinforced glass composites.

  18. Fracture behavior of glass fiber reinforced polymer composite

    SciTech Connect

    Avci, A.; Arikan, H.; Akdemir, A

    2004-03-01

    Chopped strand glass fiber reinforced particle-filled polymer composite beams with varying notch-to-depth ratios and different volume fractions of glass fibers were investigated in Mode I fracture using three-point bending tests. Effects of polyester resin content and glass fiber content on fracture behavior was also studied. Polyester resin contents were used 13.00%%, 14.75%, 16.50%, 18.00% and 19.50%, and glass fiber contents were 1% and 1.5% of the total weight of the polymer composite system. Flexural strength of the polymer composite increases with increase in polyester and fiber content. The critical stress intensity factor was determined by using several methods such as initial notch depth method, compliance method and J-integral method. The values of K{sub IC} obtained from these methods were compared.

  19. Polymer concrete reinforced with recycled-tire fibers: Mechanical properties

    NASA Astrophysics Data System (ADS)

    Martínez-Cruz, E.; Martínez-Barrera, G.; Martínez-López, M.

    2013-06-01

    Polymer Concrete was reinforced with recycled-tire fibers in order to improve the compressive and flexural strength. Polymer concrete specimens were prepared with 70% of silicious sand, 30% of polyester resin and various fiber concentrations (0.3, 0.6, 0.9 and 1.2 vol%). The results show increment of 50% in average of the compressive and flexural strength as well as on the deformation when adding 1.2 vol% of recycled-fibers.

  20. Fiber reinforced superalloys

    NASA Technical Reports Server (NTRS)

    Petrasek, Donald W.; Signorelli, Robert A.; Caulfield, Thomas; Tien, John K.

    1987-01-01

    Improved performance of heat engines is largely dependent upon maximum cycle temperatures. Tungsten fiber reinforced superalloys (TFRS) are the first of a family of high temperature composites that offer the potential for significantly raising hot component operating temperatures and thus leading to improved heat engine performance. This status review of TFRS research emphasizes the promising property data developed to date, the status of TFRS composite airfoil fabrication technology, and the areas requiring more attention to assure their applicability to hot section components of aircraft gas turbine engines.

  1. Fiber-Reinforced Composite Foam

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A two-phase method for making fiber-reinforced compositions was developed to achieve uniform fiber dispersion in a composite matrix. The first phase involved mixing together water, fibers, and a portion of a fiber dispersant to form a viscous composition. The high viscosity imparted by the dispersa...

  2. Fiber-reinforced syntactic foams

    NASA Astrophysics Data System (ADS)

    Huang, Yi-Jen

    Long fibers are generally preferred for reinforcing foams for performance reasons. However, uniform dispersion is difficult to achieve because they must be mixed with liquid resin prior to foam expansion. New approaches aiming to overcome such problem have been developed at USC's Composites Center. Fiber-reinforced syntactic foams with long fibers (over 6 mm in length) manufactured at USC's Composites Center have achieved promising mechanical properties and demonstrated lower density relative to conventional composite foams. Fiber-reinforced syntactic foams were synthesized from thermosetting polymeric microspheres (amino and phenolic microspheres), as well as thermoplastic PVC heat expandable microspheres (HEMs). Carbon and/or aramid fibers were used to reinforce the syntactic foams. Basic mechanical properties, including shear, tensile, and compression, were measured in syntactic foams and fiber-reinforced syntactic foams. Microstructure and crack propagation behavior were investigated by scanning electron microscope and light microscopy. Failure mechanisms and reinforcing mechanisms of fiber-reinforced syntactic foams were also analyzed. As expected, additions of fiber reinforcements to foams enhanced both tensile and shear properties. However, only limited enhancement in compression properties was observed, and fiber reinforcement was of limited benefit in this regard. Therefore, a hybrid foam design was explored and evaluated in an attempt to enhance compression properties. HEMs were blended with glass microspheres to produce hybrid foams, and hybrid foams were subsequently reinforced with continuous aramid fibers to produce fiber-reinforced hybrid foams. Mechanical properties of these foams were evaluated. Findings indicated that the production of hybrid foams was an effective way to enhance the compressive properties of syntactic foams, while the addition of fiber reinforcements enhanced the shear and tensile performance of syntactic foams. Another approach

  3. Microwave dielectrometry measurements of glass reinforced polyester resins

    SciTech Connect

    Schlegel, J.L.; Wagner, J.W.; Green, R.E. Jr.

    1999-10-01

    This study describes measurements of dielectric constant as a function of glass reinforcement concentration in polyester resins to use as a control parameter for online process monitoring. Microwave interferometers were constructed in the X and V bands at 9.35 and 60 GHz in both homodyne and heterodyne configurations to measure the phase difference associated with the material. This phase difference is then used to calculate the real part of the dielectric constant from the index of refraction at a microwave frequency. The homodyne X and V band measurements yielded a linear between phase difference and glass concentration. Heterodyne V band measurements produced a nonlinear relationship. Further investigation into the microscopic interactions between the reinforcement particle and the polymer resin is necessary to determine how different concentrations affect the bulk macroscopic material properties.

  4. Liquid crystal polyester-carbon fiber composites

    NASA Technical Reports Server (NTRS)

    Chung, T. S.

    1984-01-01

    Liquid crystal polymers (LCP) have been developed as a thermoplastic matrix for high performance composites. A successful melt impregnation method has been developed which results in the production of continuous carbon fiber (CF) reinforced LCP prepreg tape. Subsequent layup and molding of prepreg into laminates has yielded composites of good quality. Tensile and flexural properties of LCP/CF composites are comparable to those of epoxy/CF composites. The LCP/CF composites have better impact resistance than the latter, although epoxy/CF composites possess superior compression and shear strength. The LCP/CF composites have good property retention until 200 F (67 % of room temperature value). Above 200 F, mechanical properties decrease significantly. Experimental results indicate that the poor compression and shear strength may be due to the poor interfacial adhesion between the matrix and carbon fiber as adequate toughness of the LCP matrix. Low mechanical property retention at high temperatures may be attributable to the low beta-transition temperature (around 80 C) of the LCP matrix material.

  5. Glass fibres reinforced polyester composites degradation monitoring by surface analysis

    NASA Astrophysics Data System (ADS)

    Croitoru, Catalin; Patachia, Silvia; Papancea, Adina; Baltes, Liana; Tierean, Mircea

    2015-12-01

    The paper presents a novel method for quantification of the modifications that occur on the surface of different types of gel-coated glass fibre-reinforced polyester composites under artificial UV-ageing at 254 nm. The method implies the adsorption of an ionic dye, namely methylene blue, on the UV-aged composite, and computing the CIELab colour space parameters from the photographic image of the coloured composite's surface. The method significantly enhances the colour differences between the irradiated composites and the reference, in contrast with the non-coloured ones. The colour modifications that occur represent a good indicative of the surface degradation, alteration of surface hydrophily and roughness of the composite and are in good correlation with the ATR-FTIR spectroscopy and optical microscopy results. The proposed method is easier, faster and cheaper than the traditional ones.

  6. 77 FR 60720 - Certain Polyester Staple Fiber From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-04

    ... this review on May 1, 2012 (77 FR 25744) and determined on August 6, 2012 that it would conduct an expedited review (77 FR 50530, August 21, 2012). The Commission transmitted its determination in this review... COMMISSION Certain Polyester Staple Fiber From China Determination On the basis of the record \\1\\...

  7. 75 FR 64694 - Second Antidumping Duty Administrative Review of Certain Polyester Staple Fiber From the People's...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-20

    ... Rescission, in Part, of the Antidumping Duty Administrative Review, 75 FR 40777 (July 14, 2010... International Trade Administration Second Antidumping Duty Administrative Review of Certain Polyester Staple... the Preliminary Results of the second administrative review of certain polyester staple fiber...

  8. Viscoelastic properties of kenaf reinforced unsaturated polyester composites

    NASA Astrophysics Data System (ADS)

    Osman, Ekhlas A.; Mutasher, Saad A.

    2014-03-01

    In order to quantify the effect of temperature on the mechanical and dynamic properties of kenaf fiber unsaturated polyester composites, formulations containing 10 wt.% to 40 wt.% kenaf fiber were produced and tested at two representative temperatures of 30°C and 50°C. Dynamic mechanical analysis was performed, to obtain the strain and creep compliance for kenaf composites at various styrene concentrations. It is possible to obtain creep curves at different temperature levels which can be shifted along the time axis to generate a single curve known as a master curve. This technique is known as the time-temperature superposition principle. Shift factors conformed to a William-Landel-Ferry (WLF) equation. However, more long term creep data was needed in order to further validate the applicability of time-temperature superposition principle (TTSP) to this material. The primary creep strain model was fitted to 60 min creep data. The resulting equation was then extrapolated to 5.5 days; the creep strain model of power-law was successfully used to predict the long-term creep behavior of natural fiber/thermoset composites.

  9. Development of ultrafine polyester fiber vascular grafts with high endothelialization capability. Angiogenesis by ultrafine polyester fibers.

    PubMed

    Niu, S; Satoh, S; Shirakata, S; Oka, T; Noishiki, Y; Kurumatani, H; Watanabe, K

    1989-01-01

    The authors previously showed that a vascular prosthesis made of ultrafine polyester fibers (UFPF) had high healing ability even when of low porosity. In this study, new highly porous vascular grafts fabricated from UFPF (water porosity: 3,600 ml/min/cm2, 8 mm in inner diameter and 5 cm in length), were developed and implanted in the thoracic descending aorta of dogs to evaluate their endothelialization capability. Two weeks after implantation, many colonies of endothelial cells with openings of capillary blood vessels were noted, even in the middle portion of the grafts. Numerous fibroblasts and capillary blood vessels were also observed in the synthetic walls. These results suggest that UFPF vascular grafts provide a suitable microenvironment for infiltration and proliferation of fibroblasts, which are accompanied by the capillary formation as nutrient supply; these capillaries provide multiple sources of endothelial coverage on the luminal surface. It is expected that the new, highly porous vascular grafts may have rich endothelialization capability and stable healing properties in humans. PMID:2480800

  10. Filtration characteristics of the polyester fiber micropore blood transfusion filter.

    PubMed

    Risberg, B I; Hurley, M J; Miller, E; deJongh, D S; Litwin, M S

    1979-06-01

    The filtration characteristics of a new polyester fiber (Fenwal II) micropore blood transfusion filter were investigated. Filtration of stored human whole blood and packed cells resulted in return of screen filtration pressure (SFP) of the blood to normal. Increased filter weights verified removal of large amounts of debris and microaggregates from the blood. Filtration of large quantities of blood accomplished at very high flow rates did not adversely affect the composition of the filtered blood. We conclude that the polyester fiber (Fenwal II) micropore blood transfusion filter is effective in removing microaggregates from stored whole blood and packed cells. It has a high volume capacity, allows rapid flow, and is reliable during pressure transfusion. PMID:451646

  11. Study on moisture absorption and sweat discharge of honeycomb polyester fiber

    NASA Astrophysics Data System (ADS)

    Feng, Aifen; Zhang, Yongjiu

    2015-07-01

    The moisture absorption and liberation properties of honeycomb polyester fiber were studied in order to understand its moisture absorption and sweat discharge. Through testing moisture absorption and liberation regains of honeycomb polyester fiber and normal polyester fiber in standard atmospheric conditions, their moisture absorption and liberation curves were depicted, and the regression equations of moisture regains to time during their reaching the balance of moisture absorption and moisture liberation were obtained according to the curves. Their moisture absorption and liberation rate curves were analyzed and the regression equations of the rates to time were obtained. The results shows that the moisture regain of honeycomb polyester fiber is much bigger than the normal polyester fiber's, and the initial moisture absorption and moisture liberation rates of the former are much higher than the latter's, so that the moisture absorbance and sweat discharge of honeycomb polyester fiber are excellent.

  12. Fiber reinforced PMR polyimide composites

    NASA Technical Reports Server (NTRS)

    Cavano, P. J.; Winters, W. E.

    1978-01-01

    Commercially obtained PMR-15 polyimide prepregs with S-glass and graphite fiber reinforcements were evaluated along with in-house prepared glass and graphite cloth PMR 2 materials. A novel autoclave approach was conceived and used to demonstrate that both the PMR systems respond to 1.4 MPa (200 psi) autoclave pressures to produce void free composites equivalent to die molded laminates. Isothermal gravimetric analysis and subsequent mechanical property tests indicated that the PMR 2 system was significantly superior in thermo-oxidative stability, and that S-glass reinforcements may contribute to the accelerated degradation of composites at 316 C (600 F) when compared to graphite fiber reinforced composites. Fully reversed bending fatigue experiments were conducted with a type of fixture unused for organic matrix composites. These studies indicated that the graphite fiber composites were clearly superior in fatigue resistance to the glass fiber reinforced material and that PMR matrix composite systems yield performance of the same order as composite materials employing other families of matrices.

  13. Noise problem in a polyester fiber plant in Pakistan.

    PubMed

    Shaikh, G H

    1996-01-01

    Noise study has been undertaken in the three units of a polyester fiber plant. The level and frequency characteristics of the prevailing noise have been studied and speech interference levels evaluated. The results are discussed with reference to the maximum permissible occupational noise exposure limits as allowed by the ISO and other national standards. Some recommendations have also been made to provide safety measures to the workers against high level noise in these units. PMID:8908854

  14. Epidermabrasion for acne: the polyester fiber web sponge.

    PubMed

    Durr, N P; Orentreich, N

    1976-03-01

    Physical-mechanical exfoliation with the nonwoven polyester fiber web sponge is an effective adjunct to the treatment of comedonal and pustular acne. Precisely controlled epidermabrasion is achieved by varying pressure, velocity, duration and frequency of use. Side effects are negligible and patient acceptance is high. Effectiveness is not dependent upon erythema and scaling since the web sponge mechanically removes keratin excrescences and trapped hairs in pilosebaceous ducts. PMID:138554

  15. Bone adaptation to a polyester fiber anterior cruciate ligament replacement.

    PubMed

    Amis, A A; Kempson, S A

    1999-01-01

    A series of polyester fiber ACL implants was studied in ovine stifle joints up to 2 years postimplantation. The implants were linked to the bone-tunnel wall by oriented fibrous tissue. Cross-sections of the tunnels showed bone ingrowth among the implant fibers at 2 years. A human trial of the Apex implant yielded a series of retrievals, some associated with gross bone-tunnel enlargement. There was no evidence of bone ingrowth in the human implants. It was hypothesized that-tunnel enlargement resulted from fretting at the implant-tissue interface in response to cyclic loads in use. PMID:10537586

  16. Fiber reinforced hybrid phenolic foam

    NASA Astrophysics Data System (ADS)

    Desai, Amit

    Hybrid composites in recent times have been developed by using more than one type of fiber reinforcement to bestow synergistic properties of the chosen filler and matrix and also facilitating the design of materials with specific properties matched to end use. However, the studies for hybrid foams have been very limited because of problems related to fiber dispersion in matrix, non uniform mixing due to presence of more than one filler and partially cured foams. An effective approach to synthesize hybrid phenolic foam has been proposed and investigated here. Hybrid composite phenolic foams were reinforced with chopped glass and aramid fibers in varied proportions. On assessing mechanical properties in compression and shear several interesting facts surfaced but overall hybrid phenolic foams exhibited a more graceful failure, greater resistance to cracking and were significantly stiffer and stronger than foams with only glass and aramid fibers. The optimum fiber ratio for the reinforced hybrid phenolic foam system was found to be 1:1 ratio of glass to aramid fibers. Also, the properties of hybrid foam were found to deviate from rule of mixture (ROM) and thus the existing theories of fiber reinforcement fell short in explaining their complex behavior. In an attempt to describe and predict mechanical behavior of hybrid foams a statistical design tool using analysis of variance technique was employed. The utilization of a statistical model for predicting foam properties was found to be an appropriate tool that affords a global perspective of the influence of process variables such as fiber weight fraction, fiber length etc. on foam properties (elastic modulus and strength). Similar approach could be extended to study other fiber composite foam systems such as polyurethane, epoxy etc. and doing so will reduce the number of experimental iterations needed to optimize foam properties and identify critical process variables. Diffusivity, accelerated aging and flammability

  17. Boron fiber reinforced plastics. (Latest citations from the Rubber and Plastics Research Association database). Published Search

    SciTech Connect

    1995-02-01

    The bibliography contains citations concerning the applications, molding processes, properties, design concepts, and market trends of polyester and epoxy resins reinforced with boron fibers. Performance evaluations from nondestructive test results are also included. (Contains 250 citations and includes a subject term index and title list.)

  18. Boron fiber reinforced plastics. (Latest citations from the Rubber and Plastics Research Association database). Published Search

    SciTech Connect

    Not Available

    1994-02-01

    The bibliography contains citations concerning the applications, molding processes, properties, design concepts, and market trends of polyester and epoxy resins reinforced with boron fibers. Performance evaluations from nondestructive test results are also included. (Contains 250 citations and includes a subject term index and title list.)

  19. The assessment of metal fiber reinforced polymeric composites

    NASA Technical Reports Server (NTRS)

    Chung, Wenchiang R.

    1990-01-01

    Because of their low cost, excellent electrical conductivity, high specific strength (strength/density), and high specific modulus (modulus/density) short metal fiber reinforced composites have enjoyed a widespread use in many critical applications such as automotive industry, aircraft manufacturing, national defense, and space technology. However, little data has been found in the study of short metal fibrous composites. Optimum fiber concentration in a resin matrix and fiber aspect ratio (length-to-diameter ratio) are often not available to a user. Stress concentration at short fiber ends is the other concern when the composite is applied to a load-bearing application. Fracture in such composites where the damage will be initiated or accumulated is usually difficult to be determined. An experimental investigation is therefore carefully designed and undertaken to systematically evaluate the mechanical properties as well as electrical properties. Inconel 601 (nickel based) metal fiber with a diameter of eight microns is used to reinforce commercially available thermoset polyester resin. Mechanical testing such as tensile, impact, and flexure tests along with electrical conductivity measurements is conducted to study the feasibility of using such composites. The advantages and limitations of applying chopped metal fiber reinforced polymeric composites are also discussed.

  20. 75 FR 6352 - Certain Polyester Staple Fiber from the People's Republic of China: Extension of Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-09

    ... Countervailing Duty Administrative Reviews and Deferral of Administrative Review, 74 FR 37690 (July 29, 2009... International Trade Administration Certain Polyester Staple Fiber from the People's Republic of China: Extension... polyester staple fiber from the People's Republic of China (``PRC''). This review covers the period June...

  1. 75 FR 51442 - Polyester Staple Fiber from Taiwan: Rescission of Antidumping Duty Administrative Review in Part

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-20

    ... Reviews and Requests for Revocation in Part, 75 FR 37759 (June 30, 2010). On July 28, 2010, Invista, S.a.r... International Trade Administration Polyester Staple Fiber from Taiwan: Rescission of Antidumping Duty... Commerce initiated an administrative review of the antidumping duty order on polyester staple fiber...

  2. 76 FR 7532 - Certain Polyester Staple Fiber From the People's Republic of China: Extension of Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-10

    ... Countervailing Duty Administrative Reviews and Requests for Revocations in Part, 75 FR 44224 (July 28, 2010). The... International Trade Administration Certain Polyester Staple Fiber From the People's Republic of China: Extension... polyester staple fiber from the People's Republic of China (``PRC''). This review covers the period June...

  3. 76 FR 11268 - Certain Polyester Staple Fiber From Korea and Taiwan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-01

    ..., subparts A, D, E, and F (19 CFR part 207), as most recently amended at 74 FR 2847 (January 16, 2009). \\1... polyester staple fiber from Korea and Taiwan (65 FR 33807). Following five-year reviews by Commerce and the... of certain polyester staple fiber from Korea and Taiwan (71 FR 16558). The Commission is...

  4. Natural Curaua Fiber-Reinforced Composites in Multilayered Ballistic Armor

    NASA Astrophysics Data System (ADS)

    Monteiro, Sergio Neves; Louro, Luis Henrique Leme; Trindade, Willian; Elias, Carlos Nelson; Ferreira, Carlos Luiz; de Sousa Lima, Eduardo; Weber, Ricardo Pondé; Miguez Suarez, João Carlos; da Silva Figueiredo, André Ben-Hur; Pinheiro, Wagner Anacleto; da Silva, Luis Carlos; Lima, Édio Pereira

    2015-10-01

    The performance of a novel multilayered armor in which the commonly used plies of aramid fabric layer were replaced by an equal thickness layer of distinct curaua fiber-reinforced composites with epoxy or polyester matrices was assessed. The investigated armor, in addition to its polymeric layer (aramid fabric or curaua composite), was also composed of a front Al2O3 ceramic tile and backed by an aluminum alloy sheet. Ballistic impact tests were performed with actual 7.62 caliber ammunitions. Indentation in a clay witness, simulating human body behind the back layer, attested the efficacy of the curaua-reinforced composite as an armor component. The conventional aramid fabric display a similar indentation as the curaua/polyester composite but was less efficient (deeper indentation) than the curaua/epoxy composite. This advantage is shown to be significant, especially in favor of the lighter and cheaper epoxy composite reinforced with 30 vol pct of curaua fiber, as possible substitute for aramid fabric in multilayered ballistic armor for individual protection. Scanning electron microscopy revealed the mechanism associated with the curaua composite ballistic performance.

  5. 75 FR 34097 - Certain Polyester Staple Fiber From Taiwan: Extension of the Final Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-16

    ... certain polyester staple fiber from Taiwan. See Certain Polyester Staple Fiber from Taiwan: Preliminary Results of Antidumping Duty Administrative Review, 75 FR 5964 (February 5, 2010). The review covers the... International Trade Administration Certain Polyester Staple Fiber From Taiwan: Extension of the Final Results...

  6. Toughness of fiber reinforced shotcrete

    SciTech Connect

    Morgan, D.R.; Chen, L.; Beaupre, D.

    1995-12-31

    Fibers are added to shotcrete to improve energy absorption and impact resistance, to provide crack resistance and crack control, and to provide apparent ductility, i.e., an ability to continue to carry load after the shotcrete matrix has cracked. In order to be able to quantify the benefits of fiber addition, a variety of different toughness measuring systems have been developed in different countries. Most commonly used are flexural toughness systems which determine load vs. deflection responses and relate the area under the curve to some absolute or dimensionless index energy parameter. In North America the ASTM C1018 test method is most commonly used. In Japan the JSCE-SF4 test procedure is used. A variety of procedures have been used in Europe, but the template approach of the Norwegian Guidelines NBP No. 7, seems to be finding favor. This paper briefly assesses the relative advantages and disadvantages of the various methods of characterizing toughness. It then provides recommendations for a new procedure which uses the ASTM C1018 test method for generating the flexural load vs. deflection curve, but analyzes the data using a modified version of the Norwegian template approach. The load vs. deflection curve is directly compared against four residual strength curves and the fiber reinforced shotcrete assigned one of four toughness performance levels. It is believed that this new procedure should provide suitable within and between laboratory reproducibility and be more suitable for purposes of differentiating between different fiber types and addition rates and specifying toughness for fiber reinforced shotcrete products than any of the existing methods.

  7. Fiber reinforced composite resin systems.

    PubMed

    Giordano, R

    2000-01-01

    The Targis/Vectris and Sculpture/FibreKor systems were devised to create a translucent maximally reinforced resin framework for fabrication of crowns, bridges, inlays, and onlays. These materials are esthetic, have translucency similar to castable glass-ceramics such as OPC and Empress, and have fits that are reported to be acceptable in clinical and laboratory trials. These restorations rely on proper bonding to the remaining tooth structure; therefore, careful attention to detail must be paid to this part of the procedure. Cementation procedures should involve silane treatment of the cleaned abraded internal restoration surface, application of bonding agent to the restoration as well as the etched/primed tooth, and finally use of a composite resin. Each manufacturer has a recommended system which has been tested for success with its resin system. These fiber reinforced resins are somewhat different than classical composites, so not all cementation systems will necessarily work with them. Polishing of the restoration can be accomplished using diamond or alumina impregnated rubber wheels followed by diamond paste. The glass fibers can pose a health risk. They are small enough to be inhaled and deposited in the lungs, resulting in a silicosis-type problem. Therefore, if fibers are exposed and ground on, it is extremely important to wear a mask. Also, the fibers can be a skin irritant, so gloves also should be worn. If the fibers become exposed intraorally, they can cause gingival inflammation and may attract plaque. The fibers should be covered with additional composite resin. If this cannot be accomplished, the restoration should be replaced. The bulk of these restorations are formed using a particulate filled resin, similar in structure to conventional composite resins. Therefore, concerns as to wear resistance, color stability, excessive expansion/contraction, and sensitivity remain until these materials are proven in long-term clinical trials. They do hold the

  8. Graphite fiber reinforced thermoplastic resins

    NASA Technical Reports Server (NTRS)

    Novak, R. C.

    1975-01-01

    Mechanical properties of neat resin samples and graphite fiber reinforced samples of thermoplastic resins were characterized with particular emphasis directed to the effects of environmental exposure (humidity, temperature and ultraviolet radiation). Tensile, flexural, interlaminar shear, creep and impact strengths were measured for polysulfone, polyarylsulfone and a state-of-the-art epoxy resin samples. In general, the thermoplastic resins exhibited environmental degradation resistance equal to or superior to the reference epoxy resin. Demonstration of the utility and quality of a graphite/thermoplastic resin system was accomplished by successfully thermoforming a simulated compressor blade and a fan exit guide vane.

  9. The use of sodium hyaluronate as a lubricant in brow suspension ptosis surgery using polyester fiber mesh.

    PubMed

    Lim, B A; Choo, C T

    1998-07-01

    Polyester fiber is used as an alternative to autologous fascia lata for brow suspension ptosis surgery. The authors found it difficult to pass the polyester compound through the submuscular plane during brow suspension surgery. They used sodium hyaluronate as a lubricant to aid the passage of polyester fiber mesh. In 14 cases of brow suspension surgery with polyester fiber mesh, the authors found sodium hyaluronate to be useful in reducing tissue resistance and without untoward effect. PMID:9674014

  10. 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.

  11. Reinforcing aluminum alloys with high strength fibers

    NASA Technical Reports Server (NTRS)

    Kolpashnikov, A. I.; Manuylov, V. F.; Chukhin, B. D.; Shiryayev, Y. V.; Shurygin, A. S.

    1982-01-01

    A study is made of the possibility of reinforcing aluminum and aluminum based alloys with fibers made of high strength steel wire. The method of introducing the fibers is described in detail. Additional strengthening by reinforcement of the high alloy system Al - An - Mg was investigated.

  12. Mechanical performance of hybrid polyester composites reinforced Cloisite 30B and kenaf fibre

    NASA Astrophysics Data System (ADS)

    Bonnia, N. N.; Surip, S. N.; Ratim, S.; Mahat, M. M.

    2012-06-01

    Hybridization of rubber toughened polyester-kenaf nanocomposite was prepared by adding various percentage of kenaf fiber with 4% Cloisite 30B in unsaturated polyester resin. Composite were prepared by adding filler to modified polyester resin subsequently cross-linked using methyl ethyl ketone peroxide and the accelerator cobalt octanoate 1%. Three per hundred rubbers (phr) of liquid natural rubber (LNR) were added in producing this composite. This composite expected to be applied in the interior of passenger cars and truck cabins. This is a quality local product from a combination of good properties polyester and high performance natural fiber, kenaf that is suitable for many applications such as in automotive sector and construction sector. The mechanical and thermal properties of composite were characterized using Durometer Shore-D hardness test, Izod impact test, Scanning electron microscopy, thermogravimetry (TGA) and differential scanning calorimetry (DSC). Result shows that addition of LNR give good properties on impact, flexural and hardness compare to without LNR composite. DSC curve shows that all composition of composites is fully cured and good in thermal properties. Addition of higher percentage of kenaf will lead the composite to elastic behavior and decrease the toughened properties of the composite. Hybrid system composite showed the flexural properties within the flexural properties of kenaf - polyester and Cloisite 30B.

  13. Study on basalt fiber parameters affecting fiber-reinforced mortar

    NASA Astrophysics Data System (ADS)

    Orlov, A. A.; Chernykh, T. N.; Sashina, A. V.; Bogusevich, D. V.

    2015-01-01

    This article considers the effect of different dosages and diameters of basalt fibers on tensile strength increase during bending of fiberboard-reinforced mortar samples. The optimal dosages of fiber, providing maximum strength in bending are revealed. The durability of basalt fiber in an environment of cement, by means of microscopic analysis of samples of fibers and fiberboard-reinforced mortar long-term tests is examined. The article also compares the behavior of basalt fiber in the cement stone environment to a glass one and reveals that the basalt fiber is not subject to destruction.

  14. Long-short fiber reinforced thermoplastics

    SciTech Connect

    Gore, C.R.; Cuff, G.; Cianelli, D.A.; Travis, J.E.

    1986-01-01

    This paper presents information on a new family of fiber-reinforced thermoplastic compounds developed by ICI PLC and now produced by LNP under the trade mark ''Verton.'' Production is by a pultrusion process, rather than by the usual compounding extruder, which enables a high level of impregnation to be achieved without damaging the fibers. The result in molded parts is a 0.24-0.40 inch (6-10 mm) typical fiber length versus 0.008-0.016 inches (0.2-0.4 mm) for conventional short fiber products. Consequently, this enables fabricators to achieve typically a 10 to 20-fold increase in average fiber length in the finished component. These long-short fiber reinforced compounds exhibit substantial property improvements over short fiber system. Processing conditions are similar to corresponding short fiber compounds.

  15. Modification of unsaturated polyester resins (UP) and reinforced UP resins via plasma treatment

    NASA Astrophysics Data System (ADS)

    Li, Guanglu; Wei, Xing; Wang, Wanjun; He, Tao; Li, Xuemei

    2010-10-01

    Unsaturated polyester resins (UP) and reinforced composite unsaturated polyester resins (RCP) were made superhydrophobic by plasma assisted methods. Both CF 4-plasma-enhanced chemical vapor deposition (CF 4-PECVD) and alternative method were tested. The surfaces were characterized by water contact angle (CA) measurements and scanning electron microscopy (SEM). Water contact angle results indicated that CF 4-PECVD can significantly improve the wettability of UP surfaces, but suffer from difficulties for RCP surfaces. Alternatively, O 2 plasma followed by self-assembly of octadecyltrichlorosilane (OTS) self-assembled monolayer (SAM) was tested. It was shown that regardless of the filler percentage, O 2 plasma followed by self-assembly of OTS monolayer formation all led to superhydrophobic surfaces. The results provided a means to improve the wettability of reinforced UP resins (RCP).

  16. 78 FR 14512 - Certain Polyester Staple Fiber From the People's Republic of China: Preliminary Results and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-06

    ... Fiber from the People's Republic of China, 72 FR 30545 (June 1, 2007) (``Order''). Methodology The... Assessment Rate in Certain Antidumping Proceedings: Final Modification, 77 FR 8101 (February 14, 2012). For... Sichuan Chemical Fiber Corp. and Huvis Sichuan Polyester Fiber Ltd. (``Huvis Sichuan'') are part of...

  17. Evaluation of tensile strength of hybrid fiber (jute/gongura) reinforced hybrid polymer matrix composites

    NASA Astrophysics Data System (ADS)

    Venkatachalam, G.; Gautham Shankar, A.; Vijay, Kumar V.; Chandan, Byral R.; Prabaharan, G. P.; Raghav, Dasarath

    2015-07-01

    The polymer matrix composites attract many industrial applications due to its light weight, less cost and easy for manufacturing. In this paper, an attempt is made to prepare and study of the tensile strength of hybrid (two natural) fibers reinforced hybrid (Natural + Synthetic) polymer matrix composites. The samples were prepared with hybrid reinforcement consists of two different fibers such as jute and Gongura and hybrid polymer consists of polyester and cashew nut shell resins. The hybrid composites tensile strength is evaluated to study the influence of various fiber parameters on mechanical strength. The parameters considered here are the duration of fiber treatment, the concentration of alkali in fiber treatment and nature of fiber content in the composites.

  18. Morphological and biodegradability studies of Euphorbia latex modified polyester - Banana fiber composites

    NASA Astrophysics Data System (ADS)

    Rai, Bhuvneshwar; Kumar, Gulshan; Diwan, R. K.

    2016-05-01

    The composites of Banana fiber were prepared using polyester resin blended Euphorbia coagulum, morphology and the degree of rate of aerobic biodegradation of the prepared composites were studied. Polyester resin blended Euphorbia coagulum containing Banana fiber, Euphorbia coagulum and polyester resin taken in the ratio 40: 24: 36 was used for the study, which was the optimum composition of the composite reported in a previous study by the authors. In the biodegradability study cellulose has been used as positive reference material. Result shows that Euphorbia coagulum modified polyester - Banana fiber composites exhibited biodegradation to the extent of around 40%. The use of developed green composites may help in reducing the generation of non-biodegradable polymeric wastes.

  19. Adhesive Wear and Frictional Behavior of Multilayered Polyester Composite Based on Betelnut Fiber Mats Under Wet Contact Conditions

    NASA Astrophysics Data System (ADS)

    Yousif, B. F.; Devadas, Alvin; Yusaf, Talal F.

    In the current study, a multilayered polyester composite based on betelnut fiber mats is fabricated. The adhesive wear and frictional performance of the composite was studied against a smooth stainless steel at different sliding distances (0-6.72 km) and applied loads (20-200 N) at 2.8 m/s sliding velocity. Variations in specific wear rate and friction coefficient were evaluated at two different orientations of fiber mat; namely parallel (P-O) and normal (N-O). Results obtained were presented against sliding distance. The worn surfaces of the composite were studied using an optical microscope. The effect of the composite sliding on the stainless steel counterface roughness was investigated. The results revealed that the wear performance of betelnut fiber reinforced polyester (BFRP) composite under wet contact condition was highly dependent on test parameters and fiber mat orientation. The specific wear rate performance for each orientation showed an inverse relationship to sliding distance. BFRP composite in N-O exhibited better wear performance compared with P-O. However, the friction coefficient in N-O was higher than that in P-O at lower range of applied load. The predominant wear mechanism was debonding of fiber with no pullout or ploughing. Moreover, at higher applied loads, micro- and macrocracking and fracture were observed in the resinous region.

  20. An overview of long fiber reinforced thermoplastics

    SciTech Connect

    Bockstedt, R.J.; Skarlupka, R.J.

    1995-12-01

    Long fiber reinforced thermoplastics (LFRTP) are a class of injection molding materials that extend the physical property envelope of thermoplastics polymers. These materials are manufactured by pulling continuous fiber tows through a thermoplastic polymer melt in a specialized processing die. The strands are subsequently cooled and chopped into pellets of equal length. LFRTP materials are available in virtually every common thermoplastic resin with glass, aramid, stainless steel, or carbon fiber reinforcement at levels up to 60% by weight. Unlike short fiber reinforced thermoplastics manufactured by conventional screw compounding processes, LFRTP exhibit simultaneous improvements in both flexural modulus and impact resistance. Improvements in load transfer, creep resistance at elevated temperatures, and dimensional stability can also be attributed to the long fiber network formed in the molded part. This unique combination of properties makes LFRTP the material of choice for replacement of metal structural assemblies in many automotive, industrial, consumer and recreational applications.

  1. Clinical use of low porosity woven ultrafine polyester fiber grafts.

    PubMed

    Satoh, S; Niu, S; Kanda, K; Hirai, J; Nakazima, S; Wada, Y; Oka, T; Noishiki, Y

    1995-01-01

    A woven fabric graft made of ultrafine polyester fibers (UFPF) (Toray Graft, water porosity: 100 ml/min/cm2:120 mm Hg H2O) was clinically applied in 81 cases (28 thoracic aortic aneurysms, 6 thoracoabdominal aortic aneurysms, 42 abdominal aortic aneurysms, and 5 atherosclerotic obstructions of the peripheral arteries). Eight patients died after surgery due to causes unrelated to the graft. The other 73 patients were in good condition after surgery. For operations requiring extracorporeal circulation, the graft was presealed with human albumin. For the abdominal aortic aneurysms, the graft was preclotted in situ with nonheparinized autoblood after the completion of the proximal anastomosis. It took about 2 min to complete the preclotting. A nonsealed graft was used for the reconstruction of peripheral arteries for the intraaortic balloon pumping procedure. The graft was easy to handle. There was no cut edge fraying problem with the graft in any direction of cutting. Even after presealing, the graft was soft and pliable enough to enable easy adaptation and anastomosis. Just after implantation, bleeding was minimal from the graft wall, anastomotic sites, and suture pores, and it stopped spontaneously. These clinical data showed that the woven UFPF graft exhibited both easy handling despite in spite of low porosity and safe application in the reconstruction of arterial systems even under totally heparinized conditions during extracorporeal circulation. PMID:7741640

  2. THERMAL INSULATION PROPERTIES OF NONWOVEN SEMI-DISPOSABLE BLANKETS FROM RECYCLED POLYESTER/COTTON FIBERS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recycled polyester fibers and cotton fibers that require no chemical processing were used to produce a low-cost, semi-durable, nonwoven thermal blanket. Thermal blankets were given carboxylic acid finish to improve structural stability during use and laundering. A Steady-State Heat Flow meter FOX ...

  3. Neutron imaging of fiber-reinforced materials

    NASA Astrophysics Data System (ADS)

    Bastürk, M.; Kardjilov, N.; Rauch, H.; Vontobel, P.

    2005-04-01

    Glass-fiber-reinforced plastic laminates used for the insulation of Toroidal Field (TF) magnet-coils and fiber-reinforced silicon carbide ceramic composites used as structural material for the self-cooled Pb-17Li blanket module are attractive candidate materials for fusion reactors because of their high performance under extreme conditions. Porosity, which depends on the manufacturing process, and swelling of fiber-reinforced materials due to the high flux of radiation are the main problems. The aim of this study is to describe the experimental procedures of different imaging methods, and also to decide the most efficient imaging method for the investigations of the complex microstructure of fiber-reinforced materials. In this work, the fiber-reinforced composites were inspected with neutron and X-ray radiographies at ATI-Vienna and also at PSI-Villigen. A contrast enhancement at the edges can be achieved by means of phase contrast neutron radiography (NR), which is based on the wave properties of neutrons and arises from the neutron refraction (rather than attenuation). Elements having different refractive index within a sample cause a phase shift between coherent neutron waves. The degree of coherence can be determined by means of the coherence pattern caused by the sample, when a point source (pinhole) is used and the distance between source and sample is varied.

  4. Homogenization of long fiber reinforced composites including fiber bending effects

    NASA Astrophysics Data System (ADS)

    Poulios, Konstantinos; Niordson, Christian F.

    2016-09-01

    This paper presents a homogenization method, which accounts for intrinsic size effects related to the fiber diameter in long fiber reinforced composite materials with two independent constitutive models for the matrix and fiber materials. A new choice of internal kinematic variables allows to maintain the kinematics of the two material phases independent from the assumed constitutive models, so that stress-deformation relationships, can be expressed in the framework of hyper-elasticity and hyper-elastoplasticity for the fiber and the matrix materials respectively. The bending stiffness of the reinforcing fibers is captured by higher order strain terms, resulting in an accurate representation of the micro-mechanical behavior of the composite. Numerical examples show that the accuracy of the proposed model is very close to a non-homogenized finite-element model with an explicit discretization of the matrix and the fibers.

  5. 77 FR 4543 - Certain Polyester Staple Fiber From Taiwan: Extension of Time Limit for Preliminary Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-30

    ... for Revocation in Part, 76 FR 37781 (June 28, 2011). The preliminary results are currently due no... International Trade Administration Certain Polyester Staple Fiber From Taiwan: Extension of Time Limit for... antidumping duty order on certain polyester staple fiber from Taiwan for the period May 1, 2010, through...

  6. 76 FR 28420 - Certain Polyester Staple Fiber From the People's Republic of China: Full Extension of Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-17

    ... Countervailing Duty Administrative Reviews and Requests for Revocations in Part, 75 FR 44224 (July 28, 2010). The... International Trade Administration Certain Polyester Staple Fiber From the People's Republic of China: Full... polyester staple fiber from the People's Republic of China (``PRC''). This review covers the period June...

  7. 76 FR 60802 - Certain Polyester Staple Fiber From the Republic of Korea and Taiwan: Continuation of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-30

    ... of 1930, as amended (the Act). See Initiation of Five-Year (``Sunset'') Review, 76 FR 11202 (March 1, 2011); see also Certain Polyester Staple Fiber From Korea and Taiwan, 76 FR 11268 (March 1, 2011). \\1... Taiwan, 65 FR 33807 (May 25, 2000); Certain Polyester Staple Fiber from the Republic of Korea: Notice...

  8. 77 FR 39990 - Certain Polyester Staple Fiber From the People's Republic of China: Preliminary Results of the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-06

    ... Antidumping Duty Order: Certain Polyester Staple Fiber from the People's Republic of China, 72 FR 30545 (June... Revocation in Part, 76 FR 53404 (August 26, 2011). \\4\\ See Certain Polyester Staple Fiber from the People's... Determination: Bottle-Grade Polyethylene Terephthalate (PET) Resin From Thailand, 70 FR 13462 (March 21,...

  9. Hygrothermal response of polymer composites based on modified sisal fibers and unsaturated polyester resin

    SciTech Connect

    Singh, B.; Gupta, M.

    1995-10-01

    Polymer composites made from surface modified sisal fibers and unsaturated polyester resin were exposed to different wet environments and their physico-mechanical properties were evaluated as a function of exposure time. It was found that all types of treatments improved the performance of composites. Silane treated fiber composites displayed superior strength retention property under humid environments, while zirconate treated fiber composites resulted fairly better in immersed water condition.

  10. Damping behavior of Discontinuous Fiber Reinforced Thermoplastic Composites

    NASA Astrophysics Data System (ADS)

    Haldar, Amit Kumar; Aggarwal, Ishan; Batra, N. K.

    2010-11-01

    Discontinuous fiber reinforced composites are being used in many antivibration applications due to their time and temperature dependent specific mechanical properties. For utilization of this material to specific engineering applications there is a need to understand the damping behavior of composites under dynamic loading. For this work, unreinforced and 20% long and short reinforced glass fiber polypropylene composite materials were tested for free transverse vibration damping characteristics under static as well as fatigue loading conditions. The damping characteristics are quantified by decay pattern and natural frequency. Presence of reinforced fibers increases the damping capacity. Among reinforcements, short fiber reinforced polypropylene shows increased damping capacity then long glass fiber reinforced polypropylene.

  11. Fiber Reinforced Composite Materials Used for Tankage

    NASA Technical Reports Server (NTRS)

    Cunningham, Christy

    2005-01-01

    The Nonmetallic Materials and Processes Group is presently working on several projects to optimize cost while providing effect materials for the space program. One factor that must be considered is that these materials must meet certain weight requirements. Composites contribute greatly to this effort. Through the use of composites the cost of launching payloads into orbit will be reduced to one-tenth of the current cost. This research project involved composites used for aluminum pressure vessels. These tanks are used to store cryogenic liquids during flight. The tanks need some type of reinforcement. Steel was considered, but added too much weight. As a result, fiber was chosen. Presently, only carbon fibers with epoxy resin are wrapped around the vessels as a primary source of reinforcement. Carbon fibers are lightweight, yet high strength. The carbon fibers are wet wound onto the pressure vessels. This was done using the ENTEC Filament Winding Machine. It was thought that an additional layer of fiber would aid in reinforcement as well as containment and impact reduction. Kevlar was selected because it is light weight, but five times stronger that steel. This is the same fiber that is used to make bullet-proof vests trampolines, and tennis rackets.

  12. Nonwoven glass fiber mat reinforces polyurethane adhesive

    NASA Technical Reports Server (NTRS)

    Roseland, L. M.

    1967-01-01

    Nonwoven glass fiber mat reinforces the adhesive properties of a polyurethane adhesive that fastens hardware to exterior surfaces of aluminum tanks. The mat is embedded in the uncured adhesive. It ensures good control of the bond line and increases the peel strength.

  13. Fatigue of continuous fiber reinforced metallic materials

    NASA Technical Reports Server (NTRS)

    Johnson, W. S.; Mirdamadi, M.; Bakuckas, J. G., Jr.

    1993-01-01

    The complex damage mechanisms that occur in fiber reinforced advanced metallic materials are discussed. As examples, results for several layups of SCS-6/Ti-15-3 composites are presented. Fatigue tests were conducted and analyzed for both notched and unnotched specimens at room and elevated temperatures. Test conditions included isothermal, non-isothermal, and simulated mission profile thermomechanical fatigue. Test results indicated that the stress in the 0 degree fibers is the controlling factor for fatigue life for a given test condition. An effective strain approach is presented for predicting crack initiation at notches. Fiber bridging models were applied to crack growth behavior.

  14. Nano polypeptide particles reinforced polymer composite fibers.

    PubMed

    Li, Jiashen; Li, Yi; Zhang, Jing; Li, Gang; Liu, Xuan; Li, Zhi; Liu, Xuqing; Han, Yanxia; Zhao, Zheng

    2015-02-25

    Because of the intensified competition of land resources for growing food and natural textile fibers, there is an urgent need to reuse and recycle the consumed/wasted natural fibers as regenerated green materials. Although polypeptide was extracted from wool by alkaline hydrolysis, the size of the polypeptide fragments could be reduced to nanoscale. The wool polypeptide particles were fragile and could be crushed down to nano size again and dispersed evenly among polymer matrix under melt extrusion condition. The nano polypeptide particles could reinforce antiultraviolet capability, moisture regain, and mechanical properties of the polymer-polypeptide composite fibers. PMID:25647481

  15. Mechanical characterization and structural analysis of recycled fiber-reinforced-polymer resin-transfer-molded beams

    NASA Astrophysics Data System (ADS)

    Tan, Eugene Wie Loon

    1999-09-01

    The present investigation was focussed on the mechanical characterization and structural analysis of resin-transfer-molded beams containing recycled fiber-reinforced polymers. The beams were structurally reinforced with continuous unidirectional glass fibers. The reinforcing filler materials consisted entirely of recycled fiber-reinforced polymer wastes (trim and overspray). The principal resin was a 100-percent dicyclo-pentadiene unsaturated polyester specially formulated with very low viscosity for resin transfer molding. Variations of the resin transfer molding technique were employed to produce specimens for material characterization. The basic materials that constituted the structural beams, continuous-glass-fiber-reinforced, recycled-trim-filled and recycled-overspray-filled unsaturated polyesters, were fully characterized in axial and transverse compression and tension, and inplane and interlaminar shear, to ascertain their strengths, ultimate strains, elastic moduli and Poisson's ratios. Experimentally determined mechanical properties of the recycled-trim-filled and recycled-overspray-filled materials from the present investigation were superior to those of unsaturated polyester polymer concretes and Portland cement concretes. Mechanical testing and finite element analyses of flexure (1 x 1 x 20 in) and beam (2 x 4 x 40 in) specimens were conducted. These structurally-reinforced specimens were tested and analyzed in four-point, third-point flexure to determine their ultimate loads, maximum fiber stresses and mid-span deflections. The experimentally determined load capacities of these specimens were compared to those of equivalent steel-reinforced Portland cement concrete beams computed using reinforced concrete theory. Mechanics of materials beam theory was utilized to predict the ultimate loads and mid-span deflections of the flexure and beam specimens. However, these predictions proved to be severely inadequate. Finite element (fracture propagation

  16. Leaf spring made of fiber-reinforced resin

    NASA Technical Reports Server (NTRS)

    Hori, J.

    1986-01-01

    A leaf spring made of a matrix reinforced by at least two types of reinforcing fibers with different Young's modulus is described in this Japanese patent. At least two layers of reinforcing fibers are formed by partially arranging the reinforcing fibers toward the direction of the thickness of the leaf spring. A mixture of different types of reinforced fibers is used at the area of boundary between the two layers of reinforced fibers. The ratio of blending of each type of reinforced fiber is frequently changed to eliminate the parts where discontinuous stress may be applied to the leaf spring. The objective of this invention is to prevent the rapid change in Young's modulus at the boundary area between each layer of reinforced fibers in the leaf spring.

  17. Innovative Composites Through Reinforcement Morphology Design - a Bone-Shaped-Short-Fiber Composite

    SciTech Connect

    Zhu, Y.T.; Valdez, J.A.; Beyerlain, I.J.; Stout, M.G.; Zhou, S.; Shi, N.; Lowe, T.C.

    1999-06-29

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The objective of this project is to improve the strength and toughness of conventional short-fiber composites by using innovative bone-shaped-short (BSS) fibers as reinforcement. We fabricated a model polyethylene BSS fiber-reinforced polyester-matrix composite to prove that fiber morphology, instead of interfacial strength, solves the problem. Experimental tensile and fracture toughness test results show that BSS fibers can bridge matrix cracks more effectively, and consume many times more energy when pulled out, than conventional-straight-short (CSS) fibers. This leads to both higher strength and fracture toughness for the BSS-fiber composites. A computational model was developed to simulate crack propagation in both BSS- and CSS-fiber composites, accounting for stress concentrations, interface debonding, and fiber pullout. Model predictions were validated by experimental results and will be useful in optimizing BSS-fiber morphology and other material system parameters.

  18. 77 FR 6783 - Certain Polyester Staple Fiber From the People's Republic of China: Extension of Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-09

    ... and Deferral of Administrative Reviews, 76 FR 45227 (July 28, 2011). The preliminary results are... Act of 1930, As Amended, 70 FR 24533 (May 10, 2005). We are issuing and publishing this notice in... International Trade Administration Certain Polyester Staple Fiber From the People's Republic of China:...

  19. 75 FR 30373 - Certain Polyester Staple Fiber From the People's Republic of China: Extension of Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-01

    ... Reviews and Deferral of Administrative Review, 74 FR 37690 (July 29, 2009). On February 9, 2010, the... Duty Administrative Review, 75 FR 6352 (February 9, 2010). On February 16, 2010, the Department issued... International Trade Administration Certain Polyester Staple Fiber From the People's Republic of China:...

  20. 77 FR 19619 - Certain Polyester Staple Fiber from the People's Republic of China: Extension of Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-02

    ..., Requests for Revocations in Part and Deferral of Administrative Reviews, 76 FR 45227 (July 28, 2011). \\2... Results of Antidumping Duty Administrative Review, 77 FR 6783 (February 9, 2012). Statutory Time Limits In... International Trade Administration Certain Polyester Staple Fiber from the People's Republic of China:...

  1. 77 FR 62217 - Certain Polyester Staple Fiber From the People's Republic of China: Continuation of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-12

    ...'').\\1\\ \\1\\ See Initiation of Five-Year (``Sunset'') Review; Correction, 77 FR 28355 (May 14, 2012... of China: Final Results of Expedited Sunset Review of the Antidumping Duty Order, 77 FR 54898...\\ \\3\\ See Certain Polyester Staple Fiber from China Determination, 77 FR 60720 (October 4, 2012),...

  2. 78 FR 17637 - Polyester Staple Fiber From Taiwan: Preliminary Results of Antidumping Duty Administrative Review...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-22

    ...: Final Modification, 77 FR 8101, 8102 (February 14, 2012). The Department clarified its ``automatic... Antidumping Duties, 68 FR 23954 (May 6, 2003) (Assessment Policy Notice). Consistent with the Assessment... Antidumping Duty Orders: Certain Polyester Staple Fiber From the Republic of Korea and Taiwan, 65 FR...

  3. 77 FR 54562 - Certain Polyester Staple Fiber From the Republic of Korea: Rescission of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-05

    ..., Finding, or Suspended Investigation; Opportunity to Request Administrative Review, 77 FR 25679, 25680 (May... Reviews and Request for Revocation in Part, 77 FR 40565, 40567 (July 10, 2012). \\5\\ See Letter from... International Trade Administration Certain Polyester Staple Fiber From the Republic of Korea: Rescission...

  4. 76 FR 58040 - Certain Polyester Staple Fiber From Korea and Taiwan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-19

    ... Procedure (19 CFR 207.2(f)). Background The Commission instituted these reviews on March 1, 2011 (76 FR 11268) and determined on June 6, 2011 that it would conduct expedited reviews ( 76 FR 37830, June 28... COMMISSION Certain Polyester Staple Fiber From Korea and Taiwan Determination On the basis of the record...

  5. 78 FR 51707 - Certain Polyester Staple Fiber From the Republic of Korea: Rescission of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-21

    ... Antidumping and Countervailing Duty Administrative Reviews and Request for Revocation in Part, 78 FR 38924... International Trade Administration Certain Polyester Staple Fiber From the Republic of Korea: Rescission of...) from the Republic of Korea (Korea) for the period May 1, 2012, through April 30, 2013, based on...

  6. 75 FR 43921 - Certain Polyester Staple Fiber From Taiwan: Final Results of Antidumping Duty Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-27

    ... Polyester Staple Fiber From Taiwan: Preliminary Results of Antidumping Duty Administrative Review, 75 FR... Duties, 68 FR 23954 (May 6, 2003). The Department intends to issue assessment instructions directly to... Republic of Korea and Taiwan, 65 FR 33807 (May 25, 2000). These cash-deposit requirements shall remain...

  7. 76 FR 57955 - Certain Polyester Staple Fiber From Taiwan: Final Results of Antidumping Duty Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-19

    ...On April 21, 2011, the Department of Commerce published the preliminary results of the administrative review of the antidumping duty order on certain polyester staple fiber from Taiwan. The period of review is May 1, 2009, through April 30, 2010. We gave interested parties an opportunity to comment on the preliminary results. We received comments from Far Eastern New Century Corporation. The......

  8. 77 FR 54561 - Certain Polyester Staple Fiber From Taiwan: Final Results of Antidumping Duty Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-05

    ...On June 1, 2012, the Department of Commerce published the preliminary results of the administrative review of the antidumping duty order on certain polyester staple fiber from Taiwan. The period of review is May 1, 2010, through April 30, 2011. We gave interested parties an opportunity to comment on the preliminary results, but we received no comments. The final weighted-average dumping margin......

  9. 75 FR 4044 - Polyester Staple Fiber From Taiwan: Initiation and Preliminary Results of Changed-Circumstances...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-26

    ... Duty Orders: Certain Polyester Staple Fiber From the Republic of Korea and Taiwan, 65 FR 33807 (May 25... Taiwan: Final Results of Antidumping Duty Administrative Review, 74 FR 18348 (April 22, 2009). FET has... Changed Circumstances Antidumping Duty Administrative Review: Polychloroprene Rubber From Japan, 67 FR...

  10. Atmospheric-air plasma enhances coating of different lubricating agents on polyester fiber

    NASA Astrophysics Data System (ADS)

    Ebrahimi, I.; Kiumarsi, A.; Parvinzadeh Gashti, M.; Rashidian, R.; Norouzi, M. Hossein

    2011-10-01

    This research work involves the plasma treatment of polyethylene terephthalate fiber to improve performance of various ionic lubricating agents. To do this, polyester fabric was pre-scoured with detergent, treated with atmospheric-air plasma and then coated with anionic, cationic and nonionic emulsions. Chemical and physical properties of samples were investigated by the use of Fourier transform infrared spectroscopy (FTIR), bending lengths (BL), wrinkle recovery angles (WRA), fiber friction coefficient analysis (FFCA), moisture absorbency (MA), scanning electron microscopy (SEM) and reflectance spectroscopy (RS). Study on chemical properties of fibers revealed that the plasma pretreatment modifies the surface of fibers and increases the reactivity of substrate toward various ionic emulsions. Physical properties of textiles indicated that the combination of plasma and emulsion treatments on polyester can improve crease resistant, drapeability and water repellency due to uniform coating of various emulsions on surface of textiles.

  11. FIBER LENGTH DISTRIBUTION MEASUREMENT FOR LONG GLASS AND CARBON FIBER REINFORCED INJECTION MOLDED THERMOPLASTICS

    SciTech Connect

    Kunc, Vlastimil; Frame, Barbara J; Nguyen, Ba N.; TuckerIII, Charles L.; Velez-Garcia, Gregorio

    2007-01-01

    Procedures for fiber length distribution (FLD) measurement of long fiber reinforced injection molded thermoplastics were refined for glass and carbon fibers. Techniques for sample selection, fiber separation, digitization and length measurement for both fiber types are described in detail. Quantitative FLD results are provided for glass and carbon reinforced polypropylene samples molded with a nominal original fiber length of 12.7 mm (1/2 in.) using equipment optimized for molding short fiber reinforced thermoplastics.

  12. Fiber glass reinforced structural materials for aerospace application

    NASA Technical Reports Server (NTRS)

    Bartlett, D. H.

    1968-01-01

    Evaluation of fiber glass reinforced plastic materials concludes that fiber glass construction is lighter than aluminum alloy construction. Low thermal conductivity and strength makes the fiber glass material useful in cryogenic tank supports.

  13. Forming of fiber reinforced thermoplastic sheets

    SciTech Connect

    Bhattacharyya, D.; Burt, C.R.; Martin, T.A.

    1993-12-31

    The development of fiber reinforced thermoplastic (FRTP) sheets has added a new dimension to the manufacturing industry. The ability of the thermoplastic matrix to soften and melt with the application of heat allows secondary processing of these composites. The material can be formed into components using conventional sheet metal forming processes with necessary modification. Ideally this opens the way for low cycle-time, non-labor intensive manufacturing processes. However, before there can be any wide scale application of the fiber reinforced sheet material, a better understanding is required regarding the formability of these reinforced sheets and the parameters influencing their forming characteristics. In sheet metal industry the term formability is described as the ease of forming and can be judged by various factors which may vary with the needs of a particular manufacturer. It is not always easy to prejudge formability as in many instances the actual sheet forming mechanism is quite complex. However, often a reasonable understanding of the process characteristics can be obtained through some relatively simple laboratory experiments. The present paper describes the results of a series of such tests namely hemispherical dome forming, cup drawing and vee bending using mainly polypropylene/glass fiber composite sheets with various fiber architecture, forming temperature and speed. Grid strain analysis has been applied to measure the magnitudes and directions of the principal strains and how they are influenced by fiber orientation. A kinematic approach has been shown to theoretically predict the deformation pattern with reasonable accuracy. Some salient features such as fiber buckling, sheet wrinkling, springback have been discussed in the context of forming process variables.

  14. Development of natural fiber reinforced polylactide-based biocomposites

    NASA Astrophysics Data System (ADS)

    Arias Herrera, Andrea Marcela

    Polylactide or PLA is a biodegradable polymer that can be produced from renewable resources. This aliphatic polyester exhibits good mechanical properties similar to those of polyethylene terephthalate (PET). Since 2003, bio-based high molecular weight PLA is produced on an industrial scale and commercialized under amorphous and semicrystalline grades for various applications. Enhancement of PLA crystallization kinetics is crucial for the competitiveness of this biopolymer as a commodity material able to replace petroleum-based plastics. On the other hand, the combination of natural fibers with polymer matrices made from renewable resources, to produce fully biobased and biodegradable polymer composite materials, has been a strong trend in research activities during the last decade. Nevertheless, the differences related to the chemical structure, clearly observed in the marked hydrophilic/hydrophobic character of the fibers and the thermoplastic matrix, respectively, represent a major drawback for promoting strong fiber/matrix interactions. The aim of the present study was to investigate the intrinsic fiber/matrix interactions of PLAbased natural fiber composites prepared by melt-compounding. Short flax fibers presenting a nominal length of ˜1 mm were selected as reinforcement and biocomposites containing low to moderate fiber loading were processed by melt-mixing. Fiber bundle breakage during processing led to important reductions in length and diameter. The mean aspect ratio was decreased by about 50%. Quiescent crystallization kinetics of PLA and biocomposite systems was examined under isothermal and non-isothermal conditions. The nucleating nature of the flax fibers was demonstrated and PLA crystallization was effectively accelerated as the natural reinforcement content increased. Such improvement was controlled by the temperature at which crystallization took place, the liquid-to-solid transition being thermodynamically promoted by the degree of supercooling

  15. 75 FR 5763 - Notice of Correction to the First Administrative Review of Certain Polyester Staple Fiber From...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-04

    ... Results of Antidumping Duty Administrative Review, 75 FR 1336 (January 11, 2010) (``Final Results''). FOR... International Trade Administration Notice of Correction to the First Administrative Review of Certain Polyester... antidumping duty order on certain polyester staple fiber from the People's Republic of China (``PRC'')....

  16. Fiber breakage phenomena in long fiber reinforced plastic preparation

    NASA Astrophysics Data System (ADS)

    Huang, Chao-Tsai; Tseng, Huan-Chang; Vlcek, Jiri; Chang, Rong-Yeu

    2015-07-01

    Due to the high demand of smart green, the lightweight technologies have become the driving force for the development of automotives and other industries in recent years. Among those technologies, using short and long fiber-reinforced plastics (FRP) to replace some metal components can reduce the weight of an automotive significantly. However, the microstructures of fibers inside plastic matrix are too complicated to manage and control during the injection molding through the screw, the runner, the gate, and then into the cavity. This study focuses on the fiber breakage phenomena during the screw plastification. Results show that fiber breakage is strongly dependent on screw design and operation. When the screw geometry changes, the fiber breakage could be larger even with lower compression ratio.

  17. Method of preparing fiber reinforced ceramic material

    NASA Technical Reports Server (NTRS)

    Bhatt, Ramakrishna T. (Inventor)

    1987-01-01

    Alternate layers of mats of specially coated SiC fibers and silicon monotapes are hot pressed in two stages to form a fiber reinforced ceramic material. In the first stage a die is heated to about 600 C in a vacuum furnace and maintained at this temperature for about one-half hour to remove fugitive binder. In the second stage the die temperature is raised to about 1000 C and the layers are pressed at between 35 and 138 MPa. The resulting preform is placed in a reactor tube where a nitriding gas is flowed past the preform at 1100 to 1400 C to nitride the same.

  18. CO2-Laser Cutting Fiber Reinforced Polymers

    NASA Astrophysics Data System (ADS)

    Mueller, R.; Nuss, Rudolf; Geiger, Manfred

    1989-10-01

    Guided by experimental investigations laser cutting of glass fiber reinforced reactive injection moulded (RRIM)-polyurethanes which are used e.g. in car industry for bumpers, spoilers, and further components is described. A Comparison with other cutting techniques as there are water jet cutting, milling, punching, sawing, cutting with conventional knife and with ultrasonic excited knife is given. Parameters which mainly influence cutting results e.g. laser power, cutting speed, gas nature and pressure will be discussed. The problematic nature in characterising micro and macro geometry of laser cut edges of fiber reinforced plastic (FRP) is explained. The topography of cut edges is described and several characteristic values are introduced to specify the obtained working quality. The surface roughness of laser cut edges is measured by both, an optical and a mechanical sensor and their reliabilities are compared.

  19. Fiber Reinforced Composite Cores and Panels

    NASA Technical Reports Server (NTRS)

    Day, Stephen W. (Inventor); Campbell, G. Scott (Inventor); Tilton, Danny E. (Inventor); Stoll, Frederick (Inventor); Sheppard, Michael (Inventor); Banerjee, Robin (Inventor)

    2013-01-01

    A fiber reinforced core panel is formed from strips of plastics foam helically wound with layers of rovings to form webs which may extend in a wave pattern or may intersect transverse webs. Hollow tubes may replace foam strips. Axial rovings cooperate with overlying helically wound rovings to form a beam or a column. Wound roving patterns may vary along strips for structural efficiency. Wound strips may alternate with spaced strips, and spacers between the strips enhance web buckling strength. Continuously wound rovings between spaced strips permit folding to form panels with reinforced edges. Continuously wound strips are helically wrapped to form annular structures, and composite panels may combine both thermoset and thermoplastic resins. Continuously wound strips or strip sections may be continuously fed either longitudinally or laterally into molding apparatus which may receive skin materials to form reinforced composite panels.

  20. [Fiber-reinforced composite in fixed prosthodontics].

    PubMed

    Pilo, R; Abu Rass, Z; Shmidt, A

    2010-07-01

    Fiber reinforced composite (FRC) is composed of resin matrix and fibers filler. Common types of fibers: polyethylene, carbon and glass. Fibers can be continuous and aligned, discontinuous and aligned, discontinuous and randomly oriented. The architecture of the fibers is unidirectional, woven or braided. The two main types are: dry fibers or impregnated. Inclusion of fibers to resin composite increased its average flexural strength in 100-200 MPa. FRC can be utilized by the dentist in direct approach (splinting, temporary winged bridge) or indirect approach (laboratory made fixed partial denture). Laboratory fixed partial denture (FPD) is made from FRC substructure and Hybrid/Microfill particulate composite veneer. Main indications: interim temporary FPD or FPD in cases of questionable abutment teeth, in aesthetic cases where All Ceram FPD is not feasible. Retention is attained by adhesive cementation to minimally prepared teeth or to conventionally prepared teeth; other options are inlay-onlay bridges or hybrid bridges. Contraindications are: poor hygiene, inability to control humidity, parafunction habits, and more than two pontics. Survival rate of FRC FPD over 5 years is 75%, lower compared to porcelain fused to metal FPD which is 95%. Main reasons for failure are: fracture of framework and delamination of the veneer. Part of the failures is repairable. PMID:21485555

  1. Mechanical properties of kenaf bast and core fibre reinforced unsaturated polyester composites

    NASA Astrophysics Data System (ADS)

    Ishak, M. R.; Leman, Z.; Sapuan, S. M.; Edeerozey, A. M. M.; Othman, I. S.

    2010-05-01

    Kenaf fibre has high potential to be used for composite reinforcement in biocomposite material. It is made up of an inner woody core and an outer fibrous bark surrounding the core. The aim of this study was to compare the mechanical properties of short kenaf bast and core fibre reinforced unsaturated polyester composites with varying fibre weight fraction i.e. 0%, 5%, 10%, 20%, 30% and 40%. The compression moulding technique was used to prepare the composite specimens for tensile, flexural and impact tests in accordance to the ASTM D5083, ASTM D790 and ASTM D256 respectively. The overall results showed that the composites reinforced with kenaf bast fibre had higher mechanical properties than kenaf core fibre composites. The results also showed that the optimum fibre content for achieving highest tensile strength for both bast and core fibre composites was 20%wt. It was also observed that the elongation at break for both composites decreased as the fibre content increased. For the flexural strength, the optimum fibre content for both composites was 10%wt while for impact strength, it was at 10%wt and 5%wt for bast and core fibre composites respectively.

  2. On the suitability of fiberglass reinforced polyester as building material for mesocosms.

    PubMed

    Berghahn, R; Brandsch, J; Piringer, O; Pluta, H J; Winkler, T

    1999-07-01

    Gel- and topcoat surface layers on fiberglass [glass-reinforced plastic (GRP)] made of unsaturated resin based on isophthalic acid polyester and neopentyl glycol (ISO-NPG) were tested for leaching, ecotoxicity of water eluates, and abrasion by river sediments at a current speed of 0.5 m * s-1. Leaching from topcoat tempered at low temperature was significant, whereas it was negligible from highly tempered gelcoat. Water eluates from both gel-and topcoat were nontoxic in routinely employed biotests (bacteria, algae, daphnids). No abrasion by river sediments was detectable. Based on these results, GRP with gelcoat made of ISO-NPG is considered a suitable building material for mesocosms. PMID:10381304

  3. Fiber reinforced thermoplastic resin matrix composites

    NASA Technical Reports Server (NTRS)

    Jones, Robert J. (Inventor); Chang, Glenn E. C. (Inventor)

    1989-01-01

    Polyimide polymer composites having a combination of enhanced thermal and mechanical properties even when subjected to service temperatures as high as 700.degree. F. are described. They comprise (a) from 10 to 50 parts by weight of a thermoplastic polyimide resin prepared from 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane and (b) from 90 to 50 parts by weight of continuous reinforcing fibers, the total of (a) and (b) being 100 parts by weight. Composites based on polyimide resin formed from 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane and pyromellitic dianhydride and continuous carbon fibers retained at least about 50% of their room temperature shear strength after exposure to 700.degree. F. for a period of 16 hours in flowing air. Preferably, the thermoplastic polyimide resin is formed in situ in the composite material by thermal imidization of a corresponding amide-acid polymer prepared from 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane. It is also preferred to initially size the continuous reinforcing fibers with up to about one percent by weight of an amide-acid polymer prepared from 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane. In this way imidization at a suitable elevated temperature results in the in-situ formation of a substantially homogeneous thermoplastic matrix of the polyimide resin tightly and intimately bonded to the continuous fibers. The resultant composites tend to have optimum thermo-mechanical properties.

  4. Evaluation of Mechanical Properties of Injection Molding Composites Reinforced by Bagasse Fiber

    NASA Astrophysics Data System (ADS)

    Cao, Yong; Fukumoto, Isao

    BMC (Bulk Molding Compound) is composed of UP (Unsaturated Polyester) resin, glass fibers, and bagasse fibers which have been obtained after squeezing sugar cane. Our purpose is to use the bagasse fibers as reinforcement and filler in BMC to fabricate composites by injection molding and injection compression molding. The mechanical properties of injection molding composites were improved after adding the bagasse fibers. Observing the fracture surface of the tensile test specimen through SEM, we could notice the glass fibers were penetrated into the bagasse fibers longitudinally. Along with UP resin solidifying, the glass fibers were firmly fixed in the bagasse fibers and finally united with them. This phenomenon could bring on the same effect as the glass fibers length was prolonged, so that the adhesion interface between fiber and matrix resin became larger, which leads to the increase in the mechanical properties. Otherwise, it was observed that UP resin sufficiently permeated the bagasse fibers and solidified. This also contributes to enhancing the mechanical properties drastically.

  5. Continuous fiber-reinforced titanium aluminide composites

    NASA Technical Reports Server (NTRS)

    Mackay, R. A.; Brindley, P. K.; Froes, F. H.

    1991-01-01

    An account is given of the fabrication techniques, microstructural characteristics, and mechanical behavior of a lightweight, high service temperature SiC-reinforced alpha-2 Ti-14Al-21Nb intermetallic-matrix composite. Fabrication techniques under investigation to improve the low-temperature ductility and environmental resistance of this material system, while reducing manufacturing costs to competitive levels, encompass powder-cloth processing, foil-fiber-foil processing, and thermal-spray processing. Attention is given to composite microstructure problems associated with fiber distribution and fiber-matrix interfaces, as well as with mismatches of thermal-expansion coefficient; major improvements are noted to be required in tensile properties, thermal cycling effects, mechanical damage, creep, and environmental effects.

  6. Tungsten fiber reinforced superalloys - A status review

    NASA Technical Reports Server (NTRS)

    Petrasek, D. W.; Signorelli, R. A.

    1981-01-01

    After a review of refractory metal fiber/alloy matrix composite development, a discussion is presented of the fabrication techniques used in production of tungsten fiber reinforced superalloys (TFRS), their most significant properties, and their potential applications in the hot section components of gas turbine engines. Emphasis is given the development of airfoil-fabrication technology, with a view to the production of TFRS turbine blades, and attention is given the first-generation TFRS material, a tungsten alloy fiber/FeCrAlY composite currently under evaluation. Detailed properties, design criteria and cost data are presented for this material. Among the properties covered are stress-rupture strength, high and low cycle fatigue, thermal fatigue, impact strength, oxidation and corrosion and thermal conductivity.

  7. Experimental versus design correlations in multi-cellular fiber reinforced plastic panels

    SciTech Connect

    GangaRao, H.V.S.; Lopez-Anido, R.; Sotiropoulos, S.; Sonti, S.S.; Winegardner, T.

    1996-11-01

    Reinforced plastic (RP) multi-cellular panels have been used recently in designing low-rise buildings. These RP panels were 24 in. wide and 5{1/2} in. thick and were manufactured by pultrusion process using an existing die with a modified (bidirectional) fiber architecture. Constituent materials were rovings, mats, and bi-directional fabrics made of E-glass, and polyester resin. Bending tests were conducted to characterize the stiffness performance of the RP panels and the stiffness results were compared with a simple analytical model. The joining of panels to create a modular deck or wall system is briefly discussed.

  8. Biocomposites Prepared from Fiber Processing Wastes and Glycerol Polyesters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biocomposites were prepared by the addition of flax fiber processing waste to glycerol and adipic acid mixtures. The processing waste consisted of fiber, cuticle, and shive fragments generated during the commercial cleaning of retted flax bast fibers. These waste materials were added at 1, 3, or 5 w...

  9. Experimental Behavior of Carbon Fiber Reinforced Isolators

    NASA Astrophysics Data System (ADS)

    Russo, Gaetano; Pauletta, Margherita; Cortesia, Andrea; Dal Bianco, Alberto

    2008-07-01

    This paper describes an investigation on the experimental behavior of innovative elastomeric isolators reinforced by carbon fiber fabrics. These fabrics are very much lighter than steel plates used in conventional isolators and able to transfer to the adjacent elastomer layers tangential stresses adequate to oppose the transversal deformation of rubber under vertical loads. The isolators are not bonded to the sub- and super-structure (elimination of the steel end-plates), hence their weight and cost are reduced. The experimental investigation is carried out on small-scale isolator prototypes reinforced by quadridirectional carbon fiber fabrics. The isolators are subjected to the following qualification tests prescribed by the Italian Code "Ordinanza 3274" for steel reinforced isolators: 1) "Static assessment of the compression stiffness"; 2) "Static assessment of the shear modulus G"; 3) "Dynamic assessment of the dynamic shear modulus Gdin and of the damping coefficient ξ; 4) "Assessment of the Gdin-γ and ξ-γ diagrams by means of dynamic tests"; 5) "Assessment of creep characteristics"; 6) "Evaluation of the capacity of sustaining at least 10 cycles". As a result of the tests, the isolators survived large shear strains, comparable to those expected for conventional isolators.

  10. Experimental Behavior of Carbon Fiber Reinforced Isolators

    SciTech Connect

    Russo, Gaetano; Pauletta, Margherita; Cortesia, Andrea; Dal Bianco, Alberto

    2008-07-08

    This paper describes an investigation on the experimental behavior of innovative elastomeric isolators reinforced by carbon fiber fabrics. These fabrics are very much lighter than steel plates used in conventional isolators and able to transfer to the adjacent elastomer layers tangential stresses adequate to oppose the transversal deformation of rubber under vertical loads. The isolators are not bonded to the sub- and super-structure (elimination of the steel end-plates), hence their weight and cost are reduced. The experimental investigation is carried out on small-scale isolator prototypes reinforced by quadridirectional carbon fiber fabrics. The isolators are subjected to the following qualification tests prescribed by the Italian Code 'Ordinanza 3274' for steel reinforced isolators: 1) 'Static assessment of the compression stiffness'; 2) 'Static assessment of the shear modulus G'; 3) 'Dynamic assessment of the dynamic shear modulus G{sub din} and of the damping coefficient {xi}; 4) 'Assessment of the G{sub din}-{gamma} and {xi}-{gamma} diagrams by means of dynamic tests'; 5) 'Assessment of creep characteristics'; 6) 'Evaluation of the capacity of sustaining at least 10 cycles'. As a result of the tests, the isolators survived large shear strains, comparable to those expected for conventional isolators.

  11. Reinforcement and nucleation of acetylated cellulose nanocrystals in foamed polyester composites.

    PubMed

    Hu, Fei; Lin, Ning; Chang, Peter R; Huang, Jin

    2015-09-20

    The biodegradable foamed nanocomposites were developed from the reinforcement of surface acetylated cellulose nanocrystals (ACNC) as bionanofillers and the poly(butylene succinate) (PBS) as polymeric matrix. The surface modification of high-efficiency acetylation on the cellulose nanocrystals converted the hydrophilic hydroxyl groups to hydrophobic acetyl groups, which improved the compatibility between rigid nanoparticles and polyester matrix through the similar ester groups of two components. With the introduction of 5 wt% ACNC, the specific flexural strength (σ/ρf) and the specific flexural modulus (E/ρf) of the foamed composites significantly increased by 75.7% and 57.2% in comparison with those of the neat PBS foamed material. Meanwhile, with the change of the ACNC concentrations, the cell size and cell density of the foamed composites can be regulated and achieved the high cell density of 1.95 × 10(5)cells/cm(3) bearing the small average cell size of 178.84 μm (5 wt% ACNC). The microstructure observation of the foamed composites indicated the moderate loading levels of rigid ACNC can serve as the reinforcing phase for the stress transfer and promote the crystallinity advancement of the foamed composites. PMID:26050907

  12. Cohesive fracture model for functionally graded fiber reinforced concrete

    SciTech Connect

    Park, Kyoungsoo; Paulino, Glaucio H.; Roesler, Jeffery

    2010-06-15

    A simple, effective, and practical constitutive model for cohesive fracture of fiber reinforced concrete is proposed by differentiating the aggregate bridging zone and the fiber bridging zone. The aggregate bridging zone is related to the total fracture energy of plain concrete, while the fiber bridging zone is associated with the difference between the total fracture energy of fiber reinforced concrete and the total fracture energy of plain concrete. The cohesive fracture model is defined by experimental fracture parameters, which are obtained through three-point bending and split tensile tests. As expected, the model describes fracture behavior of plain concrete beams. In addition, it predicts the fracture behavior of either fiber reinforced concrete beams or a combination of plain and fiber reinforced concrete functionally layered in a single beam specimen. The validated model is also applied to investigate continuously, functionally graded fiber reinforced concrete composites.

  13. New technique of leukocytapheresis by the use of nonwoven polyester fiber filter for inflammatory bowel disease.

    PubMed

    Kawamura, A; Saitoh, M; Yonekawa, M; Horie, T; Ohizumi, H; Tamaki, T; Kukita, K; Meguro, J

    1999-11-01

    Leukocytapheresis (LCAP) is widely used for the treatment of immunological diseases. We studied a new treatment of LCAP using a nonwoven polyester fiber filter. In a basic study, 30-70% of leukocytes were removed. Also, 30-68% of the leukocyte subsets were removed. Sixteen inflammatory bowel disease (IBD) patients, mainly with ulcerative colitis (UC), were treated by this method. Their cytokine activity was normalized in the filter and in the peripheral blood. Eleven of 12 patients with UC were induced to remission. Four patients with Crohn's disease (CD) exhibited improvement. The LCAP using a nonwoven polyester fiber filter was very efficient for treating the patients with IBD. Also, it will be a very useful treatment for immunological diseases and extracorporeal immunomodulation. PMID:10608731

  14. Mechanics of advanced fiber reinforced lattice composites

    NASA Astrophysics Data System (ADS)

    Fan, Hua-Lin; Zeng, Tao; Fang, Dai-Ning; Yang, Wei

    2010-12-01

    Fiber reinforced lattice composites are light-weight attractive due to their high specific strength and specific stiffness. In the past 10 years, researchers developed three-dimensional (3D) lattice trusses and two-dimensional (2D) lattice grids by various methods including interlacing, weaving, interlocking, filament winding and molding hot-press. The lattice composites have been applied in the fields of radar cross-section reduction, explosive absorption and heat-resistance. In this paper, topologies of the lattice composites, their manufacturing routes, as well as their mechanical and multifunctional applications, were surveyed.

  15. Tungsten fiber reinforced superalloys: A status review

    NASA Technical Reports Server (NTRS)

    Petrasek, D. W.; Signorelli, R. A.

    1981-01-01

    Improved performance of heat engines is largely dependent upon maximum cycle temperatures. Tungsten fiber reinforced superalloys (TFRS) are the first of a family of high temperature composites that offer the potential for significantly raising hot component operating temperatures and thus leading to improved heat engine performance. This status review of TFRS research emphasizes the promising property data developed to date, the status of TFRS composite airfoil fabrication technology, and the areas requiring more attention to assure their applicability to hot section components of aircraft gas turbine engines.

  16. Fiber-Reinforced Superalloys For Rocket Engines

    NASA Technical Reports Server (NTRS)

    Lewis, Jack R.; Yuen, Jim L.; Petrasek, Donald W.; Stephens, Joseph R.

    1990-01-01

    Report discusses experimental studies of fiber-reinforced superalloy (FRS) composite materials for use in turbine blades in rocket engines. Intended to withstand extreme conditions of high temperature, thermal shock, atmospheres containing hydrogen, high cycle fatigue loading, and thermal fatigue, which tax capabilities of even most-advanced current blade material - directionally-solidified, hafnium-modified MAR M-246 {MAR M-246 (Hf) (DS)}. FRS composites attractive combination of properties for use in turbopump blades of advanced rocket engines at temperatures from 870 to 1,100 degrees C.

  17. Biodegradable polyester-based eco-composites containing hemp fibers modified with macrocyclic oligomers

    NASA Astrophysics Data System (ADS)

    Conzatti, Lucia; Utzeri, Roberto; Hodge, Philip; Stagnaro, Paola

    2016-05-01

    An original compatibilizing pathway for hemp fibers/poly(1,4-butylene adipate-co-terephtalate) (PBAT) eco-composites was explored exploiting the capability of macrocyclic oligomers (MCOs), obtained by cyclodepolymerization (CDP) of PBAT at high dilution, of being re-converted into linear chains by entropically-driven ring-opening polymerization (ED-ROP) that occurs simply heating the MCOS in the bulk. CDP reaction of PBAT was carried out varying solvent, catalyst and reaction time. Selected MCOs were used to adjust the conditions of the ED-ROP reaction. The best experimental conditions were then adopted to modify hemp fibers. Eco-composites based on PBAT and hemp fibers as obtained or modified with PBAT macrocyclics or oligomers were prepared by different process strategies. The best fiber-PBAT compatibility was observed when the fibers were modified with PBAT oligomers before incorporation in the polyester matrix.

  18. Reinforcement of acrylic denture base resin by incorporation of various fibers.

    PubMed

    Chen, S Y; Liang, W M; Yen, P S

    2001-01-01

    This study was designed to evaluate improvements in the mechanical properties of acrylic resin following reinforcement with three types of fiber. Polyester fiber (PE), Kevlar fiber (KF), and glass fiber (GF) were cut into 2, 4, and 6 mm lengths and incorporated at concentrations of 1, 2, and 3% (w/w). The mixtures of resin and fiber were cured at 70 degrees C in a water bath for 13 h, then at 90 degrees C for 1 h, in 70 x 25 x 15 mm stone molds, which were enclosed by dental flasks. The cured resin blocks were cut to an appropriate size and tested for impact strength and bending strength following the methods of ASTM Specification No. 256 and ISO Specification No. 1567, respectively. Specimens used in the impact strength test were reused for the Knoop hardness test. The results showed that the impact strength tended to be enhanced with fiber length and concentration, particularly PE at 3% and 6 mm length, which was significantly stronger than other formulations. Bending strength did not change significantly with the various formulations when compared to a control without fiber. The assessment of Knoop hardness revealed a complex pattern for the various formulations. The Knoop hardness of 3%, 6 mm PE-reinforced resin was comparable to that of the other formulations except for the control without fiber, but for clinical usage this did not adversely affect the merit of acrylic denture base resin. It is concluded that, for improved strength the optimum formulation to reinforce acrylic resin is by incorporation of 3%, 6 mm length PE fibers. PMID:11241340

  19. Nano-Aramid Fiber Reinforced Polyurethane Foam

    NASA Technical Reports Server (NTRS)

    Semmes, Edmund B.; Frances, Arnold

    2008-01-01

    Closed cell polyurethane and, particularly, polyisocyanurate foams are a large family of flexible and rigid products the result of a reactive two part process wherein a urethane based polyol is combined with a foaming or "blowing" agent to create a cellular solid at room temperature. The ratio of reactive components, the constituency of the base materials, temperature, humidity, molding, pouring, spraying and many other processing techniques vary greatly. However, there is no known process for incorporating reinforcing fibers small enough to be integrally dispersed within the cell walls resulting in superior final products. The key differentiating aspect from the current state of art resides in the many processing technologies to be fully developed from the novel concept of milled nano pulp aramid fibers and their enabling entanglement capability fully enclosed within the cell walls of these closed cell urethane foams. The authors present the results of research and development of reinforced foam processing, equipment development, strength characteristics and the evolution of its many applications.

  20. Dielectric strength of irradiated fiber reinforced plastics

    NASA Astrophysics Data System (ADS)

    Humer, Karl; Weber, Harald W.; Hastik, Ronald; Hauser, Hans; Gerstenberg, Heiko

    2001-05-01

    The insulation system for the toroidal field model coil of international thermonuclear experimental reactor is a fiber reinforced plastic (FRP) laminate, which consists of a combined Kapton/R-glass-fiber reinforcement tape, vacuum-impregnated with an epoxy DGEBA system. Pure disk-shaped laminates, disk-shaped FRP/stainless-steel sandwiches, and conductor insulation prototypes were irradiated at 5 K in a fission reactor up to a fast neutron fluence of 10 22 m -2 ( E>0.1 MeV) to investigate the radiation induced degradation of the dielectric strength of the insulation system. After warm-up to room temperature, swelling, weight loss, and the breakdown strength were measured at 77 K. The sandwich swells by 4% at a fluence of 5×10 21 m -2 and by 9% at 1×10 22 m -2. The weight loss of the FRP is 2% at 1×10 22 m -2. The dielectric strength remained unchanged over the whole dose range.

  1. Process of Making Boron-Fiber Reinforced Composite Tape

    NASA Technical Reports Server (NTRS)

    Belvin, Harry L. (Inventor); Cano, Roberto J. (Inventor); Johnston, Norman J. (Inventor); Marchello, Joseph M. (Inventor)

    2002-01-01

    The invention is an apparatus and method for producing a hybrid boron reinforced polymer matrix composition from powder pre-impregnated fiber tow bundles and a linear array of boron fibers. The boron fibers are applied onto the powder pre-impregnated fiber tow bundles and then are processed within a processing component having an impregnation bar assembly. After passing through variable-dimension forming nip-rollers, the powder pre-impregnated fiber tow bundles with the boron fibers become a hybrid boron reinforced polymer matrix composite tape. A driving mechanism pulls the powder pre-impregnated fiber tow bundles with boron fibers through the processing line of the apparatus and a take-up spool collects the formed hybrid boron-fiber reinforced polymer matrix composite tape.

  2. Quantitative radiographic analysis of fiber reinforced polymer composites.

    PubMed

    Baidya, K P; Ramakrishna, S; Rahman, M; Ritchie, A

    2001-01-01

    X-ray radiographic examination of the bone fracture healing process is a widely used method in the treatment and management of patients. Medical devices made of metallic alloys reportedly produce considerable artifacts that make the interpretation of radiographs difficult. Fiber reinforced polymer composite materials have been proposed to replace metallic alloys in certain medical devices because of their radiolucency, light weight, and tailorable mechanical properties. The primary objective of this paper is to provide a comparable radiographic analysis of different fiber reinforced polymer composites that are considered suitable for biomedical applications. Composite materials investigated consist of glass, aramid (Kevlar-29), and carbon reinforcement fibers, and epoxy and polyether-ether-ketone (PEEK) matrices. The total mass attenuation coefficient of each material was measured using clinical X-rays (50 kev). The carbon fiber reinforced composites were found to be more radiolucent than the glass and kevlar fiber reinforced composites. PMID:11261603

  3. Electromagnetic shielding mechanisms using soft magnetic stainless steel fiber enabled polyester textiles

    NASA Astrophysics Data System (ADS)

    Shyr, Tien-Wei; Shie, Jing-Wen

    2012-11-01

    This work studied the effects of conductivity, magnetic loss, and complex permittivity when using blended textiles (SSF/PET) of polyester fibers (PET) with stainless steel fibers (SSF) on electromagnetic wave shielding mechanisms at electromagnetic wave frequencies ranging from 30 MHz to 1500 MHz. The 316L stainless steel fiber used in this study had 38 vol% γ austenite and 62 vol% α' martensite crystalline phases, which was characterized by an x-ray diffractometer. Due to the magnetic and dielectric loss of soft metallic magnetic stainless steel fiber enabled polyester textiles, the relationship between the reflection/absorption/transmission behaviors of the electromagnetic wave and the electrical/magnetic/dielectric properties of the SSF and SSF/PET fabrics was analyzed. Our results showed that the electromagnetic interference shielding of the SSF/PET textiles show an absorption-dominant mechanism, which attributed to the dielectric loss and the magnetic loss at a lower frequency and attributed to the magnetic loss at a higher frequency, respectively.

  4. Development of natural fiber reinforced polylactide-based biocomposites

    NASA Astrophysics Data System (ADS)

    Arias Herrera, Andrea Marcela

    Polylactide or PLA is a biodegradable polymer that can be produced from renewable resources. This aliphatic polyester exhibits good mechanical properties similar to those of polyethylene terephthalate (PET). Since 2003, bio-based high molecular weight PLA is produced on an industrial scale and commercialized under amorphous and semicrystalline grades for various applications. Enhancement of PLA crystallization kinetics is crucial for the competitiveness of this biopolymer as a commodity material able to replace petroleum-based plastics. On the other hand, the combination of natural fibers with polymer matrices made from renewable resources, to produce fully biobased and biodegradable polymer composite materials, has been a strong trend in research activities during the last decade. Nevertheless, the differences related to the chemical structure, clearly observed in the marked hydrophilic/hydrophobic character of the fibers and the thermoplastic matrix, respectively, represent a major drawback for promoting strong fiber/matrix interactions. The aim of the present study was to investigate the intrinsic fiber/matrix interactions of PLAbased natural fiber composites prepared by melt-compounding. Short flax fibers presenting a nominal length of ˜1 mm were selected as reinforcement and biocomposites containing low to moderate fiber loading were processed by melt-mixing. Fiber bundle breakage during processing led to important reductions in length and diameter. The mean aspect ratio was decreased by about 50%. Quiescent crystallization kinetics of PLA and biocomposite systems was examined under isothermal and non-isothermal conditions. The nucleating nature of the flax fibers was demonstrated and PLA crystallization was effectively accelerated as the natural reinforcement content increased. Such improvement was controlled by the temperature at which crystallization took place, the liquid-to-solid transition being thermodynamically promoted by the degree of supercooling

  5. Fire test method for graphite fiber reinforced plastics

    NASA Technical Reports Server (NTRS)

    Bowles, K. J.

    1980-01-01

    A potential problem in the use of graphite fiber reinforced resin matrix composites is the dispersal of graphite fibers during accidential fires. Airborne, electrically conductive fibers originating from the burning composites could enter and cause shorting in electrical equipment located in surrounding areas. A test method for assessing the burning characteristics of graphite fiber reinforced composites and the effectiveness of the composites in retaining the graphite fibers has been developed. The method utilizes a modified rate of heat release apparatus. The equipment and the testing procedure are described. The application of the test method to the assessment of composite materials is illustrated for two resin matrix/graphite composite systems.

  6. Fire test method for graphite fiber reinforced plastics

    NASA Technical Reports Server (NTRS)

    Bowles, K. J.

    1980-01-01

    A potential problem in the use of graphite fiber reinforced resin matrix composites is the dispersal of graphite fibers during accidental fires. Airborne, electrically conductive fibers originating from the burning composites could enter and cause shorting in electrical equipment located in surrounding areas. A test method for assessing the burning characteristics of graphite fiber reinforced composites and the effectiveness of the composites in retaining the graphite fibers has been developed. The method utilizes a modified Ohio State University Rate of Heat Release apparatus. The equipment and the testing procedure are described. The application of the test method to the assessment of composite materials is illustrated for two resin matrix/graphite composite systems.

  7. CREATION OF MUSIC WITH FIBER REINFORCED CONCRETE

    NASA Astrophysics Data System (ADS)

    Kato, Hayato; Takeuchi, Masaki; Ogura, Naoyuki; Kitahara, Yukiko; Okamoto, Takahisa

    This research focuses on the Fiber Reinforcement Concrete(FRC) and its performance on musical tones. Thepossibility of future musical instruments made of this concrete is discussed. Recently, the technical properties of FRC had been improved and the different production styles, such as unit weight of binding material and volume of fiber in the structure, hardly affects the results of the acoustics. However, the board thickness in the FRC instruments is directly related with the variety of musical tone. The FRC musical effects were compared with those produced with wood on wind instruments. The sounds were compared with those produced with woodwind instruments. The sound pressure level was affected by the material and it becomes remarkably notorious in the high frequency levels. These differences had great influence on the spectrum analysis of the tone in the wind instruments and the sensory test. The results from the sensory test show dominant performances of brightness, beauty and power in the FRC instruments compared with those made of wood.

  8. Birefringence in heat-mechanical modified freshly moulded polyester fibers

    NASA Astrophysics Data System (ADS)

    Velev, V.; Dimov, T.; Popov, A.; Denev, Y.; Hristov, H.; Angelov, T.; Markova, K.; Zagortcheva, M.; Arhangelova, N.; Uzunov, N.

    2010-11-01

    The article submits new experimental data concerning to the role of combined thermo-mechanical treatments on the structural development of freshly moulded uncrystallized but crystallizable poly (ethylene terephthalate) (PET) fibers. The object of the present work is PET as a thermoplastic polymer with a large practical application. The report is devoted to the influence of the heat-mechanical modification temperature on the structure rearrangement in uniaxially orientated amorphous PET. The heat-mechanical modification of the investigated yarns and the optical measurements were realized by specialized gears constructed and built in the author's laboratories. The fibers heat-mechanical modification includes samples annealing at constant temperature above their glass transition temperature (Tg) without strain stress. The yarn annealing has been followed from well defined uniaxially strain-loading with values from 0 MPa up to 30 MPa during two minutes. The optical measurements were carried out by an optical system using a polarization microscope and a CCD camera. The obtained experimental data has been analyzed by Mocha-1.2 (Jandel Scientific) software. There are established dependences between the heat-mechanical modification mode and the structural rearrangements running in the studied PET samples.

  9. Use of a polyester fiber sponge as an adjunct in the treatment of psoriasis.

    PubMed

    Shellow, W V

    1978-03-01

    Twenty patients with symmetric lesions of psoriasis were asked to use a polyester fiber sponge in addition to their other anti-psoriatic medications. The sponge was used to remove scales from those lesions on the left side only. The hypothesis was that removal of scales would enhance penetration by topical corticosteroid and/or coal tar preparations. At the end of four weeks, as well as at each weekly evaluation, all patients showed a statistically significant difference between the treated and control sides. In 70 percent of the subjects, results were graded good to excellent when the treated side was compared with the control side after four weeks' evaluation. PMID:630919

  10. Graphite fiber reinforced glass matrix composites for aerospace applications

    NASA Technical Reports Server (NTRS)

    Prewo, K. M.; Bacon, J. F.; Dicus, D. L.

    1979-01-01

    The graphite fiber reinforced glass matrix composite system is described. Although this composite is not yet a mature material, it possesses low density, attractive mechanical properties at elevated temperatures, and good environmental stability. Properties are reported for a borosilicate glass matrix unidirectionally reinforced with 60 volume percent HMS graphite fiber. The flexural strength and fatigue characteristics at room and elevated temperature, resistance to thermal cycling and continuous high temperature oxidation, and thermal expansion characteristics of the composite are reported. The properties of this new composite are compared to those of advanced resin and metal matrix composites showing that graphite fiber reinforced glass matrix composites are attractive for aerospace applications.

  11. Carbon fiber reinforced thermoplastic composites for future automotive applications

    NASA Astrophysics Data System (ADS)

    Friedrich, K.

    2016-05-01

    After a brief introduction to polymer composite properties and markets, the state of the art activities in the field of manufacturing of advanced composites for automotive applications are elucidated. These include (a) long fiber reinforced thermoplastics (LFT) for secondary automotive components, and (b) continuous carbon fiber reinforced thermosetting composites for car body applications. It is followed by future possibilities of carbon fiber reinforced thermoplastic composites for e.g. (i) crash elements, (ii) racing car seats, and (iii) production and recycling of automotive fenders.

  12. A systematic study of captopril-loaded polyester fiber mats prepared by electrospinning.

    PubMed

    Zhang, Hua; Lou, Shaofeng; Williams, Gareth R; Branford-White, Christopher; Nie, Huali; Quan, Jing; Zhu, Li-Min

    2012-12-15

    In this study, drug-loaded nanofibers were prepared by electrospinning captopril (CPL) with aliphatic biodegradable polyesters. Poly(L-lactic acid) (PLLA), poly(lactic-co-glycolic acid) (PLGA), and poly(lactic-co-ε-caprolactone) (PLCL) were used as filament-forming matrix polymers, and the concentration of CPL in each fiber type was varied. Scanning electron microscopy indicated that the morphology and diameters of the fibers were influenced by the concentration of polymer in the spinning solution and the drug loading. CPL was found to be distributed in the polymer fibers in an amorphous manner using differential scanning calorimetry and X-ray diffraction. FTIR indicated that hydrogen bonding existed between the drug molecules and the carrier polymers. In vitro dissolution tests showed that drug release from the fibers was highly dependent on the release medium, temperature, and on the polymer used. A range of kinetic models were fitted to the drug-release data obtained, and indicated that release was diffusion controlled in all cases. The different polymer fibers have application in diverse areas of drug delivery, for instance as sub-lingual or sustained release systems. Furthermore, by combining different CPL-loaded fibers, it would be possible to produce a bespoke formulation with tailored drug-release properties. PMID:23043960

  13. Structural Behavior of Concrete Beams Reinforced with Basalt Fiber Reinforced Polymer (BFRP) Bars

    NASA Astrophysics Data System (ADS)

    Ovitigala, Thilan

    The main challenge for civil engineers is to provide sustainable, environmentally friendly and financially feasible structures to the society. Finding new materials such as fiber reinforced polymer (FRP) material that can fulfill the above requirements is a must. FRP material was expensive and it was limited to niche markets such as space shuttles and air industry in the 1960s. Over the time, it became cheaper and spread to other industries such as sporting goods in the 1980-1990, and then towards the infrastructure industry. Design and construction guidelines are available for carbon fiber reinforced polymer (CFRP), aramid fiber reinforced polymer (AFRP) and glass fiber reinforced polymer (GFRP) and they are currently used in structural applications. Since FRP is linear elastic brittle material, design guidelines for the steel reinforcement are not valid for FRP materials. Corrosion of steel reinforcement affects the durability of the concrete structures. FRP reinforcement is identified as an alternative to steel reinforcement in corrosive environments. Although basalt fiber reinforced polymer (BFRP) has many advantages over other FRP materials, but limited studies have been done. These studies didn't include larger BFRP bar diameters that are mostly used in practice. Therefore, larger beam sizes with larger BFRP reinforcement bar diameters are needed to investigate the flexural and shear behavior of BFRP reinforced concrete beams. Also, shear behavior of BFRP reinforced concrete beams was not yet studied. Experimental testing of mechanical properties and bond strength of BFRP bars and flexural and shear behavior of BFRP reinforced concrete beams are needed to include BFRP reinforcement bars in the design codes. This study mainly focuses on the use of BFRP bars as internal reinforcement. The test results of the mechanical properties of BFRP reinforcement bars, the bond strength of BFRP reinforcement bars, and the flexural and shear behavior of concrete beams

  14. Analytical, Numerical and Experimental Examination of Reinforced Composites Beams Covered with Carbon Fiber Reinforced Plastic

    NASA Astrophysics Data System (ADS)

    Kasimzade, A. A.; Tuhta, S.

    2012-03-01

    In the article, analytical, numerical (Finite Element Method) and experimental investigation results of beam that was strengthened with fiber reinforced plastic-FRP composite has been given as comparative, the effect of FRP wrapping number to the maximum load and moment capacity has been evaluated depending on this results. Carbon FRP qualitative dependences have been occurred between wrapping number and beam load and moment capacity for repair-strengthen the reinforced concrete beams with carbon fiber. Shown possibilities of application traditional known analysis programs, for the analysis of Carbon Fiber Reinforced Plastic (CFRP) strengthened structures.

  15. Mechanical recycling of continuous fiber-reinforced thermoplastic sheets

    NASA Astrophysics Data System (ADS)

    Moritzer, Elmar; Heiderich, Gilmar

    2016-03-01

    This contribution examines possible material recycling of offcuts generated during the production of continuous-fiber-reinforced composite sheets. These sheets consist of a polyamide 6 matrix and glass fiber fabric. In the initial step, the offcut is shredded to obtain particles; following that, the particles are processed in a twin-screw process to produce fiber-reinforced plastic pellets with varying fiber contents. These pellets are intended for use in injection molding processes as a substitution for new raw materials. This investigation centers on the mechanical properties which can be achieved with the recycled material after both the twin-screw process and injection molding.

  16. Glass matrix composites. I - Graphite fiber reinforced glass

    NASA Technical Reports Server (NTRS)

    Prewo, K. M.; Bacon, J. F.

    1978-01-01

    An experimental program is described in which graphite fibers of Hercules HMS and HTS, Thornel 300, and Celanese DG-12 were used to reinforce, both uniaxially and biaxially, borosilicate pyrex glass. Composite flexural strength distribution, strength as a function of test temperature, fracture toughness and oxidative stability were determined and shown to be primarily a function of fiber type and the quality of fiber-matrix bond formed during composite fabrication. It is demonstrated that the graphite fiber reinforced glass system offers unique possibilities as a high performance structural material.

  17. Process simulation for the compression moulding of fiber reinforced materials

    SciTech Connect

    Michaeli, W.; Goedel, M.; Heber, M.

    1994-12-31

    This paper will give a short overview about the activities of the compression moulding simulation for GMTs and SMCs. The simulation of the compression moulding process avoids the prototyping of new moulds for optimizing the process itself. That helps saving time and money. In compression moulding, a distinction is drawn between the more widespread ``Sheet Moulding Compound`` (SMC) and ``Glass Mat reinforced Thermoplastics`` (GMT). SMC is a glass fiber reinforced thermoset, while GMT has a thermoplastic matrix which is generally polypropylene. Both materials contain fibers with a fiber length of 12 to 25 mm. The fibers are not joined together in form of a fabric.

  18. Bond characteristics of steel fiber and deformed reinforcing steel bar embedded in steel fiber reinforced self-compacting concrete (SFRSCC)

    NASA Astrophysics Data System (ADS)

    Aslani, Farhad; Nejadi, Shami

    2012-09-01

    Steel fiber reinforced self-compacting concrete (SFRSCC) is a relatively new composite material which congregates the benefits of the self-compacting concrete (SCC) technology with the profits derived from the fiber addition to a brittle cementitious matrix. Steel fibers improve many of the properties of SCC elements including tensile strength, ductility, toughness, energy absorption capacity, fracture toughness and cracking. Although the available research regarding the influence of steel fibers on the properties of SFRSCC is limited, this paper investigates the bond characteristics between steel fiber and SCC firstly. Based on the available experimental results, the current analytical steel fiber pullout model (Dubey 1999) is modified by considering the different SCC properties and different fiber types (smooth, hooked) and inclination. In order to take into account the effect of fiber inclination in the pullout model, apparent shear strengths (τ (app)) and slip coefficient (β) are incorporated to express the variation of pullout peak load and the augmentation of peak slip as the inclined angle increases. These variables are expressed as functions of the inclined angle (ϕ). Furthurmore, steel-concrete composite floors, reinforced concrete floors supported by columns or walls and floors on an elastic foundations belong to the category of structural elements in which the conventional steel reinforcement can be partially replaced by the use of steel fibers. When discussing deformation capacity of structural elements or civil engineering structures manufactured using SFRSCC, one must be able to describe thoroughly both the behavior of the concrete matrix reinforced with steel fibers and the interaction between this composite matrix and discrete steel reinforcement of the conventional type. However, even though the knowledge on bond behavior is essential for evaluating the overall behavior of structural components containing reinforcement and steel fibers

  19. Bond characteristics of steel fiber and deformed reinforcing steel bar embedded in steel fiber reinforced self-compacting concrete (SFRSCC)

    NASA Astrophysics Data System (ADS)

    Aslani, Farhad; Nejadi, Shami

    2012-09-01

    Steel fiber reinforced self-compacting concrete (SFRSCC) is a relatively new composite material which congregates the benefits of the self-compacting concrete (SCC) technology with the profits derived from the fiber addition to a brittle cementitious matrix. Steel fibers improve many of the properties of SCC elements including tensile strength, ductility, toughness, energy absorption capacity, fracture toughness and cracking. Although the available research regarding the influence of steel fibers on the properties of SFRSCC is limited, this paper investigates the bond characteristics between steel fiber and SCC firstly. Based on the available experimental results, the current analytical steel fiber pullout model (Dubey 1999) is modified by considering the different SCC properties and different fiber types (smooth, hooked) and inclination. In order to take into account the effect of fiber inclination in the pullout model, apparent shear strengths ( τ ( app)) and slip coefficient ( β) are incorporated to express the variation of pullout peak load and the augmentation of peak slip as the inclined angle increases. These variables are expressed as functions of the inclined angle ( ϕ). Furthurmore, steel-concrete composite floors, reinforced concrete floors supported by columns or walls and floors on an elastic foundations belong to the category of structural elements in which the conventional steel reinforcement can be partially replaced by the use of steel fibers. When discussing deformation capacity of structural elements or civil engineering structures manufactured using SFRSCC, one must be able to describe thoroughly both the behavior of the concrete matrix reinforced with steel fibers and the interaction between this composite matrix and discrete steel reinforcement of the conventional type. However, even though the knowledge on bond behavior is essential for evaluating the overall behavior of structural components containing reinforcement and steel fibers

  20. All-round joining method with carbon fiber reinforced interface

    NASA Astrophysics Data System (ADS)

    Miwa, Noriyoshi; Tanaka, Kazunori; Kamiya, Yoshiko; Nishi, Yoshitake

    2008-08-01

    Carbon fiber reinforced polymer (CFRP) has been recently applied to not only wing, but also fan blades of turbo fan engines. To prevent impact force, leading edge of titanium was often mounted on the CFRP fan blades with adhesive force. In order to enhance the joining strength, a joining method with carbon fiber reinforced interface has been developed. By using nickel-coated carbon fibers, a joining sample with carbon fiber-reinforced interface between CFRP and CFRM has been successfully developed. The joining sample with nickel-coated carbon fiber interface exhibits the high tensile strength, which was about 10 times higher than that with conventional adhesion. On the other hand, Al-welding methods to steel, Cu and Ti with carbon fiber reinforced interface have been successfully developed to lighten the parts of machines of racing car and airplane. Carbon fibers in felt are covered with metals to protect the interfacial reaction. The first step of the welding method is that the Al coated felt is contacted and wrapped with molten aluminum solidified under gravity pressure, whereas the second step is that the felt with double layer of Ni and Al is contacted and wrapped with molten steel (Cu or Ti) solidified under gravity pressure. Tensile strength of Al-Fe (Cu or Ti) welded sample with carbon fiber reinforced interface is higher than those of Al-Fe (Cu or Ti) welded sample.

  1. CODIFICATION OF FIBER REINFORCED COMPOSITE PIPING

    SciTech Connect

    Rawls, G.

    2012-10-10

    The goal of the overall project is to successfully adapt spoolable FRP currently used in the oil industry for use in hydrogen pipelines. The use of FRP materials for hydrogen service will rely on the demonstrated compatibility of these materials for pipeline service environments and operating conditions. The ability of the polymer piping to withstand degradation while in service, and development of the tools and data required for life management are imperative for successful implementation of these materials for hydrogen pipeline. The information and data provided in this report provides the technical basis for the codification for fiber reinforced piping (FRP) for hydrogen service. The DOE has invested in the evaluation of FRP for the delivery for gaseous hydrogen to support the development of a hydrogen infrastructure. The codification plan calls for detailed investigation of the following areas: System design and applicable codes and standards; Service degradation of FRP; Flaw tolerance and flaw detection; Integrity management plan; Leak detection and operational controls evaluation; Repair evaluation. The FRP codification process started with commercially available products that had extensive use in the oil and gas industry. These products have been evaluated to assure that sufficient structural integrity is available for a gaseous hydrogen environment.

  2. Fiber reinforced superalloys for rocket engines

    NASA Technical Reports Server (NTRS)

    Petrasek, Donald W.; Stephens, Joseph R.

    1989-01-01

    High pressure turbopumps for advanced reusable liquid propellant rocket engines such as that for the Space Shuttle Main Engine (SSME) require turbine blade materials that operate under extreme conditions of temperature, hydrogen environment, high-cycle fatigue loading, thermal fatigue and thermal shock. Such requirements tax the capabilities of current blade materials. Based on projections of properties for tungsten fiber reinforced superalloy (FRS) composites, it was concluded that FRS turbine blades offer the potential of a several fold increase in life and over a 200 C increase in temperature capability over the current SSME blade material. FRS composites were evaluated with respect to mechanical property requirements for SSME blade applications. Compared to the current blade material, the thermal shock resistance of FRS materials is excellent, two to nine times better, and their thermal fatigue resistance is equal to or higher than the current blade material. FRS materials had excellent low and high-cycle fatigue strengths, and thermal shock-induced surface microcracks had no influence on their fatigue strength. The material also exhibited negligible embrittlement when exposed to a hydrogen environment.

  3. Fiber reinforced superalloys for rocket engines

    NASA Technical Reports Server (NTRS)

    Petrasek, Donald W.; Stephens, Joseph R.

    1988-01-01

    High-pressure turbopumps for advanced reusable liquid-propellant rocket engines such as that for the Space Shuttle Main Engine (SSME) require turbine blade materials that operate under extreme conditions of temperature, hydrogen environment, high-cycle fatigue loading, thermal fatigue and thermal shock. Such requirements tax the capabilities of current blade materials. Based on projections of properties for tungsten fiber reinforced superalloy (FRS) composites, it was concluded that FRS turbine blades offer the potential of a several-fold increase in life and over a 200C increase in temperature capability over current SSME blade material. FRS composites were evaluated with respect to mechanical property requirements for SSME blade applications. Compared to the current blade material, the thermal shock resistance of FRS materials is excellent, two to nine times better, and their thermal fatigue resistance is equal to or higher than the current blade material. FRS materials had excellent low and high-cycle fatigue strengths, and thermal shock-induced surface microcracks had no influence on their fatigue strength. The material also exhibited negligible embrittlement when exposed to a hydrogen environment.

  4. Microbiologically influenced degradation of fiber-reinforced polymeric composites

    SciTech Connect

    Wagner, P.A.; Ray, R.I.; Little, B.J. ); Tucker, W.C. )

    1994-04-01

    Two fiber-reinforced polymer composites were examined for susceptibility to microbiologically influenced degradation. Composites, resins, and fibers were exposed to sulfur/iron-oxidizing, calcareous-depositing, ammonium-producing, hydrogen-producing, and sulfate-reducing bacteria (SRB) in batch culture. Surfaces were uniformly colonized by all physiological types of bacteria. Epoxy and vinyl ester neat resins, carbon fibers, and epoxy composites were not adversely affected by microbiological species. SRB degraded the organic surfactant on glass fibers and preferentially colonized fiber-vinyl ester interfaces. Hydrogen-producing bacteria appeared to disrupt bonding between fibers and vinyl ester resin and to penetrate the resin at the interface.

  5. Microbiologically influenced degradation of fiber reinforced polymeric composites

    SciTech Connect

    Wagner, P.A.; Ray, R.I.; Little, B.J.; Tucker, W.C.

    1994-12-31

    Two fiber reinforced polymer composites were examined for susceptibility to microbiologically influenced degradation. Composites, resins, and fibers were exposed to sulfur/iron-oxidizing, calcareous-depositing, ammonium-producing, hydrogen-producing and sulfate-reducing bacteria (SRB) in batch culture. Surfaces were uniformly colonized by all physiological types of bacteria. Epoxy and vinyl ester neat resins, carbon fibers, and epoxy composites were not adversely affected by microbial species. SRB degraded the organic surfactant on glass fibers and preferentially colonized fiber-vinyl ester interfaces. Hydrogen-producing bacteria appeared to disrupt bonding between fibers and vinyl ester resin and to penetrate the resin at the interface.

  6. Characterization and design of steel fiber reinforced shotcrete in tunnelling

    SciTech Connect

    Casanova, P.A.; Rossi, P.C.

    1995-12-31

    A design procedure of steel fiber reinforced shotcrete tunnel linings is proposed. It is based on the analysis of a cracked section. The tensile behavior of shotcrete after cracking is obtained by a uniaxial tension test on cored notched samples. As for usual reinforced concrete structures an interaction diagram (moment-axial load) is determined.

  7. Fiber-reinforced composites in fixed partial dentures

    PubMed Central

    Vallittu, Pekka

    2006-01-01

    Fiber-reinforced composite resin (FRC) prostheses offer the advantages of good aesthetics, minimal invasive treatment, and an ability to bond to the abutment teeth, thereby compensating for less-than-optimal abutment tooth retention and resistance form. These prostheses are composed of two types of composite materials: fiber composites to build the framework and hybrid or microfill particulate composites to create the external veneer surface. This review concentrates on the use of fiber reinforcement in the fabrication of laboratory or chairsidemade composite-fixed partial dentures of conventional preparation. Other applications of FRC in dentistry are briefly mentioned. The possibilities fiber reinforcement technology offers must be emphasized to the dental community. Rather than limiting discussion to whether FRC prostheses will replace metal-ceramic or full-ceramic prostheses, attention should be focused on the additional treatment options brought by the use of fibers. However, more clinical experience is needed. PMID:21526023

  8. Micromechanical analysis of fiber-reinforced composites with interfacial phenomena. I - Modeling and analysis of discontinuous fiber-reinforced composites

    NASA Astrophysics Data System (ADS)

    Saito, Kenji; Iwamoto, Masaharu; Araki, Shigetoshi; Yano, Tadayoshi

    1992-04-01

    A mechanical analysis is presented of fiber-reinforced composite material exhibiting matrix cracking and/or interface sliding between a fiber and a matrix, i.e., the problem of a bridging fiber, by the method of micromechanics. In the case where there are many kinds of inhomogeneities, the interaction between the inhomogeneities, which are neglected in Eshelby's (1961) generally used method, must be taken into consideration. The present method is the extension of the method of Taya and Chou (1981) to the analysis of fiber-reinforced composites with interfacial sliding.

  9. Mechanical properties of fiber reinforced lightweight concrete composites

    SciTech Connect

    Perez-Pena, M. ); Mobasher, B. )

    1994-01-01

    Hybrid composites with variable strength/toughness properties can be manufactured using combinations of brittle or ductile mesh in addition to brittle and ductile matrix reinforcements. The bending and tensile properties of thin sheet fiber cement composites made from these mixtures were investigated. Composites consisted of a woven mesh of either polyvinyl chloride (PVC) coated E-glass or polypropylene (PP) fibers for the surface reinforcement. In addition, chopped polypropylene, acrylic, nylon, and alkali-resistant (AR) glass fibers were used for the core reinforcement. It is shown that by controlling fiber contents, types, and combinations, design objectives such as strength, stiffness and toughness, can be achieved. Superior post-cracking behavior was measured for composites reinforced both with glass mesh and PP mesh. Load carrying capacity of PP mesh composites can be increased with the use of 1% or higher chopped PP fibers. Glass mesh composites with short AR glass fibers as matrix reinforcement indicate an increased matrix cracking strength and modulus of rupture. Combinations of PP mesh/short AR glass did not show a substantial improvement in the matrix ultimate strength. An increased nylon fiber surface area resulted in improved post peak response.

  10. Fracture toughness of steel-fiber-reinforced bone cement.

    PubMed

    Kotha, S P; Li, C; Schmid, S R; Mason, J J

    2004-09-01

    Fractures in the bone-cement mantle (polymethyl methacrylate) have been linked to the failure of cemented total joint prostheses. The heat generated by the curing bone cement has also been implicated in the necrosis of surrounding bone tissue, leading to loosening of the implants. The addition of reinforcements may improve the fracture properties of bone cement and decrease the peak temperatures during curing. This study investigates the changes in the fracture properties and the temperatures generated in the ASTM F451 tests by the addition of 316L stainless steel fibers to bone cement. The influence of filler volume fraction (5-15% by volume) and aspect ratios (19, 46, 57) on the fracture toughness of the acrylic bone cement was assessed. Increasing the volume fraction of the steel fibers resulted in significant increases in the fracture toughness of the steel-fiber-reinforced composite. Fracture-toughness increases of up to 2.63 times the control values were obtained with the use of steel-fiber reinforcements. No clear trend in the fracture toughness was discerned for increasing aspect ratios of the reinforcements. There is a decrease in the peak temperatures reached during the curing of the steel-fiber-reinforced bone cement, though the decrease is too small to be clinically relevant. Large increases in the fatigue life of acrylic bone cement were also obtained by the addition of steel fibers. These results indicate that the use of steel fibers may enhance the durability of cemented joint prostheses. PMID:15293326

  11. 77 FR 71579 - Polyester Staple Fiber From Taiwan: Notice of Court Decision Not in Harmony With Final Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-03

    ... Certain Polyester Staple Fiber From Taiwan: Final Results of Antidumping Duty Administrative Review, 76 FR... Deadlines Pursuant to the Tariff Act of 1930, as Amended, 70 FR 24533 (May 10, 2005). FOR FURTHER... Taiwan: Preliminary Results of Antidumping Duty Administrative Review, 76 FR 22366 (April 21,...

  12. 77 FR 21733 - Certain Polyester Staple Fiber From Taiwan: Extension of Time Limit for Preliminary Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-11

    ... Results of Antidumping Duty Administrative Review, 77 FR 4543 (January 30, 2012) we extended the period of... Antidumping and Countervailing Duty Administrative Reviews and Requests for Revocation in Part, 76 FR 37781... International Trade Administration Certain Polyester Staple Fiber From Taiwan: Extension of Time Limit...

  13. 77 FR 50530 - Polyester Staple Fiber From China; Scheduling of an Expedited Five-Year Review Concerning the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-21

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE... Antidumping Duty Order on Polyester Staple Fiber From China AGENCY: United States International Trade... CONTACT: Joanna Lo (202-205-1888), Office of Investigations, U.S. International Trade Commission, 500...

  14. 76 FR 2886 - Certain Polyester Staple Fiber From the People's Republic of China: Final Results and Partial...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-18

    ... Duty Administrative Review, 75 FR 40777 (July 14, 2010) (``Preliminary Results''). We gave interested... second administrative review of the antidumping duty order on certain polyester staple fiber (``PSF... Results of the second administrative review of the antidumping duty order on certain PSF from the PRC....

  15. 75 FR 40777 - Certain Polyester Staple Fiber From the People's Republic of China: Notice of Preliminary Results...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-14

    ...: Petroleum Wax Candles from the People's Republic of China, 72 FR 52355, 52356 (September 13, 2007). In... Polyester Staple Fiber from the People's Republic of China, 72 FR 30545 (June 1, 2007) (``Order''). On July... and Deferral of Administrative Review, 74 FR 37690 (July 29, 2009) (``Initiation Notice'')....

  16. 76 FR 5331 - Certain Polyester Staple Fiber From Taiwan: Extension of Time Limit for Preliminary Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-31

    ... for Revocation in Part, 75 FR 37759 (June 30, 2010). The preliminary results are currently due no later than January 31, 2011. Extension of Time Limit for Preliminary Results Section 751(a)(3)(A) of the... International Trade Administration Certain Polyester Staple Fiber From Taiwan: Extension of Time Limit...

  17. 75 FR 33783 - Certain Polyester Staple Fiber from the Republic of Korea: Preliminary Results of the 2008 - 2009...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-15

    ... Duty Orders: Certain Polyester Staple Fiber From the Republic of Korea and Taiwan, 65 FR 33807 (May 25... Investigation; Opportunity To Request Administrative Review, 74 FR 20278 (May 1, 2009). On May 29, 2009, Huvis... for Revocation in Part, 74 FR 30052 (June 24, 2009). On July 14, 2009, the petitioners withdrew...

  18. Influence of atmospheric-air plasma on the coating of a nonionic lubricating agent on polyester fiber

    NASA Astrophysics Data System (ADS)

    Parvinzadeh, Mazeyar; Ebrahimi, Izadyar

    2011-06-01

    This research work involves the plasma treatment of polyethylene terephthalate fiber to improve the performance of a nonionic lubricating agent. To do this, a polyester fabric was pre-scoured with a detergent, treated with atmospheric-air plasma and then coated with a nonionic emulsion. Chemical and physical properties of the samples were investigated by the use of Fourier transform infrared spectroscopy, bending lengths, wrinkle recovery angles, fiber friction coefficient analysis, moisture absorbency, scanning electron microscopy and reflectance spectroscopy. The study on the chemical properties of the fibers revealed that the plasma pretreatment modifies the surface of the fibers and increases the reactivity of the substrate toward nonionic emulsion. The physical properties of the textiles indicated that the combination of plasma and emulsion treatments on polyester can improve crease resistance, drapeability and water repellency due to a uniform coating of the emulsion on the surface of the textiles.

  19. Material Properties for Fiber-Reinforced Silica Aerogels

    NASA Technical Reports Server (NTRS)

    White, Susan; Rouanet, Stephane; Moses, John; Arnold, James O. (Technical Monitor)

    1994-01-01

    Ceramic fiber-reinforced silica aerogels are novel materials for high performance insulation, including thermal protection materials. Experimental data are presented for the thermal and mechanical properties, showing the trends exhibited over a range of fiber loadings and silica aerogel densities. Test results are compared to that of unreinforced bulk aerogels.

  20. High-Temperature Creep Behavior Of Fiber-Reinforced Niobium

    NASA Technical Reports Server (NTRS)

    Petrasek, Donald W.; Titran, Robert H.

    1990-01-01

    Study conducted to determine feasibility of using composite materials in advanced space power systems, described in 22-page report. Tungsten fibers reduce creep and mass in advanced power systems. Reinforcing niobium alloys with tungsten fibers increases their resistances to creep by factors of as much as 10.

  1. Carbon nanotube reinforced polyacrylonitrile and poly(etherketone) fibers

    NASA Astrophysics Data System (ADS)

    Jain, Rahul

    The graphitic nature, continuous structure, and high mechanical properties of carbon nanotubes (CNTs) make them good candidate for reinforcing polymer fiber. The different types of CNTs including single-wall carbon nanotubes (SWNTs), few-wall carbon nanotubes (FWNTs), and multi-wall carbon nanotubes (MWNTs), and carbon nanofibers (CNFs) differ in terms of their diameter and number of graphitic walls. The desire has been to increase the concentration of CNTs as much as possible to make next generation multi-functional materials. The work in this thesis is mainly focused on MWNT and CNF reinforced polyacrylonitrile (PAN) composite fibers, and SWNT, FWNT, and MWNT reinforced poly(etherketone) (PEK) composite fibers. To the best of our knowledge, this is the first study to report the spinning of 20% MWNT or 30% CNF reinforced polymer fiber spun using conventional fiber spinning. Also, this is the first study to report the PEK/CNT composite fibers. The fibers were characterized for their thermal, tensile, mechanical, and dynamic mechanical properties. The fiber structure and morphology was studied using WAXD and SEM. The effect of two-stage heat drawing, sonication time for CNF dispersion, fiber drying temperature, and molecular weight of PAN was also studied. Other challenges associated with processing high concentrations of solutions for making composite fibers have been identified and reported. The effect of CNT diameter and concentration on fiber spinnability and electrical conductivity of composite fiber have also been studied. This work suggests that CNT diameter controls the maximum possible concentration of CNTs in a composite fiber. The results show that by properly choosing the type of CNT, length of CNTs, dispersion of CNTs, fiber spinning method, fiber draw ratio, and type of polymer, one can get electrically conducting fibers with wide range of conductivities for different applications. The PEK based control and composite fibers possess high thermal

  2. On processing development for fabrication of fiber reinforced composite, part 2

    NASA Technical Reports Server (NTRS)

    Hou, Tan-Hung; Hou, Gene J. W.; Sheen, Jeen S.

    1989-01-01

    Fiber-reinforced composite laminates are used in many aerospace and automobile applications. The magnitudes and durations of the cure temperature and the cure pressure applied during the curing process have significant consequences for the performance of the finished product. The objective of this study is to exploit the potential of applying the optimization technique to the cure cycle design. Using the compression molding of a filled polyester sheet molding compound (SMC) as an example, a unified Computer Aided Design (CAD) methodology, consisting of three uncoupled modules, (i.e., optimization, analysis and sensitivity calculations), is developed to systematically generate optimal cure cycle designs. Various optimization formulations for the cure cycle design are investigated. The uniformities in the distributions of the temperature and the degree with those resulting from conventional isothermal processing conditions with pre-warmed platens. Recommendations with regards to further research in the computerization of the cure cycle design are also addressed.

  3. Effect of reinforcement and fiber-matrix interface on dynamic fracture of fiber-reinforced composite materials

    SciTech Connect

    Khanna, S.K.

    1992-01-01

    The experimental technique of dynamic photoelasticity coupled with high speed photography has been used to study the interaction of running cracks with brittle and ductile fibers embedded in a brittle polymeric matrix. The effect of reinforcement and the fiber-matrix interface on dynamic stress intensity factor, crack bridging phenomena, crack surface morphology and toughening mechanisms occurring during dynamic fracturing of reinforced brittle matrix composites has been investigated. It is found that reinforcement reduces the crack velocity and the stress intensity factor. Thus the energy supplied to the crack tip is reduced resulting in reduction of the crack jump distance. Fiber pullout experiments were done to characterize the fiber-matrix interface. Rapid pullout results in an increase in interface shear strength. For rapid pullout of fibers the difference between maximum pullout loads. for well and weakly bonded fibers, is much smaller than for very slow pullout. A fiber-matrix interface which is weaker in the vicinity of the crack path, termed the partly debonded interface, produces higher crack closing forces and lower stress intensity factor compared to well bonded fibers. The former interface condition results in low fracture energy and shorter crack jump compared to the later. The interface condition significantly affects the fracture surface morphology. The fracture surface roughness is lower for reinforced materials compared to monolithic. Further the partly debonded fibers result in lower surface roughness compared to the well bonded fibers. Inclined fibers with various interface conditions have no significant effect on the stress intensity factor. The fiber debonded length, however, decreases, as compared to fibers which are aligned with the loading direction, due to the kinking of the fibers.

  4. Studies on natural fiber reinforced polymer matrix composites

    NASA Astrophysics Data System (ADS)

    Patel, R. H.; Kapatel, P. M.; Machchhar, A. D.; Kapatel, Y. A.

    2016-05-01

    Natural fiber reinforced composites show increasing importance in day to days applications because of their low cost, lightweight, easy availability, non-toxicity, biodegradability and environment friendly nature. But these fibers are hydrophilic in nature. Thus they have very low reactivity and poor compatibility with polymers. To overcome these limitations chemical modifications of the fibers have been carried out. Therefore, in the present work jute fibers have chemically modified by treating with sodium hydroxide (NaOH) solutions. These treated jute fibers have been used to fabricate jute fiber reinforced epoxy composites. Mechanical properties like tensile strength, flexural strength and impact strength have been found out. Alkali treated composites show better properties compare to untreated composites.

  5. Microscopic study of surface degradation of glass fiber-reinforced polymer rods embedded in concrete castings subjected to environmental conditioning

    SciTech Connect

    Bank, L.C.; Puterman, M.

    1997-12-31

    The surface degradation of glass fiber-reinforced polymer (GFRP) pultruded rods when embedded in concrete castings and subjected to environmental conditioning is discussed in this paper. Investigation of the degradation of the GFRP rods were performed using optical microscopy and scanning electron microscopy (SEM). Unidirectionally reinforced pultruded rods (6.3- and 12.7-mm diameters) containing E-glass fibers in polyester and vinylester matrices were conditioned at standard laboratory conditions (21 C, 65% relative humidity) or submerged in aqueous solutions (tap water) at 80 C for durations of 14 and 84 days. Observations of the surfaces and cross-sections of the rods by optical microscopy and SEM revealed a variety of degradation phenomena. Embedded hygrothermally conditioned rods were found to have developed surface blisters of different sizes and depths. SEM studies of the surface revealed degradation of the polymer matrix material and exposure and degradation of the fibers close to the surface of the rods. The rods with the vinylester resin matrix showed less extensive degradation than those with the polyester resin matrix; however, the degradation characteristics of the two types of rods appear to be similar.

  6. Preliminary evaluation of fiber composite reinforcement of truck frame rails

    NASA Technical Reports Server (NTRS)

    Faddoul, J. R.

    1977-01-01

    The use of graphite fiber/resin matrix composite to effectively reinforce a standard steel truck frame rail is studied. A preliminary design was made and it was determined that the reinforcement weight could be reduced by a factor of 10 when compared to a steel reinforcement. A section of a 1/3 scale reinforced rail was fabricated to demonstrate low cost manufacturing techniques. The scale rail section was then tested and increased stiffness was confirmed. No evidence of composite fatigue was found after 500,000 cycles to a fiber stress of 34,000 psi. The test specimen failed in bending in a static test at a load 50 percent greater than that predicted for a non-reinforced rail.

  7. Fretting maps of glass fiber-reinforced composites

    SciTech Connect

    Turki, C.; Salvia, M.; Vincent, L.

    1993-12-31

    Industrial development of new materials are often limited due to an insufficient knowledge in their functional properties. The paper deals with fretting behavior of glass fiber reinforced epoxy/metal contacts. Fretting is a plague for all industries, especially in the case of quasi-static loadings. Furthermore friction testing under small displacements appeared well fitted to understand the effect of fiber orientations and to relate results to microstructure (fiber, matrix and interface).

  8. Experimental research on continuous basalt fiber and basalt-fibers-reinforced polymers

    NASA Astrophysics Data System (ADS)

    Zhang, Xueyi; Zou, Guangping; Shen, Zhiqiang

    2008-11-01

    The interest for continuous basalt fibers and reinforced polymers has recently grown because of its low price and rich natural resource. Basalt fiber was one type of high performance inorganic fibers which were made from natural basalt by the method of melt extraction. This paper discusses basic mechanical properties of basalt fiber. The other work in this paper was to conduct tensile testing of continuous basalt fiber-reinforced polymer rod. Tensile strength and stress-strain curve were obtained in this testing. The strength of rod was fairly equal to rod of E-glass fibers and weaker than rod of carbon fibers. Surface of crack of rod was studied. An investigation of fracture mechanism between matrix and fiber was analyzed by SEM (Scanning electron microscopy) method. A poor adhesion between the matrix and fibers was also shown for composites analyzing SEM photos. The promising tensile properties of the presented basalt fibers composites have shown their great potential as alternative classical composites.

  9. Fiber-reinforced superalloy composites provide an added performance edge

    NASA Technical Reports Server (NTRS)

    Petrasek, D. W.; Mcdaniels, D. L.; Westfall, L. J.; Stephens, J. R.

    1986-01-01

    Fiber reinforcements are being explored as a means to increasing the performance of superalloys past 980 C. Fiber-reinforced superalloys (FRS), particularly tungsten FRS (TFRS) are candidate materials for rocket-engine turbopump blades for advanced Shuttle engines and in airbreathing and other rocket engines. Refractory metal wires are the reinforcement of choice due to tolerance to fiber/matrix interactions. W alloy fibers have a maximum tensile strength of 2165 MPa at 1095 C and a 100 hr creep rupture strength at stresses up to 1400 MPa. A TFRS has the potential of a service temperature 110 C over the strongest superalloy. Manufacturing processes being evaluated to realize the FRS components are summarized, together with design features which will be introduced in turbine blades to take advantage of the FRS materials and to extend their surface life.

  10. Damping properties of fiber reinforced composite suitable for stayed cable

    NASA Astrophysics Data System (ADS)

    Li, Jianzhi; Sun, Baochen; Du, Yanliang

    2011-11-01

    Carbon fiber reinforced plastics (CFRP) cables were initially most investigated to replace steel cables. To further explore the advantages of FRP cables, the potential ability of vibration control is studied in this paper emphasizing the designable characteristic of hybrid FRP cables. Fiber reinforced vinyl ester composites and fiber reinforced epoxy composites were prepared by the pultrusion method. Due to the extensive application of fiber reinforced composites, the temperature spectrum and frequency spectrum of loss factor for the composite were tested using dynamic mechanical analysis (DMA) equipment. The damping properties and damping mechanism of the composite were investigated and discussed at different temperatures and frequencies. The result indicates that the loss factor of the composites is increasing with the increase of the frequency from 0.1Hz to 2 Hz and decreasing with the decrease of the temperature from -20°C to 60°C. The loss factor of the carbon fiber composite is higher than that of the glass fiber for the same matrix. The loss factor of the vinyl ester composite is higher than that of the epoxy composite for the same fiber.

  11. Damping properties of fiber reinforced composite suitable for stayed cable

    NASA Astrophysics Data System (ADS)

    Li, Jianzhi; Sun, Baochen; Du, Yanliang

    2012-04-01

    Carbon fiber reinforced plastics (CFRP) cables were initially most investigated to replace steel cables. To further explore the advantages of FRP cables, the potential ability of vibration control is studied in this paper emphasizing the designable characteristic of hybrid FRP cables. Fiber reinforced vinyl ester composites and fiber reinforced epoxy composites were prepared by the pultrusion method. Due to the extensive application of fiber reinforced composites, the temperature spectrum and frequency spectrum of loss factor for the composite were tested using dynamic mechanical analysis (DMA) equipment. The damping properties and damping mechanism of the composite were investigated and discussed at different temperatures and frequencies. The result indicates that the loss factor of the composites is increasing with the increase of the frequency from 0.1Hz to 2 Hz and decreasing with the decrease of the temperature from -20°C to 60°C. The loss factor of the carbon fiber composite is higher than that of the glass fiber for the same matrix. The loss factor of the vinyl ester composite is higher than that of the epoxy composite for the same fiber.

  12. Nano-Fiber Reinforced Enhancements in Composite Polymer Matrices

    NASA Technical Reports Server (NTRS)

    Chamis, Christos C.

    2009-01-01

    Nano-fibers are used to reinforce polymer matrices to enhance the matrix dependent properties that are subsequently used in conventional structural composites. A quasi isotropic configuration is used in arranging like nano-fibers through the thickness to ascertain equiaxial enhanced matrix behavior. The nano-fiber volume ratios are used to obtain the enhanced matrix strength properties for 0.01,0.03, and 0.05 nano-fiber volume rates. These enhanced nano-fiber matrices are used with conventional fiber volume ratios of 0.3 and 0.5 to obtain the composite properties. Results show that nano-fiber enhanced matrices of higher than 0.3 nano-fiber volume ratio are degrading the composite properties.

  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. Ultrasound-assisted coating of polyester fiber with silver bromide nanoparticles.

    PubMed

    Moosavi, Raziyeh; Abbasi, Amir Reza; Yousefi, Mohammad; Ramazani, Ali; Morsali, Ali

    2012-11-01

    The growth of silver bromide nanoparticles on polyester fiber was achieved by sequential dipping steps in alternating bath of potassium bromide and silver nitrate under ultrasound irradiation. The effects of ultrasound irradiation, concentration and sequential dipping steps in growth of the AgBr nanoparticles have been studied. Particle sizes and morphology of nanoparticle are depending on power of ultrasound irradiation, sequential dipping steps and concentration. These systems depicted a decrease in the particles size accompanying an increase in the sonication power. Results suggest that an increasing of sequential dipping steps and concentration led to an increasing of particle size. The physicochemical properties of the nanoparticles were determined by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). PMID:22494594

  15. Studies of polyester fiber as carrier for microbes in a quantitative test method for disinfectants.

    PubMed

    Miner, Norman; Harris, Valerie; Stumph, Sara; Cobb, Amanda; Ortiz, Jennifer

    2004-01-01

    Tests were conducted by a Task Force on Disinfectant Test Methods that was appointed to investigate controversies regarding the accuracy of AOAC test methods for disinfectants as presented in AOAC's Official Methods of Analysis, Chapter 6. The general principles for new and improved AOAC tests are discussed, and a disinfectant test using microbes labeled onto a polyester fiber surface is described. The quantitative test measures the survival of test microbes as a function of exposure time as well as the exposure conditions required to kill 6 log10 of the test microbes. The time required was similar to that for the kinetics of the kill of Bacillus subtilis-labeled cylinders as tested by methods of the AOAC Sporicidal Test 966.04. PMID:15164838

  16. Kenaf/recycled Jute Natural Fibers Unsaturated Polyester Composites: Water Absorption/dimensional Stability and Mechanical Properties

    NASA Astrophysics Data System (ADS)

    Osman, Ekhlas A.; Vakhguelt, Anatoli; Sbarski, Igor; Mutasher, Saad A.

    2012-03-01

    Effects of water absorption on the flexural properties of kenaf-unsaturated polyester composites and kenaf/recycled jute-unsaturated polyester composites were investigated. In the hybrid composites, the total fiber content was fixed to 20 wt%. In this 20 wt%, the addition of jute fiber varied from 0 to 75%, with increment of 25%. The result demonstrates the water absorption and the thickness swelling increased with increase in immersion time. Effects of water absorption on flexural properties of kenaf fiber composites can be reduced significantly with incorporation of recycled jute in composites formulation. The process of absorption of water was found to approach Fickian diffusion behavior for both kenaf composites and hybrid composites.

  17. Investigation of Polymer Resin/Fiber Compatibility in Natural Fiber Reinforced Composite Automotive Materials

    SciTech Connect

    Fifield, Leonard S.; Huang, Cheng; Simmons, Kevin L.

    2010-01-01

    Natural fibers represent a lower density and potentially lower cost alternative to glass fibers for reinforcement of polymers in automotive composites. The high specific modulus and strength of bast fibers make them an attractive option to replace glass not only in non-structural automotive components, but also in semi-structural and structural components. Significant barriers to insertion of bast fibers in the fiber reinforced automotive composite market include the high moisture uptake of this lignocellulosic material relative to glass and the weak inherent interface between natural fibers and automotive resins. This work seeks to improve the moisture uptake and resin interfacing properties of natural fibers through improved fundamental understanding of fiber physiochemical architecture and development of tailored fiber surface modification strategies.

  18. Buckling of Fiber Reinforced Composite Plates with Nanofiber Reinforced Matrices

    NASA Technical Reports Server (NTRS)

    Chamis, Christos C.; Murthy, Pappu L. N.

    2010-01-01

    Anisotropic composite plates were evaluated with nanofiber reinforced matrices (NFRM). The nanofiber reinforcement volumes ratio in the matrix was 0.01. The plate dimensions were 20 by 10 by 1.0 in. (508 by 254 by 25.4 mm). Seven different loading condition cases were evaluated: three for uniaxial loading, three for pairs of combined loading, and one with three combined loadings. The anisotropy arose from the unidirectional plates having been at 30 from the structural axis. The anisotropy had a full 6 by 6 rigidities matrix which were satisfied and solved by a Galerkin buckling algorithm. The buckling results showed that the NFRM plates buckled at about twice those with conventional matrix.

  19. Suppression of electromechanical instability in fiber-reinforced dielectric elastomers

    NASA Astrophysics Data System (ADS)

    Xiao, Rui; Gou, Xiaofan; Chen, Wen

    2016-03-01

    The electromechanical instability of dielectric elastomers has been a major challenge for the application of this class of active materials. In this work, we demonstrate that dielectric elastomers filled with soft fiber can suppress the electromechanical instability and achieve large deformation. Specifically, we developed a constitutive model to describe the dielectric and mechanical behaviors of fiber-reinforced elastomers. The model was applied to study the influence of stiffness, nonlinearity properties and the distribution of fiber on the instability of dielectric membrane under an electric field. The results show that there exists an optimal fiber distribution condition to achieve the maximum deformation before failure.

  20. 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.

  1. High-strength fiber-reinforced plastic reinforcement of wood and wood composite

    SciTech Connect

    Tingley, D.A.; Eng, P.

    1996-12-31

    Research and development underway since 1982 has led to the development of a method of reinforcing wood and wood composite structural products (WWC) using high-strength fiber-reinforced plastic. This method allows the use of less wood fiber and lower grade wood fiber for a given load capacity. The first WWC in which reinforcement has been marketed is glulam beams. Marketed under the trade name FiRP{trademark} Reinforced glulam, the product has gained code approval and is now being used in the construction of buildings and bridges in the United States, Japan and other countries. The high-strength fiber-reinforced plastic (FiRP{trademark} Reinforced panel (RP)) has specific characteristics that are required to provide for proper use in WWC`s. This paper discusses these characteristics and the testing requirements to develop code approved allowable design values for carbon, aramid and fiberglass RP`s for such uses. Specific issues such as in-service characteristics, i.e. long term creep tests and tension-tension fatigue tests, are discussed.

  2. Durability of waste glass flax fiber reinforced mortar

    SciTech Connect

    Aly, M.; Hashmi, M. S. J.; Olabi, A. G.; Messeiry, M.

    2011-01-17

    The main concern for natural fibre reinforced mortar composites is the durability of the fibres in the alkaline environment of cement. The composites may undergo a reduction in strength as a result of weakening of the fibres by a combination of alkali attack and fibre mineralisation. In order to enhance the durability of natural fiber reinforced cement composites several approaches have been studied including fiber impregnation, sealing of the matrix pore system and reduction of matrix alkalinity through the use of pozzolanic materials. In this study waste glass powder was used as a pozzolanic additive to improve the durability performance of flax fiber reinforced mortar (FFRM). The durability of the FFRM was studied by determining the effects of ageing in water and exposure to wetting and drying cycles; on the microstructures and flexural behaviour of the composites. The mortar tests demonstrated that the waste glass powder has significant effect on improving the durability of FFRM.

  3. Response of fiber reinforced sandwich structures subjected to explosive loading

    SciTech Connect

    Perotti, Luigi E.; El Sayed, Tamer; Deiterding, Ralf; Ortiz, Michael

    2011-01-01

    The capability to numerically simulate the response of sandwich structures to explosive loading constitutes a powerful tool to analyze and optimize their design by investigating the influence of different parameters. In order to achieve this objective, the necessary models for foam core and fiber reinforced materials in finite kinematics have been developed together with a finite element scheme which includes C1 finite elements for shells and cohesive elements able to capture the fracture propagation in composite fiber reinforced materials. This computational capability has been used to investigate the response of fiber reinforced sandwich shells to explosive loading. Based on the dissipated fracture energy resulting from these simulations, a factorial design has been carried out to assess the effect of different parameters on the sandwich shell response creating a tool for its optimization.

  4. Durability of Waste Glass Flax Fiber Reinforced Mortar

    NASA Astrophysics Data System (ADS)

    Aly, M.; Hashmi, M. S. J.; Olabi, A. G.; Messeiry, M.

    2011-01-01

    The main concern for natural fibre reinforced mortar composites is the durability of the fibres in the alkaline environment of cement. The composites may undergo a reduction in strength as a result of weakening of the fibres by a combination of alkali attack and fibre mineralisation. In order to enhance the durability of natural fiber reinforced cement composites several approaches have been studied including fiber impregnation, sealing of the matrix pore system and reduction of matrix alkalinity through the use of pozzolanic materials. In this study waste glass powder was used as a pozzolanic additive to improve the durability performance of flax fiber reinforced mortar (FFRM). The durability of the FFRM was studied by determining the effects of ageing in water and exposure to wetting and drying cycles; on the microstructures and flexural behaviour of the composites. The mortar tests demonstrated that the waste glass powder has significant effect on improving the durability of FFRM.

  5. Effect of diameter of glass fibers on flexural properties of fiber-reinforced composites.

    PubMed

    Obukuro, Motofumi; Takahashi, Yutaka; Shimizu, Hiroshi

    2008-07-01

    This study investigated the effect of the diameter of glass fibers on the flexural properties of fiber-reinforced composites. Bar-shaped test specimens of highly filled fiber-reinforced composites (FRCs) and FRC of 30 vol% fiber content were made from a light-cured dimethacrylate monomer liquid (mixture of urethane dimethacrylate and triethylene glycol dimethacrylate) with silanized E-glass fibers (7, 10, 13, 16, 20, 25, 30, and 45 microm in diameter). Flexural strength and elastic modulus were measured. The flexural strength of the highly filled FRCs increased with increasing fiber diameter. In particular, the strengths of highly filled FRCs with 20-, 25-, 30-, and 45-microm-diameter fibers was significantly higher than the others (p<0.05). The flexural strength of FRC of 30 vol% fiber content increased with increasing fiber diameter, except for the FRC with 45-microm-diameter fibers; FRCs with 20-, 25-, and 30-microm-diameter fibers were significantly stronger than the others (p<0.05). Therefore, it was revealed that the diameter of glass fibers significantly affected the flexural properties of fiber-reinforced composites. PMID:18833767

  6. Automobile materials competition: energy implications of fiber-reinforced plastics

    SciTech Connect

    Cummings-Saxton, J.

    1981-10-01

    The embodied energy, structural weight, and transportation energy (fuel requirement) characteristics of steel, fiber-reinforced plastics, and aluminum were assessed to determine the overall energy savings of materials substitution in automobiles. In body panels, a 1.0-lb steel component with an associated 0.5 lb in secondary weight is structurally equivalent to a 0.6-lb fiber-reinforced plastic component with 0.3 lb in associated secondary weight or a 0.5-lb aluminum component with 0.25 lb of secondary weight. (Secondary weight refers to the combined weight of the vehicle's support structure, engine, braking system, and drive train, all of which can be reduced in response to a decrease in total vehicle weight.) The life cycle transportation energy requirements of structurally equivalent body panels (including their associated secondary weights) are 174.4 x 10/sup 3/ Btu for steel, 104.6 x 10/sup 3/ Btu for fiber-reinforced plastics, and 87.2 x 10/sup 3/ Btu for aluminum. The embodied energy requirements are 37.2 x 10/sup 3/ Btu for steel, 22.1 x 10/sup 3/ Btu for fiber-reinforced plastics, and 87.1 x 10/sup 3/ Btu for aluminum. These results can be combined to yield total energy requirements of 211.6 x 10/sup 3/ Btu for steel, 126.7 x 10/sup 3/ Btu for fiber-reinforced plastics, and 174.3 x 10/sup 3/ Btu for aluminum. Fiber-reinforced plastics offer the greatest improvements over steel in both embodied and total energy requirements. Aluminum achieves the greatest savings in transportation energy.

  7. Laser transmission welding of long glass fiber reinforced thermoplastics

    NASA Astrophysics Data System (ADS)

    van der Straeten, Kira; Engelmann, Christoph; Olowinsky, Alexander; Gillner, Arnold

    2015-03-01

    Joining fiber reinforced polymers is an important topic for lightweight construction. Since classical laser transmission welding techniques for polymers have been studied and established in industry for many years joint-strengths within the range of the base material can be achieved. Until now these processes are only used for unfilled and short glass fiber-reinforced thermoplastics using laser absorbing and laser transparent matrices. This knowledge is now transferred to joining long glass fiber reinforced PA6 with high fiber contents without any adhesive additives. As the polymer matrix and glass fibers increase the scattering of the laser beam inside the material, their optical properties, changing with material thickness and fiber content, influence the welding process and require high power lasers. In this article the influence of these material properties (fiber content, material thickness) and the welding parameters like joining speed, laser power and clamping pressure are researched and discussed in detail. The process is also investigated regarding its limitations. Additionally the gap bridging ability of the process is shown in relation to material properties and joining speed.

  8. Renewable agricultural fibers as reinforcing fillers in plastics: Mechanical properties of kenaf fiber-polypropylene composites

    SciTech Connect

    Sanadi, A.R.; Caulfield, D.F.; Jacobson, R.E.; Rowell, R.M. |

    1995-05-01

    Kenaf (Hibiscus cannabinus) is a fast growing annual growth plant that is harvested for its bast fibers. These fibers have excellent specific properties and have potential to be outstanding reinforcing fillers in plastics. In these experiments, the fibers and polypropylene (PP) were blended in a thermokinetic mixer and then injection molded, with the fiber weight fractions varying to 60%. A maleated polypropylene was used to improve the interaction and adhesion between the nonpolar matrix and the polar lignocellulosic fibers. The specific tensile and flexural moduli of a 50% by weight (39% by volume) of kenaf-PP composite compare favorably with a 40% by weight of glass fiber-PP injection-molded composite. These results suggest that kenaf fibers are a viable alternative to inorganic/mineral-based reinforcing fibers as long as the right processing conditions are used and they are used in applications where the higher water absorption is not critical.

  9. Renewable agricultural fibers as reinforcing fillers in plastics: Mechanical properties of Kenaf fiber-polpyropylene composites

    SciTech Connect

    Sanadi, A.R.; Caulfield, D.F.; Jacobson, R.E.

    1995-12-01

    Kenaf (Hibiscus Cannabinus) is a fast growing annual growth plant that is harvested for its bast fibers. These fibers have excellent specific properties and have potential to be outstanding reinforcing fillers in plastics. In our experiments, the fibers and polypropylene (PP) were blended in a thermokinetic mixer and then injection molded, with the fiber weight fractions varying to 60%. A maleated polypropylene was used to improve the interaction and adhesion between the non-polar matrix and the polar lignocellulosic fibers. The specific tensile and flexural moduli of a 50 % by volume (39 % by volume) of kenaf-PP composites compares favorably with a 40 % by weight of glass fiber-PP injection molded composites, These results suggest that kenaf fibers are a viable alternative to inorganic/mineral based reinforcing fibers as long as the right processing conditions are used and for applications where the higher water absorption is not critical.

  10. A comparison of flexural properties of aramid reinforced pultrusions having constant fiber volume and varied matrices, pretreatments, and postcures

    NASA Technical Reports Server (NTRS)

    Wilson, Maywood L.; Johnson, Gary S.; Macconochie, Ian O.

    1986-01-01

    Aramid reinforcement composite materials of equal fiber volume having varied polymer thermoset matrices have been pultruded and flexurally tested to failure. The objective was to improve flexural properties of aramid reinforced pultrusions. Pultrusions of both sized and unsized aramid fiber with four different resin systems were compared to determine the effects of sizing compounds and post-thermal treatments on the flexural strength as an indication of fiber wettability and fiber-to-resin interface bonding. Improvements in flexural strength as the result of pretreatments with sizing solutions used in this study were marginal. The most significant improvements in flexural properties were the results of postcuring. Overall improvements ranged from a low 39,647 Psi(273 Mpa) to a high of 80,390 Psi(554 Mpa), or 103 percent. The fact that post-thermal treatments improved the flexural properties of the four pultrusions indicates that a full cure did not occur in either resin system during the pultrusion process. The increased flexural strengths of the polyester and vinyl ester pultrusions were the most surprising. Based on data presented, the most promising resin system of the four examined (VE 8300, Aropol 7430, Epon 9302, and Epon 9310) for Kevlar reinforced pultrusion is Epon 9310 epoxy.

  11. Advance study of fiber-reinforced self-compacting concrete

    SciTech Connect

    Mironova, M. Ivanova, M. Naidenov, V.; Georgiev, I.; Stary, J.

    2015-10-28

    Incorporation in concrete composition of steel macro- and micro – fiber reinforcement with structural function increases the degree of ductility of typically brittle cement-containing composites, which in some cases can replace completely or partially conventional steel reinforcement in the form of rods and meshes. Thus, that can reduce manufacturing, detailing and placement of conventional reinforcement, which enhances productivity and economic efficiency of the building process. In this paper, six fiber-reinforced with different amounts of steel fiber cement-containing self-compacting compositions are investigated. The results of some of their main strength-deformation characteristics are presented. Advance approach for the study of structural and material properties of these type composites is proposed by using the methods of industrial computed tomography. The obtained original tomography results about the microstructure and characteristics of individual structural components make it possible to analyze the effective macro-characteristics of the studied composites. The resulting analytical data are relevant for the purposes of multi-dimensional modeling of these systems. Multifactor structure-mechanical analysis of the obtained with different methods original scientific results is proposed. It is presented a conclusion of the capabilities and effectiveness of complex analysis in the studies to characterize the properties of self-compacting fiber-reinforced concrete.

  12. Advance study of fiber-reinforced self-compacting concrete

    NASA Astrophysics Data System (ADS)

    Mironova, M.; Ivanova, M.; Naidenov, V.; Georgiev, I.; Stary, J.

    2015-10-01

    Incorporation in concrete composition of steel macro- and micro - fiber reinforcement with structural function increases the degree of ductility of typically brittle cement-containing composites, which in some cases can replace completely or partially conventional steel reinforcement in the form of rods and meshes. Thus, that can reduce manufacturing, detailing and placement of conventional reinforcement, which enhances productivity and economic efficiency of the building process. In this paper, six fiber-reinforced with different amounts of steel fiber cement-containing self-compacting compositions are investigated. The results of some of their main strength-deformation characteristics are presented. Advance approach for the study of structural and material properties of these type composites is proposed by using the methods of industrial computed tomography. The obtained original tomography results about the microstructure and characteristics of individual structural components make it possible to analyze the effective macro-characteristics of the studied composites. The resulting analytical data are relevant for the purposes of multi-dimensional modeling of these systems. Multifactor structure-mechanical analysis of the obtained with different methods original scientific results is proposed. It is presented a conclusion of the capabilities and effectiveness of complex analysis in the studies to characterize the properties of self-compacting fiber-reinforced concrete.

  13. Fabrication of fiber-reinforced composites by chemical vapor infiltration

    SciTech Connect

    Besmann, T.M.; McLaughlin, J.C.; Probst, K.J.; Anderson, T.J.; Starr, T.L.

    1997-12-01

    Silicon carbide-based heat exchanger tubes are of interest to energy production and conversion systems due to their excellent high temperature properties. Fiber-reinforced SiC is of particular importance for these applications since it is substantially tougher than monolithic SiC, and therefore more damage and thermal shock tolerant. This paper reviews a program to develop a scaled-up system for the chemical vapor infiltration of tubular shapes of fiber-reinforced SiC. The efforts include producing a unique furnace design, extensive process and system modeling, and experimental efforts to demonstrate tube fabrication.

  14. Quality assurance of glass fiber reinforced piping systems

    SciTech Connect

    Ende, C.A.M. van den; Bruijn, J.C.M. de

    1997-12-01

    Resin based glass fiber reinforced plastic piping systems have been in use for over 30 years in a variety of industrial purposes, e.g. cooling and potable water, crude oil, gas, etc. Glass fiber reinforced piping systems have considerable advantages over alternative materials for piping systems. This is mainly due to their high corrosion resistance. The use of GRP pipes is limited due to the lack of quality assurance. As with other piping systems the joint is the weakest point. The paper describes the effort made towards a better quality control and understanding of the failure through determination of acceptance criteria and development of nondestructive testing methods for adhesively bounded joints.

  15. Evaluation of Fiber Reinforced Cement Using Digital Image Correlation

    PubMed Central

    Melenka, Garrett W.; Carey, Jason P.

    2015-01-01

    The effect of short fiber reinforcements on the mechanical properties of cement has been examined using a splitting tensile – digital image correlation (DIC) measurement method. Three short fiber reinforcement materials have been used in this study: fiberglass, nylon, and polypropylene. The method outlined provides a simple experimental setup that can be used to evaluate the ultimate tensile strength of brittle materials as well as measure the full field strain across the surface of the splitting tensile test cylindrical specimen. Since the DIC measurement technique is a contact free measurement this method can be used to assess sample failure. PMID:26039590

  16. Evaluation of fiber reinforced cement using digital image correlation.

    PubMed

    Melenka, Garrett W; Carey, Jason P

    2015-01-01

    The effect of short fiber reinforcements on the mechanical properties of cement has been examined using a splitting tensile - digital image correlation (DIC) measurement method. Three short fiber reinforcement materials have been used in this study: fiberglass, nylon, and polypropylene. The method outlined provides a simple experimental setup that can be used to evaluate the ultimate tensile strength of brittle materials as well as measure the full field strain across the surface of the splitting tensile test cylindrical specimen. Since the DIC measurement technique is a contact free measurement this method can be used to assess sample failure. PMID:26039590

  17. In Vitro Study of Transverse Strength of Fiber Reinforced Composites

    PubMed Central

    Mosharraf, R.; Hashemi, Z.; Torkan, S.

    2011-01-01

    Objective Reinforcement with fiber is an effective method for considerable improvement in flexural properties of indirect composite resin restorations. The aim of this in-vitro study was to compare the transverse strength of composite resin bars reinforced with pre-impregnated and non-impregnated fibers. Materials and Methods Thirty six bar type composite resin specimens (3×2×25 mm) were constructed in three groups. The first group was the control group (C) without any fiber reinforcement. The specimens in the second group (P) were reinforced with pre-impregnated fibers and the third group (N) with non-impregnated fibers. These specimens were tested by the three-point bending method to measure primary transverse strength. Data were statistically analyzed with one way ANOVA and Tukey’s tests. Results There was a significant difference among the mean primary transverse strength in the three groups (P<0.001). The post-hoc (Tukey) test showed that there was a significant difference between the pre-impregnated and control groups in their primary transverse strength (P<0.001). Regarding deflection, there was also a significant difference among the three groups (P=0.001). There were significant differences among the mean deflection of the control group and two other groups (PC&N<.001 and PC&P=.004), but there was no significant difference between the non-and pre-impregnated groups (PN&P=.813). Conclusion Within the limitations of this study, it was concluded that reinforcement with fiber considerably increased the transverse strength of composite resin specimens, but impregnation of the fiber used implemented no significant difference in the transverse strength of composite resin samples. PMID:22457836

  18. Stress and strength analysis of fiber reinforced plastic pipe tees with reinforcement

    SciTech Connect

    Wei, Z.; Widera, G.E.O.; Xue, M.

    1996-12-01

    In this paper, a stress and strength analysis of fiber reinforced plastic (FRP) pipe tees with reinforcement by use of 3-D finite element method is presented. Wilson`s incompatible elements and the 16-node 3-D element with relative degrees of freedom have been employed to carry out the analysis. The reliability of the program is also investigated. Two reinforcing methods, pad and compact reinforcement, are investigated. The fact that the properties and principal directions of the materials of the two intersecting pipes and the reinforcement are different has been taken into account in the analysis. The continuity of stress and strain fields at the intersecting surface of two different materials is considered in the post processing of the FEM results. The results show that the stress concentration in a FRP pipe intersection without reinforcement (r/R = 0.4--0.7) is significant. A reasonable design can be obtained by considering both stress fields and the orthotropic strength parameters of the materials. The in-plane shear stress may be the controlling factor because of the relatively low shear strength of most composites. Use of either reinforcing method does not change the location of the maximum tensile stress and the maximum shear stress, and both alleviate the stress concentration at the intersection. It is shown that the compact reinforcing method is more effective than the pad one. The larger the reinforcing area of the compact reinforcing method, the smaller the stress concentration factor, but the lower the rate of reduction.

  19. Modelling of dimensional stability of fiber reinforced composite materials

    NASA Technical Reports Server (NTRS)

    Hahn, H. T.; Hosangadi, A.

    1982-01-01

    Various methods of predicting the expansion and diffusion properties of composite laminates are reviewed. The prediction equations for continuous fiber composites can be applied to SMC composites as the effective fiber aspect ratio in the latter is large enough. The effect of hygrothermal expansion on the dimensional stability of composite laminates was demonstrated through the warping of unsymmetric graphite/epoxy laminates. The warping is very sensitive to the size of the panel, and to the moisture content which is in turn sensitive to the relative humidity in the environment. Thus, any long term creep test must be carried out in a humidity-controlled environment. Environmental effects in SMC composites and bulk polyester were studied under seven different environments. The SMC composites chosen are SMC-R25, SMC-R40, and SMC-R65.

  20. Unified micromechanics of damping for unidirectional fiber reinforced composites

    NASA Technical Reports Server (NTRS)

    Saravanos, D. A.; Chamis, C. C.

    1989-01-01

    An integrated micromechanics methodology for the prediction of damping capacity in fiber-reinforced polymer matrix unidirectional composites has been developed. Explicit micromechanics equations based on hysteretic damping are presented relating the on-axis damping capacities to the fiber and matrix properties and volume fraction. The damping capacities of unidirectional composites subjected to off-axis loading are synthesized from thermal effect on the damping performance of unidirectional composites due to temperature and moisture variations is also modeled. The damping contributions from interfacial friction between broken fibers and matrix are incorporated. Finally, the temperature rise in continuously vibrating composite plies is estimated. Application examples illustrate the significance of various parameters on the damping performance of unidirectional and off-axis fiber reinforced composites.

  1. Skin problems among fiber-glass reinforced plastics factory workers in Japan.

    PubMed

    Minamoto, Keiko; Nagano, Megumi; Inaoka, Tsukasa; Kitano, Takao; Ushijima, Kayo; Fukuda, Yoshiharu; Futatsuka, Makoto

    2002-01-01

    Two surveys, one in winter the other in summer time, examined the skin problems of the entire manual workers (N=148) from 11 small-to-medium sized fiber-glass reinforced plastics (FRP) factories located in Kyushu, Japan. The workers were exposed to unsaturated polyester resin, including styrene and auxiliary agents such as cobalt naphthenate, hardeners such as methyl ethyl ketone peroxides, glass fiber and dust including shortened glass fiber and plastic particles. Eighty-seven workers (58.8%) reported having skin problems (mainly itching or dermatitis) since they started to work in FRP manufacturing and 25 workers had consulted a physician because of their skin problems; one worker was forced to take sick leave because of his severe dermatitis. History of allergic diseases and shorter occupational period (duration of employment) in a FRP factory were associated with greater probability of having a history of work-related skin symptoms. Workers in factories where dust-generating and lamination sites were located in different buildings were significantly less likely to have a history of skin problems than those in factories where the two sites were located in the same building. Of the 67 workers examined in both seasons closed to double the prevalence of dermatitis was found in summer (23.3%) than winter (13.4%). PMID:11926514

  2. Flexural retrofitting of reinforced concrete structures using Green Natural Fiber Reinforced Polymer plates

    NASA Astrophysics Data System (ADS)

    Cervantes, Ignacio

    An experimental study will be carried out to determine the suitability of Green Natural Fiber Reinforced Polymer plates (GNFRP) manufactured with hemp fibers, with the purpose of using them as structural materials for the flexural strengthening of reinforced concrete (RC) beams. Four identical RC beams, 96 inches long, are tested for the investigation, three control beams and one test beam. The first three beams are used as references; one unreinforced, one with one layer of Carbon Fiber Reinforced Polymer (CFRP), one with two layers of CFRP, and one with n layers of the proposed, environmental-friendly, GNFRP plates. The goal is to determine the number of GNFRP layers needed to match the strength reached with one layer of CFRP and once matched, assess if the system is less expensive than CFRP strengthening, if this is the case, this strengthening system could be an alternative to the currently used, expensive CFRP systems.

  3. Carbon fiber reinforced composites: their structural and thermal properties

    NASA Astrophysics Data System (ADS)

    Cheng, Jingquan; Yang, Dehua

    2010-07-01

    More and more astronomical telescopes use carbon fiber reinforced composites (CFRP). CFRP has high stiffness, high strength, and low thermal expansion. However, they are not isotropic in performance. Their properties are direction dependent. This paper discusses, in detail, the structural and thermal properties of carbon fiber structure members, such as tubes, plates, and honeycomb sandwich structures. Comparisons are provided both from the structural point of view and from the thermal point of view.

  4. Wear of short carbon-fiber-reinforced PAI and PPS

    SciTech Connect

    Behrens, W.W.; Jerina, K.L.; Hahn, H.T.

    1988-07-01

    Wear of short carbon-fiber-reinforced polyamide-imide and polyphenylene sulfide is described. Comparative data from thrust washer wear tests for both polymers are presented. Fiber orientation is shown to have a significant effect on wear rates. The wear mechanisms in both polymers are illustrated with optical and scanning electron micrographs. Wear is shown to be a nonlinear function of time and stress for both PPS and PAI. 15 references, 14 figures.

  5. Ceramic fiber reinforced glass-ceramic matrix composite

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P. (Inventor)

    1993-01-01

    A slurry of BSAS glass powders is cast into tapes which are cut to predetermined sizes. Mats of continuous chemical vapor deposition (CVD)-SiC fibers are alternately stacked with these matrix tapes. This tape-mat stack is warm-pressed to produce a 'green' composite which is heated to burn out organic constituents. The remaining interim material is then hot-pressed to form a BSAS glass-ceramic fiber-reinforced composite.

  6. Modeling the thermal conductivity of fiber-reinforced ceramic composites

    SciTech Connect

    Beecher, S.C.; Dinwiddie, R.B.

    1993-06-01

    A review of models for the prediction of the thermal conductivity of uni-directional fiber-reinforced composites will be presented. The ability of these models to give an accurate prediction of the composite thermal conductivity depends on the amount of information known about the constituent phase properties under the assumption that these properties do not change as a result of processing. Also presented are models that take into account the effects of fiber coatings.

  7. Initial evaluation of continuous fiber reinforced NiAl composites

    NASA Technical Reports Server (NTRS)

    Noebe, R. D.; Bowman, R. R.; Eldridge, J. I.

    1990-01-01

    NiAl is being evaluated as a potential matrix material as part of an overall program to develop and understand high-temperature structural composites. Currently, continuous fiber composites have been fabricated by the powder cloth technique incorporating either W(218) or single crystal Al2O3 fibers as reinforcements in both binary NiAl and a solute strengthened NiAl(.05 at. pct Zr) matrix. Initial evaluation of these composite systems have included: fiber push-out testing to measure matrix/fiber bond strengths, bend testing to determine strength as a function of temperature and composite structure, and thermal cycling to establish the effect of matrix and fiber properties on composite life. The effect of matrix/fiber bond strength and matrix strength on several composite properties will be discussed.

  8. Surface grafting of Kevlar fibers for improved interfacial properties of fiber-reinforced composites

    SciTech Connect

    Ravichandran, Vasudha.

    1991-01-01

    Matrix-specific chemical modification of the Kevlar fiber surfaces was carried out with the aim of enhancing adhesion, through covalent bonding, to selected thermoset matrix resins such as vinyl ester, unsaturated polyester and epoxy. A two-step grafting method, involving initial metalation followed by subsequent substitution, was used to graft vinyl and epoxy terminated groups onto Kevlar fiber surfaces. The physical changes in fiber surface were characterized by scanning-electron microscopy and surface area measurement and the chemical changes due to grafting were measured by contact angle measurement and neutron activation analysis; high concentrations of double bonds and epoxy groups were measured. The change in interfacial sear strength due to the surface grafting was measured by means of a single fiber pull out test. The results show a nearly twofold increase in the interfacial shear strength due to vinyl terminated grafts in the case of Kevlar/vinyl ester and Kevlar/polyester composites. Kevlar fibers containing the epoxy functionality on the surface had enhanced adhesion to epoxy matrix resin.

  9. NATURAL FIBER OR GLASS REINFORCED POLYPROPYLENE COMPOSITES?

    SciTech Connect

    Lorenzi, W.; Di Landro, L.; Casiraghi, A.; Pagano, M. R.

    2008-08-28

    Problems related to the recycle of conventional composite materials are becoming always more relevant for many industrial fields. Natural fiber composites (NFC) have recently gained much attention due to their low cost, environmental gains (eco-compatibility), easy disposal, reduction in volatile organic emissions, and their potential to compete with glass fiber composites (GFC). Interest in natural fibers is not only based over ecological aspects. NFC have good mechanical performances in relation to their low specific weight and low price. A characterization of mechanical properties, dynamic behavior, and moisture absorption is presented.

  10. Natural Fiber or Glass Reinforced Polypropylene Composites?

    NASA Astrophysics Data System (ADS)

    Lorenzi, W.; Di Landro, L.; Casiraghi, A.; Pagano, M. R.

    2008-08-01

    Problems related to the recycle of conventional composite materials are becoming always more relevant for many industrial fields. Natural fiber composites (NFC) have recently gained much attention due to their low cost, environmental gains (eco-compatibility), easy disposal, reduction in volatile organic emissions, and their potential to compete with glass fiber composites (GFC). Interest in natural fibers is not only based over ecological aspects. NFC have good mechanical performances in relation to their low specific weight and low price. A characterization of mechanical properties, dynamic behavior, and moisture absorption is presented.

  11. Fabrication of Fiber-Reinforced Celsian Matrix Composites

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P.; Setlock, John A.

    2000-01-01

    A method has been developed for the fabrication of small diameter, multifilament tow fiber reinforced ceramic matrix composites. Its application has been successfully demonstrated for the Hi-Nicalon/celsian system. Strong and tough celsian matrix composites, reinforced with BN/SiC-coated Hi-Nicalon fibers, have been fabricated by infiltrating the fiber tows with the matrix slurry, winding the tows on a drum, cutting and stacking of the prepreg tapes in the desired orientation, and hot pressing. The monoclinic celsian phase in the matrix was produced in situ, during hot pressing, from the 0.75BaO-0.25SrO-Al2O3-2SiO2 mixed precursor synthesized by solid state reaction from metal oxides. Hot pressing resulted in almost fully dense fiber-reinforced composites. The unidirectional composites having approx. 42 vol% of fibers exhibited graceful failure with extensive fiber pullout in three-point bend tests at room temperature. Values of yield stress and strain were 435 +/- 35 MPa and 0.27 +/- 0.01 percent, respectively, and ultimate strengths of 900 +/- 60 MPa were observed. The Young's modulus of the composites was measured to be 165 +/- 5 GPa.

  12. Smart pultruded composite reinforcements incorporating fiber optic sensors

    NASA Astrophysics Data System (ADS)

    Kalamkarov, Alexander L.; Fitzgerald, Stephen B.; MacDonald, Douglas O.; Georgiades, Anastasis V.

    1998-03-01

    The issues of processing, evaluation, experimental testing, and modeling of smart fiber reinforced polymer (FRP) composite materials are discussed. The specific application in view is the use of smart composite reinforcements for a monitoring of innovative bridges and structures. The pultrusion technology for the fabrication of fiber reinforced polymer composites with embedded fiber optic senors (Fabry Perot and Bragg Grating) is developed. The optical sensor/composite material interaction is studied. The tensile and shear properties of the pultruded carbon/vinylester and glass/vinylester rods with and without optical fibers are determined. The microstructural analysis of the smart pultruded FRP is carried out. The interfaces between the resin matrix and the acrylate and polyimide coated optical fibers are examined and interpreted in terms of the coatings's ability to resist high temperature and its compatibility with resin matrix. The strain monitoring during the pultrusion of composite parts using the embedded fiber optic sensors was performed. The strain readings from the sensors and the extensometer were compared in mechanical tensile tests.

  13. Development of ductile hybrid fiber reinforced polymer (D-H-FRP) reinforcement for concrete structures

    NASA Astrophysics Data System (ADS)

    Somboonsong, Win

    The corrosion of steel rebars has been the major cause of the reinforced concrete deterioration in transportation structures and port facilities. Currently, the Federal Highway Administration (FHWA) spends annually $31 billion for maintaining and repairing highways and highway bridges. The study reported herein represents the work done in developing a new type of reinforcement called Ductile Hybrid Fiber Reinforced Polymer or D-H-FRP using non-corrosive fiber materials. Unlike the previous FRP reinforcements that fail in a brittle manner, the D-H-FRP bars exhibit the stress-strain curves that are suitable for concrete reinforcement. The D-H-FRP stress-strain curves are linearly elastic with a definite yield point followed by plastic deformation and strain hardening resembling that of mild steel. In addition, the D-H-FRP reinforcement has integrated ribs required for concrete bond. The desirable mechanical properties of D-H-FRP reinforcement are obtained from the integrated design based on the material hybrid and geometric hybrid concepts. Using these concepts, the properties can be tailored to meet the specific design requirements. An analytical model was developed to predict the D-H-FRP stress-strain curves with different combination of fiber materials and geometric configuration. This model was used to optimize the design of D-H-FRP bars. An in-line braiding-pultrusion manufacturing process was developed at Drexel University to produce high quality D-H-FRP reinforcement in diameters that can be used in concrete structures. A series of experiments were carried out to test D-H-FRP reinforcement as well as their individual components in monotonic and cyclic tensile tests. Using the results from the tensile tests and fracture analysis, the stress-strain behavior of the D-H-FRP reinforcement was fully characterized and explained. Two series of concrete beams reinforced with D-H-FRP bars were studied. The D-H-FRP beam test results were then compared with companion

  14. Interfacial studies in fiber-reinforced thermoplastic-matrix composites

    SciTech Connect

    Brady, R.L.

    1989-01-01

    The major theme of this dissertation is structure/property relationships in fiber-reinforced thermoplastic-matrix composites. Effort has been focused on the interface: interfacial crystallization and fiber/matrix adhesion. Included are investigations on interfacial nucleation and morphology, measurement of fiber/matrix adhesion, effects of interfacial adsorption and crystallization on fiber/matrix adhesion, and composites reinforced with thermotropic liquid crystal copolyester fibers. Crystallization of a copolyester and polybutylene terephthalate with glass, carbon, or aramid fibers has been studied with regard to interfacial morphology. Techniques employed included hot-stage optical microscopy and differential scanning calorimetry. Nucleation by the fibers was found to be a general phenomenon. Morphology could be varied by changing the cooling rate. In order to better monitor fiber /matrix adhesion, a buckled plate test has been developed. The test measures transverse toughness as the parameter characterizing interfacial adhesion in unidirectional, continuous-fiber composites. The test is simple to perform yet has advantages over other interfacial evaluation techniques. The buckled plate test was found to be a sensitive measure of fiber/matrix adhesion. The buckled plate test has been used along with the transverse tensile test to examine how interfacial adsorption and crystallization affect fiber/matrix adhesion in polycarbonate/carbon fiber composites. Adsorption was found to be of primary importance in developing adhesion, while crystallization is a secondary effect. The toughness data have been fit successfully for annealing time and temperature dependence. The dependence of adsorption and transverse toughness on matrix molecular weight was found to be large, with higher molecular weights adsorbing more effectively.

  15. Fiber Reinforced Composites for Insulation and Structures

    NASA Technical Reports Server (NTRS)

    Broughton, Roy M., Jr.

    2005-01-01

    The work involves two areas: Composites, optimum fiber placement with initial construction of a pressure vessel, and the general subject of insulation, a continual concern in harsh thermal environments. Insulation

  16. Plastic matrix composites with continuous fiber reinforcement

    SciTech Connect

    1991-09-19

    Most plastic resins are not suitable for structural applications. Although many resins are extremely tough, most lack strength, stiffness, and deform under load with time. By mixing strong, stiff, fibrous materials into the plastic matrix, a variety of structural composite materials can be formed. The properties of these composites can be tailored by fiber selection, orientation, and other factors to suit specific applications. The advantages and disadvantages of fiberglass, carbon-graphite, aramid (Kevlar 49), and boron fibers are summarized.

  17. Natural Kenaf Fiber Reinforced Composites as Engineered Structural Materials

    NASA Astrophysics Data System (ADS)

    Dittenber, David B.

    The objective of this work was to provide a comprehensive evaluation of natural fiber reinforced polymer (NFRP)'s ability to act as a structural material. As a chemical treatment, aligned kenaf fibers were treated with sodium hydroxide (alkalization) in different concentrations and durations and then manufactured into kenaf fiber / vinyl ester composite plates. Single fiber tensile properties and composite flexural properties, both in dry and saturated environments, were assessed. Based on ASTM standard testing, a comparison of flexural, tensile, compressive, and shear mechanical properties was also made between an untreated kenaf fiber reinforced composite, a chemically treated kenaf fiber reinforced composite, a glass fiber reinforced composite, and oriented strand board (OSB). The mechanical properties were evaluated for dry samples, samples immersed in water for 50 hours, and samples immersed in water until saturation (~2700 hours). Since NFRPs are more vulnerable to environmental effects than synthetic fiber composites, a series of weathering and environmental tests were conducted on the kenaf fiber composites. The environmental conditions studied include real-time outdoor weathering, elevated temperatures, immersion in different pH solutions, and UV exposure. In all of these tests, degradation was found to be more pronounced in the NFRPs than in the glass FRPs; however, in nearly every case the degradation was less than 50% of the flexural strength or stiffness. Using a method of overlapping and meshing discontinuous fiber ends, large mats of fiber bundles were manufactured into composite facesheets for structural insulated panels (SIPs). The polyisocyanurate foam cores proved to be poorly matched to the strength and stiffness of the NFRP facesheets, leading to premature core shear or delamination failures in both flexure and compressive testing. The NFRPs were found to match well with the theoretical stiffness prediction methods of classical lamination

  18. Crushing characteristics of continuous fiber-reinforced composite tubes

    NASA Technical Reports Server (NTRS)

    Farley, Gary L.; Jones, Robert M.

    1992-01-01

    Composite tubes can be reinforced with continuous fibers. When such tubes are subjected to crushing loads, the response is complex and depends on interaction between the different mechanisms that control the crushing process. The modes of crushing and their controlling mechanisms are described. Also, the resulting crushing process and its efficiency are addressed.

  19. Design Guide for glass fiber reinforced metal pressure vessel

    NASA Technical Reports Server (NTRS)

    Landes, R. E.

    1973-01-01

    Design Guide has been prepared for pressure vessel engineers concerned with specific glass fiber reinforced metal tank design or general tank tradeoff study. Design philosophy, general equations, and curves are provided for safelife design of tanks operating under anticipated space shuttle service conditions.

  20. An Assessment of Self-Healing Fiber Reinforced Composites

    NASA Technical Reports Server (NTRS)

    Smith, Joseph G., Jr.

    2012-01-01

    Several reviews and books have been written concerning self-healing polymers over the last few years. These have focused primarily on the types of self-healing materials being studied, with minor emphasis given to composite properties. The purpose of this review is to assess the self-healing ability of these materials when utilized in fiber reinforced composites

  1. NDE Elastic Properties of Fiber-Reinforced Composite Materials

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Y.

    1995-01-01

    Fiber-reinforced composites are increasingly replacing metallic alloys as structural materials for primary components of fracture-critical structures. This trend is a result of the growing understanding of material behavior and recognition of the desirable properties of composites. A research program was conducted on NDE methods for determining the elastic properties of composites.

  2. Mechanical Properties of Continuous Fiber Reinforced Zirconium Diboride Matrix Composites

    NASA Technical Reports Server (NTRS)

    Stuffle, Kevin; Creegan, Peter; Nowell, Steven; Bull, Jeffrey D.; Rasky, Daniel J. (Technical Monitor)

    1995-01-01

    Continuous fiber reinforced zirconium diboride matrix composites, SCS-9a-(RBSiCZrB2)matrix, are being developed for leading edge, rocket nozzle and turbine engine applications. Recently, the composite materials have been characterized for tensile properties to 1250 C, the highest temperature tested. The tensile properties are fiber dominated as the matrix is microcracked on fabrication, but favorable failure characteristic are observed. Compression and shear mechanical testing results will be reported if completed. The effects of fiber volume fraction and matrix density on mechanical properties will be discussed. The target applications of the materials will be discussed. Specific testing being performed towards qualification for these applications will be included.

  3. Interfacial debonding versus fiber fracture in fiber-reinforced ceramic composites

    SciTech Connect

    Hsueh, C.H.; Becher, P.F.; He, M.Y.

    1998-11-01

    Toughening of fiber-reinforced ceramic composites by fiber pullout relies on debonding at the fiber/matrix interface prior to fiber fracture when composites are subjected to tensile loading. The criterion of interfacial debonding versus crack penetration has been analyzed for two semi-infinite elastic plates bonded at their interface. When a crack reaches the interface, the crack either deflects along the interface or penetrates into the next layer depending upon the ratio of the energy release rate for debonding versus that for crack penetration. This criterion has been used extensively to predict interfacial debonding versus fiber fracture for a crack propagating in a fiber-reinforced ceramic composite. Two modifications were considered in the present study to address the debonding/fracture problem. First, the authors derived the analysis for a strip of fiber, which had a finite width and was sandwiched between two semi-infinite plates of matrix. It was found that the criterion of interfacial debonding versus fiber fracture depended on the fiber width. Second, a bridging fiber behind the crack tip was considered where the crack tip initially circumvented the fiber. Subsequent to this, either the interface debonded or the fiber fractured. In this case, the authors have considered a bridging-fiber geometry to establish a new criterion.

  4. Nondestructive testing of externally reinforced structures for seismic retrofitting using flax fiber reinforced polymer (FFRP) composites

    NASA Astrophysics Data System (ADS)

    Ibarra-Castanedo, C.; Sfarra, S.; Paoletti, D.; Bendada, A.; Maldague, X.

    2013-05-01

    Natural fibers constitute an interesting alternative to synthetic fibers, e.g. glass and carbon, for the production of composites due to their environmental and economic advantages. The strength of natural fiber composites is on average lower compared to their synthetic counterparts. Nevertheless, natural fibers such as flax, among other bast fibers (jute, kenaf, ramie and hemp), are serious candidates for seismic retrofitting applications given that their mechanical properties are more suitable for dynamic loads. Strengthening of structures is performed by impregnating flax fiber reinforced polymers (FFRP) fabrics with epoxy resin and applying them to the component of interest, increasing in this way the load and deformation capacities of the building, while preserving its stiffness and dynamic properties. The reinforced areas are however prompt to debonding if the fabrics are not mounted properly. Nondestructive testing is therefore required to verify that the fabric is uniformly installed and that there are no air gaps or foreign materials that could instigate debonding. In this work, the use of active infrared thermography was investigated for the assessment of (1) a laboratory specimen reinforced with FFRP and containing several artificial defects; and (2) an actual FFRP retrofitted masonry wall in the Faculty of Engineering of the University of L'Aquila (Italy) that was seriously affected by the 2009 earthquake. Thermographic data was processed by advanced signal processing techniques, and post-processed by computing the watershed lines to locate suspected areas. Results coming from the academic specimen were compared to digital speckle photography and holographic interferometry images.

  5. Modeling of short fiber reinforced injection moulded composite

    NASA Astrophysics Data System (ADS)

    Kulkarni, A.; Aswini, N.; Dandekar, C. R.; Makhe, S.

    2012-09-01

    A micromechanics based finite element model (FEM) is developed to facilitate the design of a new production quality fiber reinforced plastic injection molded part. The composite part under study is composed of a polyetheretherketone (PEEK) matrix reinforced with 30% by volume fraction of short carbon fibers. The constitutive material models are obtained by using micromechanics based homogenization theories. The analysis is carried out by successfully coupling two commercial codes, Moldflow and ANSYS. Moldflow software is used to predict the fiber orientation by considering the flow kinetics and molding parameters. Material models are inputted into the commercial software ANSYS as per the predicted fiber orientation and the structural analysis is carried out. Thus in the present approach a coupling between two commercial codes namely Moldflow and ANSYS has been established to enable the analysis of the short fiber reinforced injection moulded composite parts. The load-deflection curve is obtained based on three constitutive material model namely an isotropy, transversely isotropy and orthotropy. Average values of the predicted quantities are compared to experimental results, obtaining a good correlation. In this manner, the coupled Moldflow-ANSYS model successfully predicts the load deflection curve of a composite injection molded part.

  6. Toughened Matrix SiC Fiber Reinforced Composites

    NASA Technical Reports Server (NTRS)

    Levine, Stanley R.; Bhatt, Ramakrishna T.; Morscher, Gregory N.; Kiser, James D.

    2005-01-01

    First matrix cracking stress is a critical parameter for application of Sic fiber reinforced composites in highly stressed, environmentally demanding applications such as turbine blades. High matrix fracture toughness is a key property that contributes to high composite fracture stress. Silicon nitride offers reduced matrix elastic modulus, lower coefficient of thermal expansion, and potentially high fracture toughness compared to Sic matrices. All of these factors can be used to advantage to increase matrix fracture stress. As a first model system we are pursuing toughened silicon nitride matrix composites reinforced with SCS-9 fibers. Fabrication is by tape casting the matrix plies and tape lay-up with fiber plies followed by hot pressing at 1800 C. Progress toward this end will be reported.

  7. Corrosion and tribological properties of basalt fiber reinforced composite materials

    NASA Astrophysics Data System (ADS)

    Ha, Jin Cheol; Kim, Yun-Hae; Lee, Myeong-Hoon; Moon, Kyung-Man; Park, Se-Ho

    2015-03-01

    This experiment has examined the corrosion and tribological properties of basalt fiber reinforced composite materials. There were slight changes of weight after the occurring of corrosion based on time and H2SO4 concentration, but in general, the weight increased. It is assumed that this happens due to the basalt fiber precipitate. Prior to the corrosion, friction-wear behavior showed irregular patterns compared to metallic materials, and when it was compared with the behavior after the corrosion, the coefficient of friction was 2 to 3 times greater. The coefficient of friction of all test specimen ranged from 0.1 to 0.2. Such a result has proven that the basalt fiber, similar to the resin rubber, shows regular patterns regardless of time and H2SO4 concentration because of the space made between resins and reinforced materials.

  8. Creep behavior of tungsten fiber reinforced niobium metal matrix composites

    NASA Technical Reports Server (NTRS)

    Grobstein, T. L.

    1989-01-01

    Tungsten fiber reinforced niobium metal matrix composites were evaluated for use in space nuclear power conversion systems. The composite panels were fabricated using the arc-spray monotape technique at the NASA Lewis Research Center. The creep behavior of W/Nb composite material was determined at 1400 and 1500 K in vacuum over a wide range of applied loads. The time to reach 1 percent strain, the time to rupture, and the minimum creep rate were measured. The W/Nb composites exceeded the properties of monolithic niobium alloys significantly even when compared on a strength to density basis. The effect of fiber orientation on the creep strength also was evaluated. Kirkendall void formation was observed at the fiber/matrix interface; the void distribution differed depending on the fiber orientation relative to the stress axis. A relationship was found between the fiber orientation and the creep strength.

  9. Anomalous rheological behavior of long glass fiber reinforced polypropylene

    NASA Astrophysics Data System (ADS)

    Kim, Dong Hak; Lee, Young Sil; Son, Younggon

    2012-12-01

    Dynamic rheological properties of PP-based long glass fiber-reinforced thermoplastics (LFT) were investigated. Weight fractions of the glass fibers investigated in the present study ranged from 0.15 to 0.5, which are higher than those of previous studies. We observed very abnormal rheological behavior. Complex viscosity (η*) of the LFT increased with the glass fiber content up to 40 wt. %. However, the η* with a weight fraction of 0.5 is observed to be lower than that of LFT with a weight fraction of 0.4 in spite of higher glass fiber content. From various experiments, we found that this abnormal behavior is analogous to the rheological behavior of a lyotropic liquid crystalline polymer solution and concluded that the abnormal rheological behavior for the LFT is attributed to the formation of a liquid crystal- like structure at high concentrations of long glass fibers.

  10. Making Glass-Fiber-Reinforced Coolant Tubes

    NASA Technical Reports Server (NTRS)

    Curtin, F.

    1985-01-01

    New use found for heat-shrinkable sleeves. Smooth, noncontaminating channels for transporting cooling water in Space Shuttle Extravehicularmobility unit made of fiberglass tubing with aid of heat-shrinkable sleeves. Previously, glass fibers from inner walls of tubes contaminate water.

  11. Micromechanical simulation of the failure of fiber reinforced composites

    NASA Astrophysics Data System (ADS)

    Landis, Chad M.; Beyerlein, Irene J.; McMeeking, Robert M.

    2000-03-01

    The strength of unidirectionally reinforced fiber composites is simulated using the three dimensional shear lag model of Landis, C. M., McGlockton, M. A. and McMeeking, R. M. (1999) (An improved shear lag model for broken fibers in composites. J. Comp. Mat. 33, 667-680) and Weibull fiber statistics. The governing differential equations for the fiber displacements and stresses are solved exactly for any configuration of breaks using an influence superposition technique. The model predicts the tensile strength of well bonded, elastic fiber/matrix systems with fibers arranged in a square array. Length and strength scalings are used which are relevant for elastic, local load sharing composites. Several hundred Monte Carlo simulations were executed to determine the statistical strength distributions of the composite for three values of the fiber Weibull modulus, m=5, 10 and 20. Stress-strain behavior and the evolution of fiber damage are studied. Bundle sizes of 10×10, 15×15, 20×20, 25×25, 30×30 and 35×35 fibers of various lengths are investigated to determine the dependence of strength on the composite size. The validity of weakest link statistics for composite strength is examined as well.

  12. Micromechanical model of crack growth in fiber reinforced brittle materials

    NASA Technical Reports Server (NTRS)

    Rubinstein, Asher A.; Xu, Kang

    1990-01-01

    A model based on the micromechanical mechanism of crack growth resistance in fiber reinforced ceramics is presented. The formulation of the model is based on a small scale geometry of a macrocrack with a bridging zone, the process zone, which governs the resistance mechanism. The effect of high toughness of the fibers in retardation of the crack advance, and the significance of the fiber pullout mechanism on the crack growth resistance, are reflected in this model. The model allows one to address issues such as influence of fiber spacing, fiber flexibility, and fiber matrix friction. Two approaches were used. One represents the fracture initiation and concentrated on the development of the first microcracks between fibers. An exact closed form solution was obtained for this case. The second case deals with the development of an array of microcracks between fibers forming the bridging zone. An implicit exact solution is formed for this case. In both cases, a discrete fiber distribution is incorporated into the solution.

  13. and Carbon Fiber Reinforced 2024 Aluminum Alloy Composites

    NASA Astrophysics Data System (ADS)

    Kaczmar, Jacek W.; Naplocha, Krzysztof; Morgiel, Jerzy

    2014-08-01

    The microstructure and mechanical properties of 2024 aluminum alloy composite materials strengthened with Al2O3 Saffil fibers or together with addition of carbon fibers were investigated. The fibers were stabilized in the preform with silica binder strengthened by further heat treatment. The preforms with 80-90% porosity were infiltrated by direct squeeze casting method. The microstructure of the as-cast specimens consisted mainly of α-dendrites with intermetallic compounds precipitated at their boundaries. The homogenization treatment of the composite materials substituted silica binder with a mixture of the Θ phase and silicon precipitates distributed in the remnants of SiO2 amorphous phase. Outside of this area at the binder/matrix interface, fine MgO precipitates were also present. At surface of C fibers, a small amount of fine Al3C4 carbides were formed. During pressure infiltration of preforms containing carbon fibers under oxygen carrying atmosphere, C fibers can burn releasing gasses and causing cracks initiated by thermal stress. The examination of tensile and bending strength showed that reinforcing of aluminum matrix with 10-20% fibers improved investigated properties in the entire temperature range. The largest increase in relation to unreinforced alloy was observed for composite materials examined at the temperature of 300 °C. Substituting Al2O3 Saffil fibers with carbon fibers leads to better wear resistance at dry condition with no relevant effect on strength properties.

  14. Micromechanical model of crack growth in fiber reinforced ceramics

    NASA Technical Reports Server (NTRS)

    Rubinstein, Asher A.; Xu, Kang

    1990-01-01

    A model based on the micromechanical mechanism of crack growth resistance in fiber reinforced ceramics is presented. The formulation of the model is based on a small scale geometry of a macrocrack with a bridging zone, the process zone, which governs the resistance mechanism. The effect of high toughness of the fibers in retardation of the crack advance, and the significance of the fiber pullout mechanism on the crack growth resistance, are reflected in this model. The model allows one to address issues such as influence of fiber spacing, fiber flexibility, and fiber matrix friction. Two approaches were used. One represents the fracture initiation and concentrated on the development of the first microcracks between fibers. An exact closed form solution was obtained for this case. The second case deals with the development of an array of microcracks between fibers forming the bridging zone. An implicit exact solution is formed for this case. In both cases, a discrete fiber distribution is incorporated into the solution.

  15. Mullite fiber reinforced reaction bonded Si3N4 composites

    NASA Technical Reports Server (NTRS)

    Saleh, T.; Sayir, A.; Lightfoot, A.; Haggerty, J.

    1996-01-01

    Fracture toughnesses of brittle ceramic materials have been improved by introducing reinforcements and carefully tailored interface layers. Silicon carbide and Si3N4 have been emphasized as matrices of structural composites intended for high temperature service because they combine excellent mechanical, chemical, thermal and physical properties. Both matrices have been successfully toughened with SiC fibers, whiskers and particles for ceramic matrix composite (CMC) parts made by sintering, hot pressing or reaction forming processes. These SiC reinforced CMCs have exhibited significantly improved toughnesses at low and intermediate temperature levels, as well as retention of properties at high temperatures for selected exposures; however, they are vulnerable to attack from elevated temperature dry and wet oxidizing atmospheres after the matrix has cracked. Property degradation results from oxidation of interface layers and/or reinforcements. The problem is particularly acute for small diameter (-20 tim) polymer derived SiC fibers used for weavable toes. This research explored opportunities for reinforcing Si3N4 matrices with fibers having improved environmental stability; the findings should also be applicable to SiC matrix CMCs.

  16. Creep of experimental short fiber-reinforced composite resin.

    PubMed

    Garoushi, Sufyan; Kaleem, Muhammad; Shinya, Akikazu; Vallittu, Pekka K; Satterthwaite, Julian D; Watts, David C; Lassila, Lippo V J

    2012-01-01

    The purpose of this study was to investigate the reinforcing effect of short E-glass fiber fillers oriented in different directions on composite resin under static and dynamic loading. Experimental short fiber-reinforced composite resin (FC) was prepared by mixing 22.5 wt% of short E-glass fibers, 22.5 wt% of resin, and 55 wt% of silane-treated silica fillers. Three groups of specimens (n=5) were tested: FC with isotropic fiber orientation, FC with anisotropic fiber orientation, and particulate-filled composite resin (PFC) as a control. Time-dependent creep and recovery were recorded. ANOVA revealed that after secondary curing in a vacuum oven and after storage in dry condition for 30 days, FC with isotropic fiber orientation (1.73%) exhibited significantly lower static creep value (p<0.05) than PFC (2.54%). For the different curing methods and storage conditions evaluated in this study, FC achieved acceptable static and dynamic creep values when compared to PFC. PMID:23037835

  17. Tungsten fiber reinforced copper matrix composites: A review

    NASA Technical Reports Server (NTRS)

    Mcdanels, David L.

    1989-01-01

    Tungsten fiber reinforced copper matrix (W/Cu) composites have served as an ideal model system with which to analyze the properties of metal matrix composites. A series of research programs were conducted to investigate the stress-strain behavior of W/Cu composites; the effect of fiber content on the strength, modulus, and conductivity of W/Cu composites; and the effect of alloying elements on the behavior of tungsten wire and of W/Cu composites. Later programs investigated the stress-rupture, creep, and impact behavior of these composites at elevated temperatures. Analysis of the results of these programs as allows prediction of the effects of fiber properties, matrix properties, and fiber content on the properties of W/Cu composites. These analyses form the basis for the rule-of-mixtures prediction of composite properties which was universally adopted as the criteria for measuring composite efficiency. In addition, the analyses allows extrapolation of potential properties of other metal matrix composites and are used to select candidate fibers and matrices for development of tungsten fiber reinforced superalloy composite materials for high temperature aircraft and rocket engine turbine applications. The W/Cu composite efforts are summarized, some of the results obtained are described, and an update is provided on more recent work using W/Cu composites as high strength, high thermal conductivity composite materials for high heat flux, elevated temperature applications.

  18. A micromorphic model for steel fiber reinforced concrete.

    PubMed

    Oliver, J; Mora, D F; Huespe, A E; Weyler, R

    2012-10-15

    A new formulation to model the mechanical behavior of high performance fiber reinforced cement composites with arbitrarily oriented short fibers is presented. The formulation can be considered as a two scale approach, in which the macroscopic model, at the structural level, takes into account the mesostructural phenomenon associated with the fiber-matrix interface bond/slip process. This phenomenon is contemplated by including, in the macroscopic description, a micromorphic field representing the relative fiber-cement displacement. Then, the theoretical framework, from which the governing equations of the problem are derived, can be assimilated to a specific case of the material multifield theory. The balance equation derived for this model, connecting the micro stresses with the micromorphic forces, has a physical meaning related with the fiber-matrix bond slip mechanism. Differently to previous procedures in the literature, addressed to model fiber reinforced composites, where this equation has been added as an additional independent ingredient of the methodology, in the present approach it arises as a natural result derived from the multifield theory. Every component of the composite is defined with a specific free energy and constitutive relation. The mixture theory is adopted to define the overall free energy of the composite, which is assumed to be homogeneously constituted, in the sense that every infinitesimal volume is occupied by all the components in a proportion given by the corresponding volume fraction. The numerical model is assessed by means of a selected set of experiments that prove the viability of the present approach. PMID:24049211

  19. Active vibration control of a smart pultruded fiber-reinforced polymer I-beam

    NASA Astrophysics Data System (ADS)

    Song, Gangbing; Qiao, Pizhong; Sethi, Vineet; Prasad, A.

    2002-06-01

    Advanced and innovative materials and structures are increasingly used in civil infrastructure applications. By combining the advantages of composites and smart sensors and actuators, active or smart composite structures can be created and be efficiently adopted in practical structural applications. This paper presents results of active vibration control of a pultruded fiber-reinforced polymer (FRP) composites thin-walled I-beams using smart sensors and actuators. The FRP I-beams are made of E-glass fibers and polyester resins. The FRP I-beam is in a cantilevered configuration. PZT (Lead zirconate titanate) type of piezoelectric ceramic patches are used as smart sensors and actuators. These patches are surface-bonded near the cantilevered end of the I-beam. Utilizing results from modal analyses and experimental modal testing, several active vibration control methods, such as position feedback control, strain rate feedback control and lead compensator, are investigated. Experimental results demonstrate that the proposed methods achieve effective vibration control of FRP I-beams. For instance, the modal damping ratio of the strong direction first bending mode increases by more than 1000 percent with a positive position feedback control.

  20. Active vibration control of a smart pultruded fiber-reinforced polymer I-beam

    NASA Astrophysics Data System (ADS)

    Song, G.; Qiao, P.; Sethi, V.; Prasad, A.

    2004-08-01

    Advanced and innovative materials and structures are increasingly used in civil infrastructure applications. By combining the advantages of composites and smart sensors and actuators, active or smart composite structures can be created and be efficiently adopted in practical structural applications. This paper presents results on active vibration control of pultruded fiber-reinforced polymer (FRP) composite thin-walled I-beams using smart sensors and actuators. The FRP I-beams are made of E-glass fibers and polyester resins. The FRP I-beam is in a cantilevered configuration. The PZT (lead zirconate titanate) type of piezoelectric ceramic patches are used as smart sensors and actuators. These patches are surface bonded near the cantilevered end of the I-beam. Utilizing results from modal analyses and experimental modal testing, several active vibration control methods, such as position feedback control, strain rate feedback control and lead compensation, are investigated. Experimental results demonstrate that the proposed methods achieve effective vibration control of FRP I-beams. For instance, the modal damping ratio of the strong direction first bending mode increases by more than 1000% with positive position feedback control.

  1. Discontinuous Fiber-reinforced Composites above Critical Length

    PubMed Central

    Petersen, R.C.

    2014-01-01

    Micromechanical physics of critical fiber length, describing a minimum filament distance for resin impregnation and stress transfer, has not yet been applied in dental science. As a test of the hypothesis that 9-micron-diameter, 3-mm-long quartz fibers would increase mechanical strength over particulate-filled composites, photocure-resin-pre-impregnated discontinuous reinforcement was incorporated at 35 wt% into 3M Corporation Z100, Kerr Corporation HerculiteXRV, and an experimental photocure paste with increased radiopaque particulate. Fully articulated four-point bend testing per ASTM C 1161-94 for advanced ceramics and Izod impact testing according to a modified unnotched ASTM D 256-00 specification were then performed. All photocure-fiber-reinforced composites demonstrated significant improvements over particulate-filled compounds (p < 0.001) for flexural strength, modulus, work of fracture, strain at maximum load, and Izod toughness, with one exception for the moduli of Z100 and the experimental reinforced paste. The results indicate that inclusion of pre-impregnated fibers above the critical aspect ratio yields major advancements regarding the mechanical properties tested. PMID:15790745

  2. SiC Fiber-Reinforced Celsian Composites

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P.

    2003-01-01

    Celsian is a promising matrix material for fiber-reinforced composites for high temperature structural applications. Processing and fabrication of small diameter multifilament silicon carbide tow reinforced celsian matrix composites are described. Mechanical and microstructural properties of these composites at ambient and elevated temperatures are presented. Effects of high-temperature exposures in air on the mechanical behavior of these composites are also given. The composites show mechanical integrity up to 1100 C but degrade at higher temperatures in oxidizing atmospheres. A model has been proposed for the degradation of these composites in oxidizing atmospheres at high temperatures.

  3. History of reinforced plastics

    SciTech Connect

    Milewski, J.V.; Rosato, D.V.

    1981-01-01

    This history of reinforced plastics is told by combining the individual histories of each reinforcement and the way in which they added to and changed the direction and rate of growth of the industry. The early history is based on all resins, fillers, and fibers found in nature. Then came the Baekeland revolution with the first synthetic resin which lasted about 25 years, at which time synthetic fiber glass and polyester resin dramatically changed the industry. Now, for the 1980s, the high modulus fibers developed 10 to 20 years ago are reshaping the industry. 32 figures.

  4. Strength variability in alumina fiber-reinforced aluminum matrix composites

    SciTech Connect

    Ramamurty, U.; Zok, F.W.; Leckie, F.A.; Deve, H.E.

    1997-11-01

    The strength variability of an Al-2% Cu alloy matrix reinforced with 65 vol.% Nextel-610 Al{sub 2}O{sub 3} fibers has been investigated, with the aim of identifying and separating the contributions associated with the variabilities in both the fiber bundle strength and the fiber volume fraction. Strength distributions have been measured using three test geometries, including three- and four-point flexure and unixaxial tension. The measured distributions are rationalized on the basis of a fiber strength distribution that follows Weibull statistics and a fiber volume fraction distribution characterized by a Gaussian. The fiber bundle strength distribution is found to be extremely narrow, with a Weibull modulus in the range of {approximately}50--60. In addition, the coefficient of variation in the fiber volume fraction distribution is inferred to be {approximately}6%; by comparison, measurements made on relatively large specimens yield a coefficient of variation of {approximately}3%. The differences in these values are attributed to local volume fraction variations which are not detectable by the global measurements. The measured strengths are compared with the predicted values based on the theoretical work of Curtin and co-workers, incorporating the effects of local load sharing between broken fibers and their neighbors. Good correlations are obtained between the experimental data and the model predictions.

  5. Creep behavior of tungsten fiber reinforced niobium metal matrix composites

    NASA Technical Reports Server (NTRS)

    Grobstein, Toni L.

    1992-01-01

    Tungsten fiber reinforced niobium metal matrix composites were evaluated for use in space nuclear power conversion systems. The composite panels were fabricated using the arc-spray monotape technique at the NASA Lewis Research Center. The creep behavior of W/Nb composite material was determined at 1400 and 1500 K in vacuum over a wide range of applied loads. The time to reach 1 percent strain, the time to rupture, and the minimum creep rate were measured. The W/Nb composites exceeded the properties of monolithic niobium alloys significantly even when compared creep strength also was evaluated. Kirkendall void formation was observed at the fiber/matrix interface; the void distribution differed depending the fiber orientation relative to the stress axis. A relationship was found between the fiber orientation and the creep strength.

  6. New Fiber Reinforced Waterless Concrete for Extraterrestrial Structural Applications

    NASA Technical Reports Server (NTRS)

    Toutanji, H.; Tucker, D.; Ethridge, E.

    2005-01-01

    Commercial use of sulfur concrete on Earth is well established, particularly in corrosive, e.g., acid and salt, environments. Having found troilite (FeS) on the Moon raises the question of using extracted sulfur as a lunar construction mate: iii an attractive alternative to conventional concrete as it does not require water For the purpose of this paper it is assumed that lunar ore is mined, refined, and the raw sulfur processed with appropriate lunar regolith to form, for example, brick and beam elements. Glass fibers produced from regolith were used as a reinforcement to improve the mechanical properties of the sulfur concrete. Glass fibers and glass rebar were produced by melting the lunar regolith simulant. Lunar regolith stimulant was melted in a 25 cc Pt-Rh crucible in a Sybron Thermoline 46100 high temperature MoSi2 furnace at melting temperatures of 1450 to 1600G. The glass melt wets the ceramic rod and long continuous glass fibers were easily hand drawn. The glass fibers were immediately coated with a protective polymer to maintain the mechanical strength. The viability of sulfur concrete as a construction material for extraterrestrial application is presented. The mechanical properties of the glass fiber reinforced sulfur concrete were investigated.

  7. Anomaly detection of microstructural defects in continuous fiber reinforced composites

    NASA Astrophysics Data System (ADS)

    Bricker, Stephen; Simmons, J. P.; Przybyla, Craig; Hardie, Russell

    2015-03-01

    Ceramic matrix composites (CMC) with continuous fiber reinforcements have the potential to enable the next generation of high speed hypersonic vehicles and/or significant improvements in gas turbine engine performance due to their exhibited toughness when subjected to high mechanical loads at extreme temperatures (2200F+). Reinforced fiber composites (RFC) provide increased fracture toughness, crack growth resistance, and strength, though little is known about how stochastic variation and imperfections in the material effect material properties. In this work, tools are developed for quantifying anomalies within the microstructure at several scales. The detection and characterization of anomalous microstructure is a critical step in linking production techniques to properties, as well as in accurate material simulation and property prediction for the integrated computation materials engineering (ICME) of RFC based components. It is desired to find statistical outliers for any number of material characteristics such as fibers, fiber coatings, and pores. Here, fiber orientation, or `velocity', and `velocity' gradient are developed and examined for anomalous behavior. Categorizing anomalous behavior in the CMC is approached by multivariate Gaussian mixture modeling. A Gaussian mixture is employed to estimate the probability density function (PDF) of the features in question, and anomalies are classified by their likelihood of belonging to the statistical normal behavior for that feature.

  8. Fabrication Routes for Continuous Fiber-Reinforced Ceramic Composites (CFCC)

    NASA Technical Reports Server (NTRS)

    DiCarlo, James A.; Bansal, Narottam P.

    1998-01-01

    The primary approaches used for fabrication of continuous fiber-reinforced ceramic composite (CFCC) components have been reviewed. The CFCC fabrication issues related to fiber, interface, and matrix have been analyzed. The capabilities. advantages and limitations of the five matrix-infiltration routes have been compared and discussed. Today. the best fabrication route for the CFCC end-user is not clear and compromises need to be made depending on the details of the CFCC application. However, with time, this problem should be reduced as research continues to develop advanced CFCC constituents and fabrication routes.

  9. Fabrication Routes for Continuous Fiber-Reinforced Ceramic Composites (CFCC)

    NASA Technical Reports Server (NTRS)

    DiCarlo, James A.; Bansal, Narottam P.

    1998-01-01

    The primary approaches used for fabrication of continuous fiber-reinforced ceramic composite (CFCC) components have been reviewed. The CFCC fabrication issues related to fiber, interface, and matrix have been analyzed. The capabilities, advantages and limitations of the five matrix-infiltration routes have been compared and discussed. Today, the best fabrication route for the CFCC end-user is not clear and compromises need to be made depending on the details of the CFCC application. However, with time, this problem should be reduced as research continues to develop advanced CFCC constituents and fabrication routes.

  10. Graphite fiber reinforced structure for supporting machine tools

    DOEpatents

    Knight, Jr., Charles E.; Kovach, Louis; Hurst, John S.

    1978-01-01

    Machine tools utilized in precision machine operations require tool support structures which exhibit minimal deflection, thermal expansion and vibration characteristics. The tool support structure of the present invention is a graphite fiber reinforced composite in which layers of the graphite fibers or yarn are disposed in a 0/90.degree. pattern and bonded together with an epoxy resin. The finished composite possesses a low coefficient of thermal expansion and a substantially greater elastic modulus, stiffness-to-weight ratio, and damping factor than a conventional steel tool support utilized in similar machining operations.