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1

Quantitative nondestructive evaluation: Requirements for tomorrow's reliability  

NASA Technical Reports Server (NTRS)

Quantitative Nondestructive Evaluation (QNDE) is the technology of measurement, analysis, and prediction of the state of material/structural systems for safety, reliability, and mission assurance. QNDE has impact on everyday life from the cars we drive, the planes we fly, the buildings we work or live in, literally to the infrastructure of our world. Here, researchers highlight some of the new sciences and technologies that are part of a safer, cost effective tomorrow. Specific technologies that are discussed are thermal QNDE of aircraft structural integrity, ultrasonic QNDE for materials characterization, and technology spinoffs from aerospace to the medical sector. In each case, examples are given of how new requirements result in enabling measurement technologies, which in turn change the boundaries of design/practice.

Heyman, Joseph S.

1991-01-01

2

Dual-band infrared thermography for quantitative nondestructive evaluation  

Microsoft Academic Search

The authors have developed dual-band infrared (DBIR) thermography that is being applied to quantitative nondestructive evaluation (NDE) of aging aircraft. The DBIR technique resolves 0.2 degrees C surface temperature differences for inspecting interior flaws in heated aircraft structures. It locates cracks, corrosion sites, disbonds or delaminations in metallic laps and composite patches. By removing clutter from surface roughness effects, the

P. F. Durbin; N. K. Del Grande; K. W. Dolan; D. E. Perkins; A. B. Shapiro

1993-01-01

3

Quantitative nondestructive evaluation of materials and structures  

NASA Technical Reports Server (NTRS)

An experimental investigation was undertaken to quantify damage tolerance and resistance in composite materials impacted using the drop-weight method. Tests were conducted on laminates of several different carbon-fiber composite systems, such as epoxies, modified epoxies, and amorphous and semicrystalline thermoplastics. Impacted composite specimens were examined using destructive and non-destructive techniques to establish the characteristic damage states. Specifically, optical microscopy, ultrasonic, and scanning electron microscopy techniques were used to identify impact induced damage mechanisms. Damage propagation during post impact compression was also studied.

Smith, Barry T.

1991-01-01

4

Nondestructive evaluation  

SciTech Connect

Research reported in the thrust area of nondestructive evaluation includes: advanced 3-D imaging technologies; new techniques in laser ultrasonic testing; infrared computed tomography for thermal NDE of materials, structures, sources, and processes; automated defect detection for large laser optics; multistatic micropower impulse radar imaging for nondestructive evaluation; and multi-modal NDE for AVLIS pod shielding components.

Martz, H.E.

1997-02-01

5

Advanced quantitative magnetic nondestructive evaluation methods - Theory and experiment  

NASA Technical Reports Server (NTRS)

The paper reviews the scale of fatigue crack phenomena in relation to the size detection capabilities of nondestructive evaluation methods. An assessment of several features of fatigue in relation to the inspection of ball and roller bearings suggested the use of magnetic methods; magnetic domain phenomena including the interaction of domains and inclusions, and the influence of stress and magnetic field on domains are discussed. Experimental results indicate that simplified calculations can be used to predict many features of these results; the data predicted by analytic models which use finite element computer analysis predictions do not agree with respect to certain features. Experimental analyses obtained on rod-type fatigue specimens which show experimental magnetic measurements in relation to the crack opening displacement and volume and crack depth should provide methods for improved crack characterization in relation to fracture mechanics and life prediction.

Barton, J. R.; Kusenberger, F. N.; Beissner, R. E.; Matzkanin, G. A.

1979-01-01

6

Quantitative Nondestructive Evaluation of Automotive Glass Fiber Composites  

Microsoft Academic Search

Thermographic, ultrasonic and acoustic emission nondestructive evalua tion (NDE) characterizations of flawed and unflawed SMC-R25, SMC-R50 and XMC-3 composites are conducted. For various flawed and unflawed states of the composites, these NDE characterizations are correlated with both flaw state and tensile fracture strength. Drilled-holes and V-notch flaws of various sizes result in correspondingly lower tensile strengths; however, in creases in

James H. Williams; Samson S. Lee; Tony K. Wang

1982-01-01

7

Review of progress in quantitative NDE. [Nondestructive Evaluation (NDE)  

SciTech Connect

This booklet is composed of abstracts from papers submitted at a meeting on quantitative NDE. A multitude of topics are discussed including analysis of composite materials, NMR uses, x-ray instruments and techniques, manufacturing uses, neural networks, eddy currents, stress measurements, magnetic materials, adhesive bonds, signal processing, NDE of mechanical structures, tomography,defect sizing, NDE of plastics and ceramics, new techniques, optical and electromagnetic techniques, and nonlinear techniques. (GHH)

Not Available

1991-01-01

8

Quantitative magneto-optic imager for nondestructive evaluation  

NASA Astrophysics Data System (ADS)

Magneto-Optical Imagers (MOI) appear to be good alternatives to conventional eddy current sensors for defect detection in large metallic structures. Indeed, they allow short time inspection of large structures such as airplanes fuselage or wings, thanks to the visualization of "real time" images relative to the presence of defects [1]. The basic principle of the MOI is to combine a magnetic inductor, used to induce the circulation of eddy currents into the structure under test, with an optical set-up used to image the resultant magnetic field, thanks to the Faraday effect occurring in a magneto-optical garnet. The MOI designed by G. L. Fitzpatrick and Physical Research Instrumentation provides two-level images relative to the presence of defects, with an adjustable detection threshold. These so-called qualitative images, although highly contrasted, are rather poor and limited in terms of defect characterization possibilities. In, this paper, the authors present a new kind of MOI, called Quantitative Magneto-Optical Imager (Q-MOI), based on the use of a dedicated "linear" magneto-optical garnet associated with a specific instrumentation. The Q-MOI should considerably reduce the inspection time and allow to fully characterize the encountered defects. First images obtained with a demonstration prototype are shown for surface and buried flaws and further enhancements of the device are proposed.

Pinassaud, Jean; Joubert, Pierre-Yves; Lemistre, Michel

2005-05-01

9

Review of progress in quantitative nondestructive evaluation. Vols. 9A 9B  

SciTech Connect

Various papers on quantitative nondestructive evaluation are presented. The general topics addressed include: fundamentals of elastic wave scattering and flaw sizing, elastic wave propagation, and eddy currents; advanced techniques in computed tomography, laser-based methods, and other new techniques; interpretative signal and image processing in neural networks and other applications; ultrasonic transducers and inductive probes; instruments and systems. Also discusssed are electronic and ceramic materials and their applications to smart structures, adhesive joints, metal-metal joints, composites, and defects in composites; characterization of the properties, nonlinear acoustic properties, deformation and fracture properties, acoustoelasticity stress and texture of materials, including ferrous and civil materials and structures; manufacturing and process control.

Thompson, D.O.; Chimenti, D.E. (Ames Lab., IA (United States) Iowa State Univ., Ames (United States) John Hopkins Univ., Baltimore, MD (United States))

1990-01-01

10

Nondestructive evaluations  

NASA Astrophysics Data System (ADS)

This report discusses Nondestructive Evaluation (NDE) thrust area which supports initiatives that advance inspection science and technology. The goal of the NDE thrust area is to provide cutting-edge technologies that have promise of inspection tools three to five years in the future. In selecting projects, the thrust area anticipates the needs of existing and future Lawrence Livermore National Laboratory (LLNL) programs. NDE provides materials characterization inspections, finished parts, and complex objects to find flaws and fabrication defects and to determine their physical and chemical characteristics. NDE also encompasses process monitoring and control sensors and the monitoring of in-service damage. For concurrent engineering, NDE becomes a frontline technology and strongly impacts issues of certification and of life prediction and extension. In FY-92, in addition to supporting LLNL programs and the activities of nuclear weapons contractors, NDE has initiated several projects with government agencies and private industries to study aging infrastructures and to advance manufacturing processes. Examples of these projects are (1) the Aging Airplanes Inspection Program for the Federal Aviation Administration, (2) Signal Processing of Acoustic Signatures of Heart Valves for Shiley, Inc., and (3) Turbine Blade Inspection for the Air Force, jointly with Southwest Research Institute and Garrett. In FY-92, the primary contributions of the NDE thrust area, described in this report, were in fieldable chemical sensor systems, computed tomography, and laser generation and detection of ultrasonic energy.

Kulkarni, S.

1993-03-01

11

Proceedings of the DARPA/AFML Review of Progress in Quantitative Nondestructive Evaluation, 8-13 July, La Jolla, California.  

National Technical Information Service (NTIS)

The edited transcripts of the DARPA/AF Review of Progress in Quantitative Nondestructive Evaluation (NDE) held on July 8-13, 1979, at Scripps Institution of Oceanography, La Jolla, California, are presented in this document. Several key topics form the co...

D. O. Thompson R. B. Thompson

1980-01-01

12

Active thermography as a quantitative method for non-destructive evaluation of porous carbon fiber reinforced polymers  

Microsoft Academic Search

In this work active thermography was successfully applied as a quantitative method for the non-destructive evaluation of porosity in carbon fiber reinforced polymers. Results showed that not only the level of porosity, but also the shape of the pores strongly influences the active thermography results, in particular the measured thermal diffusivity. In an experiment the shape of the pores was

G. Mayr; B. Plank; J. Sekelja; G. Hendorfer

2011-01-01

13

Physical interpretation and development of ultrasonic nondestructive evaluation techniques applied to the quantitative characterization of textile composite materials  

NASA Technical Reports Server (NTRS)

In this Progress Report, we describe our current research activities concerning the development and implementation of advanced ultrasonic nondestructive evaluation methods applied to the characterization of stitched composite materials and bonded aluminum plate specimens. One purpose of this investigation is to identify and characterize specific features of polar backscatter interrogation which enhance the ability of ultrasound to detect flaws in a stitched composite laminate. Another focus is to explore the feasibility of implementing medical linear array imaging technology as a viable ultrasonic-based nondestructive evaluation method to inspect and characterize bonded aluminum lap joints. As an approach to implementing quantitative ultrasonic inspection methods to both of these materials, we focus on the physics that underlies the detection of flaws in such materials.

Miller, James G.

1993-01-01

14

Ultrasonic Nondestructive Evaluation Techniques Applied to the Quantitative Characterization of Textile Composite Materials  

NASA Technical Reports Server (NTRS)

In this Progress Report, we describe our further development of advanced ultrasonic nondestructive evaluation methods applied to the characterization of anisotropic materials. We present images obtained from experimental measurements of ultrasonic diffraction patterns transmitted through water only and transmitted through water and a thin woven composite. All images of diffraction patterns have been included on the accompanying CD-ROM in the JPEG format and Adobe TM Portable Document Format (PDF), in addition to the inclusion of hardcopies of the images contained in this report. In our previous semi-annual Progress Report (NAG 1-1848, December, 1996), we proposed a simple model to simulate the effect of a thin woven composite on an insonifying ultrasonic pressure field. This initial approach provided an avenue to begin development of a robust measurement method for nondestructive evaluation of anisotropic materials. In this Progress Report, we extend that work by performing experimental measurements on a single layer of a five-harness biaxial woven composite to investigate how a thin, yet architecturally complex, material interacts with the insonifying ultrasonic field. In Section 2 of this Progress Report we describe the experimental arrangement and methods for data acquisition of the ultrasonic diffraction patterns upon transmission through a thin woven composite. We also briefly describe the thin composite specimen investigated. Section 3 details the analysis of the experimental data followed by the experimental results in Section 4. Finally, a discussion of the observations and conclusions is found in Section 5.

Miller, James G.

1997-01-01

15

Ultrasonic Nondestructive Evaluation Techniques Applied to the Quantitative Characterization of Textile Composite Materials  

NASA Technical Reports Server (NTRS)

An overall goal of this research has been to enhance our understanding of the scientific principles necessary to develop advanced ultrasonic nondestructive techniques for the quantitative characterization of advanced composite structures. To this end, we have investigated a thin woven composite (5-harness biaxial weave). We have studied the effects that variations of the physical parameters of the experimental setup can have on the ultrasonic determination of the material properties for this thin composite. In particular, we have considered the variation of the nominal center frequency and the f-number of the transmitting transducer which in turn address issues such as focusing and beam spread of ultrasonic fields. This study has employed a planar, two-dimensional, receiving pseudo-array that has permitted investigation of the diffraction patterns of ultrasonic fields. Distortion of the ultrasonic field due to the spatial anisotropy of the thin composite has prompted investigation of the phenomenon of phase cancellation at the face of a finite-aperture, piezoelectric receiver. We have performed phase-sensitive and phase-insensitive analyses to provide a measure of the amount of phase cancellation at the face of a finite-aperture, piezoelectric receiver. The pursuit of robust measurements of received energy (i.e., those not susceptible to phase cancellation at the face of a finite-aperture, piezoelectric receiver) supports the development of robust techniques to determine material properties from measure ultrasonic parameters.

Miller, James G.

1998-01-01

16

A Bayesian quantitative nondestructive evaluation (QNDE) approach to estimating remaining life of aging pressure vessels and piping*  

NASA Astrophysics Data System (ADS)

In this paper, we use a Bayesian quantitative nondestructive evaluation (QNDE) approach to estimating the remaining life of aging structures and components. Our approach depends on in-situ NDE measurements of detectable crack lengths and crack growth rates in a multi-crack region of an aging component as a basis for estimating the mean and standard deviation of its remaining life. We introduce a general theory of crack growth involving multiple cracks such that the mean and standard deviation of the initial crack lengths can be directly estimated from NDEmeasured crack length data over a period of several inspection intervals. A numerical example using synthetic NDE data for high strength steels is presented to illustrate this new methodology.

Fong, J. T.; Filliben, J. J.; Heckert, N. A.; Guthrie, W. F.

2013-01-01

17

Quantitative nondestructive in-service evaluation of stay cables of cable-stayed bridges: methods and practical experience  

NASA Astrophysics Data System (ADS)

Stay cables of cable-stayed bridges have corrosion protection systems that can be elaborate. For example, such a system may simply consist of one or several coats of paint, or--more complex--of plastic pipes that are wrapped with tape and filled with grout. Frequently, these corrosion protection systems prevent visual inspections. Therefore, alternative nondestructive examination methods are called for. For example, modern dual-function electromagnetic (EM) instruments allow the simultaneous detection of external and internal localized flaws (such as external and internal broken wires and corrosion piting) and the measurement of loss of metallic cross-sectional area (typically caused by external or internal corrosion or wear). Initially developed for mining and skiing applications, these instruments have been successfully used for the inspection of stays of cable-stayed bridges, and for the inspection of guys of smoke stacks, flare stacks, broadcast towers, suspended roofs, etc. As a rule, guys and bridge cables are not subjected to wear and bending stresses. However, their safety can be compromised by corrosion caused by the failure of corrosion protection systems. Furthermore, live loads and wind forces create intermittent tensile stresses that can cause fatigue breaks of wires. This paper discusses the use of dual-function EM instruments for the detection and the nondestructive quantitative evaluation of cable deterioration. It explains the underlying principles. Experiences with this method together with field inspection results will be presented.

Weischedel, Herbert R.; Hoehle, Hans-Werner

1995-05-01

18

[Nondestructive Evaluation (NDE) Capabilities  

NASA Technical Reports Server (NTRS)

These poster boards display the United Space Alliance's (USA) systems and equipment used for Nondestructive Evaluation. These include: (1) the Robotic Inspection Facility, (2) CAT-Scan and Laminography, (3) Laser Surface Profilometry, (4) Remote Eddy Current, (5) Ultrasonic Phased Array, (7) Infrared Flash Thermography, and (8) Backscatter X-Ray (BSX)

Born, Martin

2010-01-01

19

Ultrasonic Nondestructive Evaluation Techniques Applied to the Quantitative Characterization of Textile Composite Materials  

NASA Technical Reports Server (NTRS)

In this Progress Report, we describe our recent developments of advanced ultrasonic nondestructive evaluation methods applied to the characterization of anisotropic materials. We present images obtained from experimental measurements of ultrasonic diffraction patterns for a thin woven composite in an immersion setup. In addition, we compare apparent signal loss measurements of the thin woven composite for phase-sensitive and phase-insensitive detection methods. All images of diffraction patterns have been included on the accompanying CD-ROM in the Adobe(Trademark) Portable Document Format (PDF). Due to the extensive amount of data, however, hardcopies of only a small representative selection of the images are included within the printed report. This Progress Report presents experimental results that support successful implementation of single element as well as one and two-dimensional ultrasonic array technologies for the inspection of textile composite structures. In our previous reports, we have addressed issues regarding beam profiles of ultrasonic pressure fields transmitted through a water reference path and transmitted through a thin woven composite sample path. Furthermore, we presented experimental results of the effect of a thin woven composite on the magnitude of an insonifying ultrasonic pressure field. In addition to the study of ultrasonic beam profiles, we consider issues relevant to the application of single-element, one-dimensional, and two-dimensional array technologies towards probing the mechanical properties of advanced engineering composites and structures. We provide comparisons between phase-sensitive and phase-insensitive detection methods for determination of textile composite structure parameters. We also compare phase-sensitive and phase-insensitive - - ---- ----- apparent signal loss measurements in an effort to study the phenomenon of phase cancellation at the face of a finite-aperture single-element receiver. Furthermore, in this Progress Report we extend our work on ultrasonic beam profile issues through investigation of the phase fronts of the pressure field. In Section H of this Progress Report we briefly describe the experimental arrangement and methods for data acquisition of the ultrasonic diffraction patterns upon transmission through a thin woven composite. Section III details the analysis of the experimental data followed by the experimental results in Section IV. Finally, a discussion of the observations and conclusions is found in Section V.

Miller, James G.

1997-01-01

20

Review of progress in quantitative nondestructive evaluation. Vol. 11B; Proceedings of the 18th Annual Review, Brunswick, ME, July 28-Aug. 2, 1991 Vol. 11B  

SciTech Connect

The present volume on progress in quantitative nondestructive evaluation discusses the application of guided acoustic waves to delamination deduction, an ultrasonic evaluation of environmentally degraded adhesive joints, an assessment of aircraft structural integrity by the detection of disbonds through ultrasonic scanning, and an ultrasonic scanning technique for the quantitative determination of the cohesive properties of adhesive joints. Attention is given to the detection of a weak adhesive/adherend interface in bonded joints by ultrasonic reflection measurements, an LF ultrasonic-spectroscopy technique for NDE of adhesive joints, a quantitative nondestructive evaluation of adhesive lap joints in a sheet molding compound by adaptation of a commercial bond tester, and an ultrasonic testing technique or measurement of the Poisson's ratio of thin adhesive layers. Topics addressed include physically based feature mapping concepts in bond interface evaluation and the examination of adhesive bonds using optically generated periodic surface acoustic waves.

Thompson, D.O.; Chimenti, D.E.

1992-01-01

21

Advances in nondestructive evaluation technology  

NASA Technical Reports Server (NTRS)

Research at NASA Langley's Materials Characterization Instrumentation Section has followed the philosophy of improving the science base of nondestructive evaluation and advancing the state of the art of quantitative interpretability of physical measurements of materials. Details of several R&D programs choosen to highlight the last several years are given. Applications of these technologies are presented in the area of stress measurement, characterization of metal heat treatment, and evaluation of material internal structure. A second focus of the program is on quantitative transducers/measurements that have resulted in better data in irregular inhomogeneous materials such as composites. Examples are presented of new capabilities resulting from these advances that include fatigue and impact damage evaluation.

Heyman, J. S.

1982-01-01

22

Quantitative non-destructive evaluation of composite materials based on ultrasonic wave propagation  

NASA Technical Reports Server (NTRS)

The size, shape, and orientation of damage correlates well between the polar backscatter technique and the deply technique. There is good quantitative correlation between the areas of damage indicated by the two techniques. These results suggest that the polar backscatter technique is sensitive to specific orientations of damage. The polar backscatter technique provides a good qualitative image of the size and shape of the largest zone of damage in each of the principal orientations. A quantitative estimate of the extent of these largest damage zones is obtained from the polar backscatter technique. The selective sensitivity of polar backscatter provides a useful tool for further studies of the mechanisms of impact damage in graphite fiber reinforced composite laminates.

Miller, J. G.

1984-01-01

23

Quantitative non-destructive evaluation of porous composite materials based on ultrasonic wave propagation  

NASA Technical Reports Server (NTRS)

Two complementary ultrasonic techniques for characterizing porosity in fiber-reinforced composite laminates are evaluated. Five uniaxial graphite-fiber/epoxy-matrix composites having a range of 1 to 8 percent volume fraction of solid glass inclusions to model porosity were investigated. In one technique, signal loss was measured in transmission mode and slope of attenuation, obtained from the first order coefficient of a two-parameter polynomial fit about the center frequency of the useful bandwidth, was used as the ultrasonic parameter to characterize the porosity. The results of these transmission mode measurements displayed a good correlation between the volume fraction of porosity and the slope of attenuation. Integrated polar backscatter was used as a second ultrasonic parameter for the characterization of the porosity in these samples. A single transducer insonified the samples and measured the resulting backscatter at a polar angle of 30 deg with respect to the normal of the sample surface with the azimuthal angles centered at 0 deg with respect to the fiber orientation (i.e., along the fibers). Integrated polar backscatter also displayed good correlation with the volume fraction of porosity.

Miller, James G.

1988-01-01

24

Nondestructive evaluation technique guide  

NASA Technical Reports Server (NTRS)

A total of 70 individual nondestructive evaluation (NDE) techniques are described. Information is presented that permits ease of comparison of the merits and limitations of each technique with respect to various NDE problems. An NDE technique classification system is presented. It is based on the system that was adopted by the National Materials Advisory Board (NMAB). The classification system presented follows the NMAB system closely with the exception of additional categories that have been added to cover more advanced techniques presently in use. The rationale of the technique is explained. The format provides for a concise description of each technique, the physical principles involved, objectives of interrogation, example applications, limitations of each technique, a schematic illustration, and key reference material. Cross-index tabulations are also provided so that particular NDE problems can be referred to appropriate techniques.

Vary, A.

1973-01-01

25

Physical interpretation and development of ultrasonic nondestructive evaluation techniques applied to the quantitative characterization of textile composite materials  

NASA Technical Reports Server (NTRS)

The development and implementation of advanced ultrasonic nondestructive evaluation methods applied to the characterization of composite materials requires a better understanding of the physics underlying the interaction of ultrasound with the material. The purpose of this investigation is to identify and characterize the features of complex, three dimensional materials that limit the ability of ultrasound to detect flaws in this broad class of emerging materials. In order to explore the interaction of ultrasound with such complex media, we investigate the characteristics of ultrasonic fields which have propagated through samples with complex geometries and/or internal architecture. We focus on the physics that underlies the detection of flaws in such materials.

Miller, James G.

1992-01-01

26

Physical interpretation and development of ultrasonic nondestructive evaluation techniques applied to the quantitative characterization of textile composite materials  

NASA Technical Reports Server (NTRS)

In this Progress Report, we describe our continuing research activities concerning the development and implementation of advanced ultrasonic nondestructive evaluation methods applied to the inspection and characterization of complex composite structures. We explore the feasibility of implementing medical linear array imaging technology as a viable ultrasonic-based nondestructive evaluation method to inspect and characterize complex materials. As an initial step toward the application of linear array imaging technology to the interrogation of a wide range of complex composite structures, we present images obtained using an unmodified medical ultrasonic imaging system of two epoxy-bonded aluminum plate specimens, each with intentionally disbonded regions. These images are compared with corresponding conventional ultrasonic contact transducer measurements in order to assess whether these images can detect disbonded regions and provide information regarding the nature of the disbonded region. We present a description of a standoff/delay fixture which has been designed, constructed, and implemented on a Hewlett-Packard SONOS 1500 medical imaging system. This standoff/delay fixture, when attached to a 7.5 MHz linear array probe, greatly enhances our ability to interrogate flat plate specimens. The final section of this Progress Report describes a woven composite plate specimen that has been specially machined to include intentional flaws. This woven composite specimen will allow us to assess the feasibility of applying linear array imaging technology to the inspection and characterization of complex textile composite materials. We anticipate the results of this on-going investigation may provide a step toward the development of a rapid, real-time, and portable method of ultrasonic inspection and characterization based on linear array technology.

Miller, James G.

1994-01-01

27

Physical interpretation and development of ultrasonic nondestructive evaluation techniques applied to the quantitative characterization of textile composite materials  

NASA Technical Reports Server (NTRS)

In this Progress Report, the author describes the continuing research to explore the feasibility of implementing medical linear array imaging technology as a viable ultrasonic-based nondestructive evaluation method to inspect and characterize complex materials. Images obtained using an unmodified medical ultrasonic imaging system of a bonded aluminum plate sample with a simulated disbond region are presented. The disbond region was produced by adhering a piece of plain white paper to a piece of cellophane tape and applying the paper-tape combination to one of the aluminum plates. Because the area under the paper was not adhesively bonded to the aluminum plate, this arrangement more closely simulates a disbond. Images are also presented for an aluminum plate sample with an epoxy strip adhered to one side to help provide information for the interpretation of the images of the bonded aluminum plate sample containing the disbond region. These images are compared with corresponding conventional ultrasonic contact transducer measurements in order to provide information regarding the nature of the disbonded region. The results of this on-going investigation may provide a step toward the development of a rapid, real-time, and portable method of ultrasonic inspection and characterization based on linear array technology. In Section 2 of this Progress Report, the preparation of the aluminum plate specimens is described. Section 3 describes the method of linear array imaging. Sections 4 and 5 present the linear array images and results from contact transducer measurements, respectively. A discussion of the results are presented in Section 6.

Miller, James G.

1995-01-01

28

Reflection shearography for nondestructive evaluation  

NASA Astrophysics Data System (ADS)

Conventional nondestructive evaluation (NDE) techniques include visual inspection, eddy current scanning, ultrasonics, and fluorescent dye penetration. These techniques are limited to local evaluation, often miss small buried defects, and are useful only on polished surfaces. Advanced NDE techniques include laser ultrasonics, holographic interferometry, structural integrity monitoring, shearography, and thermography. A variation of shearography, employing reflective shearographic interferometry, has been developed. This new shearographic interferometer is discussed, together with models to optimize its performance and experiments demonstrating its use in NDE.

Kurtz, Russell M.; Piliavin, Michael A.; Pradhan, Ranjit D.; Aye, Tin M.; Savant, Gajendra D.; Jannson, Tomasz P.; Hergert, Steffen

2004-09-01

29

Overview of nondestructive evaluation technologies  

SciTech Connect

The infrastructure in the US and the world is aging. There is an increasing awareness of the need to assess the severity of the damage occurring to the infrastructure. Limited resources preclude the replacement of all structures that need repairs or have exceeded their life times. Methods to assess the amount and severity of damage are crucial to implementing a systematic, cost effective approach to repair and/or replace the damaged structures. The challenges of inspecting aging structures without impairing their usefulness rely on a variety of technologies and techniques for nondestructive evaluation (NDE). This paper will briefly describe several nondestructive evaluation technologies that are required for inspecting a variety of systems and structures.

Thomas, G.

1995-04-01

30

Magnetoresistive Sensors for Nondestructive Evaluation  

Microsoft Academic Search

New high-sensitivity solid-state magnetoresistive (MR) sensor technologies offer significant advantages in nondestructive evaluation (NDE) systems. A key advantage of MR sensors is a flat frequency response extending from dc to hundreds of MHz, making them particularly attractive for low-frequency and multi- frequency eddy current detection for deep-flaw detection and depth profiling. MR sensors are mass produced by thin film processing

Albrecht Jander; Carl Smith; Robert Schneider

31

Nondestructive evaluation of advanced ceramics  

NASA Technical Reports Server (NTRS)

A review is presented of Lewis Research Center efforts to develop nondestructive evaluation techniques for characterizing advanced ceramic materials. Various approaches involved the use of analytical ultrasonics to characterize monolythic ceramic microstructures, acousto-ultrasonics for characterizing ceramic matrix composites, damage monitoring in impact specimens by microfocus X-ray radiography and scanning ultrasonics, and high resolution computed X-ray tomography to identify structural features in fiber reinforced ceramics.

Klima, Stanley J.; Kautz, Harold E.

1988-01-01

32

Nondestructive evaluation of structural ceramics  

NASA Technical Reports Server (NTRS)

A review is presented on research and development of techniques for nondestructive evaluation and characterization of advanced ceramics for heat engine applications. Highlighted in this review are Lewis Research Center efforts in microfocus radiography, scanning laser acoustic microscopy (SLAM), scanning acoustic microscopy (SAM), scanning electron acoustic microscopy (SEAM), and photoacoustic microscopy (PAM). The techniques were evaluated by applying them to research samples of green and sintered silicon nitride and silicon carbide in the form of modulus-of-rupture bars containing seeded voids. Probabilities of detection of voids were determined for diameters as small as 20 microns for microfucus radiography, SLAM, and SAM. Strengths and limitations of the techniques for ceramic applications are identified. Application of ultrasonics for characterizing ceramic microstructures is also discussed.

Klima, Stanley J.; Baaklini, George Y.; Abel, Phillip B.

1987-01-01

33

Nondestructive evaluation of structural ceramics  

NASA Technical Reports Server (NTRS)

Research on nondestructive evaluation (NDE) of structural ceramics for heat engine applications is reviewed. Microfocus radiography and scanning laser acoustic microscopy are the NDE techniques highlighted. The techniques were applied to research samples of sintered silicon nitride and silicon carbide in the form of modulus-of-rupture (MOR) bars. The strength and limitations of the aforementioned techniques are given in terms of probablility of detection for voids in green and sintered MOR bars. Voids for this purpose were introduced by seeding green ceramic bars and characterizing each void in terms of its size, shape, location, and nature before and after sintering. The effects of material density, microstructure, surface finish, thickness, void depth, and size characteristics on detectability are summarized.

Vary, Alex

1986-01-01

34

Assessment of and standardization for quantitative nondestructive test  

NASA Technical Reports Server (NTRS)

Present capabilities and limitations of nondestructive testing (NDT) as applied to aerospace structures during design, development, production, and operational phases are assessed. It will help determine what useful structural quantitative and qualitative data may be provided from raw materials to vehicle refurbishment. This assessment considers metal alloys systems and bonded composites presently applied in active NASA programs or strong contenders for future use. Quantitative and qualitative data has been summarized from recent literature, and in-house information, and presented along with a description of those structures or standards where the information was obtained. Examples, in tabular form, of NDT technique capabilities and limitations have been provided. NDT techniques discussed and assessed were radiography, ultrasonics, penetrants, thermal, acoustic, and electromagnetic. Quantitative data is sparse; therefore, obtaining statistically reliable flaw detection data must be strongly emphasized. The new requirements for reusable space vehicles have resulted in highly efficient design concepts operating in severe environments. This increases the need for quantitative NDT evaluation of selected structural components, the end item structure, and during refurbishment operations.

Neuschaefer, R. W.; Beal, J. B.

1972-01-01

35

Nondestructive Evaluation of Aircraft and Spacecraft Wiring  

NASA Technical Reports Server (NTRS)

Spacecraft, and especially aircraft, often fry well past their original design lives and, therefore, the need to develop nondestructive evaluation procedures for inspection of vital structures in these craft is extremely important. One of the more recent problems is the degradation of wiring and wiring insulation. The present paper describes several nondestructive characterization methods which afford the possibility to detect wiring and insulation degradation in-situ prior to major problems with the safety of aircraft and spacecraft.

White, John E.; Tucholski, Edward J.; Green, Robert E., Jr.

2004-01-01

36

Electromagnetic Imaging Methods for Nondestructive Evaluation Applications  

PubMed Central

Electromagnetic nondestructive tests are important and widely used within the field of nondestructive evaluation (NDE). The recent advances in sensing technology, hardware and software development dedicated to imaging and image processing, and material sciences have greatly expanded the application fields, sophisticated the systems design and made the potential of electromagnetic NDE imaging seemingly unlimited. This review provides a comprehensive summary of research works on electromagnetic imaging methods for NDE applications, followed by the summary and discussions on future directions.

Deng, Yiming; Liu, Xin

2011-01-01

37

Advancing technologies and applications in nondestructive evaluation  

SciTech Connect

The methods used to inspect and evaluate materials, decides, and products are now based on imaging systems that collect digital data and process and interpret them through specially developed computer algorithms. Lawrence Livermore`s Nondestructive and Materials Evaluation Section has been developing a wide range of imaging systems, implementing them through a range of technologies, including digital radiography, computed tomography, machine vision, ultrasonics, and infrared computer thermography. Applications of these various technologies are described in the article. They demonstrate the range and increasing flexibility of the concept of nondestructive evaluation.

Logan, C.

1997-12-01

38

Nondestructive quantitative stress characterization of wire rope and steel cables  

NASA Astrophysics Data System (ADS)

This paper describes a new approach to nondestructive and quantitative characterization of residual and applied stress (absolute stress) on wire rope and steel cable. Examples are given from both field work as well as laboratory tests, including stress characterization of post-tensioning cables, bridge suspension cables, wire rope and thin strand steel wire. The approach is based on x-ray diffraction techniques. A detailed description of the results and the methodologies used to obtain them are provided.

Brauss, Michael E.; Pineault, James A.; Belassel, M.; Teodoropol, S. I.

1998-03-01

39

Nondestructive Evaluation (nde) of Damaged Structural Ceramics  

NASA Astrophysics Data System (ADS)

A combination of destructive and nondestructive testing methods was utilized to evaluate the impact velocity and energy conditions that caused fracture in alumina structural ceramics. Drop tower testing was used for low velocity impact with a high mass indenter and fragment simulating projectile testing was used for high velocity impact with a low mass projectile. The damaged samples were nondestructively evaluated using digital radiography and ultrasound C-scan imaging. The bulk damage detected by these techniques was compared to surface damage observed by visual inspection.

Brennan, R. E.; Green, W. H.; Sands, J. M.; Yu, J. H.

2009-03-01

40

Applications of Statistical Methods to Nondestructive Evaluation  

Microsoft Academic Search

Nondestructive evaluation (NDE) techniques are used widely in many manufacturing and operational areas of industry. NDE is a highly statistical science that has developed rapidly over the past decade with relatively little input from individuals with forma1 training in statistics. This review article describes some of the many methods and applications of NDE, including eddy-current methods for detecting fatigue in

Bryan D. Olin; William Q. Meeker

1996-01-01

41

Non-Destructive Evaluation of Aerospace Composites.  

National Technical Information Service (NTIS)

Five methods of non-destructive material evaluation (NDE) were used to inspect various forms of damage commonly found in aerospace fiberglass composites: voids, edge and sub-surface delaminations, surface burning, and cracking. The images produced by X-ra...

J. D. Johnson

2009-01-01

42

REVIEW ARTICLE: SQUIDs for nondestructive evaluation  

Microsoft Academic Search

We attempt a comprehensive review of all published research in nondestructive evaluation (NDE) performed with the superconducting quantum interference device (SQUID) magnetometer since the first work was reported in the mid-1980s. The SQUID is the most sensitive detector of magnetic flux known. The energy sensitivity of the SQUID may make it the most sensitive detector of any kind. The research

W. G. Jenks; S. S. H. Sadeghi; J. P. Wikswo Jr.

1997-01-01

43

Thermographic nondestructive evaluation: overview of recent progress  

Microsoft Academic Search

This paper presents a summary of recent research activities carried out at our laboratory in the field of Infrared Thermography for Nondestructive Evaluation (TNDE). First, we explore the latest developments in signal improvement. We describe three approaches: multiple pulse stimulation; the use of Synthetic Data for de-noising of the signal; and a new approach derived from the Fourier diffusion equation

Clemente Ibarra-Castanedo; Francois Galmiche; Akbar Darabi; Mariacristina Pilla; Matthieu Klein; Adel Ziadi; Steve Vallerand; Jean-François Pelletier; Xavier P. Maldague

2003-01-01

44

Ultrasonic wave attenuation measurement for nondestructive evaluation of concrete  

NASA Astrophysics Data System (ADS)

Various nondestructive evaluation methods using the propagating velocity and attenuation of an ultrasonic wave have been studied. The ultrasonic wave attenuation is more sensitive on evaluating to damage assessment in the medium than the ultrasonic wave velocity method. In this paper, the nondestructive evaluation technique using self-compensating frequency response function is proposed to measure the quantitative ultrasonic wave attenuation on cement-based materials. The proposed technique is able to measure inherent attenuation of material, not its relative attenuation. In advance, the reproducibility and relevancy of proposed technique are validated by an experimental comparison of conventional measurement and proposed ultrasonic wave attenuation measurement on cement-based material. In addition, the ultrasonic attenuation measurements are able to characterize the size distribution and volume fraction of entrained air voids in cement-based materials.

Yim, Hong Jae; Kim, Jae Hong; Kwak, Hyo-Gyoung

2010-03-01

45

Techniques for enhancing laser ultrasonic nondestructive evaluation  

SciTech Connect

Ultrasonic nondestructive evaluation is an extremely powerful tool for characterizing materials and detecting defects. A majority of the ultrasonic nondestructive evaluation is performed with piezoelectric transducers that generate and detect high frequency acoustic energy. The liquid needed to couple the high frequency acoustic energy from the piezoelectric transducers restricts the applicability of ultrasonics. For example, traditional ultrasonics cannot evaluate parts at elevated temperatures or components that would be damaged by contact with a fluid. They are developing a technology that remotely generates and detects the ultrasonic pulses with lasers and consequently there is no requirement for liquids. Thus the research in laser-based ultrasound allows them to solve inspection problems with ultrasonics that could not be done before. This technology has wide application in many Lawrence Livermore National Laboratory programs, especially when remote and/or non-contact sensing is necessary.

Candy, J; Chinn, D; Huber, R; Spicer, J; Thomas, G

1999-02-16

46

Nondestructive Evaluation of Adhesively Bonded Joints  

NASA Technical Reports Server (NTRS)

The final report consists of 5 published papers in referred journals and a technical letter to the technical monitor. These papers include the following: (1) Comparison of the effects of debonds and voids in adhesive; (2) On the peak shear stresses in adhesive joints with voids; (3) Nondestructive evaluation of adhesively bonded joints by acousto-ultrasonic technique and acoustic emission; (4) Multiaxial fatigue life evaluation of tubular adhesively bonded joints; (5) Theoretical and experimental evaluation of the bond strength under peeling loads. The letter outlines the progress of the research. Also included is preliminary information on the study of nondestructive evaluation of composite materials subjected to localized heat damage. The investigators studied the effects of localized heat on unidirectional fiber glass epoxy composite panels. Specimens of the fiber glass epoxy composites were subjected to 400 C heat for varying lengths of time. The specimens were subjected to nondestructive tests. The specimens were then pulled to their failure and acoustic emission of these specimens were measured. The analysis of the data was continuing as of the writing of the letter, and includes a finite element stress analysis of the problem.

Nayeb-Hashemi, Hamid; Rossettos, J. N.

1997-01-01

47

Magnetoresistive sensors for nondestructive evaluation (Invited Paper)  

Microsoft Academic Search

New high-sensitivity solid-state magnetoresistive (MR) sensor technologies offer significant advantages in nondestructive evaluation (NDE) systems. A key advantage of MR sensors is a flat frequency response extending from dc to hundreds of MHz, making them particularly attractive for low-frequency and multi-frequency eddy current detection for deep-flaw detection and depth profiling. MR sensors are mass produced by thin film processing techniques

Albrecht Jander; Carl Smith; Robert Schneider

2005-01-01

48

Nondestructive evaluation of steam traps  

Microsoft Academic Search

Many thermographers have touted infrared thermography as an effective maintenance tool for evaluating steam traps for years. However, several investigators have raised questions about thermal measurement's effectiveness in this application. This paper explores and compares infrared thermography and ultrasonic detection methods for steam trap testing and provides guidelines for a successful trap survey.

Gary L. Orlove

1999-01-01

49

Development of instrumentation for magnetic nondestructive evaluation  

SciTech Connect

The use of failure-prone components in critical applications has been traditionally governed by removing such components from service prior to the expiration of their predicted life expectancy. Such early retirement of materials does not guarantee that a particular sample will not fail in actual usage. The increasing cost of such life expectancy based operation and increased demand for improved reliability in industrial settings has necessitated an alternate form of quality control. Modern applications employ nondestructive evaluation (NDE), also known as nondestructive testing (NDT), as a means of monitoring the levels and growth of defects in a material throughout its operational life. This thesis describes the modifications made to existing instrumentation used for magnetic measurements at the Center for Nondestructive Evaluation at Iowa State University. Development of a new portable instrument is also given. An overview of the structure and operation of this instrumentation is presented. This thesis discusses the application of the magnetic hysteresis and Barkhausen measurement techniques, described in Sections 1.3.1 and 1.3.2 respectively, to a number of ferromagnetic specimens. Specifically, measurements were made on a number of railroad steel specimens for fatigue characterization, and on specimens of Damascus steel and Terfenol-D for materials evaluation. 60 refs., 51 figs., 5 tabs.

Hariharan, S.

1991-09-23

50

Nondestructive evaluation of sintered ceramics  

NASA Technical Reports Server (NTRS)

Radiography and several acoustic and thermoacoustic microscopy techniques are investigated for application to structural ceramics for advanced heat engines. A comparison is made of the results obtained from the use of scanning acoustic microscopy (SAM), scanning laser acoustic microscopy (SLAM), and thermoacoustic microscopy (TAM). These techniques are evaluated on research samples of green and sintered monolithic silicon nitrides and silicon carbides in the form of modulus-of-rupture (MOR) bars containing deliberately introduced flaws. Strengths and limitations of the techniques are described, with the emphasis being on statistics of detectability of flaws that constitute potential fracture origins. Further, it is shown that radiographic evaluation and guidance helped develop uniform high-density Si3N4 MOR bars with improved four-point flexural strength (875, 544, and 462 MPa at room temperature, 1200 C, 1370 C, respectively) and reduced scatter in bend strength.

Baaklini, George Y.; Klima, Stanley J.; Sanders, William A.

1988-01-01

51

Nondestructive evaluation by acousto-ultrasonics  

NASA Technical Reports Server (NTRS)

Acousto-ultrasonics is an ultrasonic technique that was originally devised to cope with the particular problems associated with nondestructive evaluation (NDE) of fiber/polymer composite structures. The fiber/polymer composites are more attenuating to ultrasound than any other material presently of interest. This limits the applicability of high-frequency ultrasonics. A common use of ultrasound is the imaging of flaws internal to a structure by scattering from the interface with the flaw. However, structural features of composites can scatter ultrasound internally, thus obscuring the flaws. A need relative to composites is to be able to nondestructively measure the strength of laminar boundaries in order to assess the integrity of a structure. Acousto-ultrasonics has exhibited the ability to use the internal scattering to provide information for determining the strength of laminar boundaries. Analysis of acousto-ultrasonic signals by the wave ray paths that compose it leads to waveform partitioning that enhances the sensitivity to mechanical strength parameters.

Kautz, Harold E.

1988-01-01

52

Simultaneous materials evaluation with both electronic shearography and infrared nondestructive evaluation  

Microsoft Academic Search

With the increasing use of advanced materials in the aerospace, automotive, and medical industries, improved nondestructive evaluation techniques are needed to meet industry requirements for quality and product reliability. Both shearography and infrared thermography are noncontact, single-sided inspection techniques that can provide quantitative information about a material's characteristics by means of passive or active excitation techniques. An experiment was conducted

Morteza Safai

1995-01-01

53

Simultaneous materials evaluation with both electronic shearography and infrared nondestructive evaluation  

NASA Astrophysics Data System (ADS)

With the increasing use of advanced materials in the aerospace, automotive, and medical industries, improved nondestructive evaluation techniques are needed to meet industry requirements for quality and product reliability. Both shearography and infrared thermography are noncontact, single-sided inspection techniques that can provide quantitative information about a material's characteristics by means of passive or active excitation techniques. An experiment was conducted using a focal plane array infrared camera and a traditional Michelson's shearing interferometric system. In this paper, the results of the experiment are discussed, and the advantages of using both shearography and thermography simultaneously for materials evaluation and nondestructive testing are presented.

Safai, Morteza

1995-01-01

54

Non-destructive assessment of human ribs mechanical properties using quantitative ultrasound.  

PubMed

Advanced finite element models of the thorax have been developed to study, for example, the effects of car crashes. While there is a need for material properties to parameterize such models, specific properties are largely missing. Non-destructive techniques applicable in vivo would, therefore, be of interest to support further development of thorax models. The only non-destructive technique available today to derive rib bone properties would be based on quantitative computed tomography that measures bone mineral density. However, this approach is limited by the radiation dose. Bidirectional ultrasound axial transmission was developed on long bones ex vivo and used to assess in vivo health status of the radius. However, it is currently unknown if the ribs are good candidates for such a measurement. Therefore, the goal of this study is to evaluate the relationship between ex vivo ultrasonic measurements (axial transmission) and the mechanical properties of human ribs to determine if the mechanical properties of the ribs can be quantified non-destructively. The results show statistically significant relationships between the ultrasonic measurements and mechanical properties of the ribs. These results are promising with respect to a non-destructive and non-ionizing assessment of rib mechanical properties. This ex vivo study is a first step toward in vivo studies to derive subject-specific rib properties. PMID:24581799

Mitton, David; Minonzio, Jean-Gabriel; Talmant, Maryline; Ellouz, Rafaa; Rongieras, Frédéric; Laugier, Pascal; Bruyère-Garnier, Karine

2014-04-11

55

Complementary Electromagnetic Non-Destructive Evaluation  

NASA Astrophysics Data System (ADS)

The use of non-destructive evaluation (NDE) for defect detection and failure prediction in structures and specimens is widespread in energy industries, aimed at ageing power plants and pipelines, material degradation, fatigue and radiation damage, etc. At present there are no suitable electromagnetic NDE methods for the measurement and characterization of material degradation, in irradiated samples in particular, which is very important and timely for the nuclear power industry in the UK. This paper reports recent developments in the field of electromagnetic (EM) NDE at Newcastle University, including pulsed eddy current (PEC), pulsed magnetic flux leakage (PMFL), magnetic Barkhausen emission (MBE) and magneto-acoustic emission (MAE). As different EM methods have different strengths, an integrative EM framework is introduced. Case studies through the second round robin tests organized by the Universal Network for Magnetic Non-Destructive Evaluation (UNMNDE), representing eighteen leading research groups worldwide in the area of electromagnetic NDE, are reported. Twelve samples with different ageing times and rolling reduction ratios were tested using different magnetic methods among the UNMNDE members. Based on the studies, the complementary characteristics of electromagnetic techniques for NDE are discussed.

Tian, Gui Yun; Wilson, John; Morozov, Maxim

2011-06-01

56

NONDESTRUCTIVE EVALUATION OF CERAMIC CANDLE FILTERS  

SciTech Connect

Nondestructive evaluation (NDE) techniques have been used to reduce the potential mechanical failures and to improve the reliability of a structure. Failure of a structure is usually initiated at some type of flaw in the material. NDE techniques have been developed to determine the presence of flaws larger than an acceptable size and to estimate the remaining stiffness of a damaged structure (Chen, et. al, 1995). Ceramic candle filters have been tested for use in coal-fueled gas turbine systems. They protect gas turbine components from damage due to erosion. A total of one hundred and one candle filters were nondestructively evaluated in this study. Ninety-eight ceramic candle filters and three ceramic composite filters have been nondestructively inspected using dynamic characterization technique. These ceramic filters include twelve unused Coors alumina/mullite, twenty-four unused and fifteen used Schumacher-Dia-Schumalith TF-20, twenty-five unused and nine used Refractron 326, eight unused and three used Refractron 442T, one new Schumacher-T 10-20, and one used Schumacher-Dia-Schumalith F-40. All filters were subjected to a small excitation and the dynamic response was picked up by a piezoelectric accelerometer. The evaluation of experimental results was processed using digital signal analysis technique including various forms of data transformation. The modal parameters for damage assessment for the unexposed (unused) vs. exposed (used) specimen were based on two vibration parameters: natural frequencies and mode shapes. Finite Element models were built for each specimen type to understand its dynamic response. Linear elastic modal analysis was performed using eight nodes, three-dimensional isotropic solid elements. Conclusions based on our study indicate that dynamic characterization is a feasible NDE technique in studying structural properties of ceramic candle filters. It has been shown that the degradation of the filters due to long working hours (or excessive back pulsing conditions and high temperature transient) could be reflected from the shift of vibration frequencies. These shifts are due to changes in structural properties such as stiffness, which are directly related to the Young's modulus of the candle filters. Further studies are necessary in implementing and verifying the applicability of dynamic NDE characterization methods for actual in-situ conditions, and in establishing a systematic testing procedure for field applications. Also investigations on the filter's natural frequency due to the effect of dust cake or due to the change of boundary conditions may provide insight as to how the filter will perform in the field.

Roger H.L. Chen, Ph.D.; Alejandro Kiriakidis

1999-09-01

57

Guidebook of nondestructive evaluation techniques for materials and structures  

NASA Technical Reports Server (NTRS)

Seventy nondestructive techniques for evaluating material and structures are described in guidebook. Standardized format facilitates comparison of their merits and limitations for solving various problems. Guide includes index of flaw types and tabulated guide to use of nondestructive evaluation techniques. Alternative technique names are cross-referenced.

Vary, A.

1974-01-01

58

Advanced system for automating eddy-current nondestructive evaluation  

Microsoft Academic Search

Various nondestructive evaluation (NDE) techniques are widely used in the inspection of sub-surface flaws. This paper introduces the results of a research conducted to enhance the performance of eddy-current nondestructive evaluation (ECNDE) by developing an integrated computer based system. Advantages of this system include increasing test speed, while avoiding errors due to human factors. The system can be used to

Moustafa N. I. Fahmy; Essam A. Hashish; Ibrahim Elshafiey; I. Jannound

2000-01-01

59

Thermographic nondestructive evaluation: overview of recent progress  

NASA Astrophysics Data System (ADS)

This paper presents a summary of recent research activities carried out at our laboratory in the field of Infrared Thermography for Nondestructive Evaluation (TNDE). First, we explore the latest developments in signal improvement. We describe three approaches: multiple pulse stimulation; the use of Synthetic Data for de-noising of the signal; and a new approach derived from the Fourier diffusion equation called the Differentiated Absolute Contrast method (DAC). Secondly, we examine the advances carried out in inverse solutions. We describe the use of the Wavelet Transform to manage pulsed thermographic data, and we present a summary on Neural Networks for TNDE. Finally, we look at the problem of complex geometry inspection. In this case, due to surface shape, heat variations might be incorrectly identified as flaws. We describe the Shape-from-Heating approach and we propose some potential research avenues to deal with this problem.

Ibarra-Castanedo, Clemente; Galmiche, Francois; Darabi, Akbar; Pilla, Mariacristina; Klein, Matthieu; Ziadi, Adel; Vallerand, Steve; Pelletier, Jean-François; Maldague, Xavier P.

2003-04-01

60

Non-destructive evaluation of composites  

NASA Technical Reports Server (NTRS)

The composite materials have been used in aerospace industries for quite some time. Several non-destructive evaluation (NDE) methods have been developed to inspect composites in order to detect flaws, matrix cracking, and delamination. These methods include ultrasonics, acoustic emission, shearography, thermography, X-ray, and digital image correlation. The NDE Branch of Marshall Space Flight Center has recently acquired a thermal imaging NDE system. The same system has been used at NASA Langley Research Center for detecting disbonds. In order to compare different NDE methods, three carbon/carbon composite panels were used for experiment using ultrasonic C-scan, shearography, and thermography methods. These panels have teflon inserts to simulate the delamination between plies in a composite panel. All three methods have successfully located the insert. The experiment and results are presented in the following sections.

Chu, Tsuchin Philip

1996-01-01

61

Preliminary nondestructive evaluation manual for the space shuttle. [preliminary nondestructive evaluation  

NASA Technical Reports Server (NTRS)

Nondestructive evaluation (NDE) requirements are presented for some 134 potential fracture-critical structural areas identified, for the entire space shuttle vehicle system, as those possibly needing inspection during refurbishment/turnaround and prelaunch operations. The requirements include critical area and defect descriptions, access factors, recommended NDE techniques, and descriptive artwork. Requirements discussed include: Orbiter structure, external tank, solid rocket booster, and thermal protection system (development area).

Pless, W. M.

1974-01-01

62

Magnetoresistive sensors for nondestructive evaluation (Invited Paper)  

NASA Astrophysics Data System (ADS)

New high-sensitivity solid-state magnetoresistive (MR) sensor technologies offer significant advantages in nondestructive evaluation (NDE) systems. A key advantage of MR sensors is a flat frequency response extending from dc to hundreds of MHz, making them particularly attractive for low-frequency and multi-frequency eddy current detection for deep-flaw detection and depth profiling. MR sensors are mass produced by thin film processing techniques similar to integrated circuit manufacturing, dramatically reducing the cost per sensor. The fabrication process is compatible with silicon circuit technology, allowing integration of sensors with on-chip signal processing. MR sensors can easily be produced in dense arrays for rapid, single-pass scanning of large areas. The small size and low power consumption of these solid-state magnetic sensors enable the assembly of compact arrays of sensors on a variety of substrates as well as on-chip sensor arrays. Arrays have been fabricated with sensor spacing as small as 5 ?m. This paper presents a review of the state of the art in MR sensors and applications in NDE. The physical principles, manufacturing process, and performance characteristics of the three main types of MR devices, anisotropic magnetoresistance (AMR), giant magnetoresistance (GMR) and tunneling magnetoresistance (TMR) are discussed. Their performance is compared to other magnetic sensor technologies for NDE applications. Finally, we provide a comprehensive review of the literature on NDE applications of MR sensors.

Jander, Albrecht; Smith, Carl; Schneider, Robert

2005-05-01

63

Operation of the EPRI Nondestructive Evaluation Center  

SciTech Connect

This report describes the Electric Power Research Institute (EPRI) funded nondestructive evaluation (NDE) and life assessment project activities carried out at the EPRI NDE Center in 1989. The primary support for this program is provided through contract RP 1570-2 with the EPRI Nuclear Division. Supplementary funding is provided by other contracts with the EPRI Nuclear and Generation and Storage Divisions. The major objective of this program is to provide improved and field-qualified NDE equipment, procedures, and personnel training to the electric utility industry. A second program objective involves the validation, provision, and maintenance of life assessment codes for selected plant components. Significant assistance has been provided to the utility industry under this project in the form of improved, field-theory equipment and procedures; critically needed assessments of inspection method capability; demonstrations of effectiveness of examination methods; rapid response for critical, short-term problems; assistance with selected life assessment computer codes; and training for specific utility industry needs. These efforts have specifically involved heat exchanger, piping, steam turbine, generator, and heavy section problems. Certain components of both nuclear and fossil plants have been addressed.

Stone, R.M.; Ammirato, F.V.; Becker, F.L.; Jeong, Y.H.; Krzywosz, K.J.; MacDonald, D.E.; Nottingham, L.D.; Selby, G.P.; Shankar, R.; Stephens, H.M.; Stramm, J.N.; Walker, S.M.; Willetts, A.J. (Jones (J.A.) Applied Research Co., Charlotte, NC (USA))

1990-09-01

64

Nondestructive Evaluation Correlated with Finite Element Analysis  

NASA Technical Reports Server (NTRS)

Advanced materials are being developed for use in high-temperature gas turbine applications. For these new materials to be fully utilized, their deformation properties, their nondestructive evaluation (NDE) quality and material durability, and their creep and fatigue fracture characteristics need to be determined by suitable experiments. The experimental findings must be analyzed, characterized, modeled and translated into constitutive equations for stress analysis and life prediction. Only when these ingredients - together with the appropriate computational tools - are available, can durability analysis be performed in the design stage, long before the component is built. One of the many structural components being evaluated by the NDE group at the NASA Lewis Research Center is the flywheel system. It is being considered as an energy storage device for advanced space vehicles. Such devices offer advantages over electrochemical batteries in situations demanding high power delivery and high energy storage per unit weight. In addition, flywheels have potentially higher efficiency and longer lifetimes with proper motor-generator and rotor design. Flywheels made of fiber-reinforced polymer composite material show great promise for energy applications because of the high energy and power densities that they can achieve along with a burst failure mode that is relatively benign in comparison to those of flywheels made of metallic materials Therefore, to help improve durability and reduce structural uncertainties, we are developing a comprehensive analytical approach to predict the reliability and life of these components under these harsh loading conditions. The combination of NDE and two- and three-dimensional finite element analyses (e.g., stress analyses and fracture mechanics) is expected to set a standardized procedure to accurately assess the applicability of using various composite materials to design a suitable rotor/flywheel assembly.

Abdul-Azid, Ali; Baaklini, George Y.

1999-01-01

65

Advanced Nondestructive Evaluation (NDE) Sensor Modeling For Multisite Inspection.  

National Technical Information Service (NTIS)

The Advanced Nondestructive Evaluation (NDE) Sensor Modeling for Multisite Inspection program has developed finite element models (FEM) of electromagnetic NDE for optimizing the inspection of aging aircraft structure. The program found excellent correlati...

B. Koltenbah L. Udpa L. Xin R. Bossi Y. Deng

2008-01-01

66

Nondestructive Evaluation of Electron-Beam Braze Joins.  

National Technical Information Service (NTIS)

A nondestructive evaluation (NDE) program has been carried out using holographic interferometry, microradiography, and eddy current testing for the inspection of electron beam braze joining of dissimilar metals. Stainless steel tubing was joined to a gold...

D. M. Boyd J. F. Shackelford B. W. Maxfield G. M. Taylor

1981-01-01

67

Development of Nondestructive Tests for the Evaluation of Bonded Materials.  

National Technical Information Service (NTIS)

Data obtained in the surface condition study are presented. Electric field reflectometry, at 1 KHz and 9.8 GHz, and gas-phase ultrasonic transmission methods are detailed as possible methods for nondestructively evaluating substrate surfaces. (Author)

J. R. Zurbrick

1970-01-01

68

Role of nondestructive evaluation in life cycle management.  

National Technical Information Service (NTIS)

This paper provides an overview of some common nondestructive evaluation (NDE) methods and several examples for the use of different NDE techniques throughout the life cycle of a product. NDE techniques are being used to help determine material properties...

H. Martz

1997-01-01

69

Cryogenic Storage Tank Non-Destructive Evaluation  

NASA Technical Reports Server (NTRS)

This slide presentation reviews the work in non-destructive evaluation (NDE) of cryogenic storage tanks. Four large cryogenic tanks, constructed in 1965 with perlite insulation in the annular regions, are of concern. The construction of the tanks, two Liquid Oxygen (LOX) and two Liquid Hydrogen (LH2), are described. The loss rate for the LOX tank at Pad A is slightly higher than that for the one at Pad B. The concerns for the LH2 tank at Pad B are that there is a significantly higher boil-off rate than that at Pad A, that there is mold growth, indicative of increased heat flow, that there is a long down-time needed for repairs, and that 3 of 5 full thermal cycles have been used on the Pad B LH2 tank. The advantages and disadvantages of thermal imaging are given. A detailed description of what is visible of the structures in the infra-red is given and views of the thermal images are included. Missing Perlite is given as the probable cause of the cold spot on the Pad B LH2 tank. There is no indications of problematic cold regions on the Pad A LH2 tank, as shown by the thermal images given in the presentation. There is definite indication of a cold region on the Pad A LOX tank. There is however concerns with thermal imaging, as thermal images can be significantly effected by environmental conditions, image differences on similar days but with different wind speeds. Other effects that must be considered include ambient temperature, humidity levels/dew, and cloud reflections

Arens, Ellen

2010-01-01

70

Nondestructive Evaluation of Metal Fatigue Using Nonlinear Acoustics  

NASA Technical Reports Server (NTRS)

Safe-life and damage-tolerant design philosophies of high performance structures have driven the development of various methods to evaluate nondestructively the accumulation of damage in such structures resulting from cyclic loading. Although many techniques have proven useful, none has been able to provide an unambiguous, quantitative assessment of damage accumulation at each stage of fatigue from the virgin state to fracture. A method based on nonlinear acoustics is shown to provide such a means to assess the state of metal fatigue. The salient features of an analytical model are presented of the microelastic-plastic nonlinearities resulting from the interaction of an acoustic wave with fatigue-generated dislocation substructures and cracks that predictably evolve during the metal fatigue process. The interaction is quantified by the material (acoustic) nonlinearity parameter extracted from acoustic harmonic generation measurements. The parameters typically increase monotonically by several hundred percent over the fatigue life of the metal, thus providing a unique measure of the state of fatigue. Application of the model to aluminum alloy 2024-T4, 410Cb stainless steel, and IN100 nickel-base superalloy specimens fatigued using different loading conditions yields good agreement between theory and experiment. Application of the model and measurement technique to the on-site inspection of steam turbine blades is discussed.

Cantrell, John H., Jr.

2008-01-01

71

Nondestructive Evaluation and Inspection Programs for Pershing II Motors.  

National Technical Information Service (NTIS)

Quality control inspection of Pershing II (P-II) solid-propellant rocket motors was historically the responsibility of the manufacturer. Now the U.S. Army Pueblo Depot Activity (PDA) has been assigned the task of nondestructive evaluation and inspection (...

F. W. Kearney M. D. Ginsberg R. B. Moler

1990-01-01

72

Nondestructive evaluation of electron-beam braze joins  

Microsoft Academic Search

A nondestructive evaluation (NDE) program has been carried out using holographic interferometry, microradiography, and eddy current testing for the inspection of electron beam braze joining of dissimilar metals. Stainless steel tubing was joined to a gold-copper disk using a Cusil (copper\\/silver) brazing alloy. Holographic interferometry provided an indirect measure of strength by detecting the plastic deformation occurring as a result

D. M. Boyd; J. F. Shackelford; B. W. Maxfield; G. M. Taylor

1981-01-01

73

Development of nondestructive evaluation methods for structural ceramics.  

National Technical Information Service (NTIS)

During the past year, the focus of our work on nondestructive evaluation (NDE) methods was on the development and application of these methods to technologies such as ceramic matrix composite (CMC) hot-gas filters, CMC high-temperature heat exchangers, an...

W. A. Ellingson

1998-01-01

74

SQUID-based nondestructive evaluation of carbon fiber reinforced polymer  

Microsoft Academic Search

Recent work with HTS SQUIDs in nondestructive evaluation has concentrated on the detection of flaws in aircraft-grade aluminum, with particular emphasis on surface-breaking tears beside rivets. More complex materials are now also being used in aircraft manufacture, with carbon fiber reinforced polymer (CFRP) being one of the most common. Existing technologies such as ultrasound are particularly well suited to the

C. Carr; D. Graham; J. C. Macfarlane; G. B. Donaldson

2003-01-01

75

Elastic Wave Propagation and Nondestructive Evaluation of Materials  

Microsoft Academic Search

ABSTRACT The use of elastic waves to measure elastic properties as well as flaws in solid specimens,has received much attention, and many important applications have been developed recently. This paper summarizes some,of the ,recent results in applying ,elastic waves ,to nondestructive evaluation ,(NDE) of isotropic ,as well as anisotropic materials. This paper is divided into four parts, the first part

Tsung-tsong Wu

76

Development of nondestructive evaluation methods for ceramic coatings..  

National Technical Information Service (NTIS)

Various nondestructive evaluation (NDE) technologies are being developed to study the use of ceramic coatings on components in the hot-gas path of advanced low-emission gas-fired turbines. The types of ceramic coatings include thermal barrier coatings (TB...

W. A. Ellingson C. Deemer J. G. Sun S. Erdman D. Muliere B. Wheeler

2002-01-01

77

Nondestructive evaluation of aircraft composites using terahertz time domain spectroscopy  

Microsoft Academic Search

Terahertz time domain spectroscopy was used for nondestructive evaluation of aircraft glass fiber composites stressed with bending and heating damage. Refractive index and absorption coefficients were measured for both damaged and undamaged composites. The two dimensional extent of the heat damage could be shown with either a simple phase or amplitude terahertz imaging technique.

Christopher D. Stoik; Matthew J. Bohn; James L. Blackshire

2008-01-01

78

Nondestructive evaluation of aircraft composites using terahertz time domain spectroscopy  

Microsoft Academic Search

Terahertz (THz) time domain spectroscopy (TDS) was assessed as a nondestructive evaluation technique for aircraft composites. Material properties of glass fiber composite were measured using both transmission and reflection configuration. The interaction of THz with a glass fiber composite was then analyzed, including the effects of scattering, absorption, and the index of refraction, as well as effective medium approximations. THz

Christopher D. Stoik

2008-01-01

79

Quantitative non-destructive characterisation (NDC) of plant fibre composites  

NASA Astrophysics Data System (ADS)

Composites made of plant fibres offer a new, environmentally attractive supplement to traditional glass fibre composite materials. Plant fibre composites may have similar mechanical properties as conventional (e.g. glass fibre) composites, with a lower impact strength. Since plant fibre composites constitute a relatively new group of materials, the limitations imposed on the mechanical performance due to flaws are not well known. The subject of this article is the investigation of the structure, the homogeneity and the mechanical properties of jute fibre based composites, and the correlation to quantitative data derived from X-radiography and ultrasonic scanning. The results indicates that parameters such as fibre orientation and fibre volume fraction are very important concerning sample tensile strength. These parameters can be assessed by the considered QNDC techniques. It is also shown that the samples are relatively homogeneous, and that the limitation on mechanical performance cannot by the considered techniques be related to a single defect. From the results it may be further concluded that the NDC techniques can provide quantitative data for an assessment of important manufacturing variables.

Rheinländer, Jørgen; Cendre, Emmanuelle; Debel, Christian; Borum, Kaj K.; Lilholt, Hans

1999-12-01

80

Non-destructive quantitative analysis of risperidone in film-coated tablets  

Microsoft Academic Search

A simple, non-destructive, methodology based on FT-Raman spectroscopy was developed for the quantitative analysis of risperidone in commercially available film-coated tablets. A simple linear regression model was constructed based on standard tablets, prepared using the same manufacturing process as the commercially available. The tablets contained 0.27, 0.54, 1.08, 1.62, 2.16, 3.24 and 4.32wt% risperidone. The most prominent Raman vibration of

M. G. Orkoula; C. G. Kontoyannis

2008-01-01

81

[Application of NIR quantitative analysis to nondestructive detection of loquat soluble solid content].  

PubMed

The objective of the present research was to evaluate the potential of NIR diffuse reflectance spectroscopy as a way for nondestructive measurement of loquat soluble solid content of three varieties harvested from two orchards. According to the analysis, it was shown that the correlation coefficient of curves was relatively high in the two regions of 1400-1500 nm and 1900- 2000 nm. Statistical models were developed using partial least square regression (PLSR), stepwise multiple linear regression (SMLR) and principal component regression (PCR) methods in the full spectral region from 800 to 2500 nm and in the combined region of 1400-1500 nm and 1900-2000 nm. The results of PLSR model in the full spectral region were better than those of other models. The modeling results based on derivative spectra were not as good as those based on original spectra. Finally, a model was established based on the original spectra with 17 points smoothing for all the three varieties in the full spectral region by PLSR method. The correlation coefficients of calibration and validation were 0.96 and 0.95, respectively. The results indicate that it is feasible to use NIR spectroscopy technique for quantitative analysis of loquat soluble solid content. PMID:17112027

Li, Jian-Ping; Fu, Xia-Ping; Zhou, Ying; Ying, Yi-Bin; Xie, Li-Juan; Niu, Xiao-Ying; Yan, Zhan-Ke; Yu, Hai-Yan

2006-09-01

82

The use of infrared thermography for nondestructive evaluation of joints  

NASA Astrophysics Data System (ADS)

A junction between two similar, or dissimilar, materials represents generally a weak structural point and so it requires accurate choice of the most adequate joining technique and nondestructive evaluation of joined parts whatever the joining technique. The attention of the present paper is focused on the aid provided by infrared thermography for nondestructive evaluation of three types of joints: aluminum adhesively bonded joints, stainless steel laser welded joints and Glare ® mechanical fastened joints. Both techniques, pulse and modulated thermography with optical stimulation, are used. The attention is particularly focused on the second method because phase images are practically not affected by local nonuniform heating and/or local variation of the emissivity coefficient as thermal images.

Meola, Carosena; Carlomagno, Giovanni M.; Squillace, Antonino; Giorleo, Giuseppe

2004-12-01

83

Aging management of major LWR components with nondestructive evaluation  

SciTech Connect

Nondestructive evaluation of material damage can contribute to continued safe, reliable, and economical operation of nuclear power plants through their current and renewed license period. The aging mechanisms active in the major light water reactor components are radiation embrittlement, thermal aging, stress corrosion cracking, flow-accelerated corrosion, and fatigue, which reduce fracture toughness, structural strength, or fatigue resistance of the components and challenge structural integrity of the pressure boundary. This paper reviews four nondestructive evaluation methods with the potential for in situ assessment of damage caused by these mechanisms: stress-strain microprobe for determining mechanical properties of reactor pressure vessel and cast stainless materials, magnetic methods for estimating thermal aging damage in cast stainless steel, positron annihilation measurements for estimating early fatigue damage in reactor coolant system piping, and ultrasonic guided wave technique for detecting cracks and wall thinning in tubes and pipes and corrosion damage to embedded portion of metal containments.

Shah, V.N.; MacDonald, P.E.; Akers, D.W.; Sellers, C. [Idaho National Engineering and Environmental Lab., Idaho Falls, ID (United States); Murty, K.L.; Miraglia, P.Q.; Mathew, M.D. [North Carolina State Univ., Raleigh, NC (United States); Haggag, F.M. [Advanced Technology Corp. (United States)

1997-12-31

84

Materials and Nondestructive Evaluation Laboratoriers: User Test Planning Guide  

NASA Technical Reports Server (NTRS)

The Materials and Nondestructive Evaluation Laboratory process, milestones and inputs are unknowns to first-time users. The Materials and Nondestructive Evaluation Laboratory Planning Guide aids in establishing expectations for both NASA and non- NASA facility customers. The potential audience for this guide includes both internal and commercial spaceflight hardware developers. It is intended to assist their project engineering personnel in materials analysis planning and execution. Material covered includes a roadmap of the analysis process, roles and responsibilities of facility and user, major milestones, facility capabilities, and inputs required by the facility. Samples of deliverables, products, and inputs necessary to define scope of analysis, cost, and schedule are included as an appendix to the guide.

Schaschl, Leslie

2011-01-01

85

Non-Destructive Evaluation (NDE) Applications of THz Radiation  

Microsoft Academic Search

The technology and applications of time domain terahertz (THz) imaging to non-destructive evaluation (NDE) will be discussed. THz imaging has shown great promise in 2 and 3 dimensional non-contact inspection of non-conductive materials such as plastics, foam, composites, ceramics, paper, wood and glass. THz imaging employs safe low power non-ionizing electromagnetic pulses, with lateral resolution < 200 um, and depth

David Zimdars

2005-01-01

86

Large area terahertz imaging and non-destructive evaluation applications  

Microsoft Academic Search

Abstract: Terahertz (THz) imaging,is being adopted for non-destructive evaluation (NDE) applications in aerospace and other government,and industrial settings [1-3]. NASA is currently employing ,THz reflection NDE to examine ,the space shuttle external tank sprayed on foam insulation (SOFI) for voids and disbonds. Homeland security applications such as the inspection of personnel[2], the detection of concealed explosives[2], biological agents, chemical weapons,

David Zimdars; Jeffrey S. White; G. stuk; A. chernovsky; G. Fichter; S. Williamson

2006-01-01

87

Development of nondestructive evaluation methods for structural ceramics  

Microsoft Academic Search

During the past year, the focus of our work on nondestructive evaluation (NDE) methods was on the development and application of these methods to technologies such as ceramic matrix composite (CMC) hot-gas filters, CMC high-temperature heat exchangers, and CMC ceramic\\/ceramic joining. Such technologies are critical to the ''Vision 21 Energy-Plex Fleet'' of modular, high-efficiency, low-emission power systems. Specifically, our NDE

Ellingson

1998-01-01

88

Nondestructive quantitative 3D characterization of a car brake  

NASA Astrophysics Data System (ADS)

Holographic interferometry enables the accurate measurement of 3D displacement fields. However, the determination of 3D- displacement vectors of objects with complex surfaces requires to measure the 3D-object coordinates not only to consider local sensitivities but to distinguish between in- plane deformation, i.e. strains, and out-of-plane components, i.e. shears, too. To this purpose both the surface displacement and coordinates have to be combined and it is advantageous to make the data available for CAE- systems. The object surface has to be approximated analytically from the measured point cloud to generate a surface mesh. The displacement vectors can be assigned to the nodes of this surface mesh and the components of the deformation can be evaluated for an experimental stress analysis. They also can be compared to the results of FEM- calculations. The brake saddle of a car brake is such a complex formed object where the surface cannot be described by fundamental mathematical functions. The 3D-object coordinates were measured in a separate topometric set-up using a modified fringe projection technique to acquire absolute phase values. By means of a geometrical model the phase data were mapped onto coordinates precisely. The determination of 3D-displacement vectors required the measurement of several interference phase distributions for at least three independent sensitivity directions as well as the 3D-position of each measuring point. These geometric quantities had to be transformed into a reference coordinate system of the interferometric set-up in order to calculate the geometric matrix. The necessary transformation were realized by means of a detection of object features in both data sets and a subsequent determination of the external camera orientation. This paper presents a consistent solution for the measurement and combination of shape and displacement data including their transformation into simulation systems for the car brake. This is an example, how more accurate and effective measurement techniques make it possible to bring experimental and numerical displacement analysis closer.

Jueptner, Werner P.; Osten, Wolfgang; Andrae, Peter; Nadeborn, Werner

1996-07-01

89

Nondestructive inspection and evaluation of composite-material flywheels  

SciTech Connect

Several composite panels and flywheel designs were evaluated in support of the Mechanical Energy Storage Technology (MEST) project. Conventional nondestructive evaluation (NDE) technology was used on the panels and flywheels. All flywheels and panels were radiographed and, where practical, were also inspected using ultrasonic techniques. The results provided information about the structural features of flywheels and materials. This information is useful for the quality control of fabrication procedures. The detection of apparent flaws in fabrication cannot be related to the ultimate strength until failure mechanisms in composite materials have been fully defined. Therefore, the location of detected flaws should be recorded for later comparison with dynamic and destructive evaluations.

Boyd, D M; Maxfield, B W; Kulkarni, S V; Schwarber, A J

1982-02-24

90

Nondestructive Damage Evaluation in Ceramic Matrix Composites for Aerospace Applications  

PubMed Central

Infrared thermography (IRT) and acoustic emission (AE) are the two major nondestructive methodologies for evaluating damage in ceramic matrix composites (CMCs) for aerospace applications. The two techniques are applied herein to assess and monitor damage formation and evolution in a SiC-fiber reinforced CMC loaded under cyclic and fatigue loading. The paper explains how IRT and AE can be used for the assessment of the material's performance under fatigue. IRT and AE parameters are specifically used for the characterization of the complex damage mechanisms that occur during CMC fracture, and they enable the identification of the micromechanical processes that control material failure, mainly crack formation and propagation. Additionally, these nondestructive parameters help in early prediction of the residual life of the material and in establishing the fatigue limit of materials rapidly and accurately.

Dassios, Konstantinos G.; Kordatos, Evangelos Z.; Aggelis, Dimitrios G.; Matikas, Theodore E.

2013-01-01

91

A versatile nondestructive evaluation imaging workstation  

NASA Astrophysics Data System (ADS)

Ultrasonic C-scan and eddy current imaging systems are of the pointwise type evaluation systems that rely on a mechanical scanner to physically maneuver a probe relative to the specimen point by point in order to acquire data and generate images. Since the ultrasonic C-scan and eddy current imaging systems are based on the same mechanical scanning mechanisms, the two systems can be combined using the same PC platform with a common mechanical manipulation subsystem and integrated data acquisition software. Based on this concept, we have developed an IBM PC-based combined ultrasonic C-scan and eddy current imaging system. The system is modularized and provides capacity for future hardware and software expansions. Advantages associated with the combined system are: (1) eliminated duplication of the computer and mechanical hardware, (2) unified data acquisition, processing and storage software, (3) reduced setup time for repetitious ultrasonic and eddy current scans, and (4) improved system efficiency. The concept can be adapted to many engineering systems by integrating related PC-based instruments into one multipurpose workstation such as dispensing, machining, packaging, sorting, and other industrial applications.

Chern, E. James; Butler, David W.

1994-02-01

92

A versatile nondestructive evaluation imaging workstation  

NASA Technical Reports Server (NTRS)

Ultrasonic C-scan and eddy current imaging systems are of the pointwise type evaluation systems that rely on a mechanical scanner to physically maneuver a probe relative to the specimen point by point in order to acquire data and generate images. Since the ultrasonic C-scan and eddy current imaging systems are based on the same mechanical scanning mechanisms, the two systems can be combined using the same PC platform with a common mechanical manipulation subsystem and integrated data acquisition software. Based on this concept, we have developed an IBM PC-based combined ultrasonic C-scan and eddy current imaging system. The system is modularized and provides capacity for future hardware and software expansions. Advantages associated with the combined system are: (1) eliminated duplication of the computer and mechanical hardware, (2) unified data acquisition, processing and storage software, (3) reduced setup time for repetitious ultrasonic and eddy current scans, and (4) improved system efficiency. The concept can be adapted to many engineering systems by integrating related PC-based instruments into one multipurpose workstation such as dispensing, machining, packaging, sorting, and other industrial applications.

Chern, E. James; Butler, David W.

1994-01-01

93

Nondestructive evaluation of Ni-Ti shape memory alloy  

SciTech Connect

The nondestructive evaluation of nickel titanium (Ni-Ti) alloys for applications such as heat treatment for biomaterials applications (dental) and welding was investigated. Ni-Ti alloys and its ternary alloys are valued for mechanical properties in addition to the shape memory effect. Two analytical approaches were perused in this work. Assessment of the microstructure of the alloy that determines the martensitic start temperature (Ms) of Ni-Ti alloy as a function of heat treatment, and secondly, an attempt to evaluate a Friction Stir Welding, which involves thermo-mechanical processing of the alloy.

Meir, S.; Gordon, S.; Karsh, M.; Ayers, R.; Olson, D. L. [Department of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, CO (United States); Wiezman, A. [Netania (Israel)

2011-06-23

94

Nondestructive evaluation of stresses in welds by micromagnetic method  

SciTech Connect

In the present investigation, the authors attempted to make a quantitative estimation of the stresses nondestructively by the micro-magnetic method (in and around a weld) on different grades of steel which are widely varying in magnetic hardness (coercivity). The grades of steel were plain carbon steel, 22 NiMoCr 37, and 17 MnMoV 64. There has been considerable development both on the instrumentation and the mechanical aspects of the micromagnetic, multiparameter, microstructure and stress analyzer measuring unit, or ``3MA``, to measure different micromagnetic quantities precisely to meet the specific demands of industries. The details of the 3MA unit and its potential use as an industrial non-destructive tool can be obtained elsewhere (Theiner et al., 1989). The stress sensitivity to different micromagnetic parameters e.g. maximum amplitude of the Barkhausen noise signal (M{sub MAX}), the coercivity (H{sub CM}) corresponding to M{sub MAX}, the full width at half maxima (FWHM) for the Barkhausen noise envelope, and the area {line_integral}MdH (Figure 1), are some of the measured or derived quantities used for this investigation at different locations of the weld, heat affected zone and the bulk to account for the stress variations.

Sengupta, A.K. [Bhabha Atomic Research Centre, Bombay (India). Radiometallurgy Div.; Theiner, W.A. [Univ. Gebaeude, Saarbruecken (Germany). Fraunhofer-Inst.

1995-05-01

95

Potential techniques for non-destructive evaluation of cable materials  

SciTech Connect

This paper describes the connection between mechanical degradation of common cable materials in radiation and elevated temperature environments and density increases caused by the oxidation which leads to this degradation. Two techniques based on density changes are suggested as potential non-destructive evaluation (NDE) procedures which may be applicable to monitoring the mechanical condition of cable materials in power plant environments. The first technique is direct measurement of density changes, via a density gradient column, using small shavings removed from the surface of cable jackets at selected locations. The second technique is computed X-ray tomography, utilizing a portable scanning device.

MGillen, K.T.; Clough, R.L. [Sandia National Labs., Albuquerque, NM (United States); Mattson, B.; Stenberg, B. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Polymer Technology; Oestman, E. [Skega AB, Ersmark (Sweden)

1993-03-01

96

Potential techniques for non-destructive evaluation of cable materials  

SciTech Connect

This paper describes the connection between mechanical degradation of common cable materials in radiation and elevated temperature environments and density increases caused by the oxidation which leads to this degradation. Two techniques based on density changes are suggested as potential non-destructive evaluation (NDE) procedures which may be applicable to monitoring the mechanical condition of cable materials in power plant environments. The first technique is direct measurement of density changes, via a density gradient column, using small shavings removed from the surface of cable jackets at selected locations. The second technique is computed X-ray tomography, utilizing a portable scanning device.

MGillen, K.T.; Clough, R.L. (Sandia National Labs., Albuquerque, NM (United States)); Mattson, B.; Stenberg, B. (Royal Inst. of Tech., Stockholm (Sweden). Dept. of Polymer Technology); Oestman, E. (Skega AB, Ersmark (Sweden))

1993-01-01

97

Non-Destructive Evaluation for Civil Engineering Structures and Materials  

NASA Astrophysics Data System (ADS)

This paper describes the challenges associated with the application of non-destructive evaluation techniques to the civil engineering infrastructure. Significant inspection tasks and structural defect types are first defined. Theoretical bases and experimental requirements of several current NDE techniques are then described, where case studies of application of the described techniques to specific structures are highlighted. Limitations of the current technology in achieving the inspection goals are identified. Finally, discussion about future directions of civil structure NDE, in terms of newly developed and promising NDE techniques, is presented.

Popovics, John S.

2004-02-01

98

Liberty Bell 7 Recovery Evaluation and Nondestructive Testing  

NASA Technical Reports Server (NTRS)

An inspection of the Mercury capsule, Liberty Bell 7, and its contents was made on September 1 and 2, 1999. The condition of the capsule and its contents was consistent with long-term exposure to salt water and high pressures at the bottom of the ocean. Many of the metallic materials suffered corrosion, whereas the polymer-based materials seem to have survived remarkably well. No identifiable items or structures were found that appeared to have any scientific value. At this time, no further nondestructive evaluation appears to be justified.

Madaras, Eric I.; Smith, William L.

1999-01-01

99

Simulation of Ultrasonic and Electromagnetic Nondestructive Evaluation of Corrosion  

NASA Astrophysics Data System (ADS)

The influence of corrosion on ultrasonic and electromagnetic nondestructive evaluation results has been simulated for 2-layer aluminum aircraft fuselage. Simulations have been performed with respect to ultrasonic time-of-flight measurements aiming on the detection of corrosion at the backwall of the first aluminum layer. Calculations of the eddy current probe response have been performed, where the thickness of the first and second layer and also the probe-to-specimen lift-off at several eddy current operating frequencies have been varied.

Spies, M.; Yashan, A.; Kropas-Hughes, C. V.

2003-03-01

100

Coded waveforms for optimised air-coupled ultrasonic nondestructive evaluation.  

PubMed

This paper investigates various types of coded waveforms that could be used for air-coupled ultrasound, using a pulse compression approach to signal processing. These are needed because of the low signal-to-noise ratios that are found in many air-coupled ultrasonic nondestructive evaluation measurements, due to the large acoustic mismatch between air and many solid materials. The various waveforms, including both swept-frequency signals and those with binary modulation, are described, and their performance in the presence of noise is compared. It is shown that the optimum choice of modulation signal depends on the bandwidth available and the type of measurement being made. PMID:24726137

Hutchins, David; Burrascano, Pietro; Davis, Lee; Laureti, Stefano; Ricci, Marco

2014-09-01

101

Nondestructive evaluation of FRP composite bridge components using infrared thermography  

NASA Astrophysics Data System (ADS)

This paper presents the findings of an experimental study on the use of Infrared Thermography for nondestructive evaluation of subsurface delaminations in Fiber Reinforced Polymer (FRP) composite bridge decks and concrete columns wrapped with FRP jackets. Composite bridge deck specimens were constructed in the laboratory with varying delamination sizes. The infrared images from the delaminated specimens were compared with undamaged specimens to study the effect of subsurface delaminations on the infrared images. In addition, field tests were conducted using infrared thermography on composite structural members of three bridges located in West Virginia. .

Halabe, U. B.; Alqennah, H.; Gangarao, H. V. S.; Klinkhachorn, P.; Sazonov, E. S.

2002-05-01

102

Application of Raman Spectroscopy for Nondestructive Evaluation of Composite Materials  

NASA Technical Reports Server (NTRS)

This paper will present an overview of efforts to investigate the application of Raman spectroscopy for the characterization of Kevlar materials. Raman spectroscopy is a laser technique that is sensitive to molecular interactions in materials such as Kevlar, graphite and carbon used in composite materials. The overall goal of this research reported here is to evaluate Raman spectroscopy as a potential nondestructive evaluation (NDE) tool for the detection of stress rupture in Kevlar composite over-wrapped pressure vessels (COPVs). Characterization of the Raman spectra of Kevlar yarn and strands will be presented and compared with analytical models provided in the literature. Results of testing to investigate the effects of creep and high-temperature aging on the Raman spectra will be presented.

Washer, Glenn A.; Brooks, Thomas M. B.; Saulsberry, Regor

2007-01-01

103

Proceedings of the First Annual Symposium for Nondestructive Evaluation of Bond Strength  

NASA Technical Reports Server (NTRS)

Quantitative adhesive bond strength measurement has been an issue for over thirty years. Utilization of nonlinear ultrasonic nondestructive evaluation methods has shown more effectiveness than linear methods on adhesive bond analysis, resulting in an increased sensitivity to changes in bondline conditions. Correlation to changes in higher order material properties due to microstructural changes using nonlinear ultrasonics has been shown and could relate to bond strength. Nonlinear ultrasonic energy is an order of magnitude more sensitive than linear ultrasound to these material parameter changes and to acoustic velocity changes caused by the acoustoelastic effect when a bond is prestressed. This increased sensitivity will assist in getting closer to quantitative measurement of adhesive bond strength. Signal correlations between non-linear ultrasonic measurements and initialization of bond failures have been successfully measured. This paper reviews nonlinear bond strength research efforts presented by university and industry experts at the First Annual Symposium for Nondestructive Evaluation of Bond Strength organized by the NDE Sciences Branch at NASA Langley in November 1997.

Roberts, Mark J. (Compiler)

1999-01-01

104

Nondestructive evaluation of near-surface residual stress in shot-peened nickel-base superalloys  

NASA Astrophysics Data System (ADS)

Surface enhancement methods, which produce beneficial compressive residual stresses and increased hardness in a shallow near-surface region, are widely used in a number of industrial applications, including gas-turbine engines. Nondestructive evaluation of residual stress gradients in surface-enhanced materials has great significance for turbine engine component life extension and their reliability in service. It has been recently found that, in sharp contrast with most other materials, shot-peened nickel-base superalloys exhibit an apparent increase in electrical conductivity at increasing inspection frequencies, which can be exploited for nondestructive residual stress assessment. The primary goal of this research is to develop a quantitative eddy current method for nondestructive residual stress profiles in surface-treated nickel-base superalloys. Our work have been focused on five different aspects of this issue, namely, (i) validating the noncontacting eddy current technique for electroelastic coefficients calibration, (ii) developing inversion procedures for determining the subsurface residual stress profiles from the measured apparent eddy current conductivity (AECC), (iii) predicting the adverse effect of surface roughness on the eddy current characterization of shot-peened metals, (iv) separating excess AECC caused by the primary residual stress effect from intrinsic conductivity variations caused by material inhomogeneity, and (v) investigating different mechanisms through which cold work could influence the AECC in surface-treated nickel-base superalloys. The results of this dissertation have led to a better understanding of the underlying physical phenomenon of the measured excess AECC on nickel-base engine alloys, and solved a few critical applied issues in eddy current nondestructive residual stress assessment in surface-treated engine components and, ultimately, contributed to the better utilization and safer operation of the Air Force's aging aircraft fleet.

Yu, Feng

105

Non-destructive quantitative analysis of risperidone in film-coated tablets.  

PubMed

A simple, non-destructive, methodology based on FT-Raman spectroscopy was developed for the quantitative analysis of risperidone in commercially available film-coated tablets. A simple linear regression model was constructed based on standard tablets, prepared using the same manufacturing process as the commercially available. The tablets contained 0.27, 0.54, 1.08, 1.62, 2.16, 3.24 and 4.32 wt% risperidone. The most prominent Raman vibration of the active pharmaceutical ingredient at 1533 cm(-1), recorded using a home-made rotating system, was plotted against concentration. The model was tested on commercial film-coated tablets. The results were compared against those obtained by application of HPLC on the same samples. PMID:18359600

Orkoula, M G; Kontoyannis, C G

2008-07-15

106

Nondestructive evaluation of environmental barrier coatings in CFCC combustor liners.  

SciTech Connect

Advanced combustor liners fabricated of SiC/SiC continuous fiber-reinforced ceramic composite (CFCC) and covered with environmental barrier coatings (EBCs) have been successfully tested in Solar Turbines Inc. field engines. The primary goal for the CFCC/EBC liners is to reach a 30,000-h lifetime. Because the EBCs, when applied on the hot surfaces of liners, protect the underlying CFCC from oxidation damage, their performance is critical in achieving the lifetime goal. To determine CFCC/EBC liner condition and assess operating damage, the liners were subjected to nondestructive evaluation (NDE) during various processing stages, as well as before and after the engine test. The NDE techniques included pulsed infrared thermal imaging, air-coupled ultrasonic scanning, and X-ray computerized tomography. It was found that EBC damage and spallation depend on the condition of the CFCC material. The NDE results and correlations with destructive examination are discussed.

Sun, J. G.; Benz, J.; Ellingson, W. A.; Kimmel, J. B.; Price, J. R.; Energy Technology; Solar Turbines, Inc

2007-01-01

107

Nondestructive Evaluation Methodologies Developed for Certifying Composite Flywheels  

NASA Technical Reports Server (NTRS)

Manufacturing readiness of composite rotors and certification of flywheels depend in part on the maturity of nondestructive evaluation (NDE) technology for process optimization and quality assurance, respectively. At the NASA Glenn Research Center, the capabilities and limitations of x-ray-computed tomography and radiography, as well as advanced ultrasonics were established on NDE ring and rotor standards with electrical discharge machining (EDM) notches and drilled holes. Also, intentionally seeded delamination, tow break, and insert of bagging material were introduced in hydroburst-rings to study the NDE detection capabilities of such anomalies and their effect on the damage tolerance and safe life margins of subscale rings and rotors. Examples of possible occurring flaws or anomalies in composite rings as detected by NDE and validated by destructive metallography are shown. The general NDE approach to ensure the quality of composite rotors and to help in the certification of flywheels is briefly outlined.

Baaklini, George Y.; Konno, Kevin E.; Martin, Richard E.; Thompson, Richard

2001-01-01

108

Physical Model Assisted Probability of Detection in Nondestructive Evaluation  

NASA Astrophysics Data System (ADS)

Nondestructive evaluation is used widely in many engineering and industrial areas to detect defects or flaws such as cracks inside parts or structures during manufacturing or for products in service. The standard statistical model is a simple empirical linear regression between the (possibly transformed) signal response variables and the (possibly transformed) explanatory variables. For some applications, such a simple empirical approach is inadequate. An important alternative approach is to use knowledge of the physics of the inspection process to provide information about the underlying relationship between the response and explanatory variables. Use of such knowledge can greatly increase the power and accuracy of the statistical analysis and enable, when needed, proper extrapolation outside the range of the observed explanatory variables. This paper describes a set of physical model-assisted analyses to study the capability of two different ultrasonic testing inspection methods to detect synthetic hard alpha inclusion and flat-bottom hole defects in a titanium forging disk.

Li, M.; Meeker, W. Q.; Thompson, R. B.

2011-06-01

109

Remote monitoring and nondestructive evaluation of wind turbine towers  

NASA Astrophysics Data System (ADS)

Wind turbine towers are in need of condition monitoring so as to lower the cost of unexpected maintenance. Wind loading from turbulence and gusts can cause damage in horizontal axis wind turbines even the supporting towers. Monitoring of wind turbines in service using embedded data sensor arrays usually is not targeted at the turbine-tower interaction from the perspective of structural dynamics. In this study the remote monitoring of the tower supporting a horizontal-axis wind turbine was attempted using a microwave interferometer. The dominant frequency of one tower was found to be decreased by more than 20% in 16 months. Numerical modeling using spectral finite elements is in progress and should provide further information regarding frequency shift due to stiffness variation and added mass. Expected outcome will contribute to remote monitoring procedures and nondestructive evaluation techniques for local wind turbine structures during operation.

Chiang, Chih-Hung; Yu, Chih-Peng; Hsu, Keng-Tsang; Cheng, Chia-Chi; Ke, Ying-Tzu; Shih, Yi-Ru

2014-03-01

110

Development of nondestructive evaluation methods for ceramic coatings.  

SciTech Connect

Various nondestructive evaluation (NDE) technologies are being developed to advance the knowledge of ceramic coatings for components in the hot gas-path of advanced, low-emission gas-fired turbine engines. The ceramic coating systems being studied by NDE include thermal barrier coatings (TBCs) and environmental barrier coatings (EBCs). TBCs are under development for vanes, blades and combustor liners to allow hotter gas path temperatures and EBCs are under development to reduce environmental damage to high temperature components made of ceramic matrix composites (CMCs). Data provided by NDE methods will be used to: (a) provide data to assess reliability of new coating application processes, (b) identify defective components that could cause unscheduled outages (c) track growth rates of defects during use in engines and (d) allow rational judgement for replace/repair/re-use decisions of components.

Sun, J. G. (Nuclear Engineering Division)

2007-01-01

111

Comparison of nondestructive microfailure evaluation of fiber-optic Bragg grating and acoustic emission piezoelectric sensors using fragmentation test  

Microsoft Academic Search

Nondestructive evaluation of microfailure mechanisms in two-diameter SiC fibers\\/epoxy composites is investigated using a directly embedded fiber-optic sensor attached with an acoustic emission piezoelectric (AE-PZT) sensor. Interfacial shear strength by fragmentation test, and optical failure observation inside microcomposite can contribute to analyze two sensors quantitatively. Although fiber Bragg grating (FBG) sensor exhibits sudden wavelength shift due to plastic deformation by

Joung-Man Park; Sang-Il Lee; Oh-Yang Kwon; Heung-Soap Choi; Joon-Hyun Lee

2003-01-01

112

Physical Principles Underlying Ultrasonic Nondestructive Evaluation of Anisotropic Media  

NASA Astrophysics Data System (ADS)

The research described in this thesis is aimed toward extending the physics underlying the application of ultrasound to the investigation of materials. Some of the results presented deal with isotropic materials, both homogeneous and inhomogeneous. However, the primary focus is the physics of inhomogeneous, anisotropic materials, such as fiber-reinforced plastics. Fiber-reinforced plastics exhibit very favorable strength-to-weight ratios and can be fabricated to exhibit a wide range of structural properties. From a mechanical standpoint, two types of disadvantages of otherwise well -designed composite materials are fabrication defects (e.g., delamination, fiber-misalignment, and porosity) and wear damage (e.g., environmental degradation, fatigue stress, and impact damage). In this thesis, we describe the physics underlying the use of ultrasound as a tool for the detection and characterization of damage in composite materials. The thesis is composed of two inter-related portions. The first portion serves as an introduction to wave propagation in isotropic and anisotropic media. These chapters provide a basis of insight and intuition for the non-destructive evaluation experiments described in the second portion. The second portion deals with experimental application of ultrasonic techniques to several specific problems in nondestructive evaluation. The studies reported here examine parameters of ultrasonic propagation in materials with known flaws whose location and character have been verified by independent (non-ultrasonic) means. The ultrasonic parameters employed in these studies are backscatter, attenuation measured in transmission, and attenuation estimated from backscatter. Three chapters deal with the use of a backscatter -based technique known as polar backscatter. In this technique the effects of specular reflection from the water/sample interface in an immersion-type measurement are reduced by interrogating at nonperpendicular incidence. The anisotropic nature of composite laminates makes polar backscatter a very useful tool for investigation of impact damage and porosity. Two chapters discuss a theoretical approach and experimental results for estimating attenuation in inhomogeneous materials from backscattered ultrasound.

Blodgett, Earl Daniel

113

Development of nondestructive evaluation methods and prediction of effects of flaws on the fracture behavior of structural ceramics.  

National Technical Information Service (NTIS)

To establish predictive performance (i.e., fracture behavior) of structural ceramic composites by nondestructive evaluation methods, we are undertaking (a) development of nondestructive evaluation (NDE) methods suitable for characterizing and sizing flaws...

W. A. Ellingson J. P. Singh N. Gopalsami S. L. Dieckman A. S. Wagh

1991-01-01

114

Super-resolution image reconstruction for ultrasonic nondestructive evaluation.  

PubMed

Ultrasonic testing is one of the most successful nondestructive evaluation (NDE) techniques for the inspection of carbon-fiber-reinforced polymer (CFRP) materials. This paper discusses the application of the iterative backprojection (IBP) super-resolution image reconstruction technique to carbon epoxy laminates with simulated defects to obtain high-resolution images for NDE. Super-resolution image reconstruction is an approach used to overcome the inherent resolution limitations of an existing ultrasonic system. It can greatly improve the image quality and allow more detailed inspection of the region of interest (ROI) with high resolution, improving defect evaluation and accuracy. First, three artificially simulated delamination defects in a CFRP panel were considered to evaluate and validate the application of the IBP method. The results of the validation indicate that both the contrast-tonoise ratio (CNR) and the peak signal-to-noise ratio (PSNR) value of the super-resolution result are better than the bicubic interpolation method. Then, the IBP method was applied to the low-resolution ultrasonic C-scan image sequence with subpixel displacement of two types of defects (delamination and porosity) which were obtained by the micro-scanning imaging technique. The result demonstrated that super-resolution images achieved better visual quality with an improved image resolution compared with raw C-scan images. PMID:24297023

Li, Shanglei; Chu, Tsuchin Philip

2013-12-01

115

Quantitative nondestructive electronic and magnetic property assessment of heat treated grade p91 steel  

NASA Astrophysics Data System (ADS)

Structural steels experience aging from fatigue, creep and corrosion. Prolonged high temperature service accelerates creep and stress-corrosion cracking. Microstructural degradation of structural steels is a serious problem that limits the integrity of high-temperature parts in power plants. Some power plants that utilize fossil fuels have experienced lifecycle issues with heat-treated steel alloys that have experienced progressive damage over time. A nondestructive technique for the evaluation of the microstructure of key structural materials and the prediction of lifecycle has been the focus of extensive research for many years. Advanced nondestructive wave assessment techniques are being developed using electronic and magnetic perturbation analysis. These methods are applied to ferrous materials to determine whether a designed heat-treatment provides an acceptable microstructure offering specific set of required properties for the full service life of the component. The methods used in this research include impedance spectroscopy and hysteresis measurement as preliminary assessment methods and hysteresis frequency analysis and Barkhausen noise measurement as secondary assessment methods.

Meir, Shai Shmuel

116

Institute for Materials Science and Engineering, Nondestructive Evaluation: technical activities, 1989. Annual report  

Microsoft Academic Search

A review of the Nondestructive Evaluation Program at NIST for fiscal year 1989 is presented in the annual report. Topics include the following: Intelligent processing of rapidly solidified metal powders; Nondestructive characterization of ceramic sintering; Monitoring of machined ceramic surfaces by thermal waves; Eddy-current temperature sensing; Ultrasonic sensor for sheet metal formability; Ultrasonic metrology for surface finish and part thickness;

Yolken

1989-01-01

117

Plan for Developing High-Speed, Nondestructive Testing Procedures for Both Design Evaluation and Construction Inspection.  

National Technical Information Service (NTIS)

The first project in the second Strategic Highway Research Program (SHRP 2) in the field of nondestructive evaluation (NDE) was completed in 2008. The project evaluated the existing and emerging NDE technologies and their state of implementation to satisf...

A. J. Wimsatt F. Fernando R. Lytton S. Hurlebaus T. Scullion

2009-01-01

118

Nondestructive Evaluation of Material Properties Through Use of a Thermal Inspection System.  

National Technical Information Service (NTIS)

A study was performed on thermal nondestructive evaluation of materials. Its purpose has been to establish sensitivity and resolution criteria for a group of material parameters; these parameters were chosen as being susceptible to thermal evaluation duri...

D. R. Maley W. R. Apple J. B. Card M. V. Crossan S. W. Maley

1967-01-01

119

New optoelectronic methodology for nondestructive evaluation of MEMS at the wafer level  

NASA Astrophysics Data System (ADS)

One of the approaches to fabrication of MEMS involves surface micromachining to define dies on single crystal silicon wafers, dicing of the wafers to separate the dies, and electronic packaging of the individual dies. Dicing and packaging of MEMS accounts for a large fraction of the fabrication costs, therefore, nondestructive evaluation at the wafer level, before dicing, can have significant implications on improving production yield and costs. In this paper, advances in development of optoelectronic holography (OEH) techniques for nondestructive, noninvasive, full-field of view evaluation of MEMS at the wafer level are described. With OEH techniques, quantitative measurements of shape and deformation of MEMS, as related to their performance and integrity, are obtained with sub-micrometer spatial resolution and nanometer measuring accuracy. To inspect an entire wafer with OEH methodologies, measurements of overlapping regions of interest (ROI) on a wafer are recorded and adjacent ROIs are stitched together through efficient 3D correlation analysis algorithms. Capabilities of the OEH techniques are illustrated with representative applications, including determination of optimal inspection conditions to minimize inspection time while achieving sufficient levels of accuracy and resolution.

Furlong, Cosme; Ferguson, Curtis F.; Melson, Michael J.

2004-02-01

120

Study Methods to Characterize and Implement Thermography Nondestructive Evaluation (NDE)  

NASA Technical Reports Server (NTRS)

The limits and conditions under which an infrared thermographic nondestructive evaluation can be utilized to assess the quality of aerospace hardware is demonstrated in this research effort. The primary focus of this work is on applying thermography to the inspection of advanced composite structures such as would be found in the International Space Station Instrumentation Racks, Space Shuttle Cargo Bay Doors, Bantam RP-1 tank or RSRM Nose Cone. Here, the detection of delamination, disbond, inclusion and porosity type defects are of primary interest. In addition to composites, an extensive research effort has been initiated to determine how well a thermographic evaluation can detect leaks and disbonds in pressurized metallic systems "i.e. the Space Shuttle Main Engine Nozzles". In either case, research into developing practical inspection procedures was conducted and thermographic inspections were performed on a myriad of test samples, subscale demonstration articles and "simulated" flight hardware. All test samples were fabricated as close to their respective structural counterparts as possible except with intentional defects for NDE qualification. As an added benefit of this effort to create simulated defects, methods were devised for defect fabrication that may be useful in future NDE qualification ventures.

Walker, James L.

1998-01-01

121

Research in nondestructive evaluation techniques for nuclear reactor concrete structures  

NASA Astrophysics Data System (ADS)

The purpose of the Materials Aging and Degradation (MAaD) Pathway of the Department of Energy's Light Water Reactor Sustainability (LWRS) Program is to develop the scientific basis for understanding and predicting longterm environmental degradation behavior of material in nuclear power plants and to provide data and methods to assess the performance of systems, structures, and components (SSCs) essential to safe and sustained nuclear power plant operations. The understanding of aging-related phenomena and their impacts on SSCs is expected to be a significant issue for any nuclear power plant planning for long-term operations (i.e. service beyond the initial license renewal period). Management of those phenomena and their impacts during long-term operations can be better enable by improved methods and techniques for detection, monitoring, and prediction of SSC degradation. The MAaD Pathway R&D Roadmap for Concrete, "Light Water Reactor Sustainability Nondestructive Evaluation for Concrete Research and Development Roadmap", focused initial research efforts on understanding the recent concrete issues at nuclear power plants and identifying the availability of concrete samples for NDE techniques evaluation and testing. [1] An overview of the research performed by ORNL in these two areas is presented here.

Clayton, Dwight; Smith, Cyrus

2014-02-01

122

The thermographic nondestructive evaluation of iron aluminide green sheet  

NASA Astrophysics Data System (ADS)

The recent development of manufacturing techniques for the fabrication of thin iron aluminide sheet requires advanced quantitative methods for on-line inspection. An understanding of the mechanisms responsible for flaws and the development of appropriate flaw detection methods are key elements in an effective quality management system. The first step in the fabrication of thin FeAl alloy sheet is the formation of a green sheet by cold rolling FeAl powder mixed with organic binding agents. The green sheet composite has a bulk density, which is typically less than about 3.6 g/cc. The finished sheet, with a density of about 6.1 g/cc, is obtained using a series of process steps involving binder elimination, densification, sintering, and annealing. Non-uniformities within the green sheet are the major contributor to material failure in subsequent sheet processing and the production of non-conforming finished sheet. The production environment and physical characteristics of the composite provide for unique challenges in developing a rapid nondestructive inspection capability. The method must be non-contact due to the fragile nature of the composite. Limited access to the material also demands a one-sided inspection technique. An active thermographic method providing for 100% on-line inspection within an industrial, process has been developed. This approach is cost competitive with alternative technologies, such as x-ray imaging systems, and provides the required sensitivity to the variations in material composition. The mechanism of flaw formation and the transformation of green sheet flaws into defects that appear in intermediate and finished sheet products are described. A mathematical model which describes the green sheet heat transfer propagation, in the context of the inspection technique and the compact heterogeneity, is also presented. The potential for feedback within the production process is also discussed.

Watkins, Michael Lee

123

Nondestructive methods for quality evaluation of livestock products  

Microsoft Academic Search

The muscles derived from livestock are highly perishable. Rapid and nondestructive methods are essential for quality assurance\\u000a of such products. Potential nondestructive methods, which can supplement or replace many of traditional time consuming destructive\\u000a methods, include colour and computer image analysis, NIR spectroscopy, NMRI, electronic nose, ultrasound, X-ray imaging and\\u000a biosensors. These methods are briefly described and the research work

K. Narsaiah; Shyam N. Jha

124

Review of progress in quantitative nondestructive evaluation; Proceedings of the 17th Annual Review, University of California, La Jolla, CA, July 15-20, 1990. Vols. 10A and 10B  

SciTech Connect

Various papers on quantitative NDE are presented. The general topics discussed include: fundamentals of standard techniques as they apply to elastic wave scattering, elastic wave propagation, eddy currents, radiography and CT; evolving techniques in computed tomography, laser-based methods, and exploratory techniques; interpretative signal and image processing in neural networks, signal processing, and image processing; probes and sensors in ultrasonic transducers, electromagnetic field probes, eddy current arrays, imaging, and process control; electronic and ceramic materials; engineered materials for smart structures, joints, and composites; characterization of materials, including the properties, nonlinear acoustic properties, deformation and fracture, and relationship of acoustoelasticity to stress and texture; instruments and systems; and manufacturing and reliability.

Thompson, D.O.; Chimenti, D.E. (DOE, Ames Laboratory, IA (United States) Iowa State University of Science and Technology, Ames (United States) Johns Hopkins University, Baltimore, MD (United States))

1991-01-01

125

Non-destructive evaluation of mechanical properties of magnetic materials  

SciTech Connect

A magnetic-based non-destructive evaluation (NDE) method, which employs Barkhausen effect and measurement of the hysteresis loops, is used to correlate the magnetic and mechanical properties of ultra low carbon (ULC) steel. In particular, the NDE method was used to detect small deviations from linearity that occur in the stress-strain curve well below the 0.2% offset strain, and which generally defines the yield point in materials. Results show that three parameters: jumpsum and jumpsum rate (derived from the Barkhausen spectrum), and the relative permeability (derived from the B-H loops) varies sensitively with small permanent strains, and can be related to the plastic deformation in ULC steels. Investigation of micromagnetic structure revealed that plastic deformation leaves a residual stress state in the samples; the associated magneto-elastic energy makes the favorable easy axis of magnetization in a given grain to be the one that lies closest to the tensile axis. The consequence of this realignment of domains is that wall motion becomes intergranular in nature (as opposed to intragranular in unstrained samples). As a result, the more complex grain boundaries instead of dislocations, become the dominant pinning sites for domain walls. These observations provide a microscopic interpretation of the observed changes in the measured magnetic properties.

Kankolenski, K.P.; Hua, S.Z.; Yang, D.X.; Hicho, G.E.; Swartzendruber, L.J.; Zang, Z.; Chopra, H.D.

2000-07-01

126

Development of nondestructive evaluation methods for structural ceramics  

SciTech Connect

Nondestructive evaluation (NDE) methods using three-dimensional microfocus X-ray computed tomographic imaging (3DXCT) were employed to map axial and radial density variations in hot-gas filters and heat exchanger tubes. 3D XCT analysis was conducted on (a) two 38-mm-OD, 6.5-mm wall, SiC/SiC heat exchanger tubes infiltrated by CVI; (b) eight 10 cm diam. oxide/oxide heat exchanger tubes; and (c) one 26-cm-long Nextel fiber/SiC matrix hot-gas filter. The results show that radial and axial density uniformity as well as porosity, can be assessed by 3D XCT. NDE methods are also under development to assess thermal barrier coatings which are under development as methods to protect gas-turbine first-stage hot section metallic substrates. Further, because both shop and field joining of CFCC materials will be necessary, work is now beginning on development of NDE methods for joining.

Ellingson, W.A.; Koehl, R.D.; Wilson, J.A.; Stuckey, J.B. [Argonne National Lab., IL (United States). Energy Technology Div.; Engel, H.P. [Argonne National Lab., IL (United States). Energy Technology Div.]|[Heaviside Science, Inc., Melbourne, FL (United States)

1996-04-01

127

Development of nondestructive evaluation methods for structural ceramics.  

SciTech Connect

During the past year, the focus of our work on nondestructive evaluation (NDE) methods was on the development and application of these methods to technologies such as ceramic matrix composite (CMC) hot-gas filters, CMC high-temperature heat exchangers, and CMC ceramic/ceramic joining. Such technologies are critical to the ''Vision 21 Energy-Plex Fleet'' of modular, high-efficiency, low-emission power systems. Specifically, our NDE work has continued toward faster, higher sensitivity, volumetric X-ray computed tomographic imaging with new amorphous silicon detectors to detect and measure axial and radial density variations in hot-gas filters and heat exchangers; explored the potential use of high-speed focal-plane-array infrared imaging technology to detect delaminations and variations in the thermal properties of SiC/SiC heat exchangers; and explored various NDE methods to characterize CMC joints in cooperation with various industrial partners. Work this year also addressed support of Southern Companies Services Inc., Power Systems Development Facility, where NDE is needed to assess the condition of hot-gas candle filters. This paper presents the results of these efforts.

Ellingson, W. A.

1998-08-19

128

Nondestructive Evaluation Methods for the Ares I Common Bulkhead  

NASA Technical Reports Server (NTRS)

A large scale bonding demonstration test article was fabricated to prove out manufacturing techniques for the current design of the NASA Ares I Upper Stage common bulkhead. The common bulkhead serves as the single interface between the liquid hydrogen and liquid oxygen portions of the Upper Stage propellant tank. The bulkhead consists of spin-formed aluminum domes friction stir welded to Y-rings and bonded to a perforated phenolic honeycomb core. Nondestructive evaluation methods are being developed for assessing core integrity and the core-to-dome bond line of the common bulkhead. Detection of manufacturing defects such as delaminations between the core and face sheets as well as service life defects such as crushed or sheared core resulting from impact loading are all of interest. The focus of this work will be on the application of thermographic, shearographic, and phased array ultrasonic methods to the bonding demonstration article as well as various smaller test panels featuring design specific defect types and geometric features.

Walker, James

2010-01-01

129

Overview of Mathematical Modeling in Nondestructive Evaluation (NDE)  

NASA Astrophysics Data System (ADS)

This report presents a broad overview of mathematical modeling in nondestructive evaluation (NDE). The primary emphasis is to expand the review of NDE modeling literature covered by previous general works. To provide a starting point for researchers and engineers, the discussions and references include multiple modeling approaches (analytical, asymptotic, and numerical) for a variety of NDE techniques. A second emphasis for this report is to present the pertinent modeling software packages for a variety of NDE techniques. Overviews of modeling for four NDE techniques, ultrasonic testing, eddy current testing, radiography, and thermography are presented. In order to present the broad subject of NDE modeling for this report, the discussions of modeling research and software packages are limited in scope; however, numerous references are provided in each section for further study by the reader. Given the inherent depth and importance of the field, special emphasis is given to ultrasonic NDE. Discussions are presented on the generation of ultrasound, wave propagation in elastic solids, scattering from cracks, and waves in guides and at interfaces.

Aldrin, John C.

2002-09-01

130

High resolution x-ray sensor for nondestructive evaluation  

SciTech Connect

Nondestructive evaluation (NDE) using X-rays is becoming indispensable for detecting microdefects in new materials currently used in aerospace and other engineering disciplines. Existing X-ray sensors pose limitations on the speed of operation due to persistence of the sensor and a problematic tradeoff between the sensor thickness and spatial resolution. To address these limitations the authors are developing a large area structured CsI(Tl) imaging sensor for NDE using CCD based radiographic and computed tomographic systems. The sensor is formed by vapor deposition of CsI(Tl) onto a specially designed fiberoptic substrate. The work has produced X-ray sensors with a factor of 4.5 greater light output, at least three orders of magnitude faster decay time response, and greater spatial resolution (16% modulation transfer function, MTF(f), at 14 linepairs per millimeter (lp/mm)) compared to the currently used high density Tb{sub 2}O{sub 3} doped fiberoptic glass scintillators. These performance advances will address the limitations of existing detector technology by producing high quality images and fast scan times required for real-time NDE inspection. Performance measurements for prototype CsI(Tl) scintillator converters are presented. With these new sensors the development of larger area fiberoptic taper based CCD detectors with millisecond data acquisition capabilities and high spatial resolution suitable for NDE applications will be possible.

Nagarkar, V.V.; Gordon, J.S.; Vasile, S.; Gothoskar, P. [Radiation Monitoring Devices, Inc., Watertown, MA (United States)] [Radiation Monitoring Devices, Inc., Watertown, MA (United States); Hopkins, F. [Scientific Measurement Systems, Inc., Austin, TX (United States)] [Scientific Measurement Systems, Inc., Austin, TX (United States)

1996-06-01

131

Synchronized Electronic Shutter System (SESS) for Thermal Nondestructive Evaluation  

NASA Technical Reports Server (NTRS)

The purpose of this paper is to describe a new method for thermal nondestructive evaluation. This method uses a synchronized electronic shutter system (SESS) to remove the heat lamp's influence on the thermal data during and after flash heating. There are two main concerns when using flash heating. The first concern is during the flash when the photons are reflected back into the camera. This tends to saturate the detectors and potentially introduces unknown and uncorrectable errors when curve fitting the data to a model. To address this, an electronically controlled shutter was placed over the infrared camera lens. Before firing the flash lamps, the shutter is opened to acquire the necessary background data for offset calibration. During flash heating, the shutter is closed to prevent the photons from the high intensity flash from saturating the camera's detectors. The second concern is after the flash heating where the lamps radiate heat after firing. This residual cooling introduces an unwanted transient thermal response into the data. To remove this residual effect, a shutter was placed over the flash lamps to block the infrared heat radiating from the flash head after heating. This helped to remove the transient contribution of the flash. The flash lamp shutters were synchronized electronically with the camera shutter. Results are given comparing the use of the thermal inspection with and without the shutter system.

Zalameda, Joseph N.

2001-01-01

132

Overview of space propulsion systems for identifying nondestructive evaluation and health monitoring opportunities  

NASA Technical Reports Server (NTRS)

The next generation of space propulsion systems will be designed to incorporate advanced health monitoring and nondestructive inspection capabilities. As a guide to help the nondestructive evaluation (NDE) community impact the development of these space propulsion systems, several questions should be addressed. An overview of background and current information on space propulsion systems at both the programmatic and technical levels is provided. A framework is given that will assist the NDE community in addressing key questions raised during the 2 to 5 April 1990 meeting of the Joint Army-Navy-NASA-Air Force (JANNAF) Nondestructive Evaluation Subcommittee (NDES).

Generazio, Edward R.

1991-01-01

133

Development of nondestructive evaluation methods for structural ceramics  

SciTech Connect

Development of nondestructive evaluation (NDE) methods for application to fossil energy systems continues in three areas: (a) mapping axial and radial density gradients in hot gas filters, (b) characterization of the quality of continuous fiber ceramic matrix composite (CFCC) joints and (c) characterization and detection of defects in thermal barrier coatings. In this work, X-ray computed tomographic imaging was further developed and used to map variations in the axial and radial density of two full length (2.3-m) hot gas filters. The two filters differed in through wall density because of the thickness of the coating on the continuous fibers. Differences in axial and through wall density were clearly detected. Through transmission infrared imaging with a highly sensitivity focal plane array camera was used to assess joint quality in two sets of SiC/SiC CFCC joints. High frame rate data capture suggests that the infrared imaging method holds potential for the characterization of CFCC joints. Work to develop NDE methods that can be used to evaluate electron beam physical vapor deposited coatings with platinum-aluminide (Pt-Al) bonds was undertaken. Coatings of Zirconia with thicknesses of 125 {micro}m (0.005 in.), 190 {micro}m (0.0075 in.), and 254 {micro}m (0.010 in.) with a Pt-Al bond coat on Rene N5 Ni-based superalloy were studied by infrared imaging. Currently, it appears that thickness variation, as well as thermal properties, can be assessed by infrared technology.

Ellingson, W.A.; Koehl, R.D.; Stuckey, J.B.; Sun, J.G. [Argonne National Lab., IL (United States). Energy Technology Div.; Engel, H.P. [Heaviside Science, Inc., Melbourne, FL (United States); Smith, R.G. [3M Corp., St. Paul, MN (United States)

1997-06-01

134

Evaluation of Advanced Non-Destructive Inspection Methods for Aircraft Tires.  

National Technical Information Service (NTIS)

Advanced Non-Destructive (NDT) Aircraft Tire Inspection Systems were evaluated and compared with the air needle inspection technique normally used to qualify air carrier aircraft tires for repair, retread, and return to service. The advanced NDT inspectio...

D. D. Ewing

1980-01-01

135

Investigation of Electronic Ceramic Fibers for Non-Destructive Evaluation of Advanced Composites.  

National Technical Information Service (NTIS)

The objective was to investigate the feasibility of developing and using crystal-bearing filaments as sensors in the non-destructive evaluation of fiber-reinforced plastic structural materials. The fibers or filaments contain crystalline oxidic materials ...

D. R. Ulrich E. C. Henry H. W. Rauch

1973-01-01

136

Computed Tomography for Non-Destructive Evaluation of Composites: Applications and Correlations.  

National Technical Information Service (NTIS)

The state-of-the-art fabrication techniques for composite materials are such that stringent species-specific acceptance criteria must be generated to insure product reliability. Non-destructive evaluation techniques including computed tomography (CT), X-r...

B. Goldberg L. Hediger E. Noel

1985-01-01

137

The impact of nonlinear propagation effects in water on ultrasound used in industrial nondestructive evaluation  

NASA Astrophysics Data System (ADS)

An experimental study was conducted to demonstrate the presence of, and assess the quantitative impact of nonlinear propagation effects of water on ultrasonic pulses generated by 5 MHz transducers of the type used in industrial ultrasonic nondestructive evaluation (NDE). Emphasis was placed on ultrasonic instrumentation and configurations which are representative of those widely used in the aerospace and metals industries. First, a brief description of ultrasonic NDE and some background on medical and industrial ultrasonic NDE applications, along with rationale for a study of this type, is presented. Next, the extensive theoretical and experimental work done by the medical community in the area of nonlinear ultrasound propagation is summarized. The manifestations of nonlinear propagation are described. The experimental configuration used in this study, its extensive characterization, and the methodology of pulse spectral analysis as used here are also described. Experimental data are presented which definitively show that nonlinear propagation effects, due solely to the water coupling medium, are present for typical industrial ultrasonic NDE testing configurations, and why these effects are not normally observed in practice. Also presented are experimental data used to assess the quantitative impact of these effects in commonly-used industrial ultrasonic measurements, especially with respect to interpretation and measurement uncertainty. The results conclusively demonstrate the presence of nonlinear propagation effects for these testing configurations, and their small quantitative impact on industrial NDE testing.

Slotwinski, John Anthony

1998-10-01

138

Technologies for Nondestructive Evaluation of Surfaces and Thin Coatings  

NASA Technical Reports Server (NTRS)

The effort included in this project included several related activities encompassing basic understanding, technological development, customer identification and commercial transfer of several methodologies for nondestructive evaluation of surfaces and thin surface coatings. Consistent with the academic environment, students were involved in the effort working with established investigators to further their training, provide a nucleus of experienced practitioners in the new technologies during their industrial introduction, and utilize their talents for project goals. As will be seen in various portions of the report, some of the effort has led to commercialization. This process has spawned other efforts related to this project which are supported from outside sources. These activities are occupying the efforts of some of the people who were previously supported within this grant and its predecessors. The most advanced of the supported technologies is thermography, for which the previous joint efforts of the investigators and NASA researchers have developed several techniques for extending the utility of straight thermographic inspection by producing methods of interpretation and analysis accessible to automatic image processing with computer data analysis. The effort reported for this technology has been to introduce the techniques to new user communities, who are then be able to add to the effective uses of existing products with only slight development work. In a related development, analysis of a thermal measurement situation in past efforts led to a new insight into the behavior of simple temperature probes. This insight, previously reported to the narrow community in which the particular measurement was made, was reported to the community of generic temperature measurement experts this year. In addition to the propagation of mature thermographic techniques, the development of a thermoelastic imaging system has been an important related development. Part of the work carried out in the effort reported here has been to prepare reports introducing the newly commercially available thermoelastic measurements to the appropriate user communities.

1999-01-01

139

Nondestructive evaluation of repairs on aircraft composite structures  

Microsoft Academic Search

Composite sandwiches have been used widely in flight controls of aircraft for many years; solid laminates have also begun to appear in primary structures such as the empennage. In their normal service life, composite parts may suffer damages and require repair and post-repair inspection. Nondestructive inspection is also needed for many of the rebuilt and refurbished parts in the maintenance,

David K. Hsu; Daniel J. Barnard; John J. Peters

2001-01-01

140

Nondestructive evaluation of the complex modulus master curve of asphalt concrete specimens  

NASA Astrophysics Data System (ADS)

The dynamic Young's modulus of asphalt concrete is directly related to pavement quality and is used in thickness design of pavements. There is a need for a nondestructive laboratory method to evaluate the complex modulus, which can be linked to nondestructive field measurements. This study applies seismic measurements to an asphalt concrete beam where resonant acoustic spectroscopy and optimization of frequency response functions are used to estimate the complex moduli. A good estimation of the master curve is obtained.

Gudmarsson, A.; Ryden, N.; Birgisson, B.

2013-01-01

141

Development of techniques and instrumentation for the nondestructive evaluation of multi-layer insulation  

NASA Technical Reports Server (NTRS)

The development of techniques and instrumentation suitable for the nondestructive evaluation of purged multilayer insulation prior to and after a shuttle orbiter flight is discussed. These techniques are desirable because of the possibility that corrosion, compression, or tearing of the insulation will degrade the performance of the insulation during subsequent flights. A second objective was the application of the developed technology to the evaluation of other insulation types. Three nondestructive evaluation techniques, electromagnetic, thermal, and acoustic were selected for evaluation. The results of evaluation of each technique are described.

1972-01-01

142

Nondestructive evaluation of composite materials by electrical resistance measurement  

NASA Astrophysics Data System (ADS)

This dissertation investigates electrical resistance measurement for nondestructive evaluation of carbon fiber (CF) reinforced polymer matrix composites. The method involves measuring the DC electrical resistance in either the longitudinal or through thickness direction. The thermal history and thermal properties of thermoplastic/CF composites were studied by longitudinal and through-thickness resistance measurements. The resistance results were consistent with differential scanning calorimetry (DSC) and thermomechanical analysis (TMA) results. The resistance measurements gave more information on the melting of the polymer matrix than TMA. They were more sensitive to the glass transition of the polymer matrix than DSC. The through-thickness resistance decreased as autohesion progressed. The activation energy of autohesion was 21.2 kJ/mol for both nylon-6 and polyphenylene sulfide (PPS)/CF composites. Adhesive bonding and debonding were monitored in real-time by measurement of the through-thickness resistance between the adherends in an adhesive joint during heating and subsequent cooling. Debonding occurred during cooling when the pressure or temperature during prior bonding was not sufficiently high. A long heating time below the melting temperature (T m) was found to be detrimental to subsequent PPS adhesive joint development above Tm, due to curing reactions below Tm and consequent reduced mass flow response above Tm. A high heating rate (small heating time) enhanced the bonding more than a high pressure. The longitudinal resistance measurement was used to investigate the effects of temperature and stress on the interface between a concrete substrate and its epoxy/CF composite retrofit. The resistance of the retrofit was increased by bond degradation, whether the degradation was due to heat or stress. The degradation was reversible. Irreversible disturbance in the fiber arrangement occurred slightly as thermal or load cycling occurred, as indicated by the resistance decreasing cycle by cycle. This dissertation also addresses the use of the electrical resistance method to observe thermal and mechanical damage in real time. A temperature increase caused the interlaminar contact resistance to decrease reversibly within each thermal cycle, while thermal damage caused the resistance to decrease abruptly and irreversibly, due to matrix molecular movement and the consequent increase in the chance of fibers of one lamina touching those of an adjacent lamina. The through-thickness volume resistivity irreversibly and gradually decreased upon mechanical damage, which was probably fiber-matrix debonding. Moreover, it reversibly and abruptly increased upon matrix micro-structural change, which occurred reversibly near the peak stress of a stress cycle.

Mei, Zhen

143

Nondestructive evaluation of anthocyanins in olive (Olea europaea) fruits by in situ chlorophyll fluorescence spectroscopy.  

PubMed

Anthocyanins (Anths) in olive (Olea europaea L.) fruits at different degrees of pigmentation were assessed nondestructively by measuring chlorophyll fluorescence (ChlF). The method is based on the comparison of the ChlF excitation spectra from olives with different pigmentation from green to green-red, reddish-purple, and purple. The logarithm of the ratio between the fluorescence excitation spectra (logFER) from two different colored zones gave the difference in the absorption spectrum between them. The absorbance spectrum derived from the logFER between a red olive and the same olive devoid of the skin showed the typical Anth green band (at 550 nm). It matched that recorded by microspectrophotometry on a single pulp cell and the in vitro absorbance spectrum of the olive skin extract. As expected, the in vivo Anths absorption maximum increased in intensity going from less to more mature olives and was higher in the sun-exposed olive side with respect to the sun-shaded side. Absolute quantitative nondestructive determination of Anths for each olive sample was obtained by the logFER calculated for two excitation wavelengths, 550 and 625 nm, of ChlF at 740 nm. Going from green to purple skin colors, the Log[ChlF(625)/ChlF(550)] was fairly well-correlated to the extract Anths concentration. Finally, the relationship between the Anths and the other main phenolics present in the olives analyzed by high-performance liquid chromatography was evaluated. The main result was a net increase of verbascoside with increasing Anths content. On the basis of our results, the development of a new rapid and noninvasive method for the monitoring of olive development and ripening can be envisaged. PMID:15740006

Agati, Giovanni; Pinelli, Patrizia; Cortés Ebner, Solange; Romani, Annalisa; Cartelat, Aurélie; Cerovic, Zoran G

2005-03-01

144

Development of nondestructive evaluation methods for ceramic coatings.  

SciTech Connect

Various nondestructive evaluation (NDE) technologies are being developed to study the use of ceramic coatings on components in the hot-gas path of advanced low-emission gas-fired turbines. The types of ceramic coatings include thermal barrier coatings (TBCs) and environmental barrier coatings (EBCs). TBCs are under development for vanes, blades, and combustor liners to allow hotter gas-path temperatures, and EBCs are under development to reduce environmental damage to high-temperature components made of ceramic matrix composites. The NDE methods will be used to (a) provide data to assess the reliability of new coating application processes, (b) identify defective components that could cause unscheduled outages, (c) track growth rates of defects during component use in engines, and (d) allow rational judgment for replace/repair/re-use decisions regarding components. Advances in TBC application, both electron beam-physical vapor deposition (EB-PVD) and air plasma spraying (APS), are allowing higher temperatures in the hot-gas path. However, as TBCs become ''prime reliant,'' their condition at scheduled or unscheduled outages must be known. NDE methods are under development to assess the condition of the TBC for pre-spall conditions. EB-PVD test samples with up to 70 thermal cycles have been studied by a newly developed method involving polarized laser back-scatter NDE. Results suggest a correlation between the NDE laser data and the TBC/bond-coat topography. This finding is important because several theories directed toward understanding the pre-spall condition suggest that the topography in the thermally grown oxide layer changes significantly as a function of the number of thermal cycles. Tests have also been conducted with this NDE method on APS TBCs. Results suggest that the pre-spall condition is detected for these coatings. One-sided, high-speed thermal imaging also has shown promise for NDE of APS coatings. Testing of SiC/SiC composites for combustor liners has demonstrated that environmental EBCs are required to reduce oxidation-induced recession rates. NDE technologies, primarily one-sided and through-thickness thermal imaging, are under development to detect delaminations and degradation of EBCs. Recent results have demonstrated that NDE thermal image data correctly detected pre-spall regions of a barium-strontium-alumino-silicate coating on melt-infiltrated SiC/SiC. The NDE data were verified with field test data from a combustor liner in a 4.5 MW(e) natural-gas-fired turbine. The shape of the spalled EBC region and the growth of the spalled EBC region after various engine run times were correlated with boroscope image data from field tests. An effort has recently been started to address NDE development for oxide/oxide ceramic composites with an EBC. We will discuss the NDE methods under development for TBCs, recent NDE test results from thermally cycled TBCs, NDE results from EBCs on SiC/SiC, and the new effort directed toward oxide/oxide materials.

Ellingson, W. A.; Deemer, C.; Sun, J. G.; Erdman, S.; Muliere, D.; Wheeler, B.

2002-04-29

145

Nondestructive Evaluation of Ceramic Matrix Composite Combustor Components  

NASA Technical Reports Server (NTRS)

Combustor liners fabricated from a SiC/SiC composite were nondestructively interrogated before and after combustion rig testing by X-ray, ultrasonic and thermographic techniques. In addition, mechanical test results were obtained from witness coupons, representing the as-manufactured liners, and from coupons machined from the components after combustion exposure. Thermography indications were found to correlate with reduced material properties obtained after rig testing. The thermography indications in the SiC/SiC liners were delaminations and damaged fiber tows, as determined through microstructural examinations. [copyright] 2003 American Institute of Physics

Sun, J. G.; Verrilli, M. J.; Stephan, R.; Barnett, T. R.; Ojard, G.

2003-01-01

146

Non-destructive observation of meteorite chips using quantitative analysis of optimized X-ray micro-computed tomography  

NASA Astrophysics Data System (ADS)

A method for the non-destructive observation of extraterrestrial materials using X-ray computed tomography (CT) is discussed. This method allows to image texture of objects in meteorites without destructive methods of sample preparation. Quantitative analysis of X-ray CT data was achieved by measuring X-ray linear attenuation coefficients (LACs). The histogram of the LAC value provides information regarding the meteorite structure, such as the internal components and their chemical composition. The change of the signal-to-noise ratio (S/N ratio) of CT data is investigated by optimizing the CT measurement conditions. These results form an important baseline for the initial analysis of extraterrestrial materials.

Uesugi, M.; Uesugi, K.; Oka, M.

2010-11-01

147

A system identification based approach for pulsed eddy current non-destructive evaluation  

NASA Astrophysics Data System (ADS)

This paper is concerned with the development of a new system identification based approach for pulsed eddy current non-destructive evaluation. The new approach regards the relationship between the eddy current probe excitation and sensor response as a system, uses the system identification techniques to establish a transfer function model for the system from the excitation and response data, and extracts the features of inspected structures from the identified transfer function model parameters for non-destructive evaluations. The use of the new approach in experimental studies verifies its effectiveness and demonstrates its potential in engineering applications.

Lang, Z. Q.; Agurto, A.; Tian, G. Y.; Sophian, A.

2007-07-01

148

Laser modulated scattering as a nondestructive evaluation tool for optical surfaces and thin film coatings  

SciTech Connect

Laser modulated scattering (LMS) is introduced as a non-destructive evaluation tool for defect inspection and characterization of optical surfaces and thin film coatings. This technique is a scatter sensitive version of the well-known photothermal microscopy (PTM) technique. It allows simultaneous measurement of the DC and AC scattering signals of a probe laser beam from an optical surface. By comparison between the DC and AC scattering signals, one can differentiate absorptive defects from non-absorptive ones. This paper describes the principle of the LMS technique and the experimental setup, and illustrates examples on using LMS as a tool for nondestructive evaluation of high quality optics.

Feit, M D; Kozlowski, M R; Rubenchik, A M; Sheehan, L; Wu, Z L

1999-12-22

149

Optimization of ISOCS Parameters for Quantitative Non-Destructive Analysis of Uranium in Bulk Form  

NASA Astrophysics Data System (ADS)

Quantitative calculation of the isotopic masses of fissionable U and Pu is important for forensic analysis of nuclear materials. ?-spectrometry is the most commonly applied tool for qualitative detection and analysis of key radionuclides in nuclear materials. Relative isotopic measurement of U and Pu may be obtained from ?-spectra through application of special software such as MGAU (Multi-Group Analysis for Uranium, LLNL) or FRAM (Fixed-Energy Response Function Analysis with Multiple Efficiency, LANL). If the concentration of U/Pu in the matrix is unknown, however, isotopic masses cannot be calculated. At present, active neutron interrogation is the only practical alternative for non-destructive quantification of fissionable isotopes of U and Pu. An active well coincidence counter (AWCC), an alternative for analyses of uranium materials, has the following disadvantages: 1) The detection of small quantities (?100 g) of 235U is not possible in many models; 2) Representative standards that capture the geometry, density and chemical composition of the analyzed unknown are required for precise analysis; and 3) Specimen size is severely restricted by the size of the measuring chamber. These problems may be addressed using modified ?-spectrometry techniques based on a coaxial HPGe-detector and ISOCS software (In Situ Object Counting System software, Canberra). We present data testing a new gamma-spectrometry method uniting actinide detection with commonly utilized software, modified for application in determining the masses of the fissionable isotopes in unknown samples of nuclear materials. The ISOCS software, widely used in radiation monitoring, calculates the detector efficiency curve in a specified geometry and range of photon energies. In describing the geometry of the source-detector, it is necessary to clearly describe the distance between the source and the detector, the material and the thickness of the walls of the container, as well as material, density and chemical composition of the matrix of the specimen. Obviously, not all parameters can be characterized when measuring samples of unknown composition or uranium in bulk form. Because of this, and especially for uranium materials, the IAEA developed an ISOCS optimization procedure. The target values for the optimization are ?matrixfixed, the matrix mass determined by weighing with a known mass container, and ?fixed, the 235U enrichment, determined by MGAU. Target values are fitted by varying the matrix density (?), and the concentration of uranium in the matrix of the unknown (w). For each (?i, wi), an efficiency curve is generated, and the masses of uranium isotopes, ?235Ui and ?238Ui, determined using spectral activity data and known specific activities for U. Finally, fitted parameters are obtained for ?matrixi = ?matrixfixed ± 1?, ?i = ?fixed ± 1?, as well as important parameters (?i, wi, ?235Ui, ?238Ui, ?Ui). We examined multiple forms of uranium (powdered, pressed, and scrap UO2 and U3O8) to test this method for its utility in accurately identifying the mass and enrichment of uranium materials, and will present the results of this research.

Kutniy, D.; Vanzha, S.; Mikhaylov, V.; Belkin, F.

2011-12-01

150

Ultrasound nondestructive evaluation (NDE) imaging with transducer arrays and adaptive processing.  

PubMed

This paper addresses the challenging problem of ultrasonic non-destructive evaluation (NDE) imaging with adaptive transducer arrays. In NDE applications, most materials like concrete, stainless steel and carbon-reinforced composites used extensively in industries and civil engineering exhibit heterogeneous internal structure. When inspected using ultrasound, the signals from defects are significantly corrupted by the echoes form randomly distributed scatterers, even defects that are much larger than these random reflectors are difficult to detect with the conventional delay-and-sum operation. We propose to apply adaptive beamforming to the received data samples to reduce the interference and clutter noise. Beamforming is to manipulate the array beam pattern by appropriately weighting the per-element delayed data samples prior to summing them. The adaptive weights are computed from the statistical analysis of the data samples. This delay-weight-and-sum process can be explained as applying a lateral spatial filter to the signals across the probe aperture. Simulations show that the clutter noise is reduced by more than 30 dB and the lateral resolution is enhanced simultaneously when adaptive beamforming is applied. In experiments inspecting a steel block with side-drilled holes, good quantitative agreement with simulation results is demonstrated. PMID:22368457

Li, Minghui; Hayward, Gordon

2012-01-01

151

Recent Developments of Aircraft Nondestructive Evaluation Based on Advanced Sensor Techniques  

Microsoft Academic Search

The safety and structural integrity are of great importa nce to military and commercial aircraft, and the developments of effective nondestruct ive evaluation (NDE) methods are receiving much attention in recent years. The objective o f this paper was to provide the recent developments of aircraft NDE based on advanced sensor t echniques: (a) Ultrasonic testing with piezoceramic sensor arrays,

Gongjin QI; Hong LEI; Rongsheng GENG; Peng JING

152

ELECTROMECHANICAL IMPEDANCE TECHNIQUE FOR STRUCTURAL HEALTH MONITORING AND NON-DESTRUCTIVE EVALUATION  

Microsoft Academic Search

The scientific community across the globe is thrusting significant efforts toward the development of new techniques for structural health monitoring (SHM) and non-destructive evaluation (NDE), which could be equally suitable for civil-structures, heavy machinery, aircraft and spaceships. This need arises from the fact that intensive usage combined with long endurance causes gradual but unnoticed deterioration in structures, often leading to

Suresh Bhalla; Chee-Kiong Soh

153

Assessing Primary Water Stress Corrosion Crack Morphology and Nondestructive Evaluation Reliability  

Microsoft Academic Search

A research program on primary water stress corrosion cracking (PWSCC) is being conducted by Pacific Northwest National Laboratory (PNNL). In this program, the material degradation problem in Alloys 600, 182 and 82 is being investigated, with objectives that include compiling a knowledge base on all cracking in nickel-base materials at all degradation sites in nuclear power plants, assessing nondestructive evaluation

Steven R; George J. Schuster; Michael T. Anderson

2005-01-01

154

Electromagnetic nondestructive evaluation: moving HTS SQUIDs, inducing field nulling and dual frequency measurements  

Microsoft Academic Search

We have previously shown that simple, single layer HTS SQUIDs can be used effectively in electromagnetic nondestructive evaluation (NDE) using eddy current techniques in a magnetically unshielded environment. HTS SQUID systems for NDE applications are expected to be small and portable allowing non-stationary measurements to be carried out in the Earth's field above a stationary sample. Here we present application-oriented

C. Carr; D. Mc A. McKirdy; E. J. Romans; G. B. Donaldson; A. Cochran

1997-01-01

155

Development and Evaluation of Experimental Core and Magnetic Particle/Liquid Penetrant Nondestructive Testing Training.  

National Technical Information Service (NTIS)

The study reports on the redesign of a part of the Navy Nondestructive Testing (NDT) School's curriculum and the evaluation of the redesign effort. The effort has resulted in two new NDT package courses: A core training package including material common t...

M. L. Abrams R. G. Wells

1971-01-01

156

Nondestructive evaluation of explosively welded clad rods by resonance acoustic spectroscopy  

Microsoft Academic Search

A resonance acoustic spectroscopy technique is assessed for nondestructive evaluation of explosively welded clad rods. Each rod is modeled as a two-layered cylinder with a spring-mass system to represent a thin interfacial layer containing the weld. A range of interfacial profiles is generated in a set of experimental samples by varying the speed of the explosion that drives the copper

Y. Fan; B. Tysoe; J. Sim; K. Mirkhani; A. N. Sinclair; F. Honarvar; Harry Sildva; Alexander Szecket; Roy Hardwick

2003-01-01

157

Foreword to the special section on electromagnetic and ultrasonic nondestructive evaluation  

Microsoft Academic Search

A central aim of nondestructive evaluation (NDE) is to acquire knowledge of material properties and flaws in manufactured components from measurements using sensors. New developments in NDE are motivated by the desire for quality control of manufactured parts and by the need to maintain the safe operation of industrial plant and machinery. Aircraft, nuclear power plants, gas pipelines and many

Dominique Lesselier; John Bowler

2002-01-01

158

On-line nondestructive evaluation of carbon content of steel using surface temperature during induction heating  

Microsoft Academic Search

A novel method was put forward to on-line evaluate the carbon content of low alloys and carbon steels nondestructively by measuring surface temperature of billet. The practical induction heating process for steel bar was simulated by finite element method. The regression equation for determining carbon content was derived from simulated data. The carbon content and temperature dependence of physical properties,

Sun Yafei; Niu Dongjie; Sun Jing

2009-01-01

159

Experimental Comparison of Lock-in and Pulsed Thermography for the Nondestructive Evaluation of Aerospace Materials  

Microsoft Academic Search

Infrared thermography is a nondestructive evaluation technique aimed to the detection of surface temperature variations related to the presence of subsurface defects. Several inspection techniques have been developed over the years with basically two approaches, lock-in thermography and pulsed thermography. These two techniques are based on the principle of heat diffusion and thermal wave reflection, but they differ in the

W. Ben Larbi; C. Ibarra-Castanedo; M. Klein; A. Bendada; X. Maldague

160

Nondestructive evaluation: A survey of NASA contributions, chapter 1, Chapter 11, cover page, acknowledgements, and contents  

NASA Technical Reports Server (NTRS)

A survey of nondestructive evaluation (NDE) technology, which is discussed in terms of popular demands for a greater degree of quality, reliability, and safety in industrial products, is presented as an overview of the NDE field to serve the needs of middle management. Three NDE methods are presented: acoustic emission, the use of coherent (laser)light, and ultrasonic holography.

1972-01-01

161

Nondestructive Evaluation of Aircraft Composites Using Dielectric Properties and Imaging in the Terahertz Spectrum  

Microsoft Academic Search

Terahertz imaging and dielectric property measurements were assessed as nondestructive evaluation techniques for damage to aircraft glass fiber composites. Samples with localized heat damage showed a minimal change in refractive index or absorption coefficient; however, material blistering was detected. Voids were located by terahertz imaging using amplitude and phase techniques. Delamination depths were approximated by measuring the timing of Fabry-Perot

C. D. Stoik; M. J. Bohn; J. L. Blackshire

2009-01-01

162

NONDESTRUCTIVE EVALUATION OF AIRCRAFT COMPOSITES USING DIELECTRIC PROPERTIES AND IMAGING IN THE TERAHERTZ SPECTRUM  

Microsoft Academic Search

Terahertz imaging and dielectric property measurements were assessed as nondestructive evaluation techniques for damage to aircraft glass fiber composites. Samples with localized heat damage showed a minimal change in refractive index or absorption coefficient; however, material blistering was detected. Voids were located by terahertz imaging using amplitude and phase techniques. Delamination depths were approximated by measuring the timing of Fabry-Perot

C. D. Stoik; M. J. Bohn; J. L. Blackshire

2009-01-01

163

Nondestructive evaluation of aircraft composites using reflective terahertz time domain spectroscopy  

Microsoft Academic Search

Terahertz time domain spectroscopy in reflection configuration was assessed as a nondestructive evaluation technique for aircraft glass fiber composites. A technique for measuring the material properties of glass fiber composites using reflection geometry was demonstrated in addition to imaging of damaged glass fiber composites. Surface defects such as localized burn damage, puncture holes, and paint\\/composite removal were detected using amplitude

Christopher Stoik; Matthew Bohn; James Blackshire

2010-01-01

164

Non-destructive evaluation of aerospace materials with lock-in thermography  

Microsoft Academic Search

The attention of the present study was focused on the aid provided by lock-in thermography for non-destructive evaluation of aerospace materials and structures. The experimental analysis was performed by testing several specimens, which were made of different materials employed in the fabrication of aircraft (composites, hybrid composites, sandwiches, metals) and which included the most commonly encountered kinds of damage (delamination,

Carosena Meola; Giovanni Maria Carlomagno; Antonino Squillace; Antonio Vitiello

2006-01-01

165

Acousto-ultrasonic nondestructive evaluation of materials using laser beam generation and detection  

NASA Technical Reports Server (NTRS)

Presented in viewgraph format, the possibility of using laser generation and detection of ultrasound to replace piezoelectric transducers for the acousto-ultrasonic technique is advanced. The advantages and disadvantages of laser acousto-ultrasonics are outlined. Laser acousto-ultrasonics complements standard piezoelectric acousto-ultrasonics and offers non-contact nondestructive evaluation.

Huber, Robert D.; Green, Robert E., Jr.; Vary, Alex; Kautz, Harold

1990-01-01

166

Theory and application of high temperature superconducting eddy current probes for nondestructive evaluation  

Microsoft Academic Search

Several High-T c Superconducting (HTS) eddy current probes have been developed for applications in electromagnetic nondestructive evaluation (NDE) of conducting materials. The probes utilize high-T c SUperconducting Quantum Interference Device (SQUID) magnetometers to detect the fields produced by the perturbation of induced eddy currents resulting from subsurface flaws. Localized HTS shields are incorporated to selectively screen out environmental electromagnetic interference

James Ronald Claycomb

1998-01-01

167

Design, development and application of a novel microwave nondestructive evaluation sensor based on metamaterial lens  

Microsoft Academic Search

Nondestructive Evaluation (NDE) method is one of the primary tools of inspecting different materials for structural reliability. Microwave NDE techniques attract more and more attention from the industry and academia. Microwave NDE techniques have the potential to penetrate deeper into materials such as composites and other dielectrics as compared to ultrasonic techniques. Microwave NDE sensors typically operate in two modes---far

Daniel Shreiber

2008-01-01

168

The thermographic nondestructive evaluation of iron aluminide green sheet  

Microsoft Academic Search

The recent development of manufacturing techniques for the fabrication of thin iron aluminide sheet requires advanced quantitative methods for on-line inspection. An understanding of the mechanisms responsible for flaws and the development of appropriate flaw detection methods are key elements in an effective quality management system. The first step in the fabrication of thin FeAl alloy sheet is the formation

Michael Lee Watkins

1999-01-01

169

Nondestructive Evaluation of Dual Microstructure Turbine Engine Disk Material  

NASA Astrophysics Data System (ADS)

We present development status and plans for NDE of graded material microstructures such as those found in dual microstructure turbine engine disks. These hybrid disks feature coarse grain microstructures in the rim for increased creep resistance and fine grain microstructures in the bore for optimal fracture toughness and fatigue resistance. Preliminary eddy current measurements and ultrasonic measurements, including longitudinal, shear, and Rayleigh wave velocity, frequency dependent attenuation, and backscattered grain noise resulted in clear identification of the coarse grain, transition, and fine grain regions, and are the basis for development of quantitative methods for NDE of microstructure.

Medina, E. A.; Blodgett, M. P.; Martin, R. W.; Sathish, S.

2011-06-01

170

Stress-wave nondestructive evaluation of green veneer: southern yellow pine and Douglas fir  

NASA Astrophysics Data System (ADS)

The potential of using stress wave nondestructive evaluation techniques to sort green southern yellow pine and DOuglas fir veneer into stress grades was evaluated. Stress wave nondestructive evaluation was used to separate green veneer into several grades for use in manufacturing engineered wood composites, most notably laminated veneer lumber. The effect of moisture content and preservative treatment on stress wave determined properties of green (wet) southern yellow pine and Douglas fir veneer was investigated during the preliminary stages of the project. A digital oscilloscope and a commercial stress wave timer were used to measure the transit time it took for an induced stress wave to travel the longitudinal length of each veneer. Stress wave transit times were measured in each piece in the wet condition, during drying, and at a dry equilibrated moisture content of approximately 10 percent. Strong correlative relationships exist between stress wave velocity measured in untreated and preservative treated green (wet) and dry veneer.

Brashaw, Brian K.; Ross, Robert J.; Pellerin, Roy F.

1996-11-01

171

A study of the stress wave factor technique for nondestructive evaluation of composite materials  

NASA Technical Reports Server (NTRS)

The acousto-ultrasonic method of nondestructive evaluation is an extremely sensitive means of assessing material response. Efforts continue to complete the understanding of this method. In order to achieve the full sensitivity of the technique, extreme care must be taken in its performance. This report provides an update of the efforts to advance the understanding of this method and to increase its application to the nondestructive evaluation of composite materials. Included are descriptions of a novel optical system that is capable of measuring in-plane and out-of-plane displacements, an IBM PC-based data acquisition system, an extensive data analysis software package, the azimuthal variation of acousto-ultrasonic behavior in graphite/epoxy laminates, and preliminary examination of processing variation in graphite-aluminum tubes.

Sarrafzadeh-Khoee, A.; Kiernan, M. T.; Duke, J. C., Jr.; Henneke, E. G., II

1986-01-01

172

Nondestructive Evaluation of Thermal Spray Coating Interface Quality by Eddy Current Method  

NASA Astrophysics Data System (ADS)

Thermal spray coating is usually applied through directing molten or softened particles at very high velocities onto a substrate. An eddy current non-destructive inspection technique is presented here for thermal spray coating interface quality characterization. Several high-velocity-oxy-fuel (HVOF) coated steel plates were produced with various surface preparation conditions or spray process parameters. A quad-frequency eddy current probe was used to manually scan over the coating surface to evaluate the bonding quality. Experimental results show that different surface preparation conditions and varied process parameters can be successfully differentiated by the impedance value observed from the eddy current probe. The measurement is fairly robust and consistent. This non-contact, nondestructive, easy-to-use technique has the potential for evaluating the coating quality immediately after its application so that any defects can be corrected immediately.

Mi, Bao; Zhao, Xiaoliang (George); Bayles, Robert

2007-03-01

173

Non-Destructive Evaluation of Thermal Spray Coating Interface Quality By Eddy Current Method  

SciTech Connect

Thermal spray coating is usually applied through directing molten or softened particles at very high velocities onto a substrate. An eddy current non-destructive inspection technique is presented here for thermal spray coating interface quality characterization. Several high-velocity-oxy-fuel (HVOF) coated steel plates were produced with various surface preparation conditions or spray process parameters. A quad-frequency eddy current probe was used to manually scan over the coating surface to evaluate the bonding quality. Experimental results show that different surface preparation conditions and varied process parameters can be successfully differentiated by the impedance value observed from the eddy current probe. The measurement is fairly robust and consistent. This non-contact, nondestructive, easy-to-use technique has the potential for evaluating the coating quality immediately after its application so that any defects can be corrected immediately.

B. Mi; G. Zhao; R. Bayles

2006-08-10

174

Proceedings of the Second Annual Symposium for Nondestructive Evaluation of Bond Strength  

NASA Technical Reports Server (NTRS)

Ultrasonics, microwaves, optically stimulated electron emission (OSEE), and computational chemistry approaches have shown relevance to bond strength determination. Nonlinear ultrasonic nondestructive evaluation methods, however, have shown the most effectiveness over other methods on adhesive bond analysis. Correlation to changes in higher order material properties due to microstructural changes using nonlinear ultrasonics has been shown related to bond strength. Nonlinear ultrasonic energy is an order of magnitude more sensitive than linear ultrasound to these material parameter changes and to acoustic velocity changes caused by the acoustoelastic effect when a bond is prestressed. Signal correlations between non-linear ultrasonic measurements and initialization of bond failures have been measured. This paper reviews bond strength research efforts presented by university and industry experts at the Second Annual Symposium for Nondestructive Evaluation of Bond Strength organized by the NDE Sciences Branch at NASA Langley in November 1998.

Roberts, Mark J. (Compiler)

1999-01-01

175

Step-frequency radar imaging for nondestructive evaluation (NDE) and ground-penetrating radar (GPR) applications  

Microsoft Academic Search

We describe a step-frequency microwave radar imaging system that is suitable for nondestructive evaluation (NDE) and ground-penetrating radar (GPR) applications. The system includes a computer-automated microwave measurement apparatus along with nonlinear inverse scattering imaging algorithms. Through the use of an inverse Fourier transform, the SFR data is transformed into a synthetic time-domain pulse, and imaging algorithms are applied to the

William H. Weedon; Weng C. Chew; Chad A. Ruwe

1994-01-01

176

Elastic-Wave Propagation in Random Polycrystals: Fundamentals and Application to Nondestructive Evaluation  

Microsoft Academic Search

The fundamental principles that govern the propagation of elastic waves in metal polycrystals are discussed in the context\\u000a of their influence on nondestructive evaluation. The major influence of the polycrystalline microstructure is to determine\\u000a the velocity, attenuation and backscattering of the elastic waves. For randomly oriented, equi-axed polycrystals, these effects\\u000a are reasonably well understood. Waves travel at the same velocity

Bruce R. Thompson

177

PREDICTION OF DISSOLVER LIFETIMES THROUGH NON-DESTRUCTIVE EVALUATION AND LABORATORY TESTING  

Microsoft Academic Search

Non-destructive evaluation was used as the primary method of monitoring the corrosion degradation of nuclear material dissolvers and assessing the remaining lifetimes. Materials were typically processed in nitric acid based (4-14M) solutions containing fluoride concentrations less than 0.2 M. The primary corrosion issue for the stainless steel dissolvers is the occurrence of localized corrosion near the tank bottom and the

J. Mickalonis; T. Woodsmall; W. Hinz; T. Edwards

2011-01-01

178

A novel, compact, low-cost, impulse ground-penetrating radar for nondestructive evaluation of pavements  

Microsoft Academic Search

This paper reports on the development of a novel, compact, low-cost, impulse ground-penetrating radar (GPR) and demonstrate its use for nondestructive evaluation of pavement structures. This GPR consists of an ultrashort-monocycle-pulse transmitter (330 ps), an ultrawide-band (UWB) sampling receiver (0-6 GHz), and two UWB antennas (0.2-20 GHz)-completely designed using microwave-integrated circuits with seamless electrical connections between them. An approximate analysis

Jeong Soo Lee; Cam Nguyen; Thomas Scullion

2004-01-01

179

Nondestructive Evaluation of Advanced Fiber Reinforced Polymer Matrix Composites: A Technology Assessment  

NASA Technical Reports Server (NTRS)

Because of their increasing utilization in structural applications, the nondestructive evaluation (NDE) of advanced fiber reinforced polymer composites continues to receive considerable research and development attention. Due to the heterogeneous nature of composites, the form of defects is often very different from a metal and fracture mechanisms are more complex. The purpose of this report is to provide an overview and technology assessment of the current state-of-the-art with respect to NDE of advanced fiber reinforced polymer composites.

Yolken, H. Thomas; Matzkanin, George A.

2009-01-01

180

A Geometrical Theory for Eddy-Current Non-Destructive Evaluation  

Microsoft Academic Search

In eddy-current non-destructive evaluation, an electromagnetic field is induced in a metal by means of an eddy-current probe and the presence of a flaw is indicated by a change in probe impedance. In order to predict the impedance change, it is necessary to calculate the electromagnetic field in the region of the flaw. We present a new method, based on

N. Harfield; J. R. Bowler

1997-01-01

181

Terahertz imaging for non-destructive evaluation of mural paintings  

Microsoft Academic Search

The feasibility of applying time-domain, terahertz spectroscopic imaging to the evaluation of underdrawings and paint layers embedded within wall paintings is demonstrated. Metallic and dielectric paint patterns and a graphite drawing are resolved through both paint and plaster overlayers using a pulsed-terahertz reflectometer and imaging system. We calculated the bulk refractive indices of four common pigments and used them to

J. B. Jackson; M. Mourou; J. F. Whitaker; I DULINGIII; S. L. Williamson; M. Menu; G. A. Mourou

2008-01-01

182

Terahertz imaging for non-destructive evaluation of mural paintings  

NASA Astrophysics Data System (ADS)

The feasibility of applying time-domain, terahertz spectroscopic imaging to the evaluation of underdrawings and paint layers embedded within wall paintings is demonstrated. Metallic and dielectric paint patterns and a graphite drawing are resolved through both paint and plaster overlayers using a pulsed-terahertz reflectometer and imaging system. We calculated the bulk refractive indices of four common pigments and used them to confirm color domains in a terahertz-beam spectral image of a painting.

Jackson, J. B.; Mourou, M.; Whitaker, J. F.; Duling, I. N.; Williamson, S. L.; Menu, M.; Mourou, G. A.

2008-02-01

183

Development of nondestructive evaluation methods and prediction of effects of flaws on the fracture behavior of structural ceramics.  

National Technical Information Service (NTIS)

Characterization of ceramic matrix composites (continuous and whisker-type) by nondestructive evaluation (NDE) methods and an understanding of fracture behavior, together with correlation of fracture and NDE data, may provide insight into the prediction o...

W. A. Ellingson J. P. Singh D. L. Holloway S. L. Dieckman D. Singh

1992-01-01

184

Remote visual inspection for nondestructive evaluation in power plants  

NASA Astrophysics Data System (ADS)

Remote visual inspection equipment such as borescopes, fiberscopes and videoimagescopes provide Power Plant NDE groups with the necessary tools for establishing superior corrective and preventative plant maintenance programs. These scopes allow the user to evaluate the condition of pipes, boilers, turbines, heat exchangers and other critical machinery without costly and time consuming disassembly. Overall plant efficiency is increased and the likelihood of catastrophic failure is reduced significantly. Ancillary equipment such as video and digital processors provide a permanent record of the inspection while employing sophisticated 3-D measurement, trend analysis, documentation and image manipulation.

Samsonov, Peter

1994-02-01

185

Non-destructive evaluation of YIG Films by ferromagnetic resonance  

SciTech Connect

A new technique for evaluating thick YIG films by measuring the ferromagnetic resonance (FMR) line-width on a localized area of the wafer is presented. The technique is based on the excitation of magnetostatic wave (MSW) resonances in a small area of the YIG film under a bias magnetic field well. The well is created by a small hole in a soft-iron plate in close proximity with the YIG film surface. The MSWs are excited by the electromagnetic fields emanating from a hole on the side of a waveguide. The technique is simple and straightforward and allows FMS measurements of different areas of a film.

Adams, J.D.; Talisa, S.H.; Kerestes, J.A. (Westinghouse Electric Corp., Pittsburgh, PA (USA). Research and Development Center)

1989-09-01

186

Non-Destructive Evaluation of Wire Insulation and Coatings  

NASA Technical Reports Server (NTRS)

The present invention uses the generation and detection of acoustic guided waves to evaluate the condition of the insulation on electrical wiring. Low order axisymmetric and flexural acoustic modes are generated in the insulated wire and travel partially in the center conductor and partially in the outer insulation. The stiffness of the insulation and the insulation's condition affect the overall wave speed and amplitude of the guided wave. Analysis of the received signal provides information about the age or useful life of the wire insulation. In accordance with the present invention, signal transmission occurs at one location on the electrical wire to be evaluated, and detection occurs at one or more locations along the electrical wire. Additional receivers can be used to improve measurement accuracy. Either the transmission transducer or one or more receiver transducers may be angled at other than 90 degrees to the wire. Generation of the guided waves can be accomplished by imparting a pressure pulse on the wire. Alternative embodiments include generation via a laser, such as a Q-switched laser or a laser diode.

Madaras, Eric I (Inventor); Anastasi, Robert F. (Inventor)

2004-01-01

187

[Activities of Center for Nondestructive Evaluation, Iowa State University  

NASA Technical Reports Server (NTRS)

The final report of NASA funded activities at Iowa State University (ISU) for the period between 1/96 and 1/99 includes two main areas of activity. The first is the development and delivery of an x-ray simulation package suitable for evaluating the impact of parameters affects the inspectability of an assembly of parts. The second area was the development of images processing tools to remove reconstruction artifacts in x-ray laminagraphy images. The x-ray simulation portion of this work was done by J. Gray and the x-ray laminagraphy work was done by J. Basart. The report is divided into two sections covering the two activities respectively. In addition to this work reported the funding also covered NASA's membership in the NSF University/Industrial Cooperative Research Center.

Gray, Joe

2002-01-01

188

Nondestructive evaluation for remanent life of aged 12Cr ferrite heat resisting steel by reversible permeability  

NASA Astrophysics Data System (ADS)

We present a magnetic and nondestructive method to evaluate the remanent life of advanced ferritic steel using the value of reversible permeability. The method to measure reversible permeability is based on the theory that the value of reversible permeability is the same differential of the hysteresis loop. The measurement principle is based on the foundation of harmonics voltage induced in a sensing coil using a lock-in amplifier tuned to the frequency of the exciting one. Results obtained for reversible permeability, Vickers hardness, and tensile strength on the aged samples show that the peak interval of reversible permeability, Vickers hardness and tensile strength decrease as aging time increases. We could estimate the remanent life of advanced ferritic steel by using the relationship between the peak interval of reversible permeability and the Larson-Miller parameter, non-destructively.

Ryu, Kwon-Sang; Kim, Chung-Seok; Baek, Un-bong; Lee, Jong Suk

2013-01-01

189

A Quantitative Evaluation of SAGE  

PubMed Central

Serial Analysis of Gene Expression (SAGE) is an innovative technique that offers the potential of cataloging both the identity and relative frequencies of mRNA transcripts in a given poly(A+) RNA preparation. Although it is a very effective approach for determining the expression of mRNA populations, there are significant biases in the observed results that are inherent in the experimental process. These are caused by sampling error, sequencing error, nonuniqueness, and nonrandomness of tag sequences. The quantitative information desired from SAGE experiments consists of estimates of the number of genes and the frequency distribution of transcript copy numbers. Of additional concern is the extent to which a given tag sequence can be assumed to be unique to its gene. The present study takes these mathematical biases into account and presents a basis for maximum likelihood estimation of gene number and transcript copy frequencies given a set of experimental results. These estimates of the true state of genomic expression are markedly different from those based directly on the observations from the underlying experiments. It also is shown that while in many cases it is probable that a given tag sequence is unique within the genome, in larger genomes this cannot be safely assumed.

Stollberg, Jes; Urschitz, Johann; Urban, Zsolt; Boyd, Charles D.

2000-01-01

190

Application of internal friction damping as a nondestructive evaluation technique for wire rope  

SciTech Connect

This paper discusses the technical feasibility of applying internal friction damping (IFD) as a nondestructive evaluation (NDE) technique to wire rope. The paper addresses the technical feasibility, laboratory testing on wire rope, and the associated test results on various samples of wire rope. These tests were evaluated in a series of laboratory experiments by measuring the internal friction damping during which several test parameters were changed. The test parameters including the tensile load, frequency of test load, exposure time of rope to load and variations in rope construction are discussed from the standpoint of IFD-NDE measurements.

Hochrein, A.A.; Sherrard, J.R.; Thiruvengadam, A.P.

1983-05-01

191

Nondestructive quality evaluation of periodically poled lithium niobate crystals by diffraction.  

PubMed

Quasi-phase-matching devices are usually fabricated by electric field poling over photolithographically defined electrode patterns on ferroelectric crystal substrates. For the optimal nonlinear optical performance of such devices, the micro-poled domain structure must ensure good fidelity to the designed grating structure. We present a nondestructive diffraction method to evaluate the quality of periodically poled lithium niobate crystals, by utilizing index modulation caused by the internal field effects. Our proposed method is much simpler than the conventional second-harmonic generation experiment, and provides a fast, low-cost but accurate means for micro-poling quality evaluation. PMID:19907574

Pandiyan, Krishnamoorthy; Kang, Yeon Sook; Lim, Hwan Hong; Kim, Byoung Joo; Cha, Myoungsik

2009-09-28

192

Millimeter Wave Nondestructive Evaluation of Corrosion Under Paint in Steel Structures  

SciTech Connect

Millimeter wave nondestructive evaluation techniques have shown great potential for detection of corrosion under paint in steel structures. They may also provide for detection of other anomalies associated with the corrosion process such as precursor pitting. This paper presents the results of an extensive investigation spanning a frequency range of 30-100 GHz and using magnitude- and phase-sensitive reflectometers. Using 2D automated scanning mechanisms, raster images of two corrosion patches are produced showing the spatial resolution capabilities of these systems as well as their potential for evaluating localized corrosion severity.

Kharkovsky, S.; Zoughi, R. [Applied Microwave Nondestructive Testing Laboratory (amntl), Electrical and Computer Engineering Department, University of Missouri-Rolla, Rolla, MO 65409 (United States)

2006-03-06

193

Nondestructive Evaluation of Composites Using Micro-Focused X-Ray CT Scanner  

SciTech Connect

Micro-Focused X-Ray CT (Micro CT) Scanner has been used for nondestructive evaluation (NDE) of composite materials at Institute of Space Technology and Aeronautics, Japan Aerospace Exploration Agency. Some successful examples of NDE of composites using Micro CT will be presented in this presentation. One example is debonding of fiber/matrix interface, splitting of fiber bundle and matrix crack in carbon/carbon composite. Another example is NDE of stitched CFRP. It was easy to evaluate state of stitch fiber. It has been demonstrated that Micro CT is a powerful device for detecting small damage/flaw in composites, such as delamination, matrix crack and void.

Sugimoto, Sunao; Aoki, Takuya; Iwahori, Yutaka; Ishikawa, Takashi [Advanced Composite Evaluation Technology Center, Institute of Space Technology and Aeronautics, Japan Aerospace Exploration Agency, 6-13-1 Ohsawa, Mitaka, Tokyo 181-0015 (Japan)

2005-04-09

194

Quantitative evaluation of self-checking circuits  

Microsoft Academic Search

Quantitative measures of self-checking power are defined for evaluation, comparison, and design of self-checking circuits. The self-testing and fault-secure properties have the corresponding quantitative measures testing input fraction (TIF), and secure input fraction (SIF). Averaging these measures over the fault set yields basic figures of merit. These simple averages can conceal faults with low values of TIF or SIF. Improved

D. J. Lu; E. J. McCluskey

1984-01-01

195

Quantitative evaluation of optical lock-in and pulsed thermography for aluminum foam material  

NASA Astrophysics Data System (ADS)

In this article, quantitative evaluation of optical thermographic techniques relative to the non-destructive inspection of aluminum foam material is studied. For this purpose, a set of aluminum foam specimens with flat-bottom holes (FBH) was inspected by both optical lock-in thermography (LT) and pulsed thermography (PT). Probability of detection (PoD) analysis, as a quantitative method to estimate the capability and reliability of a particular inspection technique, was studied and compared for both optical LT and PT inspection results.

Duan, Yuxia; Huebner, Stefanie; Hassler, Ulf; Osman, Ahmad; Ibarra-Castanedo, Clemente; Maldague, Xavier P. V.

2013-09-01

196

Development and validation of a direct, non-destructive quantitative method for medroxyprogesterone acetate in a pharmaceutical suspension using FT-Raman spectroscopy  

Microsoft Academic Search

A simple linear regression method was developed and statistically validated for the direct and non-destructive quantitative analysis—without sample preparation—of the active pharmaceutical ingredient (API) medroxyprogesterone acetate (MPA) in an aqueous pharmaceutical suspension (150mg in 1.0ml) using FT-Raman spectroscopy. The linear regression was modelled by plotting the highest peak intensity of the vector normalized spectral band between 1630 and 1590cm?1 against

T. R. M. De Beer; G. J. Vergote; W. R. G. Baeyens; J. P. Remon; C. Vervaet; F. Verpoort

2004-01-01

197

Evaluation of Ultrasonic and Thermal Nondestructive Evaluation for the Characterization of Aging Degradation in Braided Composite Materials  

NASA Technical Reports Server (NTRS)

This paper examines the ability of traditional nondestructive evaluation (NDE) techniques to measure the degradation of braided polymer composite materials subjected to thermal-humidity cycling to simulate aging. A series of braided composite coupons were examined using immersion ultrasonic and pulsed thermography techniques in the as received condition. These same specimens were then examined following extended thermal-humidity cycling. Results of this examination did not show a significant change in the resulting (NDE) signals.

Martin, Richard E.

2010-01-01

198

The applicability of a material-treatment laser pulse in non-destructive evaluations.  

PubMed

A practical optodynamic study was performed to determine the usability of different lengths of laser pulses for the generation of ultrasonic transients in a solid material. The aim of the study was to evaluate the possibility of a dual use for a laser pulse-for laser material processing, on the one hand, and for the ultrasonic wave generation on the other-with both processes being combined on the same production line. The propagation of the laser-generated ultrasonic waves is evaluated by detecting and measuring with a PID-controlled stabilized interferometer. Thus, both systems provided the basic tools, the generation and detection of ultrasonic waves, for an ultrasonic, laser-based, non-destructive material evaluation. The ultrasonic transients generated by 'classical' nanosecond laser pulses were compared with the transients generated by industrial laser pulses with a duration of a few tenths of a microsecond. The experimental results are compared with the results of a time-of-flight analysis that also involved part of a mode-conversion analysis for both regimes in a layered material structure. The differences between the two waveforms were assessed in terms of their visibility, wavelength and resolution. The limit values were calculated and estimated for the laser-pulse parameters, when such pulses are intended for use in an ultrasonic, laser-based, non-destructive evaluation. The possibility of using an industrial marking laser for laser ultrasound generation is thus demonstrated. PMID:17055020

Hrovatin, R; Petkovsek, R; Diaci, J; Mozina, J

2006-12-22

199

Development of nondestructive non-contact acousto-thermal evaluation technique for damage detection in materials  

NASA Astrophysics Data System (ADS)

This paper presents the development of a new non-contact acousto-thermal signature (NCATS) nondestructive evaluation technique. The physical basis of the method is the measurement of the efficiency of the material to convert acoustic energy into heat, and a theoretical model has been used to evaluate this. The increase in temperature due to conversion of acoustic energy injected into the material without direct contact was found to depend on the thermal and elastic properties of the material. In addition, it depends on the experimental parameters of the acoustic source power, the distance between sample and acoustic source, and the period of acoustic excitation. Systematic experimental approaches to optimize each of the experimental variables to maximize the observed temperature changes are described. The potential of the NCATS technique to detect microstructural-level changes in materials is demonstrated by evaluating accumulated damage due to plasticity in Ti-6Al-4V and low level thermal damage in polymer matrix composites. The ability of the technique for macroscopic applications in nondestructive evaluation is demonstrated by imaging a crack in an aluminum test sample.

Sathish, Shamachary; Welter, John T.; Jata, Kumar V.; Schehl, Norman; Boehnlein, Thomas

2012-09-01

200

Nondestructive evaluation tools and experimental studies for monitoring the health of space propulsion systems  

NASA Technical Reports Server (NTRS)

An overview is given of background and information on space propulsion systems on both the programmatic and technical levels. Feasibility experimental studies indicate that nondestructive evaluation tools such as ultrasonic, eddy current and X-ray may be successfully used to monitor the life limiting failure mechanisms of space propulsion systems. Encouraging results were obtained for monitoring the life limiting failure mechanims for three space propulsion systems: the degradation of tungsten arcjet and magnetoplasmadynamic electrodes; presence and thickness of spallable electrically conducting molybdenum films in ion thrusters; and the degradation of the catalyst in hydrazine thrusters.

Generazio, Edward R.

1991-01-01

201

Computed tomography for non-destructive evaluation of composites: Applications and correlations  

NASA Technical Reports Server (NTRS)

The state-of-the-art fabrication techniques for composite materials are such that stringent species-specific acceptance criteria must be generated to insure product reliability. Non-destructive evaluation techniques including computed tomography (CT), X-ray radiography (RT), and ultrasonic scanning (UT) are investigated and compared to determine their applicability and limitations to graphite epoxy, carbon-carbon, and carbon-phenolic materials. While the techniques appear complementary, CT is shown to provide significant, heretofore unattainable data. Finally, a correlation of NDE techniques to destructive analysis is presented.

Goldberg, B.; Hediger, L.; Noel, E.

1985-01-01

202

Nondestructive evaluation tools and experimental studies for monitoring the health of space propulsion systems  

NASA Technical Reports Server (NTRS)

An overview is given of background and information on space propulsion systems on both the programmatic and technical levels. Feasibility experimental studies indicate that nondestructive evaluation tools such as ultrasonic, eddy current and x-ray may be successfully used to monitor the life limiting failure mechanisms of space propulsion systems. Encouraging results were obtained for monitoring the life limiting failure mechanisms for three space propulsion systems; the degradation of tungsten arcjet and magnetoplasmadynamic electrodes; presence and thickness of spallable electrically conducting molybdenum films in ion thrusters; and the degradation of the catalyst in hydrazine thrusters.

Generazio, Edward R.

1991-01-01

203

Nondestructive Evaluation Tests Performed on Space Shuttle Leading- Edge Materials Subjected to Impact  

NASA Technical Reports Server (NTRS)

In support of the space shuttle Return To Flight efforts at the NASA Glenn Research Center, a series of nondestructive evaluation (NDE) tests were performed on reinforced carbon/carbon (RCC) composite panels subjected to ballistic foam impact. The impact tests were conducted to refine and verify analytical models of an external tank foam strike on the space shuttle leading edge. The NDE tests were conducted to quantify the size and location of the resulting damage zone as well as to identify hidden damage.

Roth, Don J.; Martin, Richard E.; Bodis, James R.

2005-01-01

204

Finite-element modelling of non-destructive material evaluation, an addendum: a bibliography (1997 2003)  

NASA Astrophysics Data System (ADS)

This paper gives a bibliographical review of the finite-element methods applied to the non-destructive evaluation of materials. It is a continuation of the same paper published in Modelling Simul. Mater. Sci. 7 (1999) 107-145. The bibliography at the end of this paper contains references to papers, conference proceedings and theses/dissertations on the subject that were published between 1997 and 2003. The following topics are included: electrical, magnetic and electromagnetic methods; sonic methods; mechanical methods; optical methods; condition monitoring and other methods. A total of 858 references are listed in the appendix.

Mackerle, Jaroslav

2004-09-01

205

Using the World-Wide Web to Facilitate Communications of Non-Destructive Evaluation  

NASA Technical Reports Server (NTRS)

The high reliability required for Aeronautical components is a major reason for extensive Nondestructive Testing and Evaluation. Here at Langley Research Center (LaRC), there are highly trained and certified personal to conduct such testing to prevent hazards from occurring in the workplace and on the research projects for the National Aeronautics and Space Administration (NASA). The purpose of my studies was to develop a communication source to educate others of the services and equipment offered here. This was accomplished by creating documents that are accessible to all in the industry via the World Wide Web.

McBurney, Sean

1995-01-01

206

GPU based numerical modeling for eddy current non-destructive evaluation  

NASA Astrophysics Data System (ADS)

Numerical models serve an important role in eddy current non-destructive evaluation applications. The results of computational models provide meaningful insight into the underlying physics, help theoretically visualize the field/sample interaction and help optimize sensor design and assist algorithms developing for interpreting the measured signals. However, three dimensional computational models can be time consuming. This paper presents a fast and efficient GPU based numerical model for simulating eddy current testing techniques. The model, based on boundary integral method, uses novel matrix compression techniques to optimize the solver performance on GPU architectures. Validation results of model predictions for a number of sample geometries are presented.

Lei, Naiguang; Udpa, Lalita; Udpa, Satish

2013-01-01

207

Micro-nondestructive evaluation of microelectronics using three-dimensional acoustic imaging  

NASA Astrophysics Data System (ADS)

Holographic-like three-dimensional (3D) acoustic imaging is developed for micro-nondestructive evaluation of microelectronics. It is implemented by stacking all the interface slices together to locate and identify hidden defects. Matching pursuit based acoustic time-frequency domain imaging is proposed to overcome the wavelength limit of axial resolution so that ultra-thin slices are generated. Experiments are performed on 3D acoustic data collected from microelectronic packages. Results show that the proposed technique resolves closely spaced features that are unavailable by conventional acoustic imaging, revealing more image details of defects.

Zhang, Guang-Ming; Harvey, David M.; Burton, David R.

2011-02-01

208

A DATA FUSION SYSTEM FOR THE NONDESTRUCTIVE EVALUATION OF NON-PIGGABLE PIPES  

SciTech Connect

The objectives of this research project are: (1) To design sensor data fusion algorithms that can synergistically combine defect related information from heterogeneous sensors used in gas pipeline inspection for reliably and accurately predicting the condition of the pipe-wall. (2) To develop efficient data management techniques for signals obtained during multisensor interrogation of a gas pipeline. During this reporting period, Rowan University designed, developed and exercised multisensor data fusion algorithms for identifying defect related information present in magnetic flux leakage, ultrasonic testing and thermal imaging nondestructive evaluation signatures of a test-specimen suite representative of benign and anomalous indications in gas transmission pipelines.

Shreekanth Mandayam; Robi Polikar; John C. Chen

2004-04-01

209

Nondestructive Integrity Evaluation of PC Pile Using Wigner-Ville Distribution Method  

NASA Astrophysics Data System (ADS)

Nondestructive evaluation (NDE) techniques have been used for years to provide a quality control of the construction for both drilled shafts and driven concrete piles. This trace is typically made up of transient pulses reflected from structural features of the pile or changes in its surrounding environment. It is often analyzed in conjunction with the spectral response, mobility curve, arrival time, etc. The Wigner-Ville Distribution is a new numerical analysis tool for signal process technique in the time-frequency domain and it can offer assistance and enhance signal characteristics for better resolution both easily and quickly. In this study, five single pre-cast concrete piles have been tested and evaluated by both sonic echo method and Wigner-Ville distribution (WVD). Furthermore, two difficult problems in nondestructive evaluation problems are discussed and solved: the first one is with a pile with slight defect, whose necking area percentage is less than 10%, and the other is a pile with multiple defects. The results show that WVD can not only recognize the characteristics easily, but also locate the defects more clearly than the traditional pile integrity testing method.

Ni, Sheng-Huoo; Lo, Kuo-Feng; Huang, Yan-Hong

210

Nondestructive evaluation of orthopaedic implant stability in THA using highly nonlinear solitary waves  

NASA Astrophysics Data System (ADS)

We propose a new biomedical sensing technique based on highly nonlinear solitary waves to assess orthopaedic implant stability in a nondestructive and efficient manner. We assemble a granular crystal actuator consisting of a one-dimensional tightly packed array of spherical particles, to generate acoustic solitary waves. Via direct contact with the specimen, we inject acoustic solitary waves into a biomedical prosthesis, and we nondestructively evaluate the mechanical integrity of the bone-prosthesis interface, studying the properties of the waves reflected from the contact zone between the granular crystal and the implant. The granular crystal contains a piezoelectric sensor to measure the travelling solitary waves, which allows it to function also as a sensor. We perform a feasibility study using total hip arthroplasty (THA) samples made of metallic stems implanted in artificial composite femurs using polymethylmethacrylate for fixation. We first evaluate the sensitivity of the proposed granular crystal sensor to various levels of prosthesis insertion into the composite femur. Then, we impose a sequence of harsh mechanical loading on the THA samples to degrade the mechanical integrity at the stem-cement interfaces, using a femoral load simulator that simulates aggressive, accelerated physiological loading. We investigate the implant stability via the granular crystal sensor-actuator during testing. Preliminary results suggest that the reflected waves respond sensitively to the degree of implant fixation. In particular, the granular crystal sensor-actuator successfully detects implant loosening at the stem-cement interface following violent cyclic loading. This study suggests that the granular crystal sensor and actuator has the potential to detect metal-cement defects in a nondestructive manner for orthopaedic applications.

Yang, Jinkyu; Silvestro, Claudio; Sangiorgio, Sophia N.; Borkowski, Sean L.; Ebramzadeh, Edward; De Nardo, Luigi; Daraio, Chiara

2012-01-01

211

Quantitative methods of evaluating image segmentation  

Microsoft Academic Search

Two sets of measures are proposed in this paper for quantitatively evaluating segmentation results. The first set is designed for the situation where ground truth is available; while the second for the situation where ground truth is not available. Based on a test bank of more than 50 images for which ground truth is available, we computed both sets of

Qian Huang; Byron Dom

1995-01-01

212

Scanning laser-line source technique for nondestructive evaluation of cracks in human teeth.  

PubMed

This paper describes the first application of a remote nondestructive laser ultrasonic (LU) system for clinical diagnosis of cracks in human teeth, to our knowledge. It performs non-contact cracks detection on small-dimension teeth samples. Two extracted teeth with different types of cracks (cracked tooth and craze lines), which have different crack depths, are used as experimental samples. A series of ultrasonic waves were generated by a scanning laser-line source technique and detected with a laser-Doppler vibrometer on the two samples. The B-scan images and peak-to-peak amplitude variation curves of surface acoustic waves were obtained for evaluating the cracks' position and depth. The simulation results calculated by finite element method were combined with the experimental results for accurately measuring the depth of crack. The results demonstrate that this LU system has been successfully applied on crack evaluation of human teeth. And as a remote, nondestructive technique, it has great potential for early in vivo diagnosis of cracked tooth and even the future clinical dental tests. PMID:24787406

Sun, Kaihua; Yuan, Ling; Shen, Zhonghua; Xu, Zhihong; Zhu, Qingping; Ni, Xiaowu; Lu, Jian

2014-04-10

213

Assessing Primary Water Stress Corrosion Crack Morphology and Nondestructive Evaluation Reliability  

SciTech Connect

A research program on primary water stress corrosion cracking (PWSCC) is being conducted by Pacific Northwest National Laboratory (PNNL). In this program, the material degradation problem in Alloys 600, 182 and 82 is being investigated, with objectives that include compiling a knowledge base on all cracking in nickel-base materials at all degradation sites in nuclear power plants, assessing nondestructive evaluation methods using mockups to quantify the detection, sizing, and characterization of tight cracks, determining the role of material parameters, such as welding processes, in the degradation. This work is being conducted as a part of an international cooperative research project that has been set up to leverage efforts in several countries to address a significant and common problem. The U.S. Nuclear Regulatory Commission is leading this cooperative project to address this generic problem in a systematic manner over the next four years. In this paper, published information on the failure history of Alloys 600, 182, and 82 is compiled and presented. The configurations of the welded assemblies that contain these alloys are shown to be important considerations for NDE reliability measurements. The product forms and the welding processes represented in the degraded components are described. The relevant data on crack morphology parameters such as shape and orientation are presented, and their impact on nondestructive evaluation (NDE) reliability is discussed.

Doctor, Steven R.; Schuster, George J.; Anderson, Michael T.

2005-12-01

214

Nondestructive evaluation of soluble solid content in strawberry by near infrared spectroscopy  

NASA Astrophysics Data System (ADS)

This paper indicates the feasibility to use near infrared (NIR) spectroscopy combined with synergy interval partial least squares (siPLS) algorithms as a rapid nondestructive method to estimate the soluble solid content (SSC) in strawberry. Spectral preprocessing methods were optimized selected by cross-validation in the model calibration. Partial least squares (PLS) algorithm was conducted on the calibration of regression model. The performance of the final model was back-evaluated according to root mean square error of calibration (RMSEC) and correlation coefficient (R2 c) in calibration set, and tested by mean square error of prediction (RMSEP) and correlation coefficient (R2 p) in prediction set. The optimal siPLS model was obtained with after first derivation spectra preprocessing. The measurement results of best model were achieved as follow: RMSEC = 0.2259, R2 c = 0.9590 in the calibration set; and RMSEP = 0.2892, R2 p = 0.9390 in the prediction set. This work demonstrated that NIR spectroscopy and siPLS with efficient spectral preprocessing is a useful tool for nondestructively evaluation SSC in strawberry.

Guo, Zhiming; Huang, Wenqian; Chen, Liping; Wang, Xiu; Peng, Yankun

215

Nondestructive evaluation of ceramic and metal matrix composites for NASA's HITEMP and enabling propulsion materials programs  

NASA Astrophysics Data System (ADS)

In a preliminary study, ultrasonic, x-ray opaque, and fluorescent dye penetrants techniques were used to evaluate and characterize ceramic and metal matrix composites. Techniques are highlighted for identifying porosity, fiber alignment, fiber uniformity, matrix cracks, fiber fractures, unbonds or disbonds between laminae, and fiber-to-matrix bond variations. The nondestructive evaluations (NDE) were performed during processing and after thermomechanical testing. Specific examples are given for Si3N4/SiC (SCS-6 fiber), FeCrAlY/Al2O3 fibers, Ti-15-3/SiC (SCS-6 fiber) materials, and Si3N4/SiC (SCS-6 fiber) actively cooled panel components. Results of this study indicate that the choice of the NDE tools to be used can be optimized to yield a faithful and accurate evaluation of advanced composites.

Generazio, Edward R.

1992-08-01

216

Nondestructive evaluation of ceramic and metal matrix composites for NASA's HITEMP and enabling propulsion materials programs  

NASA Technical Reports Server (NTRS)

In a preliminary study, ultrasonic, x-ray opaque, and fluorescent dye penetrants techniques were used to evaluate and characterize ceramic and metal matrix composites. Techniques are highlighted for identifying porosity, fiber alignment, fiber uniformity, matrix cracks, fiber fractures, unbonds or disbonds between laminae, and fiber-to-matrix bond variations. The nondestructive evaluations (NDE) were performed during processing and after thermomechanical testing. Specific examples are given for Si3N4/SiC (SCS-6 fiber), FeCrAlY/Al2O3 fibers, Ti-15-3/SiC (SCS-6 fiber) materials, and Si3N4/SiC (SCS-6 fiber) actively cooled panel components. Results of this study indicate that the choice of the NDE tools to be used can be optimized to yield a faithful and accurate evaluation of advanced composites.

Generazio, Edward R.

1992-01-01

217

Nondestructive evaluation of adhesive bond strength using the stress wave factor technique  

NASA Technical Reports Server (NTRS)

Acousto-ultrasonic nondestructive evaluation has been conducted to evaluate the adhesive bond strength between rubber and steel plates using the stress wave factor (SWF) measurement technique. Specimens with different bond strength were manufactured and tested using the SWF technique. Two approaches were used to define the SWF. One approach defines the SWF as the signal energy and the other approach defines the SWF as the square root of the zero moment of the frequency spectrum of the received signal. The strength of the rubber-steel adhesive joint was then evaluated using the destructive peel strength test method. It was observed that in both approaches higher values of the SWF measurements correspond to higher values of the peel strength test data. Therefore, these results show that the stress wave factor technique has the potential of being used in quality assurance of the adhesive bond strength between rubber and steel substrates.

Dos Reis, Henrique L. M.; Krautz, Harold E.

1986-01-01

218

Relative performance evaluation of pattern recognition models for nondestructive damage detection  

NASA Astrophysics Data System (ADS)

The objective of this paper is to evaluate the relative performance of several Bayesian distance-based pattern recognition models and two non-Bayesian models for non-destructive damage detection (NDD). A theory of damage localization, which yields information on the location of the damage directly from changes in mode shapes, is formulated. Next, the application of pattern recognition for NDD is established. Expressions for pattern classification using discriminate functions based on Bayes' Rule, Neyman-Pearson criteria, and neural networks are generated. A set of criteria for the evaluation of the pattern recognition models is then established. Damage localization is applied to a finite element mode of a structure which contains simulated damage at various locations using the pattern recognition and neural network models. Finally, the evaluation of the pattern recognition models is carried out using the established criteria.

Garcia, Gabriel V.; Stubbs, Norris; Butler, Karen

1996-04-01

219

Research Performed within the Non-Destructive Evaluation Team at NASA Glenn Research Center  

NASA Technical Reports Server (NTRS)

Non-destructive testing is essential in many fields of manufacturing and research in order to perform reliable examination of potentially damaged materials and parts without destroying the inherent structure of the materials. Thus, the Non-Destructive Evaluation (NDE) Team at NASA Glenn Research Center partakes in various projects to improve materials testing equipment as well as analyze materials, material defects, and material deficiencies. Due to the array of projects within the NDE Team at this time, five research aims were supplemental to some current projects. A literature survey of "DE and testing methodologies as related to rocks was performed. Also, Mars Expedition Rover technology was assessed to understand the requirements for instrumentation in harsh space environments (e.g. temperature). Potential instrumentation and technologies were also considered and documented. The literature survey provided background and potential sources for a proposal to acquire funding for ultrasonic instrumentation on board a future Mars expedition. The laboratory uses a Santec Systems AcousticScope AS200 acoustography system. Labview code was written within the current program in order to improve the current performance of the acoustography system. A sample of Reinforced Carbon/Carbon (RCC) material from the leading edge of the space shuttle underwent various non-destructive tests (guided wave scanning, thermography, computed tomography, real time x-ray, etc.) in order to characterize its structure and examine possible defects. Guided wave scan data of a ceramic matrix composite (CMC) panel was reanalyzed utilizing image correlations and signal processing variables. Additional guided wave scans and thermography were also performed on the CMC panel. These reevaluated data and images will be used in future presentations and publications. An additional axis for the guided wave scanner was designed, constructed, and implemented. This additional axis allowed incremental spacing of the previously fixed transducers for ultrasonic velocity measurements.

Burns, Erin A.

2004-01-01

220

Compressive strength evaluation of structural lightweight concrete by non-destructive ultrasonic pulse velocity method.  

PubMed

In this paper the compressive strength of a wide range of structural lightweight aggregate concrete mixes is evaluated by the non-destructive ultrasonic pulse velocity method. This study involves about 84 different compositions tested between 3 and 180 days for compressive strengths ranging from about 30 to 80 MPa. The influence of several factors on the relation between the ultrasonic pulse velocity and compressive strength is examined. These factors include the cement type and content, amount of water, type of admixture, initial wetting conditions, type and volume of aggregate and the partial replacement of normal weight coarse and fine aggregates by lightweight aggregates. It is found that lightweight and normal weight concretes are affected differently by mix design parameters. In addition, the prediction of the concrete's compressive strength by means of the non-destructive ultrasonic pulse velocity test is studied. Based on the dependence of the ultrasonic pulse velocity on the density and elasticity of concrete, a simplified expression is proposed to estimate the compressive strength, regardless the type of concrete and its composition. More than 200 results for different types of aggregates and concrete compositions were analyzed and high correlation coefficients were obtained. PMID:23351273

Bogas, J Alexandre; Gomes, M Glória; Gomes, Augusto

2013-07-01

221

A nondestructive method for evaluating in vitro osteoblast differentiation on biomaterials using osteoblast-specific fluorescence.  

PubMed

Transgenic mice with a Col1a1-promoter-driven transgene pOBCol2.3GFP were previously developed to visually identify mature osteoblasts through fluorescent expression. Our goal was to determine if this technology could be used to nondestructively evaluate the in vitro differentiation of osteoprogenitor cells on biomaterials such as biomimetic carbonated hydroxyapatite (cHA). Primary osteoprogenitor cells were harvested from calvaria of neonatal Col2.3GFP transgenic mice and cultured on cHA and a tissue culture polystyrene (TCPS) control. The distribution of intensities and area percentage of green fluorescent protein (GFP)-positive cells were quantified using fluorimetry and image analysis of fluorescent microscopy. At 14 days, an increased area and higher mean intensity of GFP-positive cells was observed on cHA as compared to TCPS, indicating more rapid differentiation on cHA. Notably, there were large continuous regions of GFP-positive osteoblasts on cHA, in contrast to the sparse, nodules of osteoblasts on TCPS, implying that cHA provides an osteogenic cue to cells. Xylenol orange staining was capable of distinguishing osteoblast-initiated mineral from the cHA substrate. With this method the unique pattern of osteoblast differentiation on cHA was clearly observed for the first time. Importantly, the generalized method can be used for rapid, high-throughput, nondestructive screening of biomaterials intended to enhance osteogenic differentiation. PMID:20337515

Kuhn, Liisa T; Liu, Yongxing; Advincula, Maria; Wang, Yu-Hsiung; Maye, Peter; Goldberg, A Jon

2010-12-01

222

Application of internal friction nondestructive evaluation technique for wire ropes used in mining operations  

SciTech Connect

This report discusses the work done, and results obtained, in a program conducted to determine the feasibility of applying the Internal Friction Damping - Nondestructive Evaluation (IFD-NDE) technique to wire rope. Samples of wire rope were evaluated in laboratory experiments by measuring the internal friction damping while varying several test parameters. These parameters included tensile load, frequency of test, time under load and others. The report includes discussion of wire rope mechanics and application history of NDE. Also included are sections detailing IFD-NDE theory, experimental apparatus, and test technique. The data obtained in the program work is reviewed with several results and conclusions drawn. The report closes with recommendations for further work.

Olver, L.; Brasfield, R.G.; Yeager, L.L.; Thiruvengadam, A.P.

1980-05-01

223

Lamb wave reflection for the quick nondestructive evaluation of large composite laminates  

SciTech Connect

The possibility of using Lamb waves for the long range nondestructive evaluation (NDE) of composite laminates has been investigated. Three different possible testing strategies using the S[sub 0] Lamb mode--S[sub 0] mode transmission, S[sub 0] mode conversion to A[sub 0], and S[sub 0] mode reflection--are described and evaluated. It is shown that the S[sub 0] mode reflection technique is the most promising method for long range inspection, 10--20 mm diameter delamination being detectable at a range of at least 500 mm. The time taken to test along a line using this technique is similar to that required to test at a point in conventional ultrasonic inspection, so considerable savings in testing time may be obtained.

Guo, Ningqun; Cawley, P. (Imperial Coll. of Science, Technology, and Medicine, London (United Kingdom). Dept. of Mechanical Engineering)

1994-03-01

224

Yucca Mountain project container fabrication, closure and non-destructive evaluation development activities; Summary and viewgraphs  

SciTech Connect

In this presentation, container fabrication, closure, and non-destructive evaluation (NDE) process development activities are described. All of these activities are interrelated, and will contribute to the metal barrier selection activity. The plan is to use a corrosion-resistant material in the form of a cylinder with a wall thickness of {approximately}1cm (2cm for pure copper.) The materials under consideration include the three austenitic alloys: stainless steel-304L, stainless steel-316L and alloy 825, as well as the three copper alloys: CDA 102, CDA 613, and CDA 715. This document reviews the recommended procedures and processes for fabricating, closing and evaluating each of the candidate materials. (KGD)

Russell, E.W.; Nelson, T.A.

1989-06-01

225

Nondestructive Evaluation of the J-2X Direct Metal Laser Sintered Gas Generator Discharge Duct  

NASA Technical Reports Server (NTRS)

The J-2X program at NASA's Marshall Space Flight Center (MSFC) procured a direct metal laser sintered (DMLS) gas generator discharge duct from Pratt & Whitney Rocketdyne and Morris Technologies for a test program that would evaluate the material properties and durability of the duct in an engine-like environment. DMLS technology was pursued as a manufacturing alternative to traditional techniques, which used off nominal practices to manufacture the gas generator duct's 180 degree turn geometry. MSFC's Nondestructive Evaluation (NDE) Team performed radiographic, ultrasonic, computed tomographic, and fluorescent penetrant examinations of the duct. Results from the NDE examinations reveal some shallow porosity but no major defects in the as-manufactured material. NDE examinations were also performed after hot-fire testing the gas generator duct and yielded similar results pre and post-test and showed no flaw growth or development.

Esther, Elizabeth A.; Beshears, Ronald D.; Lash, Rhonda K.

2012-01-01

226

Evaluation of chondral repair using quantitative MRI.  

PubMed

Various quantitative magnetic resonance imaging (qMRI) biomarkers, including but not limited to parametric MRI mapping, semiquantitative evaluation, and morphological assessment, have been successfully applied to assess cartilage repair in both animal and human studies. Through the interaction between interstitial water and constituent macromolecules the compositional and structural properties of cartilage can be evaluated. In this review a comprehensive view of a variety of quantitative techniques, particularly those involving parametric mapping, and their relationship to the properties of cartilage repair is presented. Some techniques, such as T2 relaxation time mapping and delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), are well established, while the full potential of more recently introduced techniques remain to be demonstrated. A combination of several MRI techniques is necessary for a comprehensive characterization of chondral repair. PMID:23165732

Nieminen, Miika T; Nissi, Mikko J; Mattila, Lauri; Kiviranta, Ilkka

2012-12-01

227

Nondestructive evaluation and characterization of damage and repair to continuous-fiber ceramic composite panels.  

SciTech Connect

Continuous fiber ceramic matrix composites are currently being developed for a variety of high-temperature applications. Because of the high costs of making these components, minor damage incurred during manufacturing or operation must be rewired in order to extend the life of the components. In this study, five ceramic-grade Nicalon{trademark} fiber/SiNC-matrix composite panels were intentionally damaged with a pendulum-type impactor during an impact test. The damaged panels were then repaired at Dow Corning Corporation. Three nondestructive evaluation (NDE) methods were used to study the characteristics of the panels after the damage and again after the panels were repaired. The NDE methods were X-ray radiography, infrared thermal imaging, and air-coupled ultrasound. The results showed that the impact test induced various types of damage in the panels. The NDE data that were obtained by the three NDE methods were correlated with each other.

Sun, J. G.; Petrak, D. R.; Pillai, T. A. K.; Deemer, C.; Ellingson, W. A.

1998-04-01

228

The probability of flaw detection and the probability of false calls in nondestructive evaluation equipment  

NASA Technical Reports Server (NTRS)

The space industry has developed many composite materials that have high durability in proportion to their weights. Many of these materials have a likelihood for flaws that is higher than in traditional metals. There are also coverings (such as paint) that develop flaws that may adversely affect the performance of the system in which they are used. Therefore there is a need to monitor the soundness of composite structures. To meet this monitoring need, many nondestructive evaluation (NDE) systems have been developed. An NDE system is designed to detect material flaws and make flaw measurements without destroying the inspected item. Also, the detection operation is expected to be performed in a rapid manner in a field or production environment. Some of the most recent video-based NDE methodologies are shearography, holography, thermography, and video image correlation.

Temple, Enoch C.

1994-01-01

229

Bonding and nondestructive evaluation of graphite/PEEK composite and titanium adherends with thermoplastic adhesives  

NASA Technical Reports Server (NTRS)

Bonded single overlap shear specimens were fabricated from Graphite/PEEK (Polyetheretherketone) composite adherends and titanium adherends. Six advanced thermoplastic adhesives were used for the bonding. The specimens were bonded by an electromagnetic induction technique producing high heating rates and high-strength bonds in a few minutes. This contrasts with conventionally heated presses or autoclaves that take hours to process comparable quality bonds. The Graphite/PEEK composites were highly resistant to delamination during the testing. This allowed the specimen to fail exclusively through the bondline, even at very high shear loads. Nondestructive evaluation of bonded specimens was performed ultrasonically by energizing the entire thickness of the material through the bondline and measuring acoustic impedance parameters. Destructive testing confirmed the unique ultrasonic profiles of strong and weak bonds, establishing a standard for predicting relative bond strength in subsequent specimens.

Hodges, W. T.; Tyeryar, J. R.; Berry, M.

1985-01-01

230

The Evolution of Nondestructive Evaluation Methods for the Space Shuttle External Tank Thermal Protection System  

NASA Technical Reports Server (NTRS)

Three nondestructive evaluation methods are being developed to identify defects in the foam thermal protection system (TPS) of the Space Shuttle External Tank (ET). Shearography is being developed to identify shallow delaminations, shallow voids and crush damage in the foam while terahertz imaging and backscatter radiography are being developed to identify voids and cracks in thick foam regions. The basic theory of operation along with factors affecting the results of these methods will be described. Also, the evolution of these methods from lab tools to implementation on the ET will be discussed. Results from both test panels and flight tank inspections will be provided to show the range in defect sizes and types that can be readily detected.

Walker, James L.; Richter, Joel D.

2006-01-01

231

Nondestructive Evaluation Approaches Developed for Material Characterization in Aeronautics and Space Applications  

NASA Technical Reports Server (NTRS)

At the NASA Glenn Research Center, nondestructive evaluation (NDE) approaches were developed or tailored for characterizing advanced material systems. The emphasis was on high-temperature aerospace propulsion applications. The material systems included monolithic ceramics, superalloys, and high-temperature composites. In the aeronautics area, the major applications were cooled ceramic plate structures for turbine applications, gamma-TiAl blade materials for low-pressure turbines, thermoelastic stress analysis for residual stress measurements in titanium-based and nickel-based engine materials, and acousto-ultrasonics for creep damage assessment in nickel-based alloys. In the space area, applications consisted of cooled carbon-carbon composites for gas generator combustors and flywheel rotors composed of carbon-fiber-reinforced polymer matrix composites for energy storage on the International Space Station.

Baaklini, George Y.; Kautz, Harold E.; Gyekenyesi, Andrew L.; Abdul-Aziz, Ali; Martin, Richard E.

2001-01-01

232

The National Aeronautics and Space Administration Nondestructive Evaluation Program for Safe and Reliable Operations  

NASA Astrophysics Data System (ADS)

The National Aeronautics and Space Administration (NASA) Nondestructive Evaluation (NDE) Program is presented. As a result of the loss of seven astronauts and the Space Shuttle Columbia on February 1, 2003, NASA has undergone many changes in its organization. NDE is one of the key areas that are recognized by the Columbia Accident Investigation Board (CAIB) that needed to be strengthened by warranting NDE as a discipline with Independent Technical Authority (iTA). The current NASA NDE system and activities are presented including the latest developments in inspection technologies being applied to the Space Transportation System (STS). The unfolding trends and directions in NDE for the future are discussed as they apply to assuring safe and reliable operations.

Generazio, Ed

2006-03-01

233

Nanomanipulation and Lithography for Carbon Nanotube Based Nondestructive Evaluation Sensor Development  

NASA Technical Reports Server (NTRS)

Carbon nanotubes (CNTs) offer great potential for advanced sensor development due to the unique electronic transport properties of the material. However, a significant obstacle to the realization of practical CNT devices is the formation of reliable and reproducible CNT to metallic contacts. In this work, scanning probe techniques are explored for both fabrication of metallic junctions and positioning of singlewalled CNTs across these junctions. The use of a haptic force feedback interface to a scanning probe microscope is used to enable movement of nanotubes over micron length scales with nanometer precision. In this case, imaging of the surface is performed with light or intermittent contact to the surface. Increased tip-to-sample interaction forces are then applied to either create junctions or position CNTs. The effect of functionalization of substrate surfaces on the movement and tribology of the materials is also studied. The application of these techniques to the fabrication of CNT-based sensors for nondestructive evaluation applications is discussed.

Wincheski, Buzz; Smits, Jan; Namkung, Min; Ingram, JoAnne; Watkins, Neal; Jordan, Jeffrey D.; Louie, Richard

2002-01-01

234

The National Aeronautics and Space Administration Nondestructive Evaluation Program for Safe and Reliable Operations  

NASA Technical Reports Server (NTRS)

The National Aeronautics and Space Administration (NASA) Nondestructive Evaluation (NDE) Program is presented. As a result of the loss of seven astronauts and the Space Shuttle Columbia on February 1, 2003, NASA has undergone many changes in its organization. NDE is one of the key areas that are recognized by the Columbia Accident Investigation Board (CAIB) that needed to be strengthened by warranting NDE as a discipline with Independent Technical Authority (iTA). The current NASA NDE system and activities are presented including the latest developments in inspection technologies being applied to the Space Transportation System (STS). The unfolding trends and directions in NDE for the future are discussed as they apply to assuring safe and reliable operations.

Generazio, Ed

2005-01-01

235

Challenges in Integrating Nondestructive Evaluation and Finite Element Methods for Realistic Structural Analysis  

NASA Technical Reports Server (NTRS)

Capabilities and expertise related to the development of links between nondestructive evaluation (NDE) and finite element analysis (FEA) at Glenn Research Center (GRC) are demonstrated. Current tools to analyze data produced by computed tomography (CT) scans are exercised to help assess the damage state in high temperature structural composite materials. A utility translator was written to convert velocity (an image processing software) STL data file to a suitable CAD-FEA type file. Finite element analyses are carried out with MARC, a commercial nonlinear finite element code, and the analytical results are discussed. Modeling was established by building MSC/Patran (a pre and post processing finite element package) generated model and comparing it to a model generated by Velocity in conjunction with MSC/Patran Graphics. Modeling issues and results are discussed in this paper. The entire process that outlines the tie between the data extracted via NDE and the finite element modeling and analysis is fully described.

Abdul-Aziz, Ali; Baaklini, George Y.; Zagidulin, Dmitri; Rauser, Richard W.

2000-01-01

236

Nondestructive test and evaluation at the Carderock Division, Naval Surface Warfare Center, Philadelphia site  

NASA Astrophysics Data System (ADS)

Carderock Division, Naval Surface Warfare Center, Code 623 has been involved in the nondestructive test and evaluation of US Navy surface vessels since the 1960s. In this time, CDNSWC 623 has been involved in the utilization and technical development of many forms of NDE including visual inspection, contact ultrasonics, eddy current inspections, computer- automated ultrasonics, and laser optics. The present laser optic tube inspection system (LOTIS) was developed through a joint venture between NSWCCD 623 and Quest Integrated, Inc. of Kent, WA. CDNSWC 623 is presently involved in the centralization of several fleet- wide NDE practices including boiler inspection devices, contact ultrasonics, eddy current, the ultrasonic tube inspection system, and the LOTIS. These systems all have very diverse ranges of application and have proven to be cost-saving devices when implemented throughout the US Navy.

Leinbach, Russell A., Jr.

1995-06-01

237

Nondestructive testing and evaluation of composites by non-invasive IR Imaging techniques  

NASA Astrophysics Data System (ADS)

InfraRed Thermography (IRT) is one of the promising technique for non-destructive testing method for characterization of materials. This technique relies on evaluation of the surface temperature variations to detect the presence of surface and subsurface anomalies within the material. Due to its whole field and remote testing capabilities, IRT has gained significant importance in testing of Glass Fiber Reinforced Plastic (GFRP) materials. A GFRP sample with defects of various sizes at a given depth was inspected using non-stationary thermographic techniques. In order to highlight the defect detection capabilities of the proposed non-stationary schemes, a comparison has been made using matched excitation energy in frequency domain by taking signal to noise ratio into consideration.

Mulaveesala, Ravibabu; Siddiqui, Juned A.; Arora, Vanita; Ghali, S. V.; Muniyappa, Amarnath; Takei, Masahiro

2013-05-01

238

C/C composite brake disk nondestructive evaluation by IR thermography  

NASA Astrophysics Data System (ADS)

This paper discusses the non-destructive evaluation of thick Carbon/Carbon (C/C) composite aircraft brake disks by using transient infrared thermography (IRT) approach. Thermal diffusivity measurement technique was applied to identify the subsurface anomalies in thick C/C brake disks. In addition, finite element analysis (FEA) modeling tool was used to determine the transient thermal response of the C/C disks that were subjected to flash heating. For this, series of finite element models were built and thermal responses with various thermal diffusivities subjected to different heating conditions were investigated. Experiments were conducted to verify the models by using custom built in-house IRT system and commercial turnkey system. The analysis and experimental results showed good correlation between thermal diffusivity value and anomalies within the disk. It was demonstrated that the step-heating transient thermal approach could be effectively applied to obtain the whole field thermal diffusivity value of C/C composites.

Chu, Tsuchin P.; Poudel, Anish; Filip, Peter

2012-05-01

239

System and method for non-destructive evaluation of surface characteristics of a magnetic material  

DOEpatents

A system and a related method for non-destructive evaluation of the surface characteristics of a magnetic material. The sample is excited by an alternating magnetic field. The field frequency, amplitude and offset are controlled according to a predetermined protocol. The Barkhausen response of the sample is detected for the various fields and offsets and is analyzed. The system produces information relating to the frequency content, the amplitude content, the average or RMS energy content, as well as count rate information, for each of the Barkhausen responses at each of the excitation levels applied during the protocol. That information provides a contiguous body of data, heretofore unavailable, which can be analyzed to deduce information about the surface characteristics of the material at various depths below the surface.

Jiles, David C. (Ames, IA); Sipahi, Levent B. (Ames, IA)

1994-05-17

240

Nondestructive evaluation inspection of the Arlington Memorial Bridge using a robotic assisted bridge inspection tool (RABIT)  

NASA Astrophysics Data System (ADS)

The information presented in this report provides a detailed assessment of the condition of the Arlington Memorial Bridge (AMB) deck. The field-data collection was obtained by both the RABIT™ Bridge Inspection Tool and a number of semi-automated non-destructive evaluation (NDE) tools. The deployment of the semi-automated NDE tools was performed to inspect the AMB deck condition and also to validate data obtained by the RABIT™ Bridge Inspection Tool. Data mining and analysis were accomplished through enhanced data interpretation and visualization capabilities using advanced data integration, fusion, and 2D rendering. One of the major challenges that the research team had to overcome in assessing the condition of the AMB deck was the presence of an asphalt overlay on the entire bridge deck.

Gucunski, Nenad; Boone, Shane D.; Zobel, Rob; Ghasemi, Hamid; Parvardeh, Hooman; Kee, Seong-Hoon

2014-04-01

241

Noncontact, Nondestructive Evaluation of Realistic Cracks with Surface Acoustic Waves by Scanning Excitation and Detection Lasers  

NASA Astrophysics Data System (ADS)

Nondestructive evaluation of surface-breaking cracks with a scanning laser source, a scanning laser probe, or a scanning laser pump-probe setup is discussed. Multimode scattering of laser-excited surface acoustic wave pulses by artificial slots, realistic fatigue, or impulsive cracks is considered. This includes measuring the size of cracks in the micrometer-to-millimeter range by optical recording of the complete displacement or velocity field around the crack. Results obtained with a scanning pump-probe setup for a partially closed microcrack, generated by an elastic shock pulse in silica, are compared with those achieved with a scanning source or scanning probe for machined open notches. Crack size analysis based on the frequency spectrum of the reflected Rayleigh wave and the time lag of the transmitted Rayleigh wave is discussed. Signal enhancement effects observed in the displacement and velocity field near the crack are studied.

Hess, P.; Lomonosov, A. M.

2013-09-01

242

PREDICTION OF DISSOLVER LIFETIMES THROUGH NON-DESTRUCTIVE EVALUATION AND LABORATORY TESTING  

SciTech Connect

Non-destructive evaluation was used as the primary method of monitoring the corrosion degradation of nuclear material dissolvers and assessing the remaining lifetimes. Materials were typically processed in nitric acid based (4-14M) solutions containing fluoride concentrations less than 0.2 M. The primary corrosion issue for the stainless steel dissolvers is the occurrence of localized corrosion near the tank bottom and the heat affected zones of the welds. Laboratory data for a range of operational conditions, including solution chemistry and temperature, was used to assess the impact of processing changes on the dissolver corrosion rate. Experimental and NDE-based general corrosion rates were found to be in reasonable agreement for standard dissolution chemistries consisting of nitric acid with fluorides and at temperatures less than 95 C. Greater differences were observed when chloride was present as an impurity and temperatures exceeded 100 C.

Mickalonis, J.; Woodsmall, T.; Hinz, W.; Edwards, T.

2011-10-03

243

Performance evaluation of a gamma-ray imaging system for nondestructive testing of welded pipes  

NASA Astrophysics Data System (ADS)

As a continuation of our radiographic testing (RT) R&D, we have developed a gamma-ray imaging system to be suitable for nondestructive testing of welded pipes. The system consists of an imaging detector having a CdTe/CMOS-based pixel array (AJAT, SCAN1000), a collimated 75Se gamma source having about 78.7 Ci activities, a gear track mounted around test pipes for image scan, and a computer-controlled microstep motor for precise control of the scan speed. All the components of the imaging system were assembled tightly by a chain belt. From the imaging system, we obtained useful gamma images of a stainless steel pipe (30 cm in internal diameter and 1 cm in thickness) having a weld line. Using standard techniques for evaluation of the radiography quality, we assessed the imaging characteristics of the detector in terms of the modulation transfer function (MTF), the noise power spectrum (NPS), and the detective quantum efficiency (DQE).

Cho, H. S.; Oh, J. E.; Choi, S. I.; Cho, H. M.; Park, Y. O.; Hong, D. K.; Lee, M. S.; Yang, Y. J.; Je, U. K.; Kim, D. S.; Woo, T. H.; Lee, B. S.; Lee, H. K.

2011-10-01

244

Research and Development Roadmaps for Nondestructive Evaluation of Cables, Concrete, Reactor Pressure Vessels, and Piping Fatique  

SciTech Connect

To address these research needs, the MAaD Pathway supported a series of workshops in the summer of 2012 for the purpose of developing R&D roadmaps for enhancing the use of Nondestructive Evaluation (NDE) technologies and methodologies for detecting aging and degradation of materials and predicting the remaining useful life. The workshops were conducted to assess requirements and technical gaps related to applications of NDE for cables, concrete, reactor pressure vessels (RPV), and piping fatigue for extended reactor life. An overview of the outcomes of the workshops is presented here. Details of the workshop outcomes and proposed R&D also are available in the R&D roadmap documents cited in the bibliography and are available on the LWRS Program website (http://www.inl.gov/lwrs).

Clayton, Dwight A [ORNL] [ORNL; Bakhtiari, Sasan [Argonne National Laboratory (ANL)] [Argonne National Laboratory (ANL); Smith, Cyrus M [ORNL] [ORNL; Simmons, Kevin [Pacific Northwest National Laboratory (PNNL)] [Pacific Northwest National Laboratory (PNNL); Ramuhalli, Pradeep [Pacific Northwest National Laboratory (PNNL)] [Pacific Northwest National Laboratory (PNNL); Coble, Jamie [Pacific Northwest National Laboratory (PNNL)] [Pacific Northwest National Laboratory (PNNL); Brenchley, David [Pacific Northwest National Laboratory (PNNL)] [Pacific Northwest National Laboratory (PNNL); Meyer, Ryan [Pacific Northwest National Laboratory (PNNL)] [Pacific Northwest National Laboratory (PNNL)

2013-01-01

245

Quantitative evaluation of signal integrity for magnetocardiography.  

PubMed

Magnetocardiography (MCG) is a non-invasive diagnostic tool used to investigate the activity of the heart. For applications in an unshielded environment, in order to extract the very weak signal of interest from the much higher background noise, dedicated hardware configuration and sophisticated signal processing techniques have been developed during the last decades. Being powerful in noise rejection, the signal processing may introduce signal distortions, if not properly designed and applied. However, there is a lack of an effective tool to quantitatively evaluate the signal integrity for MCG at present. In this paper, we have introduced a very simple method by using a small coil driven by a human ECG signal to generate a simulated MCG signal. Three key performance indexes were proposed, which are correlation in time domain, relative heights of different peaks and correlation in frequency domain, to evaluate the MCG system performance quantitatively. This evaluation method was applied to a synthetic gradiometer consisting of a second-order axial gradiometer and three orthogonal reference magnetometers. The evaluation turned out to be very effective in optimizing the parameters for signal processing. In addition, the method can serve as a useful tool for hardware improvement. PMID:19622849

Zhang, Shulin; Wang, Yongliang; Wang, Huiwu; Jiang, Shiqin; Xie, Xiaoming

2009-08-01

246

Advanced Image-Processing Techniques for Automatic Nondestructive Evaluation of Adhesively-Bonded Structures Using Speckle Interferometry  

Microsoft Academic Search

In conventional optical nondestructive evaluation (NDE) of structures using shearography or electronic speckle pattern interferometry (ESPI), results are typically provided in the form of fringe patterns or deformation contour plots. However, in order to fully automate the process of defect detection, it is desirable to obtain simpler results which are easier to interpret. We present here one such optical system

Pavel Fomitchov; Liu-Sheng Wang; Sridhar Krishnaswamy

1997-01-01

247

Resonant Ultrasound Spectroscopy, as Applied to Nondestructive Evaluation and Characterization of Carbon Fiber Reinforced Epoxy Composite Materials  

Microsoft Academic Search

Resonant ultrasound spectroscopy (RUS) can be an elegantly simple nondestructive evaluation tool. The resonance spectrum of any specimen is dependent on, and sensitive at ppm levels to, its density, geometry, elastic and thermal properties, and boundary conditions. The measurement of spectrum is fast, taking between 15 and 90 seconds with state-of-the-art instrumentation, making it appropriate for following properties as a

Timothy Marvin Whitney

1996-01-01

248

Comparison of two coaxial probes for the non-destructive evaluation of a steel fiber reinforced concrete layer  

Microsoft Academic Search

A coaxial probe technique for the non-destructive evaluation of steel fiber reinforced concrete is presented. An accurate open-ended coaxial probe model together with a mixing formula was used, yielding the fiber concentrations for different reinforced concrete samples. The experiments were conducted with a small and a large probe. We conclude that the proposed technique is a promising one.

Stephan Van Damme; Ann Franchois; Luc Taerwe

2004-01-01

249

Noncontact, nondestructive elasticity evaluation of sound and demineralized human dental enamel using a laser ultrasonic surface wave dispersion technique  

Microsoft Academic Search

Laser ultrasonic nondestructive evaluation (NDE) methods have been proposed to replace conventional in vivo dental clinical diagnosis tools that are either destructive or incapable of quantifying the elasticity of human dental enamel. In this work, a laser NDE system that can perform remote measurements on samples of small dimensions is presented. A focused laser line source is used to generate

Hsiao-Chuan Wang; Simon Fleming; Yung-Chun Lee; Susan Law; Michael Swain; Jing Xue

2009-01-01

250

Giant Magnetoresistive (GMR) Sensor Microelectromechanical System (MEMS) Device for Nondestructive Evaluation (NDE) Health Monitoring Applications for International Space Station (ISS)  

Microsoft Academic Search

With the imminent launch of the first International Space Station modules, NASA Oflice of Safety and Mission Assurance, specifically the Code Q Nondestructive Evaluation Program, is addressing issues of on-orbit station structural health monitoring. As part of this effort, Jet Propulsion Laboratory is working with NASA's Langley Research Center on development of novel devices and sensors for an NDE tool

R. Ramesham; J. D. Olivas; S. Stokes; W. Wilson; Edward Generazio

251

Quantitative ultrasonic evaluation of engineering properties in metals, composites and ceramics  

NASA Technical Reports Server (NTRS)

Ultrasonic technology from the perspective of nondestructive evaluation approaches to material strength prediction and property verification is reviewed. Emergent advanced technology involving quantitative ultrasonic techniques for materials characterization is described. Ultrasonic methods are particularly useful in this area because they involve mechanical elastic waves that are strongly modulated by the same morphological factors that govern mechanical strength and dynamic failure processes. It is emphasized that the technology is in its infancy and that much effort is still required before all the available techniques can be transferred from laboratory to industrial environments.

Vary, A.

1980-01-01

252

Nondestructive Evaluation of Advanced Materials with X-ray Phase Mapping  

NASA Technical Reports Server (NTRS)

X-ray radiation has been widely used for imaging applications since Rontgen first discovered X-rays over a century ago. Its large penetration depth makes it ideal for the nondestructive visualization of the internal structure and/or defects of materials unobtainable otherwise. Currently used nondestructive evaluation (NDE) tools, X-ray radiography and tomography, are absorption-based, and work well in heavy-element materials where density or composition variations due to internal structure or defects are high enough to produce appreciable absorption contrast. However, in many cases where materials are light-weight and/or composites that have similar mass absorption coefficients, the conventional absorption-based X-ray methods for NDE become less useful. Indeed, the light-weight and ultra-high-strength requirements for the most advanced materials used or developed for current flight mission and future space exploration pose a great challenge to the standard NDE tools in that the absorption contrast arising from the internal structure of these materials is often too weak to be resolved. In this presentation, a solution to the problem, the use of phase information of X-rays for phase contrast X-ray imaging, will be discussed, along with a comparison between the absorption-based and phase-contrast imaging methods. Latest results on phase contrast X-ray imaging of lightweight Space Shuttle foam in 2D and 3D will be presented, demonstrating new opportunities to solve the challenging issues encountered in advanced materials development and processing.

Hu, Zhengwei

2005-01-01

253

Automated Nondestructive Evaluation Method for Characterizing Ceramic and Metallic Hot Gas Filters  

SciTech Connect

The objective of this work was to develop a nondestructive (NDE), cost-effective and reliable method to assess the condition of rigid ceramic hot gas filters. The work was intended to provide an end user, as well as filter producers, with a nondestructive method to assess the ''quality'' or status of the filters.

Ellingson, W.A.; Pastila, P.; Koehl, E.R.; Wheeler, B.; Deemer, C.; Forster, G.A.

2002-09-19

254

A new focusing method for nondestructive evaluation by surface acoustic wave  

Microsoft Academic Search

The focalization of surface acoustic wave on piezoelectric substrates has been largely studied. It is of great interest, in the nondestructive testing area, to use focused surface acoustic waves to monitor defects like cracks which are hardly detected by acoustic bulk waves. In this paper, a new method for nondestructive testing is reported, which uses cylindrically focused surface acoustic beams.

B. Nongaillard; M. Ourak; J. M. Rouvaen; M. Houze; E. Bridoux

1984-01-01

255

Dynamic laser speckle for non-destructive quality evaluation of bread  

NASA Astrophysics Data System (ADS)

Coherent illumination of a diffuse object yields a randomly varying interference pattern, which changes over time at any modification of the object. This phenomenon can be used for detection and visualization of physical or biological activity in various objects (e.g. fruits, seeds, coatings) through statistical description of laser speckle dynamics. The present report aims at non-destructive full-field evaluation of bread by spatial-temporal characterization of laser speckle. The main purpose of the conducted experiments was to prove the ability of the dynamic speckle method to indicate activity within the studied bread samples. In the set-up for acquisition and storage of dynamic speckle patterns an expanded beam from a DPSS laser (532 nm and 100mW) illuminated the sample through a ground glass diffuser. A CCD camera, adjusted to focus the sample, recorded regularly a sequence of images (8 bits and 780 x 582 squared pixels, sized 8.1 × 8.1 ?m) at sampling frequency 0.25 Hz. A temporal structure function was calculated to evaluate activity of the bread samples in time using the full images in the sequence. In total, 7 samples of two types of bread were monitored during a chemical and physical process of bread's staling. Segmentation of images into matrixes of isometric fragments was also utilized. The results proved the potential of dynamic speckle as effective means for monitoring the process of bread staling and ability of this approach to differentiate between different types of bread.

Stoykova, E.; Ivanov, B.; Shopova, M.; Lyubenova, T.; Panchev, I.; Sainov, V.

2010-10-01

256

Thermo-elastic nondestructive evaluation of fatigue damage in PMR-15 resin  

NASA Astrophysics Data System (ADS)

Thermoset polyimide resins are used as the polymer matrix in high temperature composites for aerospace applications such as engine shrouds. At these locations the components have to withstand high temperatures and significant vibration. A number of studies have investigated the effects of thermal exposure on mechanical properties of polyimide resins, and the effects of fatigue on thermoplastics have been discussed at length. However, the effects of fatigue on thermosets, in particular polyimides, have largely been overlooked. In this paper we present studies of nondestructive evaluation of fatigue damage in a thermoset polyimide resin, PMR-15, performed by measuring the changes in the evolution of heat in the samples during cyclic loading. The temperature changes are measured using a high sensitivity IR camera as a function of number of fatigue cycles. Interrupted fatigue tests were performed on four samples. The temperature rise during an increment of fatigue cycling shows two linear regions each with a different slope (region 1 and region 2). Region 1 remains constant for every increment of fatigue, while region 2 increases. The onset of region 2 occurs at the same increase in temperature due to hysteretic heating for all samples. Experimental observations are explained using a phenomenological two phase model based on crosslinking density variations in observed in other thermoset resins at microscopic scales. The results of these experiments are discussed in reference to utilizing this technique for detection and evaluation of fatigue in PMR-15 resin and composites.

Welter, J. T.; Sathish, S.; Tandon, G. P.; Schehl, N.; Cherry, M.; Nalladega, V.; Lindgren, E. A.; Hall, R.

2012-05-01

257

Study of Electrical Potential Methods for the Nondestructive Evaluation of Peripheral Nerve Regeneration.  

National Technical Information Service (NTIS)

Repair of peripheral nerve injuries in human patients is important in both civilian and military practices because such injuries are the frequent result of combat or accident. Improved methods for the nondestructive examination of the regeneration process...

H. F. Poppendiek D. J. Connelly

1975-01-01

258

Nondestructive Evaluation (NDE) for Characterizing Oxidation Damage in Cracked Reinforced Carbon-Carbon (RCC)  

NASA Technical Reports Server (NTRS)

In this study, coated reinforced carbon-carbon (RCC) samples of similar structure and composition as that from the NASA space shuttle orbiter's thermal protection system were fabricated with slots in their coating simulating craze cracks. These specimens were used to study oxidation damage detection and characterization using nondestructive evaluation (NDE) methods. These specimens were heat treated in air at 1143 and 1200 C to create cavities in the carbon substrate underneath the coating as oxygen reacted with the carbon and resulted in its consumption. The cavities varied in diameter from approximately 1 to 3 mm. Single-sided NDE methods were used since they might be practical for on-wing inspection, while x-ray micro-computed tomography (CT) was used to measure cavity sizes in order to validate oxidation models under development for carbon-carbon materials. An RCC sample having a naturally-cracked coating and subsequent oxidation damage was also studied with x-ray micro-CT. This effort is a follow-on study to one that characterized NDE methods for assessing oxidation damage in an RCC sample with drilled holes in the coating.

Roth, Don J.; Rauser, Richard W.; Jacobson, Nathan S.; Wincheski, Russell A.; Walker, James L.; Cosgriff, Laura A.

2009-01-01

259

Nondestructive Evaluation (NDE) for Characterizing Oxidation Damage in Cracked Reinforced Carbon-Carbon  

NASA Technical Reports Server (NTRS)

In this study, coated reinforced carbon-carbon (RCC) samples of similar structure and composition as that from the NASA space shuttle orbiter's thermal protection system were fabricated with slots in their coating simulating craze cracks. These specimens were used to study oxidation damage detection and characterization using nondestructive evaluation (NDE) methods. These specimens were heat treated in air at 1143 C and 1200 C to create cavities in the carbon substrate underneath the coating as oxygen reacted with the carbon and resulted in its consumption. The cavities varied in diameter from approximately 1 to 3mm. Single-sided NDE methods were used because they might be practical for on-wing inspection, while X-ray micro-computed tomography (CT) was used to measure cavity sizes in order to validate oxidation models under development for carbon-carbon materials. An RCC sample having a naturally cracked coating and subsequent oxidation damage was also studied with X-ray micro-CT. This effort is a follow-on study to one that characterized NDE methods for assessing oxidation damage in an RCC sample with drilled holes in the coating.

Roth, Don J.; Jacobson, Nathan S.; Rauser, Richard W.; Wincheski, Russell A.; Walker, James L.; Cosgriff, Laura A.

2010-01-01

260

Comparison of ultrasonic array imaging algorithms for non-destructive evaluation  

NASA Astrophysics Data System (ADS)

Ultrasonic array imaging algorithms have been widely used and developed in nondestructive evaluation in the last 10 years. In this paper, three imaging algorithms (Total Focusing Method (TFM), Phase Coherent Imaging (PCI), and Spatial Compounding Imaging (SCI)) are compared through both simulation and experimental measurements. In the simulation, array data sets were generated using a hybrid forward model containing a single defect amongst a multitude of randomly distributed point scatterers to represent backscatter from material microstructure. The Signal to Noise Ratio (SNR) of the final images and their resolution were used to indicate the quality of the different imaging algorithms. The images of different types of defect (point reflectors and planar cracks) were used to investigate the robustness of the imaging algorithms. It is shown that PCI can yield higher image resolution than the TFM, but that the images of cracks are distorted. Overall, the TFM is the most robust algorithm across a range of different types of defects. It is also shown that the detection limit of all three imaging algorithms is almost equal for weakly scattering defects.

Zhang, J.; Drinkwater, B. W.; Wilcox, P. D.

2013-01-01

261

Automated nondestructive evaluation method for characterizing ceramic and metallic hot gas filters.  

SciTech Connect

In advanced coal-fired power generation, one technology under development to clean up hot gases before their use as fuel for gas turbines is rigid ceramic candle filters. These porous filters are typically 1.5 m long and 60 mm in diameter and are made of various ceramic materials, including clay-bonded SiC. The high costs of downtime in a large utility demands that nondestructive evaluation/characterization (NDE/C) methods be available. At shutdowns, data from such analysis are needed to decide which filters are still usable and which need to be replaced, and if possible, to estimate the remaining lifetimes. Thus our objective was to develop reliable low-cost NDE technology for these filters. Our approach was to develop NDE/C technology, referred to as acousto-ultrasonics (AU), for application to hot gas filters. Lamb waves generated by the AU method were analyzed to derive a stress wave factor (SWF). This technology was tested by comparing SWF data with the measured strength for a variety of rigid ceramic filters and was shown to work on iron-aluminide filters as well but no strength data have been obtained on the iron-aluminides at this time.

Ellingson, W. A.; Koehl, E. R.; Deemer, C.; Pastilla, P.; Wheeler, B.; Forster, G. A.

2002-06-03

262

Application of electronic imaging for characterization of defects in nondestructive evaluation  

NASA Astrophysics Data System (ADS)

Catastrophic failures of major engineering systems such as the space shuttle or nuclear reactor demands more reliable nondestructive evaluation (NDE) technology to maintain a high level of safety. Reliable defect characterization by NDE depends on its efficiency that eliminates the false confidence level in system performance. Also, the modern damage tolerant design based on fracture mechanics requires the reliability and accuracy of the NDE techniques used to detect and characterize flaws. Inspection codes for industrial components specify the sensitivity levels of an inspection method as well as the rejectable flaw size. For complete defect characterization the electronic imaging technique is widely used. In this work, imaging of defects was carried out on thick weldments of SA - 229 pressure vessel steel. Generation of natural defects like cracks were realized by an innovative and reliable welding technique, and NDE techniques, conventional and advanced ones including acoustic holography were used for the crack characterization. Specimens after the test were machined to reveal the cracks and the actual crack morphology was measured and recorded. Through a computer model, the defect image was reconstructed and visualized at different sections. A comparative analysis on the reconstructed image in a computer, the actual one and the NDE result was carried out.

Mani, C.; Homma, Hiroomi; Kanto, Yasuhiro

1997-03-01

263

Detection of thermally grown oxides in thermal barrier coatings by nondestructive evaluation  

NASA Astrophysics Data System (ADS)

The thermal-barrier coatings (TBC) sprayed on hot-section components of aircraft turbine engines commonly consist of a partially stabilized zirconia top-coat and an intermediate bond-coat applied on the metallic substrate. The bond-coat is made of an aluminide alloy that at high engine temperatures forms thermally grown oxides (TGO). Although formation of a thin layer of aluminum oxide at the interface between the ceramic top-coat and the bond-coat has the beneficial effect of protecting the metallic substrate from hot gases, oxide formation at splat boundaries or pores within the bond-coat is a source of weakness. In this study, plasma-sprayed TBC specimens are manufactured from two types of bond-coat powders and exposed to elevated temperatures to form oxides at the ceramic-bond-coat boundary and within the bond-coat. The specimens are then tested using nondestructive evaluation (NDE) and destructive metallography and compared with the as-manufactured samples. The objective is to determine if NDE can identify the oxidation within the bond-coat and give indication of its severity. While ultrasonic testing can provide some indication of the degree of bond-coat oxidation, the eddy current (EC) technique clearly identifies severe oxide formation within the bond-coat. Imaging of the EC signals as the function of probe location provides information on the spatial variations in the degree of oxidation, and thereby identifies which components or areas are prone to premature damage.

Fahr, A.; Rogé, B.; Thornton, J.

2006-03-01

264

Interrelationship of Nondestructive Evaluation Methodologies Applied to Testing of Composite Overwrapped Pressure Vessels  

NASA Technical Reports Server (NTRS)

Composite Overwrapped Pressure Vessels (COPVs) are commonly used in spacecraft for containment of pressurized gases and fluids, incorporating strength and weight savings. The energy stored is capable of extensive spacecraft damage and personal injury in the event of sudden failure. These apparently simple structures, composed of a metallic media impermeable liner and fiber/resin composite overwrap are really complex structures with numerous material and structural phenomena interacting during pressurized use which requires multiple, interrelated monitoring methodologies to monitor and understand subtle changes critical to safe use. Testing of COPVs at NASA Johnson Space Center White Sands T est Facility (WSTF) has employed multiple in-situ, real-time nondestructive evaluation (NDE) methodologies as well as pre- and post-test comparative techniques to monitor changes in material and structural parameters during advanced pressurized testing. The use of NDE methodologies and their relationship to monitoring changes is discussed based on testing of real-world spacecraft COPVs. Lessons learned are used to present recommendations for use in testing, as well as a discussion of potential applications to vessel health monitoring in future applications.

Leifeste, Mark R.

2007-01-01

265

Method and apparatus for enhancing surface absorption and emissivity in optical pulsed infrared nondestructive evaluation  

NASA Astrophysics Data System (ADS)

In the application of optical pulsed infrared NDE, the visible light absorption and IR emissivity of the detected object must be considered. One of the simple methods is spraying paint on the highly reflective and low IR emissivity surface before testing. However, for some materials such as with pore space in the surface or easily to be corrupted have to be pretreated by other method and apparatus. Two kinds of apparatus for surface pretreating are designed according to the dimension of the detected object and the testing conditions. One apparatus is independent of the former detecting system, and the other is an improvement of the former system. The basic principle of the two apparatus is covering a flexible membrane of high light absorption and IR emissivity on the specimen surface by vacuum pumping. The paper also present the applications of the method, including the detection of the metal mesh material and the honeycomb structures with aluminum coating. The experimental results show that the technique of covering thin film by vacuum pump is effective for enhancing surface absorption and emissivity; moreover, it does not pollute or damage the sample. The application of the technique has practical significance, because it extends the scope of the application of the optical pulsed thermography nondestructive evaluation.

Duan, Yuxia; Zhang, Cunlin; Jin, Wanping; Wu, Naiming

2009-07-01

266

Fiber-optic sensors for composite cure analysis and lifetime nondestructive evaluation  

SciTech Connect

A proposed multiplexed fiber-optic sensor system capable of analyzing a composite material during its curing cycle and over its service lifetime is presented. The sensor is composed of two independent sensing schemes that will ultimately be multicomplexed onto a specialized single-mode/multimode optical fiber. The first sensing scheme is a fiber-optic viscosity and temperature sensor used for composite cure analyses. This sensor is based on (1) the laser-induced viscosity-dependent fluorescence phenomena observed in epoxy-based composite materials and (2) the temperature-dependent decay-time fluorescence phenomena observed in thermographic phosphors. The second sensor is based on a low-finesse, single-mode fiber-optic Fabry-Perot interferometer and is used as a strain/vibration sensor for lifetime nondestructive evaluations on composites. Experimental results have determined that these sensor concepts are feasible alternatives to cure-analysis monitors and conventional strain-analysis techniques. 15 refs., 7 figs.

Muhs, J.D.; Cates, M.R.; Tobin, K.W.; Capps, G.J.; Beshears, D.L. (Oak Ridge National Lab., TN (USA))

1989-01-01

267

New Approaches to Nondestructive Evaluation of a Filament-Wound Composite Motor Case Using Circumferential Wave  

NASA Astrophysics Data System (ADS)

For reliable quality assurance of filament-wound composite rocket motor (FCRM) cases by use of acoustic emission during hydroproof (AE/H) testing, it is necessary both to detect defects introduced in fabrication process and to monitor damage done due to hydraulic pressurization. The circumferential wave, which has strong directivity and weak anisotropy in wave propagation in the particular FCRM case under present investigation, has high potential to address such a need. To explore these outstanding capabilities of the circumferential wave, two kinds of experiments were conducted. The pitch-catch measurements of the circumferential wave that propagated through the artificial slits demonstrated its high potential for detection of flaws. The experiments for AE source location using a particular, triangular layout of AE sensors declared its capability for monitoring of damages. Inspired from the experiments, new approaches to nondestructive evaluation of the given FCRM case were proposed using the circumferential wave: 1) an ultrasonic pitch-catch scanning and 2) an AE/H testing with a suitable triangular layout of AE sensors.

Song, Sung-Jin; Choe, Ji-Ung; Bae, Dong-Ho

268

Modal Test Technology as Non-Destructive Evaluation of Space Shuttle Structures  

NASA Technical Reports Server (NTRS)

Modal test and analysis Is being used for nondestructive evaluation of Space Shuttle structures. The purpose of modal testing is to measure the dynamic characteristics of a structure to extract its resonance frequencies, damping, and mode shapes. These characteristics are later compared to subsequently acquired characteristics. Changes in the modal characteristics indicate damage in the structure. Use of modal test technology as a damage detection tool was developed at JSC during the Shuttle acoustic certification program and subsequent test programs. The Shuttle Modal Inspection System was created in order to inspect areas that are impossible or impractical to inspect with conventional methods. Areas on which this technique has been applied include control surfaces, which are covered with thermal protection tiles, and the Forward Reaction Control Module, which is a frame structure that supports various tanks, thrusters, and fluid lines, which requires major disassembly to inspect. This paper traces the development of the technology, gives a status of its implementation on the Shuttle, explains challenges involved in implementing this type of inspection program, and suggests future improvements in data analysis and interpretation. Dual-use applications of the technology include inspections of bridges, oil-platforms, and aircraft.

Grygler, Micheal S.

1994-01-01

269

Role of nondestructive evaluation in civil aviation: historical development, current status, future challenges  

NASA Astrophysics Data System (ADS)

Nondestructive evaluation has been used in civil aviation for 50 years. Until the arrival of the jet era it was mostly applied to component inspection. Since the damage-tolerant design philosophy was introduced by mandate for large transport aircraft, it has become an integral part of their design and maintenance. In the near future its role in the maintenance of aging small transport aircraft is expected to grow significantly. The most important factor contributing to the growing importance of NDE is the fact that the industry has been operating its aircraft much longer than originally envisioned, making it necessary to carefully monitor their structural condition to assure their airworthiness. NDE is helping making it economically feasible to operate aircraft for extended life times. Another major factor is the increased use of advanced materials, such as composites. Again, monitoring has to assure integrity. More recently, in an industry which has become highly competitive, NDE is becoming an important tool in the quest for reducing maintenance costs. The importance of NDE is expected to grow further.

Weber, Hans J.

1995-07-01

270

Evaluation of scanners for C-scan imaging in nondestructive inspection of aircraft  

SciTech Connect

The goal of this project was to produce a document that contains information on the usability and performance of commercially available, fieldable, and portable scanner systems as they apply to aircraft NDI inspections. In particular, the scanners are used to generate images of eddy current, ultrasonic, or bond tester inspection data. The scanner designs include manual scanners, semiautomated scanners, and fully automated scanners. A brief description of the functionality of each scanner type, a sketch, and a fist of the companies that support the particular design are provided. Vendors of each scanner type provided hands-on demonstrations of their equipment on real aircraft samples in the FAA Aging Aircraft Nondestructive Inspection Validation Center (AANC) in Albuquerque, NM. From evaluations recorded during the demonstrations, a matrix of scanner features and factors and ranking of the capabilities and limitations of the design, portability, articulation, performance, usability, and computer hardware/software was constructed to provide a quick reference for comparing the different scanner types. Illustrations of C-scan images obtained during the demonstration are shown.

Gieske, J.H.

1994-04-01

271

Design, development and application of a novel microwave nondestructive evaluation sensor based on metamaterial lens  

NASA Astrophysics Data System (ADS)

Nondestructive Evaluation (NDE) method is one of the primary tools of inspecting different materials for structural reliability. Microwave NDE techniques attract more and more attention from the industry and academia. Microwave NDE techniques have the potential to penetrate deeper into materials such as composites and other dielectrics as compared to ultrasonic techniques. Microwave NDE sensors typically operate in two modes---far field and near field. Although in the far field the standoff distance from the sample is comfortable to a user, the resolution of such sensor is limited by the diffraction limit. This thesis describes design, fabrication and evaluation of a novel microwave NDE sensor based on a metamaterial lens. It was a purpose of this work to design a novel Microwave NDE sensor based on a metamaterial lens. The proposed sensor would combine a comfortable standoff distance from the sample with a subwavelength resolution. It was shown that in the resonant frequency range of 3--4 GHz the designed lenses can focus below the diffraction limit (0.48 lambda) and that defects as small as 0.037 lambda in diameter in a dielectric sample can be detected. The resolution was further improved by introducing a metamaterial lens with resonant frequency of 16.75 GHz. Applicability of the proposed sensor to other samples such as corrosion spot under space shuttle tile and rippling on the surface of carbon fiber composites was shown. The limitations of the method were also discussed. The proposed sensor is a viable alternative to the existing NDE methods and contributes greatly to advances in the field of non destructive evaluation.

Shreiber, Daniel

272

Development of Natural Flaw Samples for Evaluating Nondestructive Testing Methods for Foam Thermal Protection Systems  

NASA Technical Reports Server (NTRS)

Low density polyurethane foam has been an important insulation material for space launch vehicles for several decades. The potential for damage from foam breaking away from the NASA External Tank was not realized until the foam impacts on the Columbia Orbiter vehicle caused damage to its Leading Edge thermal protection systems (TPS). Development of improved inspection techniques on the foam TPS is necessary to prevent similar occurrences in the future. Foamed panels with drilled holes for volumetric flaws and Teflon inserts to simulate debonded conditions have been used to evaluate and calibrate nondestructive testing (NDT) methods. Unfortunately the symmetric edges and dissimilar materials used in the preparation of these simulated flaws provide an artificially large signal while very little signal is generated from the actual defects themselves. In other words, the same signal are not generated from the artificial defects in the foam test panels as produced when inspecting natural defect in the ET foam TPS. A project to create more realistic voids similar to what actually occurs during manufacturing operations was began in order to improve detection of critical voids during inspections. This presentation describes approaches taken to create more natural voids in foam TPS in order to provide a more realistic evaluation of what the NDT methods can detect. These flaw creation techniques were developed with both sprayed foam and poured foam used for insulation on the External Tank. Test panels with simulated defects have been used to evaluate NDT methods for the inspection of the External Tank. A comparison of images between natural flaws and machined flaws generated from backscatter x-ray radiography, x-ray laminography, terahertz imaging and millimeter wave imaging show significant differences in identifying defect regions.

Workman, Gary L.; Davis, Jason; Farrington, Seth; Walker, James

2007-01-01

273

Acousto-ultrasonic nondestructive evaluation of materials using laser beam generation and detection. M.S. Thesis  

NASA Technical Reports Server (NTRS)

The acousto-ultrasonic method has proven to be a most interesting technique for nondestructive evaluation of the mechanical properties of a variety of materials. Use of the technique or a modification thereof, has led to correlation of the associated stress wave factor with mechanical properties of both metals and composite materials. The method is applied to the nondestructive evaluation of selected fiber reinforced structural composites. For the first time, conventional piezoelectric transducers were replaced with laser beam ultrasonic generators and detectors. This modification permitted true non-contact acousto-ultrasonic measurements to be made, which yielded new information about the basic mechanisms involved as well as proved the feasibility of making such non-contact measurements on terrestrial and space structures and heat engine components. A state-of-the-art laser based acousto-ultrasonic system, incorporating a compact pulsed laser and a fiber-optic heterodyne interferometer, was delivered to the NASA Lewis Research Center.

Huber, Robert D.; Green, Robert E., Jr.

1990-01-01

274

Development of non-destructive methods to evaluate oyster quality by electronic nose technology  

Microsoft Academic Search

The effectiveness of two electronic nose (e-nose) systems to assess the quality of oysters was studied on live oysters stored\\u000a at 4 and 7°C for 14 days. E-nose data were correlated with a trained sensory panel evaluation by quantitative description\\u000a analysis and with aerobic plate count. Oysters stored at both temperatures exhibited varying degrees of microbial spoilage,\\u000a with bacterial load

Xiaopei Hu; ParameswaraKumar Mallikarjunan; David Vaughan

2008-01-01

275

Nondestructive quantitative mapping of impurities and point defects in thin films: Ga and VZn in ZnO:Ga  

NASA Astrophysics Data System (ADS)

Ga-doped ZnO (GZO) films grown by pulsed-laser deposition on quartz and other lattice-mismatched substrates can routinely attain resistivities of 2 × 10-4 ?.cm and thus compete with Sn-doped In2O3 (ITO) in large-area transparent-electrode applications. Nondestructive, high-resolution (1-mm) maps of thickness d, concentration n, and mobility ? on such films can be obtained automatically from commercial spectroscopic ellipsometers. From n and ?, degenerate-electron scattering theory yields donor ND and acceptor NA concentrations at each point. Finally, ND and NA can be identified as [Ga] and [VZn], respectively, demonstrating high-density mapping of impurities and point defects in a semiconductor thin film.

Look, David C.; Leedy, Kevin D.; Agresta, Donald L.

2014-06-01

276

Evaluation of the quality of commercial silicon carbide wafers by an optical non-destructive inspection technique  

NASA Astrophysics Data System (ADS)

There is a great need for an in-line, high-speed and non-destructive inspection system capable of evaluating and analyzing the quality SiC wafers for SiC power devices. We have examined whether the laser-based optical non-destructive inspection system by KLA-Tencor meets these requirements. By optimizing the optical setup and improving the defect recognition and classification recipe, we have successfully mapped classified defects on a SiC wafer. Using this system, incoming inspection of purchased SiC wafers has been performed. The obtained inspection data show that micropipe density is sufficiently low in a device-grade wafer and, therefore, micropipes are not the main cause of device failure. The next challenges for a device-grade SiC wafer are reduction of epitaxial defects and relatively small defects classified as "particles".

Hatakeyama, T.; Ichinoseki, K.; Fukuda, K.; Higuchi, N.; Arai, K.

2008-03-01

277

Non-destructive microwave evaluation of TBC delamination induced by acute angle laser drilling  

NASA Astrophysics Data System (ADS)

Laser drilling has been applied to the production of cooling holes of various size and angles in the modern aerospace gas turbine components such as turbine blades, nozzle guide vanes, combustion chambers and afterburner. These parts are usually made of heat resistant nickel superalloys. The superalloy substrate is coated with yttria-stabilized zirconia thermal barrier coatings (TBCs) to protect them from reaching excessive temperatures in hot engine environments. Drilling the parts at acute angles to the surface is complicated because (i) multiple layers are being drilled through, (ii) the melt ejection and heat flow patterns around the hole are non-symmetrical and (iii) the drilling distance is greater than when drilling normal to the surface. In a previous investigation by the authors, delamination of TBC was addressed as a main problem of angled drilling and mechanisms involved were discussed. Characterization of delamination cracks was normally performed via metallographic techniques. It involves sectioning the samples using an abrasive cutting machine, grinding with successively finer silicon carbide paper up to the centre of the hole and polishing to allow optical microscopic analysis of the cracks. However, clamping and sectioning process of thermal-spray-coated workpieces can introduce cracks in brittle coatings due to the drag of the cut-off wheels. Hence, it is not possible to decide if the delamination is caused as a result of post-process sectioning or laser drilling. In this paper, a microwave non-destructive testing (NDT) technique is employed to evaluate the integrity of TBC after acute angle laser drilling. An Agilent 8510 XF network analyser operating over the frequency range of 45 MHz to 110 GHz was used to measure the amplitude and phase variations of scattered waves. The results significantly indicated the existence of delamination of 1-1.5 mm long at the TBC/substrate interface on the leading edge part of an acute-angled hole laser drilled using a 400 W Nd:YAG laser.

Sezer, H. K.; Li, Lin; Wu, Z.; Anderson, B.; Williams, P.

2007-01-01

278

Review of embedded particle tagging methods for nondestructive evaluation (NDE) of composite materials and structures  

NASA Astrophysics Data System (ADS)

Acceptance of advanced composites in both retrofit applications and new construction necessitates quality control (QC)/quality assurance (QA) and in-service monitoring techniques to ensure the performance and serviceability of the composites. A technology that enhances the inspectability of the advanced composites is the particle tagging method. The concept of particle tagging involves embedding micron-sized particles into materials, such as composites, or adhesive layers to make them an integral part of the host material. When interrogated by suitable instrumentation, the embedded particle sensors interact with their host material and generate certain types of measurable signatures. The signatures can be correlated with the material and structural conditions, such as internal stress states, voids, inclusions, state-of- cure, and delaminations. This paper presents a technology assessment of the current and emerging state-of-the-art tagging methods. The objective of this review is to provide a framework for further understanding the physics and mechanisms involved in using the tagging method for in-field nondestructive evaluation (NDE) of composite materials. Information concerning the development of this technique has been obtained from patents, publications, databases within Newman Library at Virginia Polytechnic Institute and State University (Virginia Tech), and previous work and in-progress research at the Center for Intelligent Material Systems and Structures (CIMSS) at Virginia Tech. This paper includes a historic review of tagging techniques, a description of the tagging systems used for in-situ NDE of composites, and experimental results to date. The current and potential applications of this technique are also addressed. The analysis presented in this paper will assist in further efforts to develop the tagging approach that may be used as a new NDE technique for quality assurance of advanced composites.

Zhou, Su-Wei; Chaudhry, Zaffir A.; Rogers, Craig A.; Quattrone, Robert

1995-04-01

279

Microwave and Millimeter Wave Nondestructive Evaluation of the Space Shuttle External Tank Insulating Foam  

NASA Technical Reports Server (NTRS)

The Space Shuttle Columbia s catastrophic failure has been attributed to a piece of external fuel tank insulating SOFI (Spray On Foam Insulation) foam striking the leading edge of the left wing of the orbiter causing significant damage to some of the protecting heat tiles. The accident emphasizes the growing need to develop effective, robust and life-cycle oriented methods of nondestructive testing and evaluation (NDT&E) of complex conductor-backed insulating foam and protective acreage heat tiles used in the space shuttle fleet and in future multi-launch space vehicles. The insulating SOFI foam is constructed from closed-cell foam. In the microwave regime this foam is in the family of low permittivity and low loss dielectric materials. Near-field microwave and millimeter wave NDT methods were one of the techniques chosen for this purpose. To this end several flat and thick SOFI foam panels, two structurally complex panels similar to the external fuel tank and a "blind" panel were used in this investigation. Several anomalies such as voids and disbonds were embedded in these panels at various locations. The location and properties of the embedded anomalies in the "blind" panel were not disclosed to the investigating team prior to the investigation. Three frequency bands were used in this investigation covering a frequency range of 8-75 GHz. Moreover, the influence of signal polarization was also investigated. Overall the results of this investigation were very promising for detecting the presence of anomalies in different panels covered with relatively thick insulating SOFI foam. Different types of anomalies were detected in foam up to 9 in thick. Many of the anomalies in the more complex panels were also detected. When investigating the blind panel no false positives were detected. Anomalies in between and underneath bolt heads were not easily detected. This paper presents the results of this investigation along with a discussion of the capabilities of the method used.

Shrestha, S.; Kharkovsky, S.; Zoughi, R.; Hepburn, F

2005-01-01

280

Low-Cost Quality Control and Nondestructive Evaluation Technologies for General Aviation Structures  

NASA Technical Reports Server (NTRS)

NASA's Advanced General Aviation Transport Experiments (AGATE) Program has as a goal to reduce the overall cost of producing private aviation aircraft while maintaining the safety of these aircraft. In order to successfully meet this goal, it is necessary to develop nondestructive inspection techniques which will facilitate the production of the materials used in these aircraft and assure the quality necessary to maintain airworthiness. This paper will discuss a particular class of general aviation materials and several nondestructive inspection techniques that have proven effective for making these inspections. Additionally, this paper will discuss the investigation and application of other commercially available quality control techniques applicable to these structures.

Cramer, K. Elliott; Gavinsky, Bob; Semanskee, Grant

1998-01-01

281

The development of ultrasonic techniques for nondestructive evaluation of adhesive bonds  

NASA Astrophysics Data System (ADS)

Demands for improvements in aerospace and automotive energy-efficiency, performance, corrosion resistance, body stiffness and style have increased the use of adhesive bonds to help meet those demands by providing joining technology that accommodates a wider variety of materials and design options. However, the history of adhesive bond performance clearly indicates the need for a robust method of assuring the existence of the required consistent level of adhesive bond integrity in every bonded region. This investigation seeks to meet that need by the development of new, complementary ultrasonic techniques for the evaluation of these bonds, and thus provide improvements over previous methods by extending the range of resolution, speed and applications. The development of a 20 MHz pulse-echo method for nondestructive evaluation of adhesive bonds will accomplish the assessment of bond joints with adhesive as thin as 0.1 mm. This new method advances the state of the art by providing a high-resolution, phase-sensitive procedure that identifies the bond state at each interface of the adhesive with the substrate(s), by the acquisition and analysis of acoustic echoes reflected from interfaces between layers with large acoustic impedance mismatch. Because interface echo amplitudes are marginal when the acoustic impedance of the substrate is close to that of the adhesive, a 25 kHz Lamb wave technique was developed to be employed in such cases, albeit with reduced resolution. Modeling the ultrasonic echoes and Lamb-wave signals was accomplished using mathematical expressions developed from the physics of acoustic transmission, attenuation and reflection in layered media. The models were validated by experimental results from a variety of bond joint materials, geometries and conditions, thereby confirming the validity of the methodology used for extracting interpretations from the phase-sensitive indications, as well as identifying the range and limits of applications. Results from the application of both methodologies to laboratory specimens and to samples from production operations are reported herein, and show that bond joint integrity can be evaluated effectively over the range of materials and geometries addressed.

Chapman, Gilbert B., II

282

A Hybrid Approach to Structural Health Monitoring Using Nondestructive Evaluation (NDE) and Active Damage Interrogation  

Microsoft Academic Search

With the useful lives of many aircraft being extended, in-service inspection, repair, and related support activities represent a considerable commitment of resources. Periodic maintenance operations involve comprehensive nondestructive inspections (NDI) and significant aircraft downtime for compilation of data, disposition of results, and any needed repairs. Confining the inspections to known or suspected problem areas still requires time to cover the

R. W. Engelbart; D. D. Palmer; D. M. Pitt

2003-01-01

283

Evaluation of thermal cameras for non-destructive thermal testing applications  

Microsoft Academic Search

Thermal cameras are nowadays often used in industry and science for non-destructive thermal testing (NDTT). There have been published, by the American Society for Testing of Materials, two standards that present detailed measurement procedures of the minimum resolvable temperature difference (MRTD) and the minimum detectable temperature difference (MDTD) of commercial thermal cameras for NDTT applications. However, the standards provide only

K. Chrzanowski; S. N. Park

2001-01-01

284

The nondestructive evaluation of thermal barrier coatings: Measurements of thermal properties and associated defects  

Microsoft Academic Search

Phase of thermal emission spectroscopy is developed to nondestructively determine the thermal properties of thermal barrier coatings (TBC). Harmonic heating of the coating is established using a CO2 laser. The phase of thermal emission is measured from the front surface as a function of laser frequency. A mathematical model is developed to describe the heat transport in the measurement and

Fengling Yu

2005-01-01

285

Nondestructive testing  

Microsoft Academic Search

In order to determine the effectiveness of a given nondestructive testing inspection procedure, trials must be conducted to compare predicted and actual defect sizes. Procedures based on magnetic particle inspection seem to be the most appropriate for detecting surface breaking cracks. Other procedures are required to measure crack depth. It will soon be possible for properly validated nondestructive testing equipment

1985-01-01

286

An Evaluation of Leaf Biomass : Length Ratio as a Tool for Nondestructive Assessment in Eelgrass (Zostera marina L.)  

PubMed Central

The characterization of biomass and its dynamics provides valuable information for the assessment of natural and transplanted eelgrass populations. The need for simple, nondestructive assessments has led to the use of the leaf biomass-to-length ratio for converting leaf-length measurements, which can be easily obtained, to leaf growth rates through the plastochrone method. Using data on leaf biomass and length collected in three natural eelgrass populations and a mesocosm, we evaluated the suitability of a leaf weight-to-length ratio for nondestructive assessments. For the data sets considered, the isometric scaling that sustains the weight-to-length proxy always produced inconsistent fittings, and for leaf-lengths greater than a threshold value, the conversion of leaf length to biomass generated biased estimations. In contrast, an allometric scaling of leaf biomass and length was highly consistent in all the cases considered. And these nondestructive assessments generated reliable levels of reproducibility in leaf biomass for all the ranges of variability in leaf lengths. We argue that the use of allometric scaling for the representation of leaf biomass in terms of length provides a more reliable approach for estimating eelgrass biomass.

Echavarria-Heras, Hector; Solana-Arellano, Elena; Lee, Kun-Seop; Hosokawa, Shinya; Franco-Vizcaino, Ernesto

2012-01-01

287

Nondestructive evaluation of loading and fatigue effects in Haynes(R) 230(R) alloy  

NASA Astrophysics Data System (ADS)

Nondestructive evaluation is a useful method for studying the effects of deformation and fatigue. In this dissertation I employed neutron and X-ray diffraction, nonlinear resonant ultrasound spectroscopy (NRUS), and infrared thermography to study the effects of deformation and fatigue on two different nickel based superalloys. The alloys studied were HAYNES 230, a solid solution strengthened alloy with 4% M6C carbides, and secondarily HASTELLOY C-2000 a similar single phase alloy. Using neutron and X-ray diffraction, the deformation behavior of HAYNES 230 was revealed to be composite-like during compression, but unusual in tension, where the carbides provide strengthening until just after the macroscopic yield strength and then they begin to debond and crack, creating a tension-compression asymmetry that is revealed clearly by in situ diffraction. In fatigue of HAYNES 230, the hkl elastic strains changed very little in tension-tension fatigue. However, in situ tension-compression studies showed large changes over the initial stages of fatigue. The HAYNES 230 samples studies had two distinct starting textures, measured by neutron diffraction. Some samples were texture free initially and deformed in tension and compression to fiber textures. Other samples started with a bimodal texture due to cross-rolling and incomplete annealing. The final texture of these bimodal samples is shown through modeling to be a superposition of the initial texture and typical FCC deformation mechanisms. The texture-free samples deformed significantly more macroscopically and in internal elastic strains than the samples with the cross-rolled texture. In contrast to the relative insensitivity of neutron diffraction to the effects of tension-tension fatigue, NRUS revealed large differences between as-received and progressively fatigued samples. This showed that microcracking and void formation are the primary mechanisms responsible for fatigue damage in tension-tension fatigue. NRUS is shown to be a useful complimentary technique to neutron diffraction to evaluate fatigue damage. Finally, infrared thermography is used to show temperature changes over the course of fatigue in HASTELLOY C-2000. Four stages of temperature are shown over the course of a single fatigue test. Both empirical and theoretical relationships between steady state temperature and fatigue life are developed and presented.

Saleh, Tarik Adel

288

Quantitative Methods for Evaluating Hospital Designs.  

National Technical Information Service (NTIS)

The study provides an integrated quantitative-qualitative basis for decisions involving the relative locations of functions, and hence facilities, within the individual short-term, general, voluntary hospital. The approach used in attacking the problem wa...

G. L. Delon H. E. Smalley

1970-01-01

289

The RAMANITA method for non-destructive and in situ semi-quantitative chemical analysis of mineral solid-solutions by multidimensional calibration of Raman wavenumber shifts.  

PubMed

The "RAMANITA" method, for semi-quantitative chemical analysis of mineral solid-solutions by multidimensional calibration of Raman wavenumber shifts and mathematical calculation by simultaneous equations, is published here in detail in English for the first time. It was conceived by the present writer 20 years ago for binary and ternary pyroxene and garnet systems. The mathematical description was set out in 1989, but in an abstract in an obscure French special publication. Detailed "step-by-step" calibration of two garnet ternaries, followed by their linking, in the early 1990s provided a hexary garnet database. Much later, using this garnet database, which forms part of his personal database called RAMANITA, the present writer began to develop the method by improving the terminology, automating the calculations, discussing problems and experimenting with different real chemical problems in archaeometry. Although this RAMANITA method has been very briefly mentioned in two recent books, the necessary full mathematical explanation is given only here. The method will find application in any study which requires obtaining a non-destructive semi-quantitative chemical analysis from mineral solid solutions that cannot be analysed by any destructive analytical method, in particular for archaeological, geological or extraterrestrial research projects, e.g. Recently some other workers have begun deducing chemical compositions from Raman wavenumber shifts in multivariate chemical space, but the philosophical approach is quite different. PMID:16029851

Smith, David C

2005-08-01

290

Evaluation of Four Quantitative Laboratory Fume Hood Performance Test Methods.  

National Technical Information Service (NTIS)

Four quantitative laboratory fume hood performance test methods were evaluated, including: EPA uranine dye; ASHRAE Freon; EPA SF sub 6 ; and modified EPA SF sub 6 . Each of these methods were evaluated, based on: variability and reproducibility; practical...

L. M. Woodrow

1987-01-01

291

Guidelines to Evaluate Human Observational Studies for Quantitative Risk Assessment  

Microsoft Academic Search

Background: Careful evaluation of the quality of human observational studies (HOS) is required to assess the suitability of HOS for quantitative risk assessment (QRA). In particular, the quality of quantitative exposure assessment is a crucial aspect of HOS to be considered for QRA. Objective: We aimed to develop guidelines for the evaluation of HOS for QRA and to apply these

Jelle Vlaanderen; Roel Vermeulen; Dick Heederik; Hans Kromhout

2008-01-01

292

Evaluation of electrode shape and nondestructive evaluation method for welded solar cell interconnects  

NASA Technical Reports Server (NTRS)

Resistance welds of solar cell interconnect tabs were evaluated. Both copper-silver and silver-silver welds were made with various heat inputs and weld durations. Parallel gap and annular gap weld electrode designs were used. The welds were analyzed by light microscope, electron microprobe and scanning laser acoustic microscope. These analyses showed the size and shape of the weld, the relationship between the acoustic micrographs, the visible electrode footprint, and the effect of electrode misalignment. The effect of weld heat input on weld microstructure was also shown.

Baraona, C. R.; Klima, S. J.; Moore, T. J.; Frey, W. E.; Forestieri, A. F.

1982-01-01

293

Development of a new processing technique of sequential temperature data after pulse heating for quantitative nondestructive testing  

Microsoft Academic Search

Pulse thermography has been developed by several researchers as one of effective quantitative thermographic NDT techniques. The interest of the researchers has been focused on how to process transient temperature data after pulse heating to conduct successful identification of defect parameters such as its depth, shape and size. In this paper, a simple thermographic NDT technique termed \\

Takahide Sakagami; Shiro Kubo; Takeshi Endo; Yoshifumi Asakura

2004-01-01

294

Optical Calibration Process Developed for Neural-Network-Based Optical Nondestructive Evaluation Method  

NASA Technical Reports Server (NTRS)

A completely optical calibration process has been developed at Glenn for calibrating a neural-network-based nondestructive evaluation (NDE) method. The NDE method itself detects very small changes in the characteristic patterns or vibration mode shapes of vibrating structures as discussed in many references. The mode shapes or characteristic patterns are recorded using television or electronic holography and change when a structure experiences, for example, cracking, debonds, or variations in fastener properties. An artificial neural network can be trained to be very sensitive to changes in the mode shapes, but quantifying or calibrating that sensitivity in a consistent, meaningful, and deliverable manner has been challenging. The standard calibration approach has been difficult to implement, where the response to damage of the trained neural network is compared with the responses of vibration-measurement sensors. In particular, the vibration-measurement sensors are intrusive, insufficiently sensitive, and not numerous enough. In response to these difficulties, a completely optical alternative to the standard calibration approach was proposed and tested successfully. Specifically, the vibration mode to be monitored for structural damage was intentionally contaminated with known amounts of another mode, and the response of the trained neural network was measured as a function of the peak-to-peak amplitude of the contaminating mode. The neural network calibration technique essentially uses the vibration mode shapes of the undamaged structure as standards against which the changed mode shapes are compared. The published response of the network can be made nearly independent of the contaminating mode, if enough vibration modes are used to train the net. The sensitivity of the neural network can be adjusted for the environment in which the test is to be conducted. The response of a neural network trained with measured vibration patterns for use on a vibration isolation table in the presence of various sources of laboratory noise is shown. The output of the neural network is called the degradable classification index. The curve was generated by a simultaneous comparison of means, and it shows a peak-to-peak sensitivity of about 100 nm. The following graph uses model generated data from a compressor blade to show that much higher sensitivities are possible when the environment can be controlled better. The peak-to-peak sensitivity here is about 20 nm. The training procedure was modified for the second graph, and the data were subjected to an intensity-dependent transformation called folding. All the measurements for this approach to calibration were optical. The peak-to-peak amplitudes of the vibration modes were measured using heterodyne interferometry, and the modes themselves were recorded using television (electronic) holography.

Decker, Arthur J.

2004-01-01

295

Nondestructive Evaluation of Rubber Compounds by Terahertz Time-Domain Spectroscopy  

NASA Astrophysics Data System (ADS)

Rubber compounds were investigated by terahertz time-domain spectroscopy. Terahertz absorption spectra of crude rubbers and additives were measured as well as those of acrylonitrile-butadiene rubber compounds, which included the additives. It was found that carbon black, which is one of the additives and serves as a filler, dominates the terahertz absorption owing to its metallic characteristics. Thus, terahertz spectroscopy is a useful method for rapid nondestructive inspection during the rubber production.

Hirakawa, Yasuyuki; Ohno, Yoshitomo; Gondoh, Toyohiko; Mori, Tetsuo; Takeya, Kei; Tonouchi, Masayoshi; Ohtake, Hideyuki; Hirosumi, Tomoya

2011-12-01

296

Effectiveness of nondestructive testing for the evaluation of alkali–silica reaction in concrete  

Microsoft Academic Search

This paper deals with the application of various test methods for monitoring the progression of alkali–silica reaction (ASR) in laboratory concrete mixtures. The effectiveness of each method is reported. Concrete specimens were stored at 38°C in high humidity environment according to the Canadian CSA A23.2-14A standard. Mechanical properties were assessed with conventional destructive test and with nondestructive tests (ultrasonic pulse

Maryam Sargolzahi; Serge A. Kodjo; Patrice Rivard; Jamal Rhazi

2010-01-01

297

Tele-shearography for nondestructive evaluation (NDE) of aircraft\\/composite panels: an analysis  

Microsoft Academic Search

Tele-shearographic system based on bulk optics shearing and optical fiber based illumination have been used for the Non-Destructive Testing (NDT)of aircraft\\/composite laminates. This paper describes the application of this system and a detailed experimental analysis to assess defects in Carbon Fiber Reinforced Plastic (CFRP) composite laminates by analyzing the fringe patterns. CFRP laminates and honeycomb panels have been studied using

Chee Keong Ng; Vadakke M. Murukeshan; Seng L. Ong; Brian S. Wong; Anand K. Asundi

2001-01-01

298

Nondestructive evaluation of the semiconductor interface states' density using the transverse acoustoelectric voltage  

NASA Astrophysics Data System (ADS)

Nondestructive determination of the interface states' density ( Dit) is presented. The measurement technique, utilizing the surface acoustic waves, is applied to silicon/thermal oxide structure. The detected signal is the transverse acoustoelectric voltage amplitude (TAV) which is monitored as a function of the applied bias voltage (TAV- V). Dit is measured by comparing the theoretical and experimental TAV- V curves. The calculation procedure of the Dit and the experimental example are presented.

Davari, B.; Azar, M. Tabib; Liu, T.; Das, P.

1986-01-01

299

Nondestructive Evaluation on Hydrided LWR Fuel Cladding by Small Angle Incoherent Neutron Scattering of Hydrogen  

SciTech Connect

A non-destructive neutron scattering method was developed to precisely measure the uptake of total hydrogen in nuclear grade Ziraloy-4 cladding. The hydriding apparatus consists of a closed stainless steel vessel that contains Zr alloy specimens and H gas. By controlling the initial H gas pressure in the vessel and the temperature profile, target H concentrations from tens of ppm to a few thousands of wppm have been successfully achieved. Following H charging, the H content of the hydrided specimens was measured using the vacuum hot extraction method (VHE), by which the samples with desired H concentration were selected for the neutron study. Small angle neutron incoherent scattering (SANIS) were performed in the High Flux Isotope Reactor at Oak Ridge national Laboratory (ORNL). Our study indicates that a very small amount ( 20 ppm) H in commercial Zr cladding can be measured very accurately in minutes for a wide range of H concentration by a nondestructive method. The H distribution in a tube sample was obtained by scaling the neutron scattering rate with a factor, which is determined by calibration process with direct chemical analysis method on the specimen. This scale factor can be used for future test with unknown H concentration, thus provide a nondestructive method for absolute H concentration determination.

Yan, Yong [ORNL] [ORNL; Qian, Shuo [ORNL] [ORNL; Littrell, Ken [ORNL] [ORNL; Parish, Chad M [ORNL] [ORNL; Bell, Gary L [ORNL] [ORNL; Plummer, Lee K [ORNL] [ORNL

2013-01-01

300

Three-dimensional non-destructive optical evaluation of laser-processing performance using optical coherence tomography  

PubMed Central

We demonstrate the use of optical coherence tomography (OCT) as a non-destructive diagnostic tool for evaluating laser-processing performance by imaging the features of a pit and a rim. A pit formed on a material at different laser-processing conditions is imaged using both a conventional scanning electron microscope (SEM) and OCT. Then using corresponding images, the geometrical characteristics of the pit are analyzed and compared. From the results, we could verify the feasibility and the potential of the application of OCT to the monitoring of the laser-processing performance.

Kim, Youngseop; Choi, Eun Seo; Kwak, Wooseop; Shin, Yongjin; Jung, Woonggyu; Ahn, Yeh-Chan; Chen, Zhongping

2014-01-01

301

Development of Standards for Nondestructive Evaluation of COPVs Used in Aerospace Applications  

NASA Technical Reports Server (NTRS)

Composite OverWrapped Pressure Vessels (COPVs) are currently accepted by NASA based on design and qualification requirements and generally not verified by NDE for the following reasons: (1) Manufactures and end users generally do not have experience and validated quantitative methods of detecting flaws and defects of concern (1-a) If detected, the flaws are not adequately quantified and it is unclear how they may contribute to degradation in mechanical response (1-b) Carbon-epoxy COPVs also extremely sensitive to impact damage and impacts may be below the visible detection threshold (2) If damage is detected, this generally results in rejection since the effect on mechanical response is generally not known (3) NDE response has not generally been fully characterized, probability of detection (POD) established, and processes validated for evaluation of vessel condition as manufactured and delivered.

Waller, Jess M.; Saulsberry, Regor L.

2012-01-01

302

Nondestructive Evaluation of Tissue Engineered Articular Cartilage Using Time-Resolved Fluorescence Spectroscopy and Ultrasound Backscatter Microscopy  

PubMed Central

The goal of this study is to evaluate the ability of a bimodal technique integrating time-resolved fluorescence spectroscopy (TRFS) and ultrasound backscatter microscopy (UBM) for nondestructive detection of changes in the biochemical, structural, and mechanical properties of self-assembled engineered articular cartilage constructs. The cartilage constructs were treated with three chemical agents (collagenase, chondroitinase-ABC, and ribose) to induce changes in biochemical content (collagen and glycosaminoglycan [GAG]) of matured constructs (4 weeks); and to subsequently alter the mechanical properties of the construct. The biochemical changes were evaluated using TRFS. The microstructure and the thickness of the engineered cartilage samples were characterized by UBM. The optical and ultrasound results were validated against those acquired via conventional techniques including collagen and GAG quantification and measurement of construct stiffness. Current results demonstrated that a set of optical parameters (e.g., average fluorescence lifetime and decay constants) showed significant correlation (p<0.05) with biochemical and mechanical data. The high-resolution ultrasound images provided complementary cross-section information of the cartilage samples morphology. Therefore, the technique was capable of nondestructively evaluating the composition of extracellular matrix and the microstructure of engineered tissue, demonstrating great potential as an alternative to traditional destructive assays.

Responte, Donald; Xie, Hongtao; Liu, Jing; Fatakdawala, Hussain; Hu, Jerry; Athanasiou, Kyriacos A.

2012-01-01

303

Noncontact, nondestructive elasticity evaluation of sound and demineralized human dental enamel using a laser ultrasonic surface wave dispersion technique.  

PubMed

Laser ultrasonic nondestructive evaluation (NDE) methods have been proposed to replace conventional in vivo dental clinical diagnosis tools that are either destructive or incapable of quantifying the elasticity of human dental enamel. In this work, a laser NDE system that can perform remote measurements on samples of small dimensions is presented. A focused laser line source is used to generate broadband surface acoustic wave impulses that are detected with a simplified optical fiber interferometer. The measured surface wave velocity dispersion spectrum is in turn used to characterize the elasticity of the specimen. The NDE system and the analysis technique are validated with measurements of different metal structures and then applied to evaluate human dental enamel. Artificial lesions are prepared on the samples to simulate different states of enamel elasticity. Measurement results for both sound and lesioned regions, as well as lesions of different severity, are clearly distinguishable from each other and fit well with physical expectations and theoretical value. This is the first time, to the best of our knowledge, that a laser-based surface wave velocity dispersion technique is successfully applied on human dental enamel, demonstrating the potential for noncontact, nondestructive in vivo detection of the development of carious lesions. PMID:19895147

Wang, Hsiao-Chuan; Fleming, Simon; Lee, Yung-Chun; Law, Susan; Swain, Michael; Xue, Jing

2009-01-01

304

Noncontact, nondestructive elasticity evaluation of sound and demineralized human dental enamel using a laser ultrasonic surface wave dispersion technique  

NASA Astrophysics Data System (ADS)

Laser ultrasonic nondestructive evaluation (NDE) methods have been proposed to replace conventional in vivo dental clinical diagnosis tools that are either destructive or incapable of quantifying the elasticity of human dental enamel. In this work, a laser NDE system that can perform remote measurements on samples of small dimensions is presented. A focused laser line source is used to generate broadband surface acoustic wave impulses that are detected with a simplified optical fiber interferometer. The measured surface wave velocity dispersion spectrum is in turn used to characterize the elasticity of the specimen. The NDE system and the analysis technique are validated with measurements of different metal structures and then applied to evaluate human dental enamel. Artificial lesions are prepared on the samples to simulate different states of enamel elasticity. Measurement results for both sound and lesioned regions, as well as lesions of different severity, are clearly distinguishable from each other and fit well with physical expectations and theoretical value. This is the first time, to the best of our knowledge, that a laser-based surface wave velocity dispersion technique is successfully applied on human dental enamel, demonstrating the potential for noncontact, nondestructive in vivo detection of the development of carious lesions.

Wang, Hsiao-Chuan; Fleming, Simon; Lee, Yung-Chun; Law, Susan; Swain, Michael; Xue, Jing

2009-09-01

305

Development and optimization of thermographic techniques for Non-Destructive Evaluation of multilayered structures  

NASA Astrophysics Data System (ADS)

Quality control of modern materials is of the utmost importance in science and industry. Methods for nondestructive evaluation of material properties and the presence of defects are numerous. They differ in terms of their sensitivity and applicability in various conditions, and they provide different kinds of data such as the speed of sound in the material, its hardness, radiation absorption, etc. Based on measured characteristics an analyst makes a decision on the material studied. This work addresses a class of methods known as active thermographic analysis. Thermography analyzes the temperature of the surface of the sample under different external conditions. By keeping track of temperature changes at the surface caused by a deposition of heat on the sample one can determine its material properties such as theand processing the data captured it is possible to make decisions on parameters of this sample. Among the data which can be acquired are such important information as the location of internal defects (e.g., detachments, hollows, inclusions), thickness of the material layers, thermal parameters of the material and the location of internal defects (e.g., detachments, hollows, inclusions). The first part of this research investigates a method for analysis of layered composite materials using the approach based on interference of so called temperature waves. As demonstrated using the expressions derived, one can determine the thermal properties of the layers of the sample by applying a harmonically modulated heat flux to the surfaces and measuring the phase of the periodically changing surface temperature. This approach can be of use in the field of designing and analysis of composite thermal insulation coatings. In the second part of this work a method of analyzing objects of fine art was investigated, particularly - detection of subsurface defects. In the process of preserving art it is of primary importance to determine whether restoration is necessary. Moreover, this analysis should be done on a regular basis to prevent defects from increasing in size over time. Conventional methods, such as infrared photography and X-ray radiography may not be suitable for this application, because most of detachments are too deep for infrared to reach them, and too thin for providing enough contrast on X-ray images. This highlights the need for the development of methodsfor detection of hidden defects and structure of art pieces to detect the structure of art pieces and any hidden defects present. Thermography has strong potential as a tool for non-invasive analysis of works of art and only recently has it been actively promoted into this field. However, due to the general unpredictability of the structure of brushstrokes as well as the properties of paint, it is difficult to apply a physical model to the analysis of paintings. In addition, an improved method is proposed. This proposed method is mainly based on PCT, but it is capable of returning clear images of subsurface defects and the structure of the support. Unlike standard PCT images, the images acquired by this method do not exhibit visually similar features.

Gavrilov, Dmitry J.

306

Non-Destructive Evaluation of Material System Using Highly Nonlinear Acoustic Waves  

NASA Astrophysics Data System (ADS)

A chain of granular particles is one of the most studied examples of highly nonlinear systems deriving its response from the nonlinear Hertzian contact interaction between particles. Interest in these systems derives from their tunable dynamic response, encompassing linear, weakly nonlinear, and strongly nonlinear regimes, controlled by varying the static and dynamic load applied. In chains with a very weak (or zero) static precompression, the system supports the formation and propagation of highly nonlinear solitary waves (HNSWs). The dual-nonlinear interaction between particles (i.e., a power-law type contact potential in compression, and zero strength in tension) combined with discreteness of the system, makes the granular system highly tunable. The propagation properties of these waves, such as traveling pulse width, wave speed, number of separated pulses (single or train of pulses), etc., can be controlled by modifying one or many of the parameters, like the particle's dimension, material properties, static and dynamic force amplitude, the type and duration of the initial excitation applied to the system, and/or the periodicity of the chain. The ability to control the wave properties in such chains has been proposed for several different practical engineering applications. The dynamic properties of these granular chains have been conventionally studied using discrete particle models (DPMs) which consider the particles in the chains as point masses connected by nonlinear Hertzian springs with the neighboring particles. Although, this is a good approximation under proper circumstances, it does not capture many features of the three dimensional elastic particles such as the elastic wave propagation within the particles, the local deformation of the particles in the vicinity of the contact point, the corresponding changes in the contact area, and the collective vibrations of the particles among others. This thesis focuses on the development of a finite element model (FEM) using the commercially available software Abaqus, which takes into account many of these characteristic features. The finite element model discretizes particles by considering them as three-dimensional deformable bodies of revolution and describes the nonlinear dynamic response of one-dimensional granular chains composed of particles with various geometries and orientations. We showed that particles' geometries and orientations provide additional design parameters for controlling the dynamic response of the system, compared to chains composed of spherical particles. We also showed that the tunable and compact nature of these waves can be used to tailor the properties of HNSWs for specific application, such as information carriers for actuation and sensing of mechanical properties and boundary effects of adjoining media in Non-Destructive Evaluation (NDE) and Structural Health Monitoring (SHM). Using experiments and numerics, we characterized interface dynamics between granular media and adjoining linear elastic media, and found that the coupling produced temporary localization of the incident waves at the boundaries between the two media and their decomposition into reflected waves. We monitored the formation of reflected solitary waves propagating back from the interface and found that their properties are sensitive to the geometric and material properties of the adjoining media. The work done in this research enhances our understanding of the basic physics and tunability of nonlinear granular media, and further establishes a theoretical and numerical foundation in the applications of HNSWs as information carriers.

Khatri, Devvrath

307

Pod Generator Project, Development of Numerical Modeling Tools for Quantitative Assessment of the Performance of Non-Destructive Inspection Techniques  

NASA Astrophysics Data System (ADS)

Risk based inspection strategies rely on detailed knowledge of the performance of inspection techniques. It is well known that every inspection technique has limitations in terms of reliability and effectiveness. Moreover, these are influenced by many factors. E.g. it depends on operator skills, inspection procedure, defect and object geometry as well as technique specific instrument properties and settings. The objective of the ``POD generator'' project is to develop a numerical modeling approach to assess inspection effectiveness for a specific technique and situation flexibly and reliably yet at acceptable costs. Besides the models to simulate various degradation mechanisms, numerical models have been developed and validated for accurately simulating the physics of inspection techniques. Also the human factor is taken into account. These numerical models are then used to generate quantitative probability of detection (POD) curves. This will be illustrated for ultrasonic time-of-flight-diffraction (TOFD) inspection of fatigue cracks.

Bloom, J. G. P.; Stelwagen, U.; Mast, A.; Volker, A. W. F.; Krom, A. H. M.; Mohamoud, A. A.; van Gils, G. P.

2009-03-01

308

Nondestructive Evaluation (NDE) Results on Sikorsky Aircraft Survivable Affordable Reparable Airframe Program (SARAP) Samples  

NASA Technical Reports Server (NTRS)

The Survivable, Affordable, Reparable Airframe Program (SARAP) will develop/produce new structural design concepts with lower structural weight, reduced manufacturing complexity and development time, increased readiness, and improved threat protection. These new structural concepts will require advanced field capable inspection technologies to help meet the SARAP structural objectives. In the area of repair, damage assessment using nondestructive inspection (NDI) is critical to identify repair location and size. The purpose of this work is to conduct an assessment of new and emerging NDI methods that can potentially satisfy the SARAP program goals.

Zalameda, Joseph N.; Anastasi, Robert F.; Madaras, Eric I.

2004-01-01

309

Application of Advanced Nondestructive Evaluation Techniques for Cylindrical Composite Test Samples  

NASA Technical Reports Server (NTRS)

Two nondestructive methods were applied to composite cylinder samples pressurized to failure in order to determine manufacturing quality and monitor damage progression under load. A unique computed tomography (CT) image processing methodology developed at NASA Glenn Research was used to assess the condition of the as-received samples while acoustic emission (AE) monitoring was used to identify both the extent and location of damage within the samples up to failure. Results show the effectiveness of both of these methods in identifying potentially critical fabrication issues and their resulting impact on performance.

Martin, Richard E.; Roth, Donald J.; Salem, Jonathan A.

2013-01-01

310

The RAMANITA © method for non-destructive and in situ semi-quantitative chemical analysis of mineral solid-solutions by multidimensional calibration of Raman wavenumber shifts  

NASA Astrophysics Data System (ADS)

The "RAMANITA ©" method, for semi-quantitative chemical analysis of mineral solid-solutions by multidimensional calibration of Raman wavenumber shifts and mathematical calculation by simultaneous equations, is published here in detail in English for the first time. It was conceived by the present writer 20 years ago for binary and ternary pyroxene and garnet systems. The mathematical description was set out in 1989, but in an abstract in an obscure French special publication. Detailed "step-by-step" calibration of two garnet ternaries, followed by their linking, by M. Pinet and D.C. Smith in the early 1990s provided a hexary garnet database. Much later, using this garnet database, which forms part of his personal database called RAMANITA ©, the present writer began to develop the method by improving the terminology, automating the calculations, discussing problems and experimenting with different real chemical problems in archaeometry. Although this RAMANITA © method has been very briefly mentioned in two recent books, the necessary full mathematical explanation is given only here. The method will find application in any study which requires obtaining a non-destructive semi-quantitative chemical analysis from mineral solid solutions that cannot be analysed by any destructive analytical method, in particular for archaeological, geological or extraterrestrial research projects, e.g. from gemstones or other crystalline artworks of the cultural heritage (especially by Mobile Raman Microscopy (MRM)) in situ in museums or at archaeological sites, including under water for subaquatic archaeometry; from scientifically precious mineral microinclusions (such as garnet or pyroxene within diamond); from minerals in rocks analysed in situ on planetary bodies by a rover (especially "at distance" by telescopy). Recently some other workers have begun deducing chemical compositions from Raman wavenumber shifts in multivariate chemical space, but the philosophical approach is quite different.

Smith, David C.

2005-08-01

311

Pulse thermography for quantitative nondestructive evaluation of sound, de-mineralized and re-mineralized enamel  

NASA Astrophysics Data System (ADS)

Current limitations for diagnosing mineralization state of tooth enamel can lead to improper surgical treatments. A method is investigated by which the tooth health state is characterized according to its thermal response, which is hypothesized to be sensitive to increased porosity in enamel that is caused by demineralization. Several specimens consisting of previously extracted human teeth a re prepared by exposure to Streptococcus mutans A32-2 in trypticase-soy-borth supplemented with 5% sucrose at 37°C for 3 or 6 days to de-mineralize two 1×1mm2-windows on each tooth. One of these windows is then re-mineralized with 250 or 1,100ppm-F as NaF for 10 days by pH-cyclic-model. Pulse thermography is used to measure the thermal response of these sections as well as the sound (healthy) portions of the specimen. A spatial profile of the thermal parameters of the specimens is then extracted from the thermography data and are used to compare the sound, de-mineralized, and re-mineralized areas. Results show that the thermal parameters are sensitive to the mineralization state of the tooth and that this method has the potential to accurately and quickly characterize the mineralization state of teeth, thereby allowing future dentists to make informed decisions regarding the best treatment for teeth that have experienced demineralization.

Ando, Masatoshi; Sharp, Nathan; Adams, Douglas

2012-03-01

312

Applications of pulse heating thermography and lock-in thermography to quantitative nondestructive evaluations  

Microsoft Academic Search

This paper describes several experimental investigations of newly developed thermographic NDT techniques based on the transient temperature measurements. Several experimental results of the pulse heating thermographic NDT and the lock-in thermographic NDT are shown.

Takahide Sakagami; Shiro Kubo

2002-01-01

313

Nondestructive evaluation of the oxidation and strength of the Fort Saint Vrain HTGR support block  

SciTech Connect

Non-destructive detection of changes in the strength of graphite support structures in a HTGR appears to be feasible using sonic velocity measurements where access for through transmission is possible. Therefore, future HTGR designs should consider providing such access. Where access is not available, strength changes can be correlated with oxidation profiles in the support member. These oxidation profiles can be determined non-destructively by a combination of eddy current measurements to detect near surface oxidation and sonic backscattering measurements designed to determine oxidation in depth. The Fort Saint Vrain reactor provides an operating reactor to test the applicability of the eddy current and sonic backscattering techniques for determination of oxidation in a support block. Furthermore, such tests in Fort Saint Vrain will supply base line data which will be useful in assuring an adequate strength of the support structure for the lifetime of the reactor. Equipment is, therefore, being developed for tests to be conducted during the next major refueling of the reactor.

Tingey, G.L.; Posakony, G.J.; Morgan, W.C.; Prince, J.M.; Hill, R.W.; Lessor, D.L.

1982-04-01

314

Nondestructive evaluation of damage in SiC/Al metal matrix composite using x ray tomographic microscopy  

SciTech Connect

A fundamental understanding of damage evolution will be required before metal matrix composites (MMC) can be utilized safely for structural applications. Although macroscopic mechanical response to cyclic loading has been monitored in many mechanical and thermal test programs, little is known about the nucleation and growth of damage in MMC's. The goal of the present work is to improve the understanding of damage accumulation in SiC/Al using a new microscopic non-destructive volume-imaging technique, X-ray Tomographic Microscopy (XTM), which has resolution comparable to optical microscopy. Correlation of damage initiation and accumulation mechanisms and the macroscopic mechanical response of samples are discussed for continuous fiber SiC/Al MMC's. A series of mechanical tests were performed on a continuous, aligned fiber SiC/Al MMC, and the ensuing three-dimensional damage state was nondestructively characterized using XTM to map the x-ray absorptivity within the sample. The types of damage detected include: fiber fracture (SiC sheath, and C core), fiber-matrix interface microcracking, intra-ply matrix voids, and cracks. Quantitative three-dimensional measurements of damage are reported in as-fabricated, monotonically loaded and mechanically fatigue loaded SiC/Al. The XTM results indicate that increases in observed macroscopic structural stiffness during monotonic loading and the first few fatigue cycles of an MMC coupon correspond to elimination of processing-related matrix porosity and to displacement of the fibers from a somewhat irregular arrangement into a more nearly hexagonal array. The XTM of monotonically loaded samples also show that the carbon cores begin to fracture at or below 828 MPa, that is, at loads far less than those for fracture of the entire fiber. The fracture of the SiC sheath appears to be significantly affected by the fracture of the C cores.

Breunig, T.M.

1992-01-01

315

Evaluation of non-destructive methods for estimating biomass in marshes of the upper Texas, USA coast  

USGS Publications Warehouse

The estimation of aboveground biomass is important in the management of natural resources. Direct measurements by clipping, drying, and weighing of herbaceous vegetation are time-consuming and costly. Therefore, non-destructive methods for efficiently and accurately estimating biomass are of interest. We compared two non-destructive methods, visual obstruction and light penetration, for estimating aboveground biomass in marshes of the upper Texas, USA coast. Visual obstruction was estimated using the Robel pole method, which primarily measures the density and height of the canopy. Light penetration through the canopy was measured using a Decagon light wand, with readings taken above the vegetation and at the ground surface. Clip plots were also taken to provide direct estimates of total aboveground biomass. Regression relationships between estimated and clipped biomass were significant using both methods. However, the light penetration method was much more strongly correlated with clipped biomass under these conditions (R2 value 0.65 compared to 0.35 for the visual obstruction approach). The primary difference between the two methods in this situation was the ability of the light-penetration method to account for variations in plant litter. These results indicate that light-penetration measurements may be better for estimating biomass in marshes when plant litter is an important component. We advise that, in all cases, investigators should calibrate their methods against clip plots to evaluate applicability to their situation. ?? 2006, The Society of Wetland Scientists.

Whitbeck, M.; Grace, J. B.

2006-01-01

316

Preliminary technique assessment for nondestructive evaluation certification of the NNWSI [Nevada Nuclear Waste Storage Investigations] disposal container closure  

SciTech Connect

Under the direction of the Department of Energy`s (DOE) Office of Civilian Radioactive Waste Management (OCRWM) program, the Nevada Nuclear Waste Storage Investigations (NNWSI) project is evaluating a candidate repository site at Yucca Mountain, Nevada, for permanent disposal of high-level nuclear waste. The Lawrence Livermore National Laboratory (LLNL), a participant in the NNWSI project, is developing waste package designs to meet the NRC requirements. One aspect of this waste package is the nondestructive testing of the final closure of the waste container. The container closure weld can best be nondestructively examined (NDE) by a combination of ultrasonics and liquid penetrants. This combination can be applied remotely and can meet stringent quality control requirements common to nuclear applications. Further development in remote systems and inspection will be required to meet anticipated requirements for flaw detection reliability and sensitivity. New research is not required but might reduce cost or inspection time. Ultrasonic and liquid penetrant methods can examine all closure methods currently being considered, which include fusion welding and inertial welding, among others. These NDE methods also have a history of application in high radiation environments and a well developed technology base for remote operation that can be used to reduce development and design costs. 43 refs., 23 figs., 3 tabs.

Day, R.A.

1988-12-31

317

Impedance-based non-destructive evaluation of the FRP adhesive joints in corrosive environment with re-usable technique  

NASA Astrophysics Data System (ADS)

In this study, a Non-Destructive Evaluation (NDE) method is introduced for evaluating the effects of FRP adhesive joint bond strength subjected to various environmental conditions using electromechanical impedance (EMI) method. The applicability of Fibre Reinforced Plastics (FRP) as a construction material is being globally recognized for their high stiffness and strength to weight ratio and this method proposes a possibility of detecting any strength loss to the adhesive bond without damaging the structure, such as FRP joint itself. PZT (Lead-Zirconate-Titanate) patches were utilized to detect any changes to the bond strength of the FRP adhesive joint exposed to different kinds of environmental conditions by measuring the electrical admittance of the PZT sensors. In addition, a re-usable technique has been introduced with a utilization of magnet to allow multiple sensing of specimens with a single sensor. The results show a possibility of detecting decrease in the bond strength of FRP adhesive using the EMI method.

Na, S.; Tawie, R.; Lee, H. K.

2011-03-01

318

Qualitative and Quantitative Evaluation of Liver Diseases  

PubMed Central

A large number of biochemical tests and procedures is used for the evaluation of the many different functional activities (cholestasis, biosynthesis etc.) of the liver, but their usefulness for an effective improvement in the diagnostic assessment is questionable. This paper deals with the problem of evaluating and comparing the information content of single tests or groups of tests with respect to their ability in evaluating liver functions. The studied subjects (245) have been submitted to the usual clinical and laboratory investigations for hepatobiliary diseases. A degree of impairment (null, very light, medium, relevant) for each considered functional activity has been evaluated by six groups of experienced physicians. Two different approaches have been used for the selection of the most informative tests. The first one makes use of classical statistical allocation and feature selection methods. The second approach consists in deriving, from the measured values, an index of impairment, continuously varying from zero (null) to three (relevant). Two methods have been used: the first one based on possibility theory and fuzzy sets, the second one on principal components techniques in modeling non linear models. The ordering of the tests is made evaluating (by means of the cross-validation method) the prediction errors of the computed impairment degree. The second approach seems more suitable for the evaluation of functional activities and this is confirmed by the numerical results. However all the methods are in good agreement in ordering the groups of tests. The obtained results appear quite relevant from a clinical point of view: for example about twenty tests can give indication of each of the considered functional activity, but the use of more than four or five suitably selected tests gives no effective improvement in their assessment.

Milanese, M.; Molino, G.; Belforte, G.; Cravetto, C.; Frediani, S.; Bonn, B.; Saitta, L.

1980-01-01

319

Quantitative computed tomography evaluation of pulmonary disease.  

PubMed

Objective assessment of pulmonary disease from computed tomography (CT) examinations is desirable but difficult. When such assessments can be made, it is important that they are related to some part of the pathophysiologic process present. Herein we propose that automated volume histogram analysis can yield data that allow differentiation of normal from abnormal lung, and that the magnitude of disease will have an association with objective CT indices. Data from pulmonary CT images from 34 foxes (six uninfected controls and 28 infected with Angiostrongylus vasorum, subdivided by age and infective dose) were available. Lung tissue was segmented from surrounding tissue using an automated segmentation method. A volume histogram showing voxel frequency for each CT number in the range -1024 to -250 HU was created from the entire image stack from each fox. Using these data, the inter-quartile range and the CT number at the 95th percentile were determined. The results showed that segmentation could be readily achieved but that areas of severely diseased lung were excluded. Based on two-way analysis of variance for both the inter-quartile range and the CT number at the 95th percentile, both quantities were significantly affected by the infection status of the animal and were related to worm burden (P < 0.001). The study shows that this form of analysis is readily achieved and provides quantitative data that can be used to assess disease severity, progression, and response to treatment. PMID:19241753

McEvoy, Fintan J; Buelund, Lene; Strathe, Anders B; Willesen, Jakob L; Koch, Jørgen; Webster, Pia; Hørlyck, Lasse; Svalastoga, Eiliv

2009-01-01

320

Magnetic non-destructive evaluation of ruptures of tensile armor in oil risers  

NASA Astrophysics Data System (ADS)

Risers are flexible multilayered pipes formed by an inner flexible metal structure surrounded by polymer layers and spiral wound steel ligaments, also known as armor wires. Since these risers are used to link subsea pipelines to floating oil and gas production installations, and their failure could produce catastrophic consequences, some methods have been proposed to monitor the armor integrity. However, until now there is no practical method that allows the automatic non-destructive detection of individual armor wire rupture. In this work we show a method using magnetic Barkhausen noise that has shown high efficiency in the detection of armor wire rupture. The results are examined under the cyclic and static load conditions of the riser. This work also analyzes the theory behind the singular dependence of the magnetic Barkhausen noise on the applied tension in riser armor wires.

Pérez-Benitez, J. A.; Padovese, L. R.

2012-04-01

321

Nondestructive evaluation of mechanical and fracture characteristics of ferritic steels using automated ball identation testing  

SciTech Connect

Mechanical properties of various ferritic steels commonly used for pressure boundary applications in light water reactors are characterized using a novel portable stress-strain microprobe (SSM) system. The SSM system utilizes an automated ball indentation (ABI) technique to measure yield strength, stress-strain curve, strength coefficient, and strain-hardening-exponent (uniform ductility). The technique is essentially nondestructive, albeit small indentations are left following the tests. These, however, leave surface compressive stresses that could actually retard crack initiation characteristics. The ABI-derived mechanical properties agreed with those obtained using conventional destructive tensile tests. To minimize specimen-to-specimen scatter, the grip/shoulder sections were used for ABI testing. In addition, the fracture properties are characterized in terms of a new fracture parameter, indentation energy to fracture (IEF), derived from the temperature variation of the true stress compared with true strain using the critical-stress-to-fracture concept.

Murty, K.L.; Mathew, M.D.; Miraglia, P.Q. [North Carolina State Univ., Raleigh, NC (United States)] [and others

1997-12-01

322

Nondestructive Impedance Spectroscopy Evaluation of the Bond Coat Oxidation in Thermal Barrier Coatings  

NASA Astrophysics Data System (ADS)

In this paper, the impedance spectroscopy technique was employed to examine nondestructively the isothermal oxidation of air plasma sprayed (APS) thermal barrier coatings (TBCs) in air at 800°C. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) were also used to characterize the microstructure evolution of TBCs. After oxidation, the thermally grown oxide (TGO), which was mainly composed of alumina as confirmed by EDX, formed at the upper ceramic coat/bond coat interface, the lower bond coat/substrate interface, and the bond coat. Impedance diagrams obtained from impedance measurements at room temperature were analyzed according to the equivalent circuit model proposed for the TBCs. Various observed electrical responses relating to the growth of oxides and the sintering of YSZ were explained by simulating the impedance spectra of the TBCs.

Yang, L.; Zhou, Y. C.; Mao, W. G.; Liu, Q. X.

323

Quantitative evaluation of Ocean Thermal Energy Conversion (OTEC): Executive briefing  

NASA Astrophysics Data System (ADS)

The results of an independent quantitative evaluation of Ocean Thermal Energy Conversion (OTEC) for central station applications are summarized. A central station power plant located in the Gulf of Mexico and delivering power to the mainland United States was emphasized. The evaluation of OTEC is based on three important issues: resource availability, technical feasibility, and cost.

Gritton, E. C.; Pei, R. Y.; Hess, R. W.

1980-08-01

324

Simulation of transducer-couplant effects on broadband ultrasonic signals. [in nondestructive flaw evaluation and materials tests  

NASA Technical Reports Server (NTRS)

The increasing use of broadband, pulse-echo ultrasonics in nondestructive evaluation of flaws and material properties has generated a need for improved understanding of the way signals are modified by coupled and bonded thin-layer interfaces associated with transducers. This understanding is most important when using frequency spectrum analyses for characterizing material properties. In this type of application, signals emanating from material specimens can be strongly influenced by couplant and bond-layers in the acoustic path. Computer synthesized waveforms were used to simulate a range of interface conditions encountered in ultrasonic transducer systems operating in the 20to 80-MHz regime. The adverse effects of thin-layer multiple reflections associated with various acoustic impedance conditions are demonstrated. The information presented is relevant to ultrasonic transducer design, specimen preparation, and couplant selection.

Vary, A.

1980-01-01

325

Nondestructive Evaluation of the Gimbal Joint Flowliner Slots in the Space Shuttle Main Propulsion System Hydrogen Feedline  

NASA Technical Reports Server (NTRS)

Fatigue cracks were discovered in the STS-112 Liquid Hydrogen Feedline flowliners in 2002. This led to a development program aimed at providing nondestructive evaluation methods and techniques to verify the existence of these types of cracks in oval shaped slots cut into the ends of the feedlines above the bellows joints. These slots were used to improve flow dynamics and to facilitate cleaning in the bellow joint region. These types of fatigue cracks posed a possible metal debris ingestion threat for the Space Shuttle Main Engines, which attached to these particular joints. Results of this program produced three reliable inspection techniques utilizing the imaging of replisets with a Scanning Electron microscope, eddy current, and ultrasound. The program developed unique probes and fixtures and in the case of eddy current and ultrasound, provided qualification and certification of the particular techniques by various Design of Experiments and Probability of Detection studies utilizing multiple inspectors.

Suits, Michael W.; Bryson, Craig C.

2006-01-01

326

Nondestructive evaluation of acoustic properties of fuel cell proton-exchange membranes by vector contrast acoustic microscopy  

NASA Astrophysics Data System (ADS)

In recent years, the interest in the research and development of "green energy" has increased dramatically, with numerous research grants and investment in the areas of wind power, solar power and fuel cell technology. We present results obtained from the evaluation of the acoustic properties of proton-exchange membranes used in hydrogen fuel cells, which relate directly to the microelastic properties of such membranes. These properties play an important role in the durability and applicability as well as the efficiency of such membranes. DuPont Nafion membranes are the most commonly used polymeric membranes in hydrogen/oxygen fuel cells and are therefore used as examples in this study. The microscope used in this non-destructive characterization study is a vector-contrast version of the scanning acoustic microscope which yields images in magnitude- and phase contrast.

Kamanyi, Albert E.; Grill, Wolfgang

2012-03-01

327

Non-destructive evaluation means and method of flaw reconstruction utilizing an ultrasonic multi-viewing transducer data acquistion system  

DOEpatents

A multi-viewing ultrasound transducer acquisition system for non-destructive evaluation, flaw detection and flaw reconstruction in materials. A multiple transducer assembly includes a central transducer surrounded by a plurality of perimeter transducers, each perimeter transducer having an axis of transmission which can be angularly oriented with respect to the axis of transmission of the central transducer to intersect the axis of transmission of the central transducer. A control apparatus automatically and remotely positions the transducer assembly with respect to the material by a positioning apparatus and adjusts the pe GRANT REFERENCE This invention was conceived and reduced to practice at least in part under a grant from the Department of Energy under Contract No. W-7407-ENG-82.

Thompson, Donald O. (Ames, IA); Wormley, Samuel J. (Ames, IA)

1989-03-28

328

Nondestructive evaluation and real-time monitoring of laser surface hardening.  

SciTech Connect

An infrared process monitor was used to monitor in real-time the infrared emissions during laser surface hardening of ferrous alloys. The signals from the monitor were correlated with the hardness and case depth of the laser-treated tracks. Test data show that a linear relationship exists between the monitor output DC level voltage and hardness up to the maximum hardness possible and also between the monitor output DC level voltage and case depth. This simple relationship makes it easy to monitor process hardness, case depth and quality of laser heat-treated workpiece. A calibration test on a prototypic material can be used to determine the upper and lower bounds of the voltage signals for a sound quality treatment. In-process monitoring or real-time nondestructive measurement of the hardness and depth of the laser transformation hardened case can then be achieved. The monitor is also capable of tracking changes in surface quality or flatness of the part that is being treated.

Xu, Z.; Leong, K.; Reed, C.; Nuclear Engineering Division

2008-09-12

329

Comparison of radiation sources and filtering safety glasses for fluorescent nondestructive evaluation  

NASA Astrophysics Data System (ADS)

This study was directed toward the question of whether recent advancements in radiation sources and test media offered significant improvements over the current state of the art. Included were experiments characterizing common penetrant and magnetic particle materials to determine their fluorescent excitation spectra, and a comparison between the fluorescent excitation spectra and the emission spectra of common excitation sources. The relationship between exciter and test medium directly controls the luminance of a defect indication. As indication luminance increases, the probability of it being detected by the inspector increases. Fluorescent penetrant and magnetic particle test media were originally designed around the widely available filtered medium pressure mercury vapor lamp, which remains the standard excitation radiation source. Test media properties, and the types of available excitation sources have changed with time, and it was unclear whether present-day media was still best excited by the historical standard ultraviolet radiation source. Predictions and experimental work was performed to determine the optimal excitation source for fluorescent nondestructive testing, and to determine which safety lens option would offer the highest probability of detection. Improvement in radiation sources was primarily judged by an increase in fluorophore luminance versus background, which led to an increase in signal-to-noise ratio facilitating better indication detectability. Other factors considered were improved health and safety, and ease of use.

Lopez, Richard Daniel

330

A Hybrid Approach to Structural Health Monitoring Using Nondestructive Evaluation (NDE) and Active Damage Interrogation  

NASA Astrophysics Data System (ADS)

With the useful lives of many aircraft being extended, in-service inspection, repair, and related support activities represent a considerable commitment of resources. Periodic maintenance operations involve comprehensive nondestructive inspections (NDI) and significant aircraft downtime for compilation of data, disposition of results, and any needed repairs. Confining the inspections to known or suspected problem areas still requires time to cover the area adequately, and to detect and assess flaws. Reducing this inspection time requires advance knowledge of the condition of the structure with respect to the existence and probable location of defects. Recent work has demonstrated the viability of active damage interrogation (ADI) for continuous monitoring of structural health. Piezoelectric transducers are used to actively excite and sense the vibration characteristics of the structure and use this information to make estimates regarding the health of the structure. By detecting changes in the structure's vibration signature, damage can be detected, localized, and assessed; however, additional information may be needed to accurately quantify flaws or damage. This paper will present a concept for a hybridization of ADI and NDI technologies.

Engelbart, R. W.; Palmer, D. D.; Pitt, D. M.

2003-03-01

331

Nondestructive thermoelectric evaluation of the grit blasting induced effects in metallic biomaterials  

NASA Astrophysics Data System (ADS)

Grit blasting is a surface treatment process widely used to enhance mechanical fixation of the implants through increasing their roughness. Test samples of two metallic biomaterial alloys such 316LVM and Ti6Al4V were blasted by projecting Al2O3 and ZrO2 particles which yield a coarse and a fine rough surface. Then, the blasted samples were thermally treated before and after partial stress relaxation and measured by non-destructive thermoelectric techniques (NDTT), the non-contacting and contacting thermoelectric power (TEP) measurements respectively. It has been found that the TEP measurements are associated directly with the subtle material variations such as cold work and compressive residual stresses due to plastic deformation produced by grit blasting. The TEP measurements clearly demonstrate that the non-contact NDTT technique is very sensitive to the reverse transformation of the ?'-martensite (blasted 316LVM) and the expected relaxation of compressive residual stresses with increasing the severity of the thermal treatment (blasted 316LVM and Ti-6Al-4V), while the contact NDTT results are closely related to grain size refinement and work hardening.

Carreon, H.; Ruiz, A.; Barriuso, S.; González-Carrasco, J. L.; Caballero, F. G.; Lieblich, M.

2013-01-01

332

Damage threshold prediction of hafnia -silica multilayer coatings by nondestructive evaluation of fluence-limiting defects  

NASA Astrophysics Data System (ADS)

A variety of microscopic techniques were employed to characterize fluence-limiting defects in hafnia -silica multilayer coatings manufactured for the National Ignition Facility, a fusion laser with a wavelength of 1.053 m and a pulse width of 3 ns. Photothermal microscopy, with the surface thermal lens effect, was used to map the absorption and thermal characteristics of 3 mm x 3 mm areas of the coatings. High-resolution subaperture scans, with a 1- m step size and a 3- m pump-beam diameter, were conducted on the defects to characterize their photothermal properties. Optical and atomic force microscopy were used to identify defects and characterize their topography. The defects were then irradiated by a damage testing laser (1.06 m and 3 ns) in single-shot mode until damage occurred. The results were analyzed to determine the role of nodular and nonnodular defects in limiting the damage thresholds of the multilayer coatings. It was found that, although different types of defect were present in these coatings, the fluence-limiting ones had the highest photothermal signals (up to 126 x over the host coating). The implication of this study is that coating process improvements for hafnia -silica multilayer coatings should have a broader focus than just elimination of source ejection, since high photothermal signals frequently occur at nodule-free regions. The study also demonstrates that, for optics subject to absorption-induced thermal damage, photothermal microscopy is an appropriate tool for nondestructive identification of fluence-limiting defects.

Wu, Zhouling; Stolz, Christopher J.; Weakley, Shannon C.; Hughes, James D.; Zhao, Qiang

2001-04-01

333

Quantitative non-destructive testing  

NASA Technical Reports Server (NTRS)

The work undertaken during this period included two primary efforts. The first is a continuation of theoretical development from the previous year of models and data analyses for NDE using the Optical Thermal Infra-Red Measurement System (OPTITHIRMS) system, which involves heat injection with a laser and observation of the resulting thermal pattern with an infrared imaging system. The second is an investigation into the use of the thermoelastic effect as an effective tool for NDE. As in the past, the effort is aimed towards NDE techniques applicable to composite materials in structural applications. The theoretical development described produced several models of temperature patterns over several geometries and material types. Agreement between model data and temperature observations was obtained. A model study with one of these models investigated some fundamental difficulties with the proposed method (the primitive equation method) for obtaining diffusivity values in plates of thickness and supplied guidelines for avoiding these difficulties. A wide range of computing speeds was found among the various models, with a one-dimensional model based on Laplace's integral solution being both very fast and very accurate.

Welch, C. S.

1985-01-01

334

Non-Destructive Evaluation of Rock Bolts Associated With Optical Strain Sensors at the Homestake Gold Mine  

NASA Astrophysics Data System (ADS)

Fiber-Bragg Grating (FBG) optical strain sensors have been installed in the former Homestake Gold Mine (Lead, SD) as part of an early science project at the Deep Underground Science and Engineering Laboratory (DUSEL). FBG sensors are anchored within an alcove at the 4100’ level of the mine using rock bolts and coupled to the rock mass with resin epoxy and cement grout. The quality of the coupling between the rock bolt and the rock mass is essential to assure that true rock mass strains are being recorded. To evaluate the integrity of the installed rock bolt system, guided ultrasonic waves can be used as a non-destructive monitoring system. The propagation of reflected ultrasonic waves capture information about the degree of coupling between the steel rock bolt and resin epoxy/cement grout and between the resin epoxy/cement grout and the surrounding rock mass, and hence the integrity of the installed rock bolt system. In this study, we use the phase velocity obtained from ultrasonic wave propagation to estimate the rock modulus. In our initial testing we generated a broadband elastic wave along the length of a rock bolt anchored in a concrete cylinder while monitoring multiple reflections with a single accelerometer affixed at the exposed end of the rock bolt. The captured waveforms include several reflections that were then analyzed to obtain frequency response, coherence, phase velocity, and damping between multiple reflections. As the wavelength increases, the response captures first elastic properties of the steel and then the combined elastic properties of the rock bolt/rock mass system. Challenges associated with implementing this non-destructive testing technique in rock masses include the generation of wide bandwidth signals having enough strength to produce multiple reflections with high enough signal-to-noise ratios to capture properties of multi-scale systems.

Kogle, M. M.; Fratta, D.; Wang, H. F.; Geox^Tm

2010-12-01

335

Mixed Waste Focus Area/Characterization Monitoring Sensor Technology Nondestructive Waste Assay Capability Evaluation Project End-User Summary Report  

SciTech Connect

The Mixed Waste Focus Area (MWFA) in conjunction with the Characterization Monitoring and Sensor Technology (CMST) crosscut program identified the need to objectively evaluate the capability of nondestructive waste assay (NDA) technologies. This was done because of a general lack of NDA technology performance data with respect to a representative cross section of waste form configurations comprising the Department of Energy (DOE) contact-handled alpha contaminated [e.g., transuranic (TRU) waste]. The overall objective of the Capability Evaluation Project (CEP) was to establish a known and unbiased NDA data and information base that can be used to support end-user decisions with regards to technology system selection and to support technology development organizations in identifying technology system deficiencies. The primary performance parameters evaluated in the CEP were measurement bias and relative precision. The performance of a given NDA technology is a direct function of the attributes represented by the waste matrix configuration. Such attributes include matrix density, matrix elemental composition, radionuclidic composition, radionuclide mass loading, and the spatial variation of these components. Analyzing the manner in which bias and precision vary as a function of test sample attribute and NDA technology provides a foundation for deriving performance capability and limitation statements and determines which waste matrix attributes, or combinations of attributes, are compatible or incompatible with existing technologies. The CEP achieved the stated end-user objective. The data indicate that the nondestructive waste assay systems evaluated have a definite capability to perform assay of contact-handled TRU waste packaged in 55-gallon drums. There is, however, a performance envelope where this capability exists, an area near the envelope boundaries where it is questionable, and a realm outside the envelope where the technologies do not perform. Therefore, the end user must be aware of this envelope and ensure the appropriate technology is selected. This program provides the end user with waste type specific performance data to assist in the assessment and selection of a given waste NDA technology. Additionally, the CEP afforded the private sector participants the opportunity to evaluate system performance using National Institute of Standards and Technology traceable radioactive significant enhancements to their respective systems and supported all participants in attaining DOE-CAO certification. Ultimately, the DOE end users will benefit from these enhancements.

G. K. Becker; M. E. McIlwain; M. J. Connolly

1998-11-01

336

Rapid Nondestructive Plutonium Isotopic Analysis.  

National Technical Information Service (NTIS)

Methods for plutonium isotopic measurements have been evaluated for nuclear safeguards inventory verification. A mobile, real-time, nondestructive assay, gamma-ray spectrometric measurement system has been assembled, moved and operated at several nuclear ...

J. E. Fager F. P. Brauer

1978-01-01

337

Non-destructive evaluation on optical components for high power density applications  

NASA Astrophysics Data System (ADS)

The development of high power laser for large instruments such as LMJ and NIF, as well as the use of smaller optical structures with high densities of energy lead to consider laser induce damage threshold (LIDT) as a critical criterion in optical components development. Furthermore in the same time some applications need an increase of the lifetime of the laser source (up to 109 shots for spatial applications). In this context to improve optical components numerous studies are undertaken to determine the origin of laser damage process. Through these studies, it is now commonly admitted that the first stage of the laser damage process in the nanosecond regime is caused by localized defects included in the material. In order to determine the laser damage threshold, it is necessary to perform a statistical study of damage on materials. This destructive technique beyond the determination of damage threshold allows to determine the density of precursor centers and to discriminate different kinds of precursors by using adapted beam sizes. However the nature and therefore the origin of the defects remain unknown. In order to get information on this nature, non destructive tools have to be involved. Indeed on one hand photothermal microscopy permits to make measurement of the local absorption under irradiation, on the other hand, photoluminescence cartography and spectroscopy gives information on material composition. The coupling of the different techniques on a laser damage test set-up optimizes the chance to have a complete signature of precursor center and information about the mechanism of damage process. Furthermore, nondestructive diagnostic under mutilple irradiations permit to study "fatigue" and conditioning process.

Natoli, Jean-Yves; Wagner, Frank; Ciapponi, A.; Palmier, S.; Gallais, Laurent; Commandré, Mireille

2008-09-01

338

Quantitative evaluation of a mammographic software phantom generator  

Microsoft Academic Search

This paper presents an evaluation of an algorithm for generation of 3D breast software phantoms for mammography. For this purpose, thirty breast phantoms of different shape, size and composition and with no pathology included were generated. Mammographic images of these breast models were produced by simulating mammographic image acquisition. Quantitative texture analysis included calculation of fractal dimension, skewness, kurtosis, and

Kristina S. Bliznakova; Nicolas E. Pallikarakis

2009-01-01

339

Evaluation of cockpit design by using quantitative and qualitative tools  

Microsoft Academic Search

Cockpit displays and the controls are sophisticated human machine interface applications. Display systems, present at cockpits are complex environments causing excessive mental workload and the consequences of errors can be catastrophic. In order to prevent any human error a user-friendly display panel must be designed. In this study quantitative and qualitative approaches are used to evaluate the positions of analogue

M. B. Senol; M. Dagdeviren; M. Kurt; C. Cilingir

2009-01-01

340

The Evaluation of a Peer Tutoring Program: A Quantitive Approach.  

ERIC Educational Resources Information Center

A quantitative way of measuring peer tutor training programs and peer tutor effectiveness is presented. The evaluation of a peer group training course at Baruch College (City University of New York), for which this questionnaire was developed, is described. This measure is adaptable to most higher education peer tutoring programs. (Author/BS)

Brandwein, Ann Cohen; DiVittis, Anthony

1985-01-01

341

Quantitative, Notional, and Comprehensive Evaluations of Spontaneous Engaged Speech  

ERIC Educational Resources Information Center

This study provides specific evidence regarding the extent to which quantitative measures, common sense notional measures, and comprehensive measures adequately characterize spontaneous, although engaged, speech. As such, the study contributes to the growing body of literature describing the current limits of automatic systems for evaluating

Molholt, Garry; Cabrera, Maria Jose; Kumar, V. K.; Thompsen, Philip

2011-01-01

342

Waterless coupling of ultrasound from planar contact transducers to curved and irregular surfaces during non-destructive ultrasonic evaluations  

NASA Astrophysics Data System (ADS)

The Applied Physics group at the Pacific Northwest National Laboratory (PNNL) in Richland, WA has evaluated a method for waterless/liquidless coupling of ultrasonic energy from planar ultrasonic contact transducers to irregular test surfaces for ultrasonic non-destructive evaluation applications. Dry couplant material placed between a planar transducer face and a curved or uneven steel or plastic surface allows for effective sound energy coupling and preserves the integrity of the planar transducer sound field by serving as an acoustic impedance matching layer, providing good surface area contact between geometrically dissimilar surfaces and conforming to rough and unsmooth surfaces. Sound fields radiating from planar ultrasonic contact transducers coupled to curved and uneven surfaces using the dry coupling method were scanned and mapped using a Pinducer receiver connected to a raster scanner. Transducer sound field coverage at several ultrasonic frequencies and several distances from the transducer contact locations were found to be in good agreement with theoretical beam divergence and sound field coverage predictions for planar transducers coupled to simple, planar surfaces. This method is valuable for applications that do not allow for the use of traditional liquid-based ultrasonic couplants due to the sensitivity of the test materials to liquids and for applications that might otherwise require curved transducers or custom coupling wedges. The selection of dry coupling material is reported along with the results of theoretical sound field predictions, the laboratory testing apparatus and the empirical sound field data.

Denslow, Kayte; Diaz, Aaron; Jones, Mark; Meyer, Ryan; Cinson, Anthony; Wells, Mondell

2012-03-01

343

Waterless Coupling of Ultrasound from Planar Contact Transducers to Curved and Irregular Surfaces during Non-destructive Ultrasonic Evaluations  

SciTech Connect

The Applied Physics group at the Pacific The Applied Physics group at the Pacific Northwest National Laboratory (PNNL) in Richland, WA has evaluated a method for waterless/liquidless coupling of ultrasonic energy from planar ultrasonic contact transducers to irregular test surfaces for ultrasonic non-destructive evaluation applications. Dry couplant material placed between a planar transducer face and a curved or uneven steel or plastic surface allows for effective sound energy coupling and preserves the integrity of the planar transducer sound field by serving as an acoustic impedance matching layer, providing good surface area contact between geometrically dissimilar surfaces and conforming to rough and unsmooth surfaces. Sound fields radiating from planar ultrasonic contact transducers coupled to curved and uneven surfaces using the dry coupling method were scanned and mapped using a Pinducer receiver connected to a raster scanner. Transducer sound field coverage at several ultrasonic frequencies and several distances from the transducer contact locations were found to be in good agreement with theoretical beam divergence and sound field coverage predictions for planar transducers coupled to simple, planar surfaces. This method is valuable for applications that do not allow for the use of traditional liquid-based ultrasonic couplants due to the sensitivity of the test materials to liquids and for applications that might otherwise require curved transducers or custom coupling wedges. The selection of dry coupling material is reported along with the results of theoretical sound field predictions, the laboratory testing apparatus and the empirical sound field data.

Denslow, Kayte M.; Diaz, Aaron A.; Jones, Anthony M.; Meyer, Ryan M.; Cinson, Anthony D.; Wells, Mondell D.

2012-04-30

344

EVALUATION OF GLASS FIBER\\/POLYPROPYLENE COMPOSITES BY QUANTITATIVE LASER ULTRASONIC AND ACOUSTIC EMISSION TECHNIQUES  

Microsoft Academic Search

The objective of this work is to study the influence of the moulding conditions of manufacture on the mechanical behaviour of the composites, when which they are submitted to mechanical loading. In order to evaluate the quality of interfacial adhesion, two non-destructive testing procedures were combined. Laser ultrasonic was employed to evaluate the state of the composite microstructure depending on

A. Maslouhi; G. Douchy; S. J. Palm

345

A quantitative method for evaluating alternatives. [aid to decision making  

NASA Technical Reports Server (NTRS)

When faced with choosing between alternatives, people tend to use a number of criteria (often subjective, rather than objective) to decide which is the best alternative for them given their unique situation. The subjectivity inherent in the decision-making process can be reduced by the definition and use of a quantitative method for evaluating alternatives. This type of method can help decision makers achieve degree of uniformity and completeness in the evaluation process, as well as an increased sensitivity to the factors involved. Additional side-effects are better documentation and visibility of the rationale behind the resulting decisions. General guidelines for defining a quantitative method are presented and a particular method (called 'hierarchical weighted average') is defined and applied to the evaluation of design alternatives for a hypothetical computer system capability.

Forthofer, M. J.

1981-01-01

346

Nondestructive Evaluation of Strain Distribution and Fatigue Distribution from Austenitic Stainless Steel by Using Magnetic Sensors  

SciTech Connect

Austenitic stainless steel transforms from austenitic crystal structure to martensitic crystal structure after applying strain or stress. Because martensitic crystal structures have magnetization, strain evaluation and fatigue evaluation can be performed by measuring magnetic properties. This paper describes the measurement of leakage magnetic flux density of remanent magnetization for the strain evaluation and the fatigue evaluation by a typical Hall element sensor for SUS 304 and SUS 304L and by a high-sensitivity thin-film flux-gate magnetic sensor for SUS 316 and SUS 316L.

Tsuchida, Y.; Enokizono, M. [Department of Electrical and Electronic Engineering, Oita University, 700 Dannoharu, Oita 870-1192 (Japan); Oka, M.; Yakushiji, T. [Department of Computer and Control Engineering, Oita National College of Technology, 1666 Maki, Oita 870-0152 (Japan)

2007-03-21

347

Nondestructive Evaluation of Strain Distribution and Fatigue Distribution from Austenitic Stainless Steel by Using Magnetic Sensors  

NASA Astrophysics Data System (ADS)

Austenitic stainless steel transforms from austenitic crystal structure to martensitic crystal structure after applying strain or stress. Because martensitic crystal structures have magnetization, strain evaluation and fatigue evaluation can be performed by measuring magnetic properties. This paper describes the measurement of leakage magnetic flux density of remanent magnetization for the strain evaluation and the fatigue evaluation by a typical Hall element sensor for SUS 304 and SUS 304L and by a high-sensitivity thin-film flux-gate magnetic sensor for SUS 316 and SUS 316L.

Tsuchida, Y.; Oka, M.; Yakushiji, T.; Enokizono, M.

2007-03-01

348

Development of nondestructive evaluation methods and prediction of effects of flaws on the fracture behavior of structural ceramics.  

National Technical Information Service (NTIS)

To establish predictive performance (i.e., fracture behavior) of structural ceramic composites, we undertook in combination (1) a study of flaws and material variations as they relate to mechanical properties and (2) development of non-destructive devalua...

W. A. Ellingson J. P. Singh N. Gopalsami S. L. Dieckman C. Y. Chu

1990-01-01

349

Non-Destructive Evaluation of the Thickness of Linings and Pavements in Two Tunnels Using Ground Penetrating Radar.  

National Technical Information Service (NTIS)

The objectives of this project involved determination of the following parameters using a combination of non-destructive and traditional test techniques, with additional limited coring for validation purposes: 1. Thickness of the concrete lining in both t...

B. F. Payne J. R. Thiel W. T. Scannell

2000-01-01

350

Nondestructive Evaluation (NDE) of Crack Formation in Advanced Composite Materials and Aluminum During Dynamic Fatigue Tests by SQUID Magnetometry.  

National Technical Information Service (NTIS)

This report results from a contract tasking Universite Pierre et Marie Curie (Paris 6) as follows: The contractor will investigate the use or high sensitivity, nondestructive, SQUID magnetometry to detect and understand crack formation and propagation in ...

H. R. Kokabi

2003-01-01

351

Development of nondestructive evaluation methods and prediction of effects of flaws on the fracture behavior of structural ceramics  

SciTech Connect

Continuous fiber ceramic matrix composites are being developed for turbine engine components, heat exchangers, and hot-gas filters in fossil energy systems. Reliable application requires nondestructive evaluation (NDE) methods that provide data for quality assurance and inputs to life time prediction models and that aid in process development. NDE developments at Argonne have focused on methods to assess density distribution, fiber orientation (for mechanical properties), and defect detection in both SiC/SiC and A1{sub 2}O{sub 3}/A1{sub 2}O{sub 3} materials. and that also assess the chemical state at fiber/matrix interfaces. 2-D cloth lay-up and 3-D weave CVI-infiltrated SiC/SiC specimens were studied by X-ray imaging methods now under development. Microfocus X-ray computerized tomography (MXCT) methods are being developed to provide these data. Multinuclear Nuclear Magnetic Resonance spectroscopy (13C, 29Si, and 11B) is under development for quantizing B content at fiber/matrix interfaces. Magic angle spinning techniques on SiC/SiC specimens with different coating thicknesses showed that quantification of B at the Interface is achievable. NDE data are being coupled to room- and elevated-temperature fracture studies to evaluate effects of fiber orientation and fiber coating thickness on resulting flaw morphology and mechanical properties of Nicalon-fiber-reinforced SiC matrix composites. Specifically, composites with fiber cloth lay-up sequences of varying coating thicknesses were evaluated. For room-temperature mechanical evaluation, composites with carbon-fiber coating thicknesses of 0 and 0.2 {mu}m were used, while elevated-temperature studies used composites with a coating thickness of 0.4 {mu}m. Composites with uncoated fibers failed in a brittle mode, while composites with 0.2 {mu}m fiber coating showed noncatastrophic failure.

Ellingson, W.A.; Singh, J.P.; Sivers, E.A. [and others

1995-04-01

352

Neutron tomography for nondestructive evaluation of hydrogen in titanium compressor blades  

SciTech Connect

Entrapment and precipitation of hydrogen in metals are undesirable phenomena that occur in many alloys of steel and titanium. In general, metals suffer a loss of mechanical properties, embrittlement, after long exposures to hydrogen. Neutron radiography has already proven itself to be a reliable method for the detection of hydrogenous substances, such as moisture and corrosion, in aircraft components. Traditional radiography has limits because it only provides information on the total attenuation integrated over the path of the radiation through the material. As an extension to radiographic methods, the McClellan Nuclear Radiation Center (MNRC) is investigating the use of neutron tomography to obtain quantitative hydrogen concentration data for titanium aircraft engine compressor blades.

Gibbons, M.R.; Lades, M. [Lawrence Livermore National Lab., CA (United States); Richards, W.J. [McClellan Nuclear Radiation Center, McClellan AFB, CA (United States)] [and others

1997-12-01

353

Evaluation of an automated liquid hybridization method for DNA quantitation.  

PubMed

The AluQuant (Promega Corporation) liquid hybridization DNA quantitation method was evaluated on an automated robotic platform (Biomek 2000, Beckman Coulter, Fullerton, CA) for use in forensic PCR-STR systems. DNA from bloodstains and buccal swabs was extracted by three different methods: Chelex, Qiagen and DNA IQ (Promega). Samples were quantitated using both the Quantiblot and the AluQuant systems. Concordance between methods was determined by comparing the average AluQuant DNA concentrations for samples having matching (binned) Quantiblot values. Studies testing the "accuracy" (STR analysis), precision, sensitivity, and specifies specificity of the AluQuant method were also conducted. The effect of inhibitors (carpet, denim, and suede) was evaluated. The results indicate that the AluQuant quantitation system equals the Quantiblot system in "accuracy", sensitivity, precision, and primate-specificity. While extracts from denim and suede affected (inhibited) both systems minimally, the carpet extracts produced a sharp increase in DNA quantitation values in the AluQuant but not the Quantiblot system. The speed and user-friendliness of the AluQuant system on a robotic platform offer specific advantages to the forensic community. PMID:14979349

Hayn, Sandra; Wallace, Margaret M; Prinz, Mechthild; Shaler, Robert C

2004-01-01

354

Field Performance of Structures and Nondestructive Evaluation of Subsurface Infrastructure. Soils, Geology, and Foundations.  

National Technical Information Service (NTIS)

The 13 papers in this volume are related to geotechnical and structural engineering. The first eight papers present recent findings on soil-structure interaction as evaluated on the basis of field behavior. Diverse structures are covered, including bridge...

1993-01-01

355

Nondestructive Evaluation of Irradiation Embrittlement of SQV2A Steel by Using Magnetic Method  

NASA Astrophysics Data System (ADS)

Irradiation embrittlement of SQV2A steel was evaluated by magnetic methods. Thermal aging (TA) and electron irradiation (EI) specimens were prepared to evaluate the thermal aging and the irradiation damage effects separately. B-H loops changed with TA and EI. Higher harmonics of AC magnetization signals were sensitive to micro-structure changing of specimens. The intensity of the 3rd harmonics increased linearly with over 100 years of equivalent operation time by Larson-Miller parameter of nuclear power plants.

Shiwa, Mitsuharu; Weiying, Cheng; Nakahigashi, Shigeo; Komura, Ichiro; Fujiwara, Koji; Takahashi, Norio

2006-03-01

356

Non-destructive evaluation of nano-sized structure of thin film devices by using small angle neutron scattering.  

PubMed

Nano-sized multi-layers copper-doped SrZrO3, platinum (Pt) and silicon oxide (SiO2) on silicon substrates were prepared by dense plasma focus (DPF) device with the high purity copper anode tip and analyzed by using small angle neutron scattering (SANS) to establish a reliable method for the non-destructive evaluation of the under-layer structure. Thin film was well formed at the time-to-dip of 5 microsec with stable plasma of DPF. Several smooth intensity peaks were periodically observed when neutron beam penetrates the thin film with multi-layers perpendicularly. The platinum layer is dominant to intensity peaks, where the copper-doped SrZnO3 layer next to the platinum layer causes peak broadening. The silicon oxide layer has less effect on the SANS spectra due to its relative thick thickness. The SANS spectra shows thicknesses of platinum and copper-doped SrZnO3 layers as 53 and 25 nm, respectively, which are well agreement with microstructure observation. PMID:21446565

Shin, E J; Seong, B S; Choi, Y; Lee, J K

2011-01-01

357

Method Developed for the High-Temperature Nondestructive Evaluation of Fiber-Reinforced Silicon Carbide Ceramic Matrix Composites  

NASA Technical Reports Server (NTRS)

Ceramic matrix composites have emerged as candidate materials to allow higher operating temperatures (1000 to 1400 C) in gas turbine engines. A need, therefore, exists to develop nondestructive methods to evaluate material integrity at the material operating temperature by monitoring thermal and mechanical fatigue. These methods would also have potential as quality inspection tools. The goal of this investigation at the NASA Lewis Research Center is to survey and correlate the temperature-dependent damping and stiffness of advanced ceramic composite materials with imposed thermal and stress histories that simulate in-service turbine engine conditions. A typical sample size of 100 by 4 by 2 cubic millimeters, along with the specified stiffness and density, placed the fundamental vibration frequencies between 100 and 2000 Hz. A modified Forster apparatus seemed most applicable to simultaneously measure both damping and stiffness. Testing in vacuum reduced the effects of air on the measurements. In this method, a single composite sample is vibrated at its fundamental tone; then suddenly, the mechanical excitation is removed so that the sample's motion freely decays with time. Typical results are illlustrated in this paper.

Goldsby, Jon C.

1998-01-01

358

Non-destructive evaluation of degradation in EB-PVD thermal barrier coatings by infrared reflectance spectroscopy  

NASA Astrophysics Data System (ADS)

At room temperature and atmospheric conditions infrared reflectance spectroscopy and X-ray diffraction were employed for the detection of the phase transformation and residual stress within thermal barrier coatings (TBC). The TBC's samples initially consisted of the porous ceramic topcoat deposited by electron beam plasma vapor deposition, a bond coat and a superalloy substrate. Reflectance spectroscopy scans were performed from 7497 cm-1 to 68 cm-1 to analysis the fingerprint region as well as the chemical bonding region. These regions should indicate if a detectable change within the TBC response is a result of thermal degradation of the microstructure and the changes in yttrium dispersion throughout the yttrium stabilized zirconium. The thermal degradation was induced by thermal cycling the samples to 1100° C and then cooling them in an atmospheric environment. X-ray diffraction was also used to detect the phase composition within the TBC samples and see if either would clearly identify failure prior to actual spallation. The eventual measurability and quantify-ability of the phase changes within the TBC's may be used as an effective non-destructive evaluation (NDE) technique that would allow personnel in the field to know when servicing of the turbine blade was necessary.

Flattum, Richard Y.; Cooney, Adam T.

2013-01-01

359

Non-destructive evaluation of degradation in EB-PVD thermal barrier coatings by infrared reflectance spectroscopy  

SciTech Connect

At room temperature and atmospheric conditions infrared reflectance spectroscopy and X-ray diffraction were employed for the detection of the phase transformation and residual stress within thermal barrier coatings (TBC). The TBC's samples initially consisted of the porous ceramic topcoat deposited by electron beam plasma vapor deposition, a bond coat and a superalloy substrate. Reflectance spectroscopy scans were performed from 7497 cm{sup -1} to 68 cm{sup -1} to analysis the fingerprint region as well as the chemical bonding region. These regions should indicate if a detectable change within the TBC response is a result of thermal degradation of the microstructure and the changes in yttrium dispersion throughout the yttrium stabilized zirconium. The thermal degradation was induced by thermal cycling the samples to 1100 Degree-Sign C and then cooling them in an atmospheric environment. X-ray diffraction was also used to detect the phase composition within the TBC samples and see if either would clearly identify failure prior to actual spallation. The eventual measurability and quantify-ability of the phase changes within the TBC's may be used as an effective non-destructive evaluation (NDE) technique that would allow personnel in the field to know when servicing of the turbine blade was necessary.

Flattum, Richard Y.; Cooney, Adam T. [Air Force Research Laboratory, Materials and Manufacturing Directorate, NonDestructive Evaluation Branch, Wright-Patterson AFB, OH (United States)

2013-01-25

360

Ultrasonic Imaging Technology Helps American Manufacturer of Nondestructive Evaluation Equipment Become More Competitive in the Global Market  

NASA Technical Reports Server (NTRS)

Sonix, Inc., of Springfield, Virginia, has implemented ultrasonic imaging methods developed at the NASA Lewis Research Center. These methods have heretofore been unavailable on commercial ultrasonic imaging systems and provide significantly more sensitive material characterization than conventional high-resolution ultrasonic c-scanning. The technology transfer is being implemented under a cooperative agreement between NASA and Sonix, and several invention disclosures have been submitted by Dr. Roth to protect Lewis interests. Sonix has developed ultrasonic imaging systems used worldwide for microelectronics, materials research, and commercial nondestructive evaluation (NDE). In 1993, Sonix won the U.S. Department of Commerce "Excellence in Exporting" award. Lewis chose to work with Sonix for two main reasons: (1) Sonix is an innovative leader in ultrasonic imaging systems, and (2) Sonix was willing to apply the improvements we developed with our in-house Sonix equipment. This symbiotic joint effort has produced mutual benefits. Sonix recognized the market potential of our new and highly sensitive methods for ultrasonic assessment of material quality. We, in turn, see the cooperative effort as an effective means for transferring our technology while helping to improve the product of a domestic firm.

1995-01-01

361

Roadmap for Nondestructive Evaluation of Reactor Pressure Vessel Research and Development by the Light Water Reactor Sustainability Program  

SciTech Connect

The Department of Energy s (DOE) Light Water Reactor Sustainability (LWRS) Program is a five year effort which works to develop the fundamental scientific basis to understand, predict, and measure changes in materials and systems, structure, and components as they age in environments associated with continued long-term operations of existing commercial nuclear power reactors. This year, the Materials Aging and Degradation (MAaD) Pathway of this program has placed emphasis on emerging Non-Destructive Evaluation (NDE) methods which support these objectives. DOE funded Research and Development (R&D) on emerging NDE techniques to support commercial nuclear reactor sustainability is expected to begin next year. This summer, the MAaD Pathway invited subject matter experts to participate in a series of workshops which developed the basis for the research plan of these DOE R&D NDE activities. This document presents the results of one of these workshops which are the DOE LWRS NDE R&D Roadmap for Reactor Pressure Vessels (RPV). These workshops made a substantial effort to coordinate the DOE NDE R&D with that already underway or planned by the Electric Power Research Institute (EPRI) and the Nuclear Regulatory Commission (NRC) through their representation at these workshops.

Smith, Cyrus M [ORNL; Nanstad, Randy K [ORNL; Clayton, Dwight A [ORNL; Matlack, Katie [Georgia Institute of Technology; Ramuhalli, Pradeep [Pacific Northwest National Laboratory (PNNL); Light, Glenn [Southwest Research Institute, San Antonio

2012-09-01

362

Interfacial Aspects of Electrodeposited Conductive Fibers/Epoxy Composites using Electro-Micromechanical Technique and Nondestructive Evaluation.  

PubMed

Interfacial adhesion and nondestructive behavior of the electrodeposited (ED) carbon fiber reinforced composites were evaluated using the electro-micromechanical technique and acoustic emission (AE). Interfacial shear strength (IFSS) of the ED carbon fiber/epoxy composites was higher than that of the untreated case. This might be expected because of the possible chemical and hydrogen bonding based on an electrically adsorbed polymeric interlayer. Logarithmic electrical resistivity of the untreated single-carbon fiber composite increased suddenly to infinity when the fiber fracture occurred, whereas that of the ED composite increased relatively broadly up to infinity. This may be due to the retarded fracture time as a result of the enhanced IFSS. In single- and 10-carbon fiber composites, the number of AE signals coming from the interlayer failure of the ED carbon fiber composite was much larger than that of the untreated composite. As the number of each first fiber fracture increased in the 10-carbon fiber composite, the electrical resistivity increased stepwise, and the slope of logarithmic electrical resistance increased. In the three-graphite filament composite with a narrow 1 time inter-filament distance, the total numbers of the filament fracture and the IFSS were smaller than those of the wider 5 times case. This might be because the interacting fracture energy caused by a filament break could affect the adjacent filaments. Copyright 2001 Academic Press. PMID:11334518

Park, Joung-Man; Lee, Sang-Il; Kim, Ki-Won; Yoon, Dong-Jin

2001-05-01

363

The use of complementary non-destructive evaluation methods to evaluate the integrity of the cement-bone interface.  

PubMed

The integrity of the cement-bone interface is vital to the long-term stability of cemented hip arthroplasty. Most of the previous studies investigating the interface have been confined to the continuum level, neglecting the effects of microstructure. Microscopic damage at the interface may eventually lead to macroscopic loosening of the implant. However, as the strength of the interface depends on the interlock of the cement with bone and because the properties of cancellous bone depend on its microstructure, the study of the behaviour of the interface at the microstructural level may help to gain an understanding of the factors governing initiation of loosening. In this study, two complementary non-destructive methods, acoustic emission (AE) and computed tomography (CT), have been implemented to study the initiation and progression of damage of an analogue cement-bone interface sample under four-point bending. Early failure was detected, localized, and characterized using AE. CT images of the sample before and after loading were used to visualize damage in three dimensions. Damage initiated at the interface and was found to be related to stress-raising microstructural features in the cement. These were caused by irregularities in the geometry of the bone analogue and recesses and notches formed by the flow of cement. PMID:19239069

Leung, S Y; New, A M; Browne, M

2009-01-01

364

Compact 950 keV X-band (9.4GHz) Linac X-ray Source for On-site Nondestructive Evaluation  

Microsoft Academic Search

We are developing a compact X-ray nondestructive evaluation (NDE) system using 9.4 GHz X-band linac with 250 kW magnetron. A conventional 1 MeV X-band machines use a large 1 MW magnetron system. We have chosen the 250 kW magnetron so that the RF heat loss is remarkably reduced. This design yields compactness and portable. This system consists of the X-band

Tomohiko Yamamoto; Takuya Natsui; Noritaka Yusa; Katsuhiro Dobashi; Mitsuru Uesaka; Toshiyasu Higo; Shigeki Fukuda; Mitsuo Akemoto; Mitsuhiro Yoshida; Toshikazu Takatomi; Noboru Kudoh; Eiji Tanabe; Naoki Nakamura; Seiki Morita; Masahi Yamamoto

2007-01-01

365

950 keV, 3.95 MeV and 6 MeV X-band linacs for nondestructive evaluation and medicine  

Microsoft Academic Search

We are developing compact X-band linac X-ray sources for nondestructive evaluation and medicine. First, we develop a portable X-ray system by a 950keV 9.4GHz X-band linac to realize on-site inspection. We use a low power (250kW) magnetron as an RF source for compactness of the whole system. Since the RF power source is quite small and the stored energy in

Mitsuru Uesaka; Takuya Natsui; Kiwoo Lee; Katsuhiro Dobashi; Tomohiko Yamamoto; Takeshi Fujiwara; Haito Zhu; Kazuyuki Demachi; Eiji Tanabe; Masashi Yamamoto; Naoki Nakamura; Joichi Kusano; Toshiyasu Higo; Shigeki Fukuda; Mitsuhiro Yoshida; Shuji Matsumoto

2011-01-01

366

Time Domain Terahertz Non-Destructive Evaluation of Aeroturbine Blade Thermal Barrier Coatings  

NASA Astrophysics Data System (ADS)

Time domain terahertz (TD-THz) non destructive evaluation (NDE) imaging is used to two-dimensionally map the thickness of yttria stabilized zirconia (YSZ) thermal barrier coatings (TBC) on aircraft engine turbine blades. Indications of thermal degradation can be seen. The method is non-contact, rapid, and requires no special preparation of the blade.

White, Jeffrey; Fichter, G.; Chernovsky, A.; Whitaker, John F.; Das, D.; Pollock, Tresa M.; Zimdars, David

2009-03-01

367

Non-destructive evaluation techniques, high temperature ceramic component parts for gas turbines  

NASA Technical Reports Server (NTRS)

This report concerns studies conducted on various tests undertaken on material without destroying the material. Tests included: microradiographic techniques, vibration analysis, high-frequency ultrasonic tests with the addition of evaluation of defects and structure through analysis of ultrasonic scattering data, microwave tests and analysis of sound emission.

Reiter, H.; Hirsekorn, S.; Lottermoser, J.; Goebbels, K.

1984-01-01

368

Development and applications of nondestructive evaluation at Marshall Space Flight Center  

NASA Technical Reports Server (NTRS)

A brief description of facility design and equipment, facility usage, and typical investigations are presented for the following: Surface Inspection Facility; Advanced Computer Tomography Inspection Station (ACTIS); NDE Data Evaluation Facility; Thermographic Test Development Facility; Radiographic Test Facility; Realtime Radiographic Test Facility; Eddy Current Research Facility; Acoustic Emission Monitoring System; Advanced Ultrasonic Test Station (AUTS); Ultrasonic Test Facility; and Computer Controlled Scanning (CONSCAN) System.

Whitaker, Ann F.

1990-01-01

369

Signal extraction using ensemble empirical mode decomposition and sparsity in pipeline magnetic flux leakage nondestructive evaluation  

Microsoft Academic Search

The commonly used and cost effective corrosion inspection tools for the evaluation of pipelines utilize the magnetic flux leakage (MFL) technique. The MFL signal is usually contaminated by various noise sources. In this paper, we propose that the pipeline flaw MFL signal is extracted using the ensemble empirical mode decomposition (EEMD) and the sparsity. At first, we introduce the EEMD

Liang Chen; Xing Li; Xun-Bo Li; Zuo-Ying Huang

2009-01-01

370

The applicability of a material-treatment laser pulse in non-destructive evaluations  

Microsoft Academic Search

A practical optodynamic study was performed to determine the usability of different lengths of laser pulses for the generation of ultrasonic transients in a solid material. The aim of the study was to evaluate the possibility of a dual use for a laser pulse—for laser material processing, on the one hand, and for the ultrasonic wave generation on the other—with

R. Hrovatin; R. Petkovšek; J. Diaci; J. Možina

2006-01-01

371

Relationship between non-destructive OCT evaluation of resins composites and bond strength in a cavity  

NASA Astrophysics Data System (ADS)

Objectives: Formation of microgaps under the composite restorations due to polymerization stress and other causes compromise the adhesion to the dental substrate and restoration durability. However, the relationship between cavity adaptation and bond strength is not clear. In this paper, we introduce a new testing method to assess cavity adaptation by swept-source optical coherence tomography (SS-OCT) and microtensile bond strength (MTBS) in the same class-I cavity. Methods: Round class-I cavities 3 mm in diameter and 1.5 mm in depth were prepared on 10 human premolars. After application of Tokuyama Bond Force adhesive, the cavities were filled by one of the two techniques; incremental technique using Estelite Sigma Quick universal composite or flowable lining using Palfique Estelite LV with bulk filling using the universal composite. Ten serial B-scan images were obtained throughout each cavity by SS-OCT. Significant peaks in the signal intensity were detected at the bonded interface of the cavity floor and to compare the different filling techniques. The specimens were later cut into beams (0.7x0.7 mm) and tested to measure MTBS at the cavity floor. Results: Flowable lining followed by bulk filling was inferior in terms of cavity adaptation and MTBS compared to the incremental technique (p<0.05, t-test). The adaptation (gap free cavity floor) and MTBS followed similar trends in both groups. Conclusion: Quantitative assessment of dental restorations by OCT can provide additional information on the performance and effectiveness of dental composites and restoration techniques. This study was supported by Global Center of Excellence, Tokyo Medical and Dental University and King Abdulaziz University.

Bakhsh, T. A.; Sadr, A.; Shimada, Y.; Khunkar, S.; Tagami, J.; Sumi, Y.

2012-02-01

372

A Step-Frequency Radar Imaging System for Microwave Nondestructive Evaluation  

Microsoft Academic Search

We describe a step-frequency radar (SFR) imaging system that is suitable for microwavenondestructive evaluation (NDE) applications. The system includes a computerautomatedmicrowave measurement apparatus, calibration software, and nonlinear inversescattering imaging algorithms. Through the use of an inverse Fourier transform, the rawSFR data is transformed into a synthetic time-domain pulse. A calibration procedure involvingthe use of calibration targets may then be used

W. H. Weedon; W. C. Chew

2000-01-01

373

Nondestructive evaluation/characterization of composite materials and structures using the acousto-ultrasonic techniques  

NASA Technical Reports Server (NTRS)

This paper introduces the nature and the underlying rational of the acousto-ultrasonic stress wave factor technique and some of its applications to composite materials and structures. Furthermore, two examples of successful application of the acousto-ultrasonic technique are presented in detail. In the first example, the acousto-ultrasonic technique is used to evaluate the adhesive bond strength between rubber layers and steel plates, and in the seocnd example the tehcnique is used to monitor progressive damage in wire rope.

Dos Reis, H. L. M.; Vary, A.

1988-01-01

374

Embedded Non-destructive Evaluation for Structural Health Monitoring, Damage Detection, and Failure Prevention  

Microsoft Academic Search

In this paper we review the state of the art in an emerging new technology: embedded ultrasonic non-destruc- tive evaluation (NDE). Embedded ultrasonic NDE permits active structural health monitoring, i.e. the on-demand inter- rogation of the structure to determine its current state of structural health. The enabling element of embedded ultra- sonic NDE is the piezoelectric wafer active sensor (PWAS).

Victor Giurgiutiu; Adrian Cuc

2005-01-01

375

Monitoring of Reinforced Concrete Corrosion and Deterioration by Periodic Multi-Sensor Non-Destructive Evaluation  

NASA Astrophysics Data System (ADS)

The paper showcases a collaborative benchmark project evaluating NDE methods for deterioration monitoring of laboratory bridge decks. The focus of this effort is to design and build concrete test specimens, artificially induce and monitor corrosion, periodically perform multi-sensor NDE inspections, followed by 3D imaging and destructive validations. NDE methods used include ultrasonic echo array, ground penetrating radar (GPR), active infrared thermography with induction heating, and time-resolved thermography with induction heating.

Arndt, R. W.; Cui, J.; Huston, D. R.

2011-06-01

376

Image correlation nondestructive evaluation of impact damage in a glass fiber composite  

NASA Technical Reports Server (NTRS)

Presented in viewgraph format, digital image correlation, damage in fibrous composites, and damaged coupons (cross-ply scotchply GI-Ep laminate) are outlined. It was concluded that the image correlation accuracy was 0.03 percent; strains can be processed through Tsai-Hill failure criteria to qualify the damage; the statistical data base must be generated to evaluate certainty of the damage estimate; size effects need consideration; and better numerical techniques are needed.

Russell, Samuel S.

1990-01-01

377

Risperidone solid dispersion for orally disintegrating tablet: its formulation design and non-destructive methods of evaluation.  

PubMed

The focus of present investigation was to assess the utility of non-destructive techniques in the evaluation of risperidone solid dispersions (SD) with methyl-?-cyclodextrin (MBCD) and subsequent incorporation of the SD into orally disintegrating tablets (ODT) for a faster release of risperidone. The SD was prepared by a solvent evaporation method and evaluated by scanning electron microscopy (SEM), Fourier transform infrared (FTIR), near infrared spectroscopy (NIR), NIR-chemical imaging (NIR-CI), powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC). DSC and XRD analysis indicated that crystallinity of SD has reduced significantly. FTIR showed no interaction between risperidone and MBCD. Partial least square (PLS) was applied to the NIR data for the construction of chemometric models to determine both components of the SD. Good correlations were obtained for calibration and prediction as indicated by correlation coefficients >0.9965. The model was more accurate and less biased in predicting the MBCD than risperidone as indicated by its lower mean accuracy and mean bias values. SD-3 (risperidone:MBCD, 1:3) was incorporated into ODT tablets containing diluent (D-mannitol, FlowLac(®) 100 or galenIQ™-721) and superdisintegrant (Kollidon(®) CL-SF, Ac-Di-Sol or sodium starch glycolate). Disintegration time, T(50) and T(90) were decreased in the formulations containing mannitol and Kollidon(®) CL-SF, but increased with galenIQ™-721 and sodium starch glycolate, respectively. NIR-CI images confirmed the homogeneity of SD and ODT formulations. PMID:20801200

Rahman, Ziyaur; Zidan, Ahmed S; Khan, Mansoor A

2010-11-15

378

Nondestructive analysis and development  

NASA Technical Reports Server (NTRS)

This final report summarizes the achievements of project #4 of the NASA/UCF Cooperative Agreement from January 1990 to December 1992. The objectives of this project are to review NASA's NDE program at Kennedy Space Center (KSC) and recommend means for enhancing the present testing capabilities through the use of improved or new technologies. During the period of the project, extensive development of a reliable nondestructive, non-contact vibration technique to determine and quantify the bond condition of the thermal protection system (TPS) tiles of the Space Shuttle Orbiter was undertaken. Experimental modal analysis (EMA) is used as a non-destructive technique for the evaluation of Space Shuttle thermal protection system (TPS) tile bond integrity. Finite element (FE) models for tile systems were developed and were used to generate their vibration characteristics (i.e. natural frequencies and mode shapes). Various TPS tile assembly configurations as well as different bond conditions were analyzed. Results of finite element analyses demonstrated a drop in natural frequencies and a change in mode shapes which correlate with both size and location of disbond. Results of experimental testing of tile panels correlated with FE results and demonstrated the feasibility of EMA as a viable technique for tile bond verification. Finally, testing performed on the Space Shuttle Columbia using a laser doppler velocimeter demonstrated the application of EMA, when combined with FE modeling, as a non-contact, non-destructive bond evaluation technique.

Moslehy, Faissal A.

1993-01-01

379

Portable microwave instrument for non-destructive evaluation of structural characteristics  

DOEpatents

A portable microwave instrument for evaluating characteristics of a structural member includes a source of microwave energy, a transmitter coupled to the source of microwave energy for transmitting a microwave signal at the structural member, and a receiver positioned on the same side of the structural member as the transmitter and being disposed to receive a microwave signal reflected by the structural member. A phase angle difference is determined between the transmitted microwave signal and the received microwave signal using a signal splitter and a balanced mixer. The difference in phase angle varies in accordance with differences in size, shape and locations of constituent materials within the structural member. 6 figures.

Bible, D.W.; Crutcher, R.I.; Sohns, C.W.; Maddox, S.R.

1995-01-24

380

Portable microwave instrument for non-destructive evaluation of structural characteristics  

DOEpatents

A portable microwave instrument for evaluating characteristics of a structural member includes a source of microwave energy, a transmitter coupled to the source of microwave energy for transmitting a microwave signal at the structural member, and a receiver positioned on the same side of the structural member as the transmitter and being disposed to receive a microwave signal reflected by the structural member. A phase angle difference is determined between the transmitted microwave signal and the received microwave signal using a signal splitter and a balanced mixer. The difference in phase angle varies in accordance with differences in size, shape and locations of constituent materials within the structural member.

Bible, Don W. (Clinton, TN); Crutcher, Richard I. (Knoxville, TN); Sohns, Carl W. (Oak Ridge, TN); Maddox, Stephen R. (Loudon, TN)

1995-01-01

381

A comparison between ultrasonic array beamforming and super resolution imaging algorithms for non-destructive evaluation.  

PubMed

In this paper the total focusing method, the so called gold standard in classical beamforming, is compared with the widely used time-reversal MUSIC super resolution technique in terms of its ability to resolve closely spaced scatterers in a solid. The algorithms are tested with simulated and experimental array data, each containing different noise levels. The performance of the algorithms is evaluated in terms of lateral resolution and sensitivity to noise. It is shown that for the weak noise situation (SNR>20dB), time-reversal MUSIC provides significantly enhanced lateral resolution when compared to the total focusing method, breaking the diffraction limit. However, for higher noise levels, the total focusing method is shown to be robust, whilst the performance of time-reversal MUSIC is degraded. The influence of multiple scattering on the imaging algorithms is also investigated and shown to be small. PMID:24457032

Fan, Chengguang; Caleap, Mihai; Pan, Mengchun; Drinkwater, Bruce W

2014-09-01

382

Comparison between beamforming and super resolution imaging algorithms for non-destructive evaluation  

NASA Astrophysics Data System (ADS)

In this paper the performance of total focusing method is compared with the widely used time-reversal MUSIC super resolution technique. The algorithms are tested with simulated and experimental ultrasonic array data, each containing different noise levels. The simulated time domain signals allow the effects of array geometry, frequency, scatterer location, scatterer size, scatterer separation and random noise to be carefully controlled. The performance of the imaging algorithms is evaluated in terms of resolution and sensitivity to random noise. It is shown that for the low noise situation, time-reversal MUSIC provides enhanced lateral resolution when compared to the total focusing method. However, for higher noise levels, the total focusing method shows robustness, whilst the performance of time-reversal MUSIC is significantly degraded.

Fan, Chengguang; Drinkwater, Bruce W.

2014-02-01

383

GRI pipeline simulation facility nondestructive evaluation laboratory. Topical report, 1990-1994  

SciTech Connect

The NDE laboratory consists of three elements, the linear test rig, electromagnetic finite element modeling capability, and the experimental field measurement system. The linear test rig is the centerpiece of the NDE Laboratory. The linear test rig can be used to simulate in-line inspection conditions in a laboratory environment for the evaluation and development of new technologies. The electromagnetic finite element modeling capability is used to calculate magnetic flux leakage fields and signals from metal loss defects under static and dynamic conditions and examine magnetization methods. Finally, an experimental magnetic field mapping system provides precise sensor positioning and data recording for sensor and inspecion technology development. The finite element modeling and experimental field mapping systems can be used to develop in-line inspection technology. The linear test rig facilitates the implementation of technology from the laboratory to the pull rig, flow loop, and eventually in-line inspection tools.

Nestleroth, J.B.; Davis, R.J.; Bubenik, T.A.

1995-04-01

384

Voluntary Consensus Organization Standards for Nondestructive Evaluation of Thin-Walled Metallic Liners and Composite Overwraps in Composite Overwrapped Pressure Vessels  

NASA Technical Reports Server (NTRS)

NASA fracture control requirements outlined in NASA-STD-5009 and NASA-STD-5014 are predicated on the availability and use of sensitive nondestructive evaluation (NDE) methods that can detect and monitor defects, thereby providing data that can be used to predict failure or reduce the risk of failure in fracture critical components. However, in the case of composite materials and components, including composite overwrapped pressure vessels (COPVs), the effect of defects is poorly understood, the NDE methods used to evaluate locate and size defects are typically at lower technical readiness level than analogous NDE methods used for metals, and demonstration studies to verify the probability of detection (POD) are generally lacking or unavailable. These factors together make failure prediction of fracture critical composite materials and components based on size, quantity, or orientation of defects nearly impossible. Also, when inspecting metal liners in as-manufactured COPVs, sensitivity is lost and only the inner surface of the liner is accessible. Also, NDE of COPVs as applied during manufacturing varies significantly from manufacturer to manufacturer and has not yet been standardized. Although requirements exist to perform NDE immediately after manufacturing to establish initial integrity of the parts, procedural detail for NDE of composites is still nonexistent or under development. For example, in practice, only a visual inspection of COPVs is performed during manufacturing and service, leaving in question whether defects of concern, for example, bridging, overwrap winding anomalies, impact damage below visible threshold, out-of-family strain growth, and liner buckling have been adequately detected and monitored. To address these shortcomings, in 2005 the NASA Nondestructive Evaluation Working Group (NNWG) began funding work to develop and adopt standards for nondestructive evaluation of aerospace composites in collaboration with the American Society for Testing and Materials (ASTM) Committee E07 on Nondestructive Testing. Similarly, in 2006 the NASA Engineering and Safety Center (NESC) recommended that nondestructive evaluation methods that can predict composite failure in COPVs should be developed and verified, and integrated into the damage control plan for these vessels

Waller, Jess; Saulsberry, Regor

2012-01-01

385

Exploratory nondestructive evaluation (NDE) research for advanced materials and processes: Volume 3 -- Interactive multimedia computer based training (IMCBT) for nondestructive evaluation\\/inspection (NDE\\/I) personnel. Final report, 1 July 1995--30 April 1998  

Microsoft Academic Search

Interactive Multimedia Computer Based Training (IMCBT) for Nondestructive Inspection (NDE\\/I) Personnel: Computer Based Training (CBT) is a highly effective method for industrial training that has been growing in popularity. Text, graphics, sound, movies and animation enhance the learning activity. Interactive Multimedia CBT (IMCBT) allows students to learn in an environment where the training material is presented on a computer workstation

Bossi; B. Knutson; R. Nerenberg; L. Deobald; J. Nelson

1998-01-01

386

Development of nondestructive evaluation methods and prediction of effects of flaws on the fracture behavior of structural ceramics  

SciTech Connect

Characterization of ceramic matrix composites (continuous and whisker-type) by nondestructive evaluation (NDE) methods and an understanding of fracture behavior, together with correlation of fracture and NDE data, may provide insight into the prediction of component performance and the development of process technology. Knowledge of the degradation extent of fiber tows or monofilament degradation after processing, extent of open porosity before densification, and filament/fiber alignments before and after processing are also examples of important variables to be measured. Work in this program has emphasized continuous fiber ceramic matrix composites (CFCCs) that use chemical vapor infiltration (CVI)-infiltrated SiC/SiC materials, primarily those made of Nicalon satin or plain weave with 16 {times} 16 tows/in. in 2-D layups. All studied samples were provided by Oak Ridge National Laboratory and were made using 100 layers per inch. CVI specimens with 0/30/60, 0/90, and 0/45 were examined by 3-D X-ray microtomography to characterize in-plane fiber orientations. Current information suggests that for Nicalon-type fiber architecture, a {plus minus}2--1/2{degrees} misalignment may not affect mechanical properties. Thus the near-term goal has been to establish a detection capability for angular orientation. By using 512 {times} 512 images from 3-D X-ray CT data with pixel sizes of < 140 {mu}m and a special 2-D fast-Fourier transform image processing analysis, we have shown that fiber orientations to {plus minus}2--1/2{degrees} with SiC/SiC CVI type 2-D weave architecture can be measured.

Ellingson, W.A.; Singh, J.P.; Holloway, D.L.; Dieckman, S.L.; Singh, D.; Sivers, E.A.; Sheen, S.H.; Wheeler, M.J.

1992-05-01

387

Development of nondestructive evaluation methods and prediction of effects of flaws on the fracture behavior of structural ceramics  

SciTech Connect

Characterization of ceramic matrix composites (continuous and whisker-type) by nondestructive evaluation (NDE) methods and an understanding of fracture behavior, together with correlation of fracture and NDE data, may provide insight into the prediction of component performance and the development of process technology. Knowledge of the degradation extent of fiber tows or monofilament degradation after processing, extent of open porosity before densification, and filament/fiber alignments before and after processing are also examples of important variables to be measured. Work in this program has emphasized continuous fiber ceramic matrix composites (CFCCs) that use chemical vapor infiltration (CVI)-infiltrated SiC/SiC materials, primarily those made of Nicalon satin or plain weave with 16 {times} 16 tows/in. in 2-D layups. All studied samples were provided by Oak Ridge National Laboratory and were made using 100 layers per inch. CVI specimens with 0/30/60, 0/90, and 0/45 were examined by 3-D X-ray microtomography to characterize in-plane fiber orientations. Current information suggests that for Nicalon-type fiber architecture, a {plus_minus}2--1/2{degrees} misalignment may not affect mechanical properties. Thus the near-term goal has been to establish a detection capability for angular orientation. By using 512 {times} 512 images from 3-D X-ray CT data with pixel sizes of < 140 {mu}m and a special 2-D fast-Fourier transform image processing analysis, we have shown that fiber orientations to {plus_minus}2--1/2{degrees} with SiC/SiC CVI type 2-D weave architecture can be measured.

Ellingson, W.A.; Singh, J.P.; Holloway, D.L.; Dieckman, S.L.; Singh, D.; Sivers, E.A.; Sheen, S.H.; Wheeler, M.J.

1992-05-01

388

Autonomous corrosion detection in gas pipelines: a hybrid-fuzzy classifier approach using ultrasonic nondestructive evaluation protocols.  

PubMed

In this paper, a customized classifier is presented for the industry-practiced nondestructive evaluation (NDE) protocols using a hybrid-fuzzy inference system (FIS) to classify the corrosion and distinguish it from the geometric defects or normal/healthy state of the steel pipes used in the gas/petroleum industry. The presented system is hybrid in the sense that it utilizes both soft computing through fuzzy set theory, as well as conventional parametric modeling through H(infinity) optimization methods. Due to significant uncertainty in the power spectral density of the noise in ultrasonic NDE procedures, the use of optimal H(2) estimators for defect characterization is not so accurate. A more appropriate criterion is the H(infinity) norm of the estimation error spectrum which is based on minimization of the magnitude of this spectrum and hence produces more robust estimates. A hybrid feature set is developed in this work that corresponds to a) geometric features extracted directly from the raw ultrasonic A-scan data (which are the ultrasonic echo pulses in 1-Dtraveling inside the metal perpendicular to its 2 surfaces) and b) mapped features from the impulse response of the estimated model of the defect waveform under study. An experimental strategy is first outlined, through which the necessary data are collected as A-scans. Then, using the H(infinity) estimation approach, a parametric transfer function is obtained for each pulse. In this respect, each A-scan is treated as output from a defining function when a pure/healthy metal's A-scan is used as its input. Three defining states are considered in the paper; healthy, corroded, and defective, where the defective class represents metal with artificial or other defects. The necessary features are then calculated and are then supplied to the fuzzy inference system as input to be used in the classification. The resulting system has shown excellent corrosion classification with very low misclassification and false alarm rates. PMID:20040402

Qidwai, Uvais A

2009-12-01

389

Nondestructive evaluation methods to measure inside diameters of steam generator tubing: Topical report  

SciTech Connect

Numerous steam generators have experienced tube deformation or denting at support plate intersections due to localized mechanical forces exerted by a magnetite corrosion product within tube and carbon steel support plate annulus. In extreme cases, this denting has led to the early replacement of some steam generators, i.e., Surry and Turkey Point. In addition to monitoring the steam generator for tube wall degradation it has become apparent that it is also desirable to monitor the condition of dented tube-support plate intersections during scheduled inservice inspections. To this end, the acquisition of accurate and reliable information with regards to dent shape is important in establishing tube strain and identifying dent growth rates. This report summarizes the results of a round-robin evaluation conducted in 1983 using then available state-of-the-art technology for assessing dented tubes. More specifically, the capability of various systems for profiling and providing estimates of tube inner diameter on known dent shapes was demonstrated.

Brown, S.; Krzywosz, K.; Cox, J.; Elmo, P.M.

1988-07-01

390

Signal extraction using ensemble empirical mode decomposition and sparsity in pipeline magnetic flux leakage nondestructive evaluation  

NASA Astrophysics Data System (ADS)

The commonly used and cost effective corrosion inspection tools for the evaluation of pipelines utilize the magnetic flux leakage (MFL) technique. The MFL signal is usually contaminated by various noise sources. In this paper, we propose that the pipeline flaw MFL signal is extracted using the ensemble empirical mode decomposition (EEMD) and the sparsity. At first, we introduce the EEMD method. The EEMD defines the true intrinsic mode function (IMF) components as the mean of an ensemble of trials, each consisting of the signal plus a white noise of finite amplitude. Moreover, sparsity selection restriction was defined. Then, The MFL signal is decomposed into several IMFs used for signal reconstruction. Some modes are selected to reconstruct a new signal considering their sparsity. Finally, the comparison is made with the empirical mode decomposition. At the same time, the comparison of the selection restriction between the sparsity and the energy is described. The results show that the EEMD and the sparsity is an efficient technology with the pipeline flaw extraction.

Chen, Liang; Li, Xing; Li, Xun-Bo; Huang, Zuo-Ying

2009-02-01

391

Signal extraction using ensemble empirical mode decomposition and sparsity in pipeline magnetic flux leakage nondestructive evaluation.  

PubMed

The commonly used and cost effective corrosion inspection tools for the evaluation of pipelines utilize the magnetic flux leakage (MFL) technique. The MFL signal is usually contaminated by various noise sources. In this paper, we propose that the pipeline flaw MFL signal is extracted using the ensemble empirical mode decomposition (EEMD) and the sparsity. At first, we introduce the EEMD method. The EEMD defines the true intrinsic mode function (IMF) components as the mean of an ensemble of trials, each consisting of the signal plus a white noise of finite amplitude. Moreover, sparsity selection restriction was defined. Then, The MFL signal is decomposed into several IMFs used for signal reconstruction. Some modes are selected to reconstruct a new signal considering their sparsity. Finally, the comparison is made with the empirical mode decomposition. At the same time, the comparison of the selection restriction between the sparsity and the energy is described. The results show that the EEMD and the sparsity is an efficient technology with the pipeline flaw extraction. PMID:19256676

Chen, Liang; Li, Xing; Li, Xun-bo; Huang, Zuo-ying

2009-02-01

392

Quantitative Evaluation for Two-Dimensional Electromagnetic Propagation in a Dielectric Medium using Markov Chain Monte Carlo Method (Preprint).  

National Technical Information Service (NTIS)

The motivation of this work is to quantify the degradation of aging electrical cables. The dielectric material parameter of insulation can be correlated with degradation. In this paper, the forward problem is posed as a microwave nondestructive evaluation...

F. Kojima J. S. Knopp

2012-01-01

393

Simulation evaluation of quantitative myocardial perfusion assessment from cardiac CT  

NASA Astrophysics Data System (ADS)

Contrast enhancement on cardiac CT provides valuable information about myocardial perfusion and methods have been proposed to assess perfusion with static and dynamic acquisitions. There is a lack of knowledge and consensus on the appropriate approach to ensure 1) sufficient diagnostic accuracy for clinical decisions and 2) low radiation doses for patient safety. This work developed a thorough dynamic CT simulation and several accepted blood flow estimation techniques to evaluate the performance of perfusion assessment across a range of acquisition and estimation scenarios. Cardiac CT acquisitions were simulated for a range of flow states (Flow = 0.5, 1, 2, 3 ml/g/min, cardiac output = 3,5,8 L/min). CT acquisitions were simulated with a validated CT simulator incorporating polyenergetic data acquisition and realistic x-ray flux levels for dynamic acquisitions with a range of scenarios including 1, 2, 3 sec sampling for 30 sec with 25, 70, 140 mAs. Images were generated using conventional image reconstruction with additional image-based beam hardening correction to account for iodine content. Time attenuation curves were extracted for multiple regions around the myocardium and used to estimate flow. In total, 2,700 independent realizations of dynamic sequences were generated and multiple MBF estimation methods were applied to each of these. Evaluation of quantitative kinetic modeling yielded blood flow estimates with an root mean square error (RMSE) of ~0.6 ml/g/min averaged across multiple scenarios. Semi-quantitative modeling and qualitative static imaging resulted in significantly more error (RMSE = ~1.2 and ~1.2 ml/min/g respectively). For quantitative methods, dose reduction through reduced temporal sampling or reduced tube current had comparable impact on the MBF estimate fidelity. On average, half dose acquisitions increased the RMSE of estimates by only 18% suggesting that substantial dose reductions can be employed in the context of quantitative myocardial blood flow estimation. In conclusion, quantitative model-based dynamic cardiac CT perfusion assessment is capable of accurately estimating MBF across a range of cardiac outputs and tissue perfusion states, outperforms comparable static perfusion estimates, and is relatively robust to noise and temporal subsampling.

Bindschadler, Michael; Modgil, Dimple; Branch, Kelley R.; La Riviere, Patrick J.; Alessio, Adam M.

2014-03-01

394

Steam Generator Group Project: Task 9 final report, Nondestructive evaluation round robin: Volume 2, Raw inspection data  

Microsoft Academic Search

The Steam Generator Group Project (SGGP) is using the retired-from service Surry 2A pressurized water reactor steam generator as a test bed to investigate the reliability and effectiveness of inservice nondestructive eddy current inspection equipment and procedures. The information developed will provide the technical basis for updating the Regulatory Guides governing inservice inspection and tube plugging criteria of steam generators.

H. Harty; R. H. Ferris; A. S. Birks

1989-01-01

395

Steam Generator Group Project: Task 9 final report, Nondestructive evaluation round robin: Volume 1, Description and summary data  

Microsoft Academic Search

The Steam Generator Group Project (SGGP) is using the retired-from-service Surry 2A pressurized water reactor steam generator as a test bed to investigate the reliability and effectiveness of inservice nondestructive eddy current inspection equipment and procedures. The information developed will provide the technical basis for updating the Regulatory Guides governing inservice inspection and tube plugging criteria of steam generators. This

H. Harty; R. H. Ferris; A. S. Birks

1989-01-01

396

Evaluation of nondestructive evaluation techniques for determination of flawed conditions and the effects of flaws on the burst pressure in Kevlar-epoxy filament-wound spherical test specimens  

Microsoft Academic Search

A study of nondestructive evaluation techniques on spherical filament-wound Kevlar-epoxy test specimens has been performed, and the results are presented. The objectives of the study were (1) to determine the sensitivity of several NDE techniques for the detection of a series of flaw conditions in an enclosed geometry and (2) to determine which flaw conditions affected the mechanical strength of

W. D. Brosey; M. T. Calfee; J. W. Whittaker; D. A. Waldrop; E. G. Henneke; D. Post; K. L. Reifsnider; R. A. Blake

1989-01-01

397

A Computational Framework for Quantitative Evaluation of Movement during Rehabilitation  

NASA Astrophysics Data System (ADS)

This paper presents a novel generalized computational framework for quantitative kinematic evaluation of movement in a rehabilitation clinic setting. The framework integrates clinical knowledge and computational data-driven analysis together in a systematic manner. The framework provides three key benefits to rehabilitation: (a) the resulting continuous normalized measure allows the clinician to monitor movement quality on a fine scale and easily compare impairments across participants, (b) the framework reveals the effect of individual movement components on the composite movement performance helping the clinician decide the training foci, and (c) the evaluation runs in real-time, which allows the clinician to constantly track a patient's progress and make appropriate adaptations to the therapy protocol. The creation of such an evaluation is difficult because of the sparse amount of recorded clinical observations, the high dimensionality of movement and high variations in subject's performance. We address these issues by modeling the evaluation function as linear combination of multiple normalized kinematic attributes y = ?wiJi(xi) and estimating the attribute normalization function Ji(.) by integrating distributions of idealized movement and deviated movement. The weights wi are derived from a therapist's pair-wise comparison using a modified RankSVM algorithm. We have applied this framework to evaluate upper limb movement for stroke survivors with excellent results--the evaluation results are highly correlated to the therapist's observations.

Chen, Yinpeng; Duff, Margaret; Lehrer, Nicole; Sundaram, Hari; He, Jiping; Wolf, Steven L.; Rikakis, Thanassis

2011-06-01

398

Structural Anomalies Detected in Ceramic Matrix Composites Using Combined Nondestructive Evaluation and Finite Element Analysis (NDE and FEA)  

NASA Technical Reports Server (NTRS)

Most reverse engineering approaches involve imaging or digitizing an object and then creating a computerized reconstruction that can be integrated, in three dimensions, into a particular design environment. The rapid prototyping technique builds high-quality physical prototypes directly from computer-aided design files. This fundamental technique for interpreting and interacting with large data sets is being used here via Velocity2 (an integrated image-processing software, ref. 1) using computed tomography (CT) data to produce a prototype three-dimensional test specimen model for analyses. A study at the NASA Glenn Research Center proposes to use these capabilities to conduct a combined nondestructive evaluation (NDE) and finite element analysis (FEA) to screen pretest and posttest structural anomalies in structural components. A tensile specimen made of silicon nitrite (Si3N4) ceramic matrix composite was considered to evaluate structural durability and deformity. Ceramic matrix composites are being sought as candidate materials to replace nickel-base superalloys for turbine engine applications. They have the unique characteristics of being able to withstand higher operating temperatures and harsh combustion environments. In addition, their low densities relative to metals help reduce component mass (ref. 2). Detailed three-dimensional volume rendering of the tensile test specimen was successfully carried out with Velocity2 (ref. 1) using two-dimensional images that were generated via computed tomography. Subsequent, three-dimensional finite element analyses were performed, and the results obtained were compared with those predicted by NDE-based calculations and experimental tests. It was shown that Velocity2 software can be used to render a three-dimensional object from a series of CT scan images with a minimum level of complexity. The analytical results (ref. 3) show that the high-stress regions correlated well with the damage sites identified by the CT scans and the experimental data. Furthermore, modeling of the voids collected via NDE offered an analytical advantage that resulted in more accurate assessments of the material s structural strength. The top figure shows a CT scan image of the specimen test section illustrating various hidden structural entities in the material and an optical image of the test specimen considered in this study. The bottom figure represents the stress response predicted from the finite element analyses (ref .3 ) for a selected CT slice where it clearly illustrates the correspondence of the high stress risers due to voids in the material with those predicted by the NDE. This study is continuing, and efforts are concentrated on improving the modeling capabilities to imitate the structural anomalies as detected.

Abdul-Aziz, Ali; Baaklini, George Y.; Bhatt, Ramakrishna T.

2003-01-01

399

Nondestructive quantitative analysis of a heavy element in solution or suspension by single-shot computed tomography with a polychromatic X-ray source.  

PubMed

X-ray computed tomography (CT) images obtained with a polychromatic X-ray source were simulated by computer for homogeneous solutions and suspensions containing a heavy element. When the K-edge of the element was near the peak energy of the polychromatic X-ray spectrum, the degree of beam hardening in the simulated CT image strongly depended on the atomic number and molar concentration of the heavy element. We analyzed the beam hardening of a single measured CT image of a CeCl(3) aqueous solution sample, and successfully estimated the atomic number and the molar concentration of Ce simultaneously within a certain error. This single-shot, or single-energy (as opposed to dual-energy), CT method permits quick, nondestructive screening of a hazardous heavy element in a solution or suspension confined in a container. PMID:23232231

Nakashima, Yoshito; Nakano, Tsukasa

2012-01-01

400

Multiscale monitoring of interface failure of brittle coating/ductile substrate systems: A non-destructive evaluation method combined digital image correlation with acoustic emission  

NASA Astrophysics Data System (ADS)

In this paper, we proposed a non-destructive evaluation method combined digital image correlation with acoustic emission techniques. The method was used to in situ monitor interface failure and internal damage of brittle coating/ductile substrate systems with different size scales. The results show that there is a good relationship between digital image correlation and acoustic emission signals, which can be applied to judge cracking formation and coating delamination and to determine fracture toughness of a thermal barrier coating system subjected to bending.

Mao, W. G.; Wu, D. J.; Yao, W. B.; Zhou, M.; Lu, C.

2011-10-01

401

Quantitative evaluation of sparfloxacin binding to urological catheter surfaces.  

PubMed

Our aim was to apply high-performance liquid chromatography method for quantitative evaluation of the total amount of sparfloxacin (SPA) immobilized on the surface of the antimicrobial urological catheters. The amounts of SPA bound to catheter were determined indirectly on the basis of the differences in SPA concentrations before and after the immobilization process (they have been shown to vary from 0.11 to 5.66 mg/g of catheter). We estimated the immobilization yield, which altered from 14% to 70% depending on the SPA concentration used. As in vitro release studies show, the antibiotic binds to the catheter matrix in two modes: relatively stable covalent bond and weak non-covalent bond. Antibacterial activity of the modified catheter samples with SPA was controlledby using the zone of inhibition test against gram positive and gram negative bacteria. PMID:22393826

Kowalczuk, D; Gowin, E; Miazga-Karska, M

2012-01-01

402

Nuclear medicine and imaging research (instrumentation and quantitative methods of evaluation)  

SciTech Connect

This document is the annual progress report for project entitled 'Instrumentation and Quantitative Methods of Evaluation.' Progress is reported in separate sections individually abstracted and indexed for the database. Subject areas reported include theoretical studies of imaging systems and methods, hardware developments, quantitative methods of evaluation, and knowledge transfer: education in quantitative nuclear medicine imaging.

Beck, R.N.; Cooper, M.; Chen, C.T.

1992-07-01

403

NON-DESTRUCTIVE TECHNIQUES FOR THE EVALUATION OF OVERLAY AND THERMAL BARRIER COATINGS ON GAS TURBINE COMPONENTS  

SciTech Connect

There is currently no satisfactory method for the non-destructive examination (NDE) of coatings on gas turbine parts and determination of coating thickness, for example, has to be carried out by sectioning of the component and subsequent metallographic analysis. This method, which is both time-consuming and expensive, has nevertheless been used extensively for aero-engine parts to monitor coating quality and to gather statistical information for process control. For large components from utility size gas turbines costs are high and compared with aero-engines, only a limited number of parts can be examined so that the destructive method becomes less attractive both as an inspection technique and for obtaining process control data to measure part to part variations in coating thickness, for example. During engine service protective coatings slowly degrade and this degradation process effectively controls the life of the part, particularly in situations where a thermal barrier coating (TBC) is used to protect against excessive metal temperatures. In this case growth of the oxide at the interface between the bond coat and the TBC leads to a build-up of stress in the TBC which can be relieved by a spalling of the ceramic layer and loss of the protection from the thermal barrier. In situations where the integrity of the TBC system is critical to the survival of the part, some non-destructive method of determining the degradation condition of the bond coat would clearly be advantageous. In this report the results are described of recent progress in a program to develop non-destructive methods to measure coating quality and to monitor the condition of coatings in service. The work which has formed part of the Advanced Turbine Systems (ATS) Project funded by DOE, has involved the use of eddy-current (ET) and ultrasonic (US) methods developed by SouthWest Research Institute (SwRI) who have been responsible for development of the technique.

Michael Cybulsky

1998-03-10

404

Current and future developments in civil aircraft non-destructive evaluation from an operator's point of view  

NASA Technical Reports Server (NTRS)

In June, 1988, the first International Conference on aging aircraft was held to address nondestructive tests (NDT) of aging aircraft and other issues. From this meeting, a research program was initiated and funded by the FAA. As a result of this program, a lot of work has been done to study current NDT practices in the aviation industry and secondly, to research and develop new NDT methods to improve the reliability and efficiency of in-service inspection of aircraft structures and powerplants. The following is an overview of the current and future developments in civil aircraft NDT, as viewed by an air carrier and the concerns for NDT in the future.

Register, Jeff

1992-01-01

405

Evaluation of quantitative debriefing after pediatric cardiac arrest?  

PubMed Central

Aim Our primary objective was to describe and determine the feasibility of implementing a care environment targeted pediatric post-cardiac arrest debriefing program. A secondary objective was to evaluate the usefulness of debriefing content items. We hypothesized that a care environment targeted post-cardiac arrest debriefing program would be feasible, well-received, and result in improved self-reported knowledge, confidence and performance of pediatric providers. Methods Physician-led multidisciplinary pediatric post-cardiac arrest debriefings were conducted using data from CPR recording defibrillators/central monitors followed by a semi-quantitative survey. Eight debriefing content elements divided, a priori, into physical skill (PS) related and cognitive skill (CS) related categories were evaluated on a 5-point Likert scale to determine those most useful (5-point Likert scale: 1 = very useful/5 = not useful). Summary scores evaluated the impact on providers’ knowledge, confidence, and performance. Results Between June 2010 and May 2011, 6 debriefings were completed. Thirty-four of 50 (68%) front line care providers attended the debriefings and completed surveys. All eight content elements were rated between useful to very useful (Median 1; IQR 1–2). PS items scored higher than CS items to improve knowledge (Median: 2 (IQR 1–3) vs. 1 (IQR 0–2); p < 0.02) and performance (Median: 2 (IQR 1–3) vs. 1 (IQR 0–1); p < 0.01). Conclusions A novel care environment targeted pediatric post-cardiac arrest pediatric debriefing program is feasible and useful for providers regardless of their participation in the resuscitation. Physical skill related elements were rated more useful than cognitive skill related elements for knowledge and performance.

Zebuhr, C.; Sutton, R.M.; Morrison, W.; Niles, D.; Boyle, L.; Nishisaki, A.; Meaney, P.; Leffelman, J.; Berg, R.A.; Nadkarni, V.M.

2012-01-01

406

Quantitative metrics to evaluate image quality for computed radiographic images  

NASA Astrophysics Data System (ADS)

Traditional methods of evaluating a computed radiography (CR) imaging system's performance (e.g. the noise power spectrum (NPS), the modulation transfer function (MTF), the detective quantum efficiency (DQE) and contrast-detail analysis) were adapted in order to evaluate the feasibility of identifying a quantitative metric to evaluate image quality for digital radiographic images. The addition of simulated patient scattering media when acquiring the images to calculate these parameters altered their fundamental meaning. To avoid confusion with other research they were renamed the clinical noise power spectrum (NPSC), the clinical modulation transfer function (MTFC), the clinical detective quantum efficiency (DQEC) and the clinical contrast detail score (CDSC). These metrics were then compared to the subjective evaluation of radiographic images of an anthropomorphic phantom representing a one-year old pediatric patient. Computer algorithms were developed to implement the traditional mathematical procedures for calculating the system performance parameters. In order to easily compare these three metrics, the integral up to the system Nyquist frequency was used as the final image quality metric. These metrics are identified as the INPSC, the IMTFC and the IDQEC respectively. A computer algorithm was also developed, based on the results of the observer study, to determine the threshold contrast to noise ratio (CNRT) for objects of different sizes. This algorithm was then used to determine the CDSC by scoring images without the use of observers. The four image quality metrics identified in this study were evaluated to determine if they could distinguish between small changes in image acquisition parameters e.g., current-time product and peak-tube potential. All of the metrics were able to distinguish these small changes in at least one of the image acquisition parameters, but the ability to digitally manipulate the raw image data made the identification of a broad indicator of image quality not possible. The contrast-detail observer study revealed important information about how the noise content in an image affects the low-contrast detectability of different sized objects. Since the CNRT for each object size in the contrast-detail phantoms was almost independent of the exposure level, the minimum CNRT that would be necessary for an object of that size to be 'visible' in a clinical image was identified. Finally, in order to determine more refined CNRT values (due to possible observer biases from the physical construction of the contrast-detail phantoms available for this study) the design of new contrast detail phantoms is proposed.

Pitcher, Christopher D.

407

Quantitative evaluation of phase processing approaches in susceptibility weighted imaging  

NASA Astrophysics Data System (ADS)

Susceptibility weighted imaging (SWI) takes advantage of the local variation in susceptibility between different tissues to enable highly detailed visualization of the cerebral venous system and sensitive detection of intracranial hemorrhages. Thus, it has been increasingly used in magnetic resonance imaging studies of traumatic brain injury as well as other intracranial pathologies. In SWI, magnitude information is combined with phase information to enhance the susceptibility induced image contrast. Because of global susceptibility variations across the image, the rate of phase accumulation varies widely across the image resulting in phase wrapping artifacts that interfere with the local assessment of phase variation. Homodyne filtering is a common approach to eliminate this global phase variation. However, filter size requires careful selection in order to preserve image contrast and avoid errors resulting from residual phase wraps. An alternative approach is to apply phase unwrapping prior to high pass filtering. A suitable phase unwrapping algorithm guarantees no residual phase wraps but additional computational steps are required. In this work, we quantitatively evaluate these two phase processing approaches on both simulated and real data using different filters and cutoff frequencies. Our analysis leads to an improved understanding of the relationship between phase wraps, susceptibility effects, and acquisition parameters. Although homodyne filtering approaches are faster and more straightforward, phase unwrapping approaches perform more accurately in a wider variety of acquisition scenarios.

Li, Ningzhi; Wang, Wen-Tung; Sati, Pascal; Pham, Dzung L.; Butman, John A.

2012-02-01

408

Quantitative evaluation of intracellular sense: antisense RNA hybrid duplexes.  

PubMed Central

Previous studies have demonstrated that for an antisense RNA to be effective in attenuating gene expression, a large but indeterminate excess of antisense RNA is required. To quantitatively evaluate RNA hybrid duplex formation, expression vectors containing antisense dihydrofolate reductase (DHFR) cDNAs were transfected into KB and KB-1BT (a DHFR overexpressing variant) cells and transfectants expressing antisense transcripts of exon 1 through intron I (ex1-I) or exons 1 through 4 (ex1-4) were analyzed for hybrid duplex formation. Stable duplexes were detectable in KB-1BT but not in KB cells. Approximately 5-9% of antisense ex1-I RNA and 20-37% of antisense ex1-4 RNA were found in duplexes. The amount of each hybrid duplex RNA was found to be a linear function of intracellular single-stranded antisense RNA levels and a hybrid index, Hs:as, was devised to describe this relationship. Based upon the value of Hs:as for each antisense RNA:mRNA duplex, it is calculated that an approximate 2,800- and 600-fold excess of ex1-I and ex1-4 antisense RNA are respectively required for 50% of DHFR mRNA to be present in duplexes. Results support the hypothesis that intracellular sense:antisense RNA hybrid duplex formation is inefficient and dependent upon the levels, lengths and possibly the structures of the RNAs involved. Images

Wang, S; Dolnick, B J

1993-01-01

409

Quantitative evaluation of photoplethysmographic artifact reduction for pulse oximetry  

NASA Astrophysics Data System (ADS)

Motion artefact corruption of pulse oximeter output, causing both measurement inaccuracies and false alarm conditions, is a primary restriction in the current clinical practice and future applications of this useful technique. Artefact reduction in photoplethysmography (PPG), and therefore by application in pulse oximetry, is demonstrated using a novel non-linear methodology recently proposed by the authors. The significance of these processed PPG signals for pulse oximetry measurement is discussed, with particular attention to the normalization inherent in the artefact reduction process. Quantitative experimental investigation of the performance of PPG artefact reduction is then utilized to evaluate this technology for application to pulse oximetry. While the successfully demonstrated reduction of severe artefacts may widen the applicability of all PPG technologies and decrease the occurrence of pulse oximeter false alarms, the observed reduction of slight artefacts suggests that many such effects may go unnoticed in clinical practice. The signal processing and output averaging used in most commercial oximeters can incorporate these artefact errors into the output, while masking the true PPG signal corruption. It is therefore suggested that PPG artefact reduction should be incorporated into conventional pulse oximetry measurement, even in the absence of end-user artefact problems.

Hayes, Matthew J.; Smith, Peter R.

1999-01-01

410

Nonlethal and Nondestructive Combat in Cities Overseas.  

National Technical Information Service (NTIS)

The report examines nonlethal and nondestructive weapons--both present and potential--for their applicability to military operations in cities overseas. Classes of criteria for evaluation are suggested, and the suitability of various weapons concepts for ...

J. F. Coates

1970-01-01

411

A new apparatus for non-destructive evaluation of green-state powder metal compacts using the electrical-resistivity method  

NASA Astrophysics Data System (ADS)

This paper presents a new apparatus developed for non-destructive evaluation (NDE) of green-state powder metal compacts. A green-state compact is an intermediate step in the powder metallurgy (PM) manufacturing process, which is produced when a metal powder-lubricant mixture is compacted in a press. This compact is subsequently sintered in a furnace to produce the finished product. Non-destructive material testing is most cost effective in the green state because early flaw detection permits early intervention in the manufacturing cycle and thus avoids scrapping large numbers of parts. Unfortunately, traditional NDE methods have largely been unsuccessful when applied to green-state PM compacts. A new instrumentation approach has been developed, whereby direct currents are injected into the green-state compact and an array of spring-loaded needle contacts records the voltage distributions on the surface. The voltage distribution is processed to identify potentially dangerous surface and sub-surface flaws. This paper presents the custom-designed hardware and software developed for current injection, voltage acquisition, pre-amplification and flaw detection. In addition, the testing algorithm and measurement results are discussed. The success of flaw detection using the apparatus is established by using controlled samples, which are PM compacts with dielectric inclusions inserted.

Bogdanov, Gene; Ludwig, Reinhold; Michalson, William R.

2000-02-01

412

Development of the Non-Destructive Evaluation System Using an Eddy Current Probe for Detection of Fatigue Damage in a Stainless Steel  

NASA Astrophysics Data System (ADS)

The non-destructive evaluation system which is developed using an eddy current probe to evaluate fatigue damage in an austenitic stainless steel is reported in this paper. This probe is composed of the ferrite core and two pick-up coils connected differentially. The eddy current induced by the excitation coil is disarranged by nonuniform distribution of electromagnetic characteristics due to fatigue damage. The structural function of the eddy current probe proposed, enable to detect the eddy current disarrangement by fatigue damage. This probe detects the change of electromagnetic characteristics in the direction of X. In this paper, SUS304, a austenitic stainless steel was used as the sample. The experimental results show that the output voltage of the probe clearly depends on the number of stress cycles.

Oka, M.; Yakushiji, T.; Tsuchida, Y.; Enokizono, M.

2006-03-01

413

Cost-risk optimization of nondestructive inspection level. Technical report  

Microsoft Academic Search

This paper develops a quantitative methodology for determining the nondestructive inspection (NDI) level that will result in a minimum cost product considering both type one inspection errors, acceptance of defective material units, and type two inspection errors, rejection of sound material units. This methodology represents an advance over fracture mechanics - nondestructive inspection (FM-NDI) design systems that do not consider

Johnson

1975-01-01

414

Physical interpretation and development of ultrasonic nondestructive evaluation techniques applied to the quantitative characterization of textile composite materials  

NASA Technical Reports Server (NTRS)

The further development and application of linear array imaging technology to inspect and characterize a series of complex structures is described. Images of three types of adhesively-bonded aluminum plate specimens, each with a specific type of intentionally disbonded region, obtained with an unmodified medical ultrasonic imaging system are presented. Linear array imaging is applied to the inspection of a woven composite plate specimen that was machined to include intentional flaws. This allows us to assess the feasibility of applying linear array imaging technology to the inspection and characterization of complex textile composite materials. We describe the adhesively-bonded aluminum plate specimens and the woven composite plate specimen interrogated. The linear-array imaging methods section briefly reviews how the images were obtained. Results of linear array imaging are primarily presented on an accompanying videotape. Descriptive text as well as still-frame images are provided to aid in the linear array image interpretation.

Miller, James G.

1994-01-01

415

Quantitative non-destructive evaluation of high-temperature superconducting materials. Technical progress report, September 1, 1989--August 30, 1990.  

National Technical Information Service (NTIS)

Even though the currently intensive research efforts on high-temperature superconducting materials have not yet converged on a well specified material, the strong indications are that such a material will be brittle, anisotropic, and may contain many flaw...

J. D. Achenbach

1990-01-01

416

Quantitative non-destructive evaluation of high-temperature superconducting materials. Progress report, September 1, 1990--August 31, 1991.  

National Technical Information Service (NTIS)

Even though the currently intensive research efforts on high- temperature superconducting materials have not yet converged on a well specified practical material, the indications are that such a material may be quite brittle, anisotropic, and may contain ...

J. D. Achenbach

1991-01-01

417

Nuclear medicine and quantitative imaging research (instrumentation and quantitative methods of evaluation). Progress report, January 15-September 1, 1990.  

National Technical Information Service (NTIS)

This report summarizes goals and accomplishments of the research program supported under DOE Grant No. FG02-86ER60418 entitled Instrumentation and Quantitative Methods of Evaluation, with R. Beck, P. I. and M. Cooper, Co-P.I. during the period January 15,...

R. N. Beck M. D. Cooper

1990-01-01

418

Quantitative comparison between crowd models for evacuation planning and evaluation  

NASA Astrophysics Data System (ADS)

Crowd simulation is rapidly becoming a standard tool for evacuation planning and evaluation. However, the many crowd models in the literature are structurally different, and few have been rigorously calibrated against real-world egress data, especially in emergency situations. In this paper we describe a procedure to quantitatively compare different crowd models or between models and real-world data. We simulated three models: (1) the lattice gas model, (2) the social force model, and (3) the RVO2 model, and obtained the distributions of six observables: (1) evacuation time, (2) zoned evacuation time, (3) passage density, (4) total distance traveled, (5) inconvenience, and (6) flow rate. We then used the DISTATIS procedure to compute the compromise matrix of statistical distances between the three models. Projecting the three models onto the first two principal components of the compromise matrix, we find the lattice gas and RVO2 models are similar in terms of the evacuation time, passage density, and flow rates, whereas the social force and RVO2 models are similar in terms of the total distance traveled. Most importantly, we find that the zoned evacuation times of the three models to be very different from each other. Thus we propose to use this variable, if it can be measured, as the key test between different models, and also between models and the real world. Finally, we compared the model flow rates against the flow rate of an emergency evacuation during the May 2008 Sichuan earthquake, and found the social force model agrees best with this real data.

Viswanathan, Vaisagh; Lee, Chong Eu; Lees, Michael Harold; Cheong, Siew Ann; Sloot, Peter M. A.

2014-02-01

419

Nondestructive evaluation and material properties of advanced materials; Proceedings of the Symposium, TMS Annual Meeting, New Orleans, LA, Feb. 17-21, 1991  

SciTech Connect

Papers presented in these proceedings include those on the high-frequency ultrasonic inspection of green and hipped silicon nitride cylindrical samples, an NDE characterization of the microstructure and mechanical properties of Al-Li alloys, modeling the interaction of ultrasound with pores, and elastic properties of uniaxial-fiber reinforced composites. Attention is also given to anisotropic elastic properties of SiC particulate reinforced aluminum composites, a nondestructive evaluation technology for metal matrix composite billets, ultrasonic techniques for monitoring texture, and the overload effects on fatigue crack growth characteristics of 2014-Al 20 percent SiC composite. Other papers are on dynamic fracture properties of Inco 625 braze joint, laser speckle correlation studies of compression-compression fatigue damage in thick composites, acoustic emission-fracture strength relations for Al/Gr composites, and computed tomography of advanced materials and processes.

Liaw, P.K.; Buck, O.; Wolf, S.M.

1991-01-01

420

Nondestructive evaluation and material properties of advanced materials; Proceedings of the Symposium, TMS Annual Meeting, New Orleans, LA, Feb. 17-21, 1991  

NASA Astrophysics Data System (ADS)

Papers presented in these proceedings include those on the high-frequency ultrasonic inspection of green and hipped silicon nitride cylindrical samples, an NDE characterization of the microstructure and mechanical properties of Al-Li alloys, modeling the interaction of ultrasound with pores, and elastic properties of uniaxial-fiber reinforced composites. Attention is also given to anisotropic elastic properties of SiC particulate reinforced aluminum composites, a nondestructive evaluation technology for metal matrix composite billets, ultrasonic techniques for monitoring texture, and the overload effects on fatigue crack growth characteristics of 2014-Al 20 percent SiC composite. Other papers are on dynamic fracture properties of Inco 625 braze joint, laser speckle correlation studies of compression-compression fatigue damage in thick composites, acoustic emission-fracture strength relations for Al/Gr composites, and computed tomography of advanced materials and processes.

Liaw, P. K.; Buck, O.; Wolf, S. M.

1991-07-01

421

Progress in evaluation and improvement in nondestructive examination reliability for inservice inspection of Light Water Reactors (LWRs) and characterize fabrication flaws in reactor pressure vessels  

SciTech Connect

This paper is a review of the work conducted under two programs. One (NDE Reliability Program) is a multi-year program addressing the reliability of nondestructive evaluation (NDE) for the inservice inspection (ISI) of light water reactor components. This program examines the reliability of current NDE, the effectiveness of evolving technologies, and provides assessments and recommendations to ensure that the NDE is applied at the right time, in the right place with sufficient effectiveness that defects of importance to structural integrity will be reliably detected and accurately characterized. The second program (Characterizing Fabrication Flaws in Reactor Pressure Vessels) is assembling a data base to quantify the distribution of fabrication flaws that exist in US nuclear reactor pressure vessels with respect to density, size, type, and location. These programs will be discussed as two separate sections in this report. 4 refs., 7 figs.

Doctor, S.R.; Bowey, R.E.; Good, M.S.; Friley, J.R.; Kurtz, R.J.; Simonen, F.A.; Taylor, T.T.; Heasler, P.G.; Andersen, E.S.; Diaz, A.A.; Greenwood, M.S.; Hockey, R.L.; Schuster, G.J.; Spanner, J.C.; Vo, T.V.

1991-10-01

422

A Quantitative Evaluation of Video-based 3D Person Tracking  

Microsoft Academic Search

The Bayesian estimation of 3D human motion from video sequences is quantitatively evaluated using synchronized, multi-camera, calibrated video and 3D ground truth poses acquired with a commercial motion capture system. While many methods for human pose estimation and tracking have been proposed, to date there has been no quantitative comparison. Our goal is to evaluate how different design choices influence

A. O. Balan; Leonid Sigal; Michael J. Black

2005-01-01

423

Evaluation of limb compartments with increased interstitial pressure. An improved noninvasive method for determining quantitative hardness  

Microsoft Academic Search

The purpose of this project was to study a noninvasive method of evaluating limbs at risk of compartment syndrome. Untreated limb compartment syndrome may lead to irreversible dysfunction, chronic pain and contracture. An improved means of obtaining quantitative hardness measurements is reported. The handheld noninvasive compartment syndrome evaluator (NCSE) device formulates a quantitative hardness curve of force verse depth of

Bruce D. Steinberg

2005-01-01

424

Non-destructive evaluation of chlorophyll content in quinoa and amaranth leaves by simple and multiple regression analysis of RGB image components.  

PubMed

Leaf chlorophyll content provides valuable information about physiological status of plants; it is directly linked to photosynthetic potential and primary production. In vitro assessment by wet chemical extraction is the standard method for leaf chlorophyll determination. This measurement is expensive, laborious, and time consuming. Over the years alternative methods, rapid and non-destructive, have been explored. The aim of this work was to evaluate the applicability of a fast and non-invasive field method for estimation of chlorophyll content in quinoa and amaranth leaves based on RGB components analysis of digital images acquired with a standard SLR camera. Digital images of leaves from different genotypes of quinoa and amaranth were acquired directly in the field. Mean values of each RGB component were evaluated via image analysis software and correlated to leaf chlorophyll provided by standard laboratory procedure. Single and multiple regression models using RGB color components as independent variables have been tested and validated. The performance of the proposed method was compared to that of the widely used non-destructive SPAD method. Sensitivity of the best regression models for different genotypes of quinoa and amaranth was also checked. Color data acquisition of the leaves in the field with a digital camera was quick, more effective, and lower cost than SPAD. The proposed RGB models provided better correlation (highest R (2)) and prediction (lowest RMSEP) of the true value of foliar chlorophyll content and had a lower amount of noise in the whole range of chlorophyll studied compared with SPAD and other leaf image processing based models when applied to quinoa and amaranth. PMID:24442792

Riccardi, M; Mele, G; Pulvento, C; Lavini, A; d'Andria, R; Jacobsen, S-E

2014-06-01

425

Quantitative evaluation of stiffness of commercial suture materials.  

PubMed

The bending stiffness of 22 commercial suture materials of varying size, chemical structure and physical form was quantitatively evaluated using a stiffness tester (Taber V-5, model 150B, Teledyne). The commercial sutures were Chromic catgut; Dexon (polyglycolic acid); Vicryl (polyglactin 910); PDS (polydioxanone); Maxon (polyglycolide-trimethylene carbonate); Silk (coated with silicone); Mersilene (polyester fiber); Tycron (polyester fiber); Ethibond (polyethylene terephthalate coated with polybutylene); Nurolon (nylon 66); Surgilon (nylon 66 coated with silicone); Ethilon (coated nylon 66), Prolene (polypropylene); Dermalene (polyethylene), and Gore-tex (polytetraflouroethylene). These are both natural and synthetic, absorbable and nonabsorbable and monofilament and multifilament sutures. All of these sutures were size 2-0, but Prolene sutures with sizes ranging from 1-0 to 9-0 were also tested to determine the effect of suture size on stiffness. The bending stiffness data obtained showed that a wide range of bending stiffness was observed among the 22 commercial sutures. The most flexible 2-0 suture was Gore-tex, followed by Dexon, Silk, Surgilon, Vicryl (uncoated), Tycron, Nurolon, Mersilene, Ethibond, Maxon, PDS, Ethilon, Prolene, Chromic catgut, coated Vicryl, and lastly, Dermalene. The large porous volume inherent in Gore-tex monofilament suture was the reason for its lowest flexural stiffness. Sutures with a braided structure were generally more flexible than those of a monofilament structure, irrespective of the chemical constituents. Coated sutures had significantly higher stiffness than the corresponding uncoated ones. This is particularly true when polymers rather than wax were used as the coating material. This increase in stiffness is attributable to the loss of mobility under bending force in the fibers and yarns that make up the sutures. An increase in the size of the suture significantly increased the stiffness, and the magnitude of increase depended on the chemical constituent of the suture. The flexural stiffness of sutures was also found to depend on the duration of bending in the test for stiffness. In general, monofilament sutures exhibited the largest time-dependent stiffness. This was most pronounced with the Gore-tex suture. Most braided sutures also showed less time-dependence in stiffness. Nylon sutures did not exhibit this time-dependent phenomenon regardless of physical form. PMID:2919353

Chu, C C; Kizil, Z

1989-03-01

426

Non-destructive testing  

Microsoft Academic Search

This text covers, the underlying principles and some major applications of non-destructive inspection methods. Complete chapters are devoted to each of the following: liquid penetration inspection, magnetic particle inspection, electrical testing, ultrasonic testing and radiography. The concluding chapter introduces the reader to some of the more recent developments in non-destructive inspection.

B. Hull; V. John

1988-01-01

427