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Sample records for nondestructive evaluation center

  1. Operation of the EPRI Nondestructive Evaluation Center

    SciTech Connect

    Stone, R.M.; Ammirato, F.V.; Becker, F.L.; Bremser, K.; Krzywosz, K.J.; MacDonald, D.E.; Nottingham, L.D.; Selby, G.P.; Shankar, R.; Stephens, H.M. Applied Research Co., Charlotte, NC )

    1989-11-01

    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 1988. 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, Coal Combustion, and Electrical Systems 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-ready 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. 56 refs., 48 figs., 13 tabs.

  2. Operation of the EPRI Nondestructive Evaluation Center

    SciTech Connect

    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. Applied Research Co., Charlotte, NC )

    1990-09-01

    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.

  3. Operation of the EPRI nondestructive evaluation center: 1985 annual report

    SciTech Connect

    Nemzek, T.A.; Stone, R.M.; Ammirato, F.V.; Becker, F.L.; Krzywosz, K.; Pherigo, G.L.; Wilson, G.H. III

    1986-08-01

    This report describes the Electric Power Research Institute (EPRI) Nuclear Division funded nondestructive evaluation (NDE) project activities carried out at the EPRI NDE Center in 1985. The continuing objective of the Center is transfer of research and development results funded by EPRI and other related projects to useful field application. This is being accomplished by qualification and refinement of equipment and techniques, training under realistic conditions, and encouragement of greater involvement of the academic community in NDE education. Significant assistance has been provided to the nuclear utility industry under this project in the form of improved, field-ready equipment and procedures; critically needed assessments of inspection method capability; demonstrations of effectiveness of examination methods; rapid response for critical, short-term problems; and training for specific utility industry needs. This effort has specifically addressed steam generator, piping, steam turbine, and heavy section inspection problems.

  4. Nondestructive evaluation

    SciTech Connect

    Martz, H.E.

    1997-02-01

    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.

  5. [Activities of Center for Nondestructive Evaluation, Iowa State University

    NASA Technical Reports Server (NTRS)

    Gray, Joe

    2002-01-01

    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.

  6. Nondestructive evaluation

    SciTech Connect

    Martz, H E

    1998-01-01

    The Nondestructive Evaluation (NDE) thrust area at Lawrence Livermore National Laboratory (LLNL) supports initiatives that advance inspection science and technology. The goal is to provide cutting-edge technologies, that show promise for quantitative inspection and characterization tools two to three years into the future. The NDE thrust area supports a multidisciplinary team, consisting of mechanical and electronics engineers, physicists, materials and computer scientists, chemists, technicians, and radiographers. These team members include personnel that cross departments within LLNL, and some are from academia and industry, within the US and abroad. This collaboration brings together the necessary and diver disciplines to provide the key scientific and technological advancements required to meet LLNL programmatic and industrial NDE challenges. The primary contributions of the NDE thrust area this year are described in these five reports: (1) Image Recovery Techniques for X-Ray Computed Tomography for Limited-Data Environments; (2) Techniques for Enhancing Laser Ultrasonic Nondestructive Evaluation; (3) Optical Inspection of Glass-Epoxy Bonds; (4) Miniature X-Ray Source Development; and (5) Improving Computed Tomography Design and Operation Using Simulation Tools.

  7. Nondestructive evaluations

    SciTech Connect

    Kulkarni, S.

    1993-03-01

    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.

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

    NASA Technical Reports Server (NTRS)

    Burns, Erin A.

    2004-01-01

    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

  9. [Nondestructive Evaluation (NDE) Capabilities

    NASA Technical Reports Server (NTRS)

    Born, Martin

    2010-01-01

    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)

  10. Nondestructive evaluation of advanced ceramics

    NASA Technical Reports Server (NTRS)

    Klima, Stanley J.; Kautz, Harold E.

    1988-01-01

    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.

  11. Nondestructive Evaluation for Aerospace Composites

    NASA Technical Reports Server (NTRS)

    Leckey, Cara; Cramer, Elliott; Perey, Daniel

    2015-01-01

    Nondestructive evaluation (NDE) techniques are important for enabling NASA's missions in space exploration and aeronautics. The expanded and continued use of composite materials for aerospace components and vehicles leads to a need for advanced NDE techniques capable of quantitatively characterizing damage in composites. Quantitative damage detection techniques help to ensure safety, reliability and durability of space and aeronautic vehicles. This presentation will give a broad outline of NASA's range of technical work and an overview of the NDE research performed in the Nondestructive Evaluation Sciences Branch at NASA Langley Research Center. The presentation will focus on ongoing research in the development of NDE techniques for composite materials and structures, including development of automated data processing tools to turn NDE data into quantitative location and sizing results. Composites focused NDE research in the areas of ultrasonics, thermography, X-ray computed tomography, and NDE modeling will be discussed.

  12. Nondestructive evaluation technique guide

    NASA Technical Reports Server (NTRS)

    Vary, A.

    1973-01-01

    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.

  13. Nondestructive evaluation of structural ceramics

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

    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.

  14. Overview of nondestructive evaluation technologies

    SciTech Connect

    Thomas, G.

    1995-04-01

    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.

  15. Development of instrumentation for magnetic nondestructive evaluation

    SciTech Connect

    Hariharan, S.

    1991-09-23

    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.

  16. Advances in nondestructive evaluation technology

    NASA Technical Reports Server (NTRS)

    Heyman, J. S.

    1982-01-01

    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.

  17. EPRI Nondestructive Evaluation Center: Assessment of the intergranular stress corrosion cracking training and qualification program: Interim report

    SciTech Connect

    Not Available

    1988-02-01

    Formal training programs for ultrasonic inspection of boiling water reactor (BWR) piping for intergranular stress-corrosion cracking (IGSCC) have been provided by the EPRI NDE Center since 1983. Separate courses are available for detection and sizing of IGSCC in unrepaired piping. A third course addresses inspection for IGSCC in piping which has been repaired by the weld overlay method. It is the policy of EPRI and EPRI NDE Center management to review these programs periodically, using both expertise internal to the NDE Center staff and from outside sources. This report provides the results of a review of the NDE Center IGSCC ultrasonic inspection training by a group of individuals who have no permanent relationshiip with the NDE Center, but who possess recognized expertise in the subject area.

  18. Non-destructive evaluation of composites

    NASA Technical Reports Server (NTRS)

    Chu, Tsuchin Philip

    1996-01-01

    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.

  19. Nondestructive Evaluation of Aircraft and Spacecraft Wiring

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

    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.

  20. Electromagnetic Imaging Methods for Nondestructive Evaluation Applications

    PubMed Central

    Deng, Yiming; Liu, Xin

    2011-01-01

    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. PMID:22247693

  1. Thermal Nondestructive Evaluation Report: Inspection of the Refurbished Manipulator Arm System in the Manipulator Development Facility at Johnson Space Center 10-12 January 2001

    NASA Technical Reports Server (NTRS)

    Cramer, K. Elliott

    2002-01-01

    On 4 December 2002, a failure of the Refurbished Manipulator Arm System (RMAS) occurred in the Manipulator Development Facility (MDF) at Johnson Space Center. When the Test Director commanded a should pitch maneuver to lift the arm from its payload bay pedestal, the yaw controls failed. This, coupled with a gravitational forces (due to the angle of the shoulder joint with respect to vertical), resulted in uncontrolled arm motion. The shoulder yaw joint moved approximately 20 degrees, causing the extended arm to strike and severely damage the port side MDF catwalk handrails. The arm motion stopped after impact with the handrails. On 10-12 January 2001, inspections were performed on the port face of the lower and upper arms of the RMAS using a infrared thermography developed at Langley Research Center. This paper presents the results of those nondestructive inspections and provides a complete description of the anomalies found and their locations.

  2. NONDESTRUCTIVE EVALUATION (NDE) OF DAMAGED STRUCTURAL CERAMICS

    SciTech Connect

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

    2009-03-03

    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.

  3. SQUIDs: microscopes and nondestructive evaluation

    NASA Astrophysics Data System (ADS)

    Mück, Michael

    2005-03-01

    SQUIDs (Superconducting Quantum Interference Devices) are magnetic field sensores with unsurpassed sensitivity. They are amazingly versatile, being able to measure all physical quantities which can be converted to magnetic flux. They are routinely fabricated in thin film technology from two classes of superconducting materials: high-temperature superconductors (HTS) which are usually cooled to 77 K, and low-temperature superconductors (LTS), which have to be cooled to 4.2 K. SQUIDs have many applications, two of which shall be discussed in this paper. In SQUID microscopy, a SQUID scans a sample, which preferrably is at room temperature, and measures the two-dimensional magnetic field distribution at the surface of the sample. In order to achieve a relatively high spatial resolution, the stand-off distance between the sample and the SQUID is made as small as possible. SQUIDs show also promising results in the field of nondestructive testing of various materials. For example, ferromagnetic impurities in stainless steel formed by aging processes in the material can be detected with high probability, and cracks in conducting materials, for example aircraft parts, can be located using eddy current methods. Especially for the case of thick, highly conductive, or ferromagnetic materials, as well as sintered materials, it can be shown that a SQUID-based NDE system exhibits a much higher sensitivity compared to conventional eddy current NDE and ultrasonic testing.

  4. Techniques for enhancing laser ultrasonic nondestructive evaluation

    SciTech Connect

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

    1999-02-16

    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.

  5. Nondestructive Evaluation Correlated with Finite Element Analysis

    NASA Technical Reports Server (NTRS)

    Abdul-Azid, Ali; Baaklini, George Y.

    1999-01-01

    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.

  6. Nondestructive Evaluation of Adhesively Bonded Joints

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

    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.

  7. Nondestructive evaluation of sintered ceramics

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

    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.

  8. Nondestructive evaluation by acousto-ultrasonics

    NASA Technical Reports Server (NTRS)

    Kautz, Harold E.

    1988-01-01

    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.

  9. Nondestructive evaluation of pyroshock propagation using hydrocodes

    NASA Astrophysics Data System (ADS)

    Lee, Juho; Hwang, Dae-Hyeon; Jang, Jae-Kyeong; Lee, Jung-Ryul; Han, Jae-Hung

    2016-04-01

    Pyroshock or pyrotechnic shock generated by explosive events of pyrotechnic devices can induce fatal failures in electronic payloads. Therefore, understanding and estimation of pyroshock propagation through complex structures are necessary. However, an experimental approach using real pyrotechnic devices is quite burdensome because pyrotechnic devices can damage test structures and newly manufactured test structures are necessary for each experiment. Besides, pyrotechnic experiments are quite expensive, time-consuming, and dangerous. Consequently, nondestructive evaluation (NDE) of pyroshock propagation without using real pyrotechnic devices is necessary. In this study, nondestructive evaluation technique for pyroshock propagation estimation using hydrocodes is proposed. First, pyroshock propagation is numerically analyzed using AUTODYN, a commercial hydrocodes. Hydrocodes can handle stress wave propagation including elastic, plastic, and shock wave in the time domain. Test structures are modeled and pyroshock time history is applied to where the pyroshock propagation originates. Numerical NDE results of pyroshock propagation on test structures are analyzed in terms of acceleration time histories and acceleration shock response spectra (SRS) results. To verify the proposed numerical methodology, impact tests using airsoft gun are performed. The numerical analysis results for the impact tests are compared with experimental results and they show good agreements. The proposed numerical techniques enable us to nondestructively characterize pyroshock propagation.

  10. Nondestructive evaluation techniques for enhanced bridge inspection

    SciTech Connect

    Thomas, G.; Benson, S.; Durbin, P.; Del Grande, N.; Haskins, J.; Brown, A.; Schneberk, D.

    1993-10-01

    Nondestructive evaluation of bridges is a critical aspect in the US aging infrastructure problem. For example in California there are 26,000 bridges, 3000 are made of steel, and of the steel bridges, 1000 are fracture critical. California Department of Transportation (Caltrans), Federal Highway Administration, and Lawrence Livermore National Laboratory (LLNL) are collaborating to develop and field NDE techniques to improve bridge inspections. We have demonstrated our NDE technologies on several bridge inspection applications. An early collaboration was to ultrasonically evaluate the steel pins in the E-9 pier on the San Francisco Bay Bridge. Following the Loma-Prieta earthquake in 1989 and the road way collapse at the E-9 pier, a complete nondestructive evaluation was conducted by Caltrans inspectors and several ultrasonic indications were noted. LLNL worked with Caltrans to help identify the source of these reflections. Another project was to digitally enhance high energy radiographs of bridge components such as cable end caps. We demonstrated our ability to improve the detection of corrosion and fiber breakage inside the end cap. An extension of this technology is limited view computer tomography (CT). We implemented our limited view CT software and produced cross-sectional views of bridge cables from digitized radiographic films. Most recently, we are developing dual band infrared imaging techniques to assess bridge decks for delaminations. We have demonstrated the potential of our NDE technology for enhancing the inspection of the country`s aging bridges.

  11. Nondestructive Evaluation of Nuclear-Grade Graphite

    SciTech Connect

    Dennis C. Kunerth; Timothy R. McJunkin

    2011-07-01

    Nondestructive Evaluation of Nuclear Grade Graphite Dennis C. Kunerth and Timothy R. McJunkin Idaho National Laboratory Idaho Falls, ID, 83415 This paper discusses the nondestructive evaluation of nuclear grade graphite performed at the Idaho National Laboratory. Graphite is a composite material highly dependent on the base material and manufacturing methods. As a result, material variations are expected within individual billets as well billet to billet and lot to lot. Several methods of evaluating the material have been explored. Particular technologies each provide a subset of information about the material. This paper focuses on techniques that are applicable to in-service inspection of nuclear energy plant components. Eddy current examination of the available surfaces provides information on potential near surface structural defects and although limited, ultrasonics can be utilized in conventional volumetric inspection. Material condition (e.g. micro-cracking and porosity induced by radiation and stress) can be derived from backscatter or acousto-ultrasound (AU) methods. Novel approaches utilizing phased array ultrasonics have been attempted to expand the abilities of AU techniques. By combining variable placement of apertures, angle and depth of focus, the techniques provide the potential to obtain parameters at various depths in the material. Initial results of the study and possible procedures for application of the techniques are discussed.

  12. Nondestructive evaluation of thick concrete structures

    NASA Astrophysics Data System (ADS)

    Clayton, Dwight A.

    2015-03-01

    Concrete has been used in the construction of nuclear power plants (NPPs) due to three primary properties: its low cost, structural strength, and ability to shield radiation. Examples of concrete structures important to the safety of Light Water Reactor (LWR) plants include the containment building, spent fuel pool, and cooling towers. Use in these structures has made concrete's long-term performance crucial for the safe operation of commercial NPPs. Extending LWR operating period to 60 years and beyond will likely increase susceptibility and severity of known forms of degradation. New mechanisms of materials degradation are also possible. This creates the need to be able to nondestructively evaluate the current subsurface concrete condition of aging concrete material in NPP structures. The size and complexity of NPP containment structures and heterogeneity of Portland cement concrete make characterization of the degradation extent a difficult task. Specially designed and fabricated test specimens can provide realistic flaws that are similar to actual flaws in terms of how they interact with a particular nondestructive evaluation (NDE) technique. Artificial test blocks allow the isolation of certain testing problems as well as the variation of certain parameters. Representative large heavily reinforced concrete specimens would allow for comparative testing to evaluate the state-of-the-art NDE in this area and to identify additional developments necessary to address the challenges potentially found in NPPs.

  13. Nondestructive Evaluation Program. Progress in 1985

    SciTech Connect

    Dau, G.J.; Behravesh, M.M.; Liu, S.N.; Oldberg, T.; Avioli, M.J. Jr.; Scheibel, J.R.; Sharma, D.; Norris, D.M.; Tagart, S.W. Jr.; Griesbach, T.J.

    1986-05-01

    The increasing cost of equipment for power generating plants and the potential increases in productivity and safety available through rapidly developing Nondestructive Evaluation (NDE) technology led EPRI to initiate a Nondestructive Evaluation Program in 1974. To date, the major focus has been on light water reactor inspection problems; however, increased application to other systems is now under way. This report presents a comprehensive review of the EPRI effort in the NDE area. Most of the report consists of contractor-supplied progress on each current project. An organizational plan of the program is presented in overview. In addition, organization from several viewpoint is presented, e.g., in-service inspection operators, R and D personnel, and utility representatives. As the seventh in a planned series of annual progress reports on EPRI-funded NDE activities, this report also serves as the proceedings of the EPRI Joint NDE/Structural Mechanics information meeting held in Palo Alto, California, on November 20-21, 1986. It summarizes progress made since the previous EPRI Special Report NP-3821-SR was issued in May 1985. Section 1 contains information about the program organization, and the sections that follow contains contractor-supplied progress reports of each current project. The progress reports are grouped by plant components - pipe, pressure vessel, steam generator and boiler tubes, and turbine. In addition, Part 6 is devoted to discussions of technology transfer.

  14. Complementary Electromagnetic Non-Destructive Evaluation

    NASA Astrophysics Data System (ADS)

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

    2011-06-01

    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.

  15. Nondestructive evaluation of nuclear-grade graphite

    SciTech Connect

    Kunerth, D. C.; McJunkin, T. R.

    2012-05-17

    The material of choice for the core of the high-temperature gas-cooled reactors being developed by the U.S. Department of Energy's Next Generation Nuclear Plant Program is graphite. Graphite is a composite material whose properties are highly dependent on the base material and manufacturing methods. In addition to the material variations intrinsic to the manufacturing process, graphite will also undergo changes in material properties resulting from radiation damage and possible oxidation within the reactor. Idaho National Laboratory is presently evaluating the viability of conventional nondestructive evaluation techniques to characterize the material variations inherent to manufacturing and in-service degradation. Approaches of interest include x-ray radiography, eddy currents, and ultrasonics.

  16. NONDESTRUCTIVE EVALUATION OF CERAMIC CANDLE FILTERS

    SciTech Connect

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

    1999-09-01

    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

  17. Quantitative nondestructive evaluation: Requirements for tomorrow's reliability

    NASA Technical Reports Server (NTRS)

    Heyman, Joseph S.

    1991-01-01

    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.

  18. Thermographic nondestructive evaluation: overview of recent progress

    NASA Astrophysics Data System (ADS)

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

    2003-04-01

    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.

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

    NASA Technical Reports Server (NTRS)

    Pless, W. M.

    1974-01-01

    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).

  20. Nondestructive Evaluation Program: Progress in 1987

    SciTech Connect

    Avioli, M.J. Jr.; Dau, G.J.; Edmonds, J.; Gehl, S.; Liu, S.N.; Stein, J.; Viswanathan, R.; Welty, C.S.

    1988-06-01

    The increasing cost of equipment for power generating plants and the potential increases in productivity and safety available through rapidly developing Nondestructive Evaluation (NDE) technology led EPRI to initiate a Nondsetructive Evaluation Program in 1974. To date, the major focus has been on light water reactor inspection problems; however, increased application to other systems is now under way. This report presents a comprehensive review of the EPRI effort in the NDE area. Most of the report consists of contractor-supplied progress reports on each current project. An organization from several viewpoints is presented, e.g., in-service inspection operators, RandD personnel, and utility representatives. As the ninth in a planned series of annual progress reports of EPRI-funded NDE activities, this report also serves as the proceedings of the Eighth Annual EPRI NDE Information Meeting held in Palo Alto, California, on November 17-18, 1987. It summarizes significant progress made since the previous EPRI Special Report NP-4902-SR was issued in July 1987. Section 1 contains information about the program organization, and the sections that follow contain contractor-supplied progress reports on each current project. The progress reports are grouped by plant components/emdash/pipe, pressure vessel, steam generator and boiler tubes, and turbine. In addition, Part 6 is devoted to discussions of technology transfer. The individual reports have been cataloged separately.

  1. Nondestructive evaluation development for process control

    SciTech Connect

    Ellingson, W.A.; Holloway, D.L.; Sivers, E.A. ); Ling, J. . Inst. for Ceramics); Pollinger, J.P.; Yeh, H.C. . Garrett Ceramic Components Div.)

    1991-01-01

    A joint project between Garrett Ceramic Components (GCC) of Allied Signal Aerospace Corporation and Argonne National Laboratory (ANL) is ongoing to evaluate nondestructive characterization (NDC) methods to detect and measure process-induced variations in ceramic materials. The process methods of current focus on slip-casting and injection molding and the NDC methods being evaluated are microfocus X-ray computed tomography (XCT) and nuclear magnetic resonance computed tomography (MRCT). As part of this work, SiC whisker reinforced Si{sub 3}N{sub 4} (GCC's GN-10 material) has been pressure slip-cast at two casting pressures, 15 and 40 psi; and at length/diameter ratios of 1.5, 2.5 and 3.0 with whisker contents of 20, 23, 27 and 30 wt %. Three-dimensional microfocus XCT has been used to study density variations in billets produced by different process conditions. Destructive measurement of density variation has been compared to the XCT measurements and correlations established. XCT has been shown to be able to detect <5% variations in as-cast density and these were destructively verified.

  2. Nondestructive evaluation development for process control

    SciTech Connect

    Ellingson, W.A.; Holloway, D.L.; Sivers, E.A.; Ling, J.; Pollinger, J.P.; Yeh, H.C.

    1991-12-31

    A joint project between Garrett Ceramic Components (GCC) of Allied Signal Aerospace Corporation and Argonne National Laboratory (ANL) is ongoing to evaluate nondestructive characterization (NDC) methods to detect and measure process-induced variations in ceramic materials. The process methods of current focus on slip-casting and injection molding and the NDC methods being evaluated are microfocus X-ray computed tomography (XCT) and nuclear magnetic resonance computed tomography (MRCT). As part of this work, SiC whisker reinforced Si{sub 3}N{sub 4} (GCC`s GN-10 material) has been pressure slip-cast at two casting pressures, 15 and 40 psi; and at length/diameter ratios of 1.5, 2.5 and 3.0 with whisker contents of 20, 23, 27 and 30 wt %. Three-dimensional microfocus XCT has been used to study density variations in billets produced by different process conditions. Destructive measurement of density variation has been compared to the XCT measurements and correlations established. XCT has been shown to be able to detect <5% variations in as-cast density and these were destructively verified.

  3. Nondestructive Evaluation of Reactive Powder Concrete

    NASA Astrophysics Data System (ADS)

    Washer, Glenn; Fuchs, Paul; Graybeal, Benjamin; Rezaizadeh, Ali

    2004-02-01

    Reactive powder concrete (RPC) has been introduced as a structural material for civil engineering applications. The material consists of a finely graded combination of cement, sand, ground quartz and silica fume which combined with water form a cement paste. Small steel fibers measuring approximately 0.2 mm in diameter and 12 mm in length are distributed throughout the cement matrix and the combined material has very high compressive strength and toughness. The material is proposed for use in the primary load bearing members in bridges, and as such nondestructive evaluation technologies are needed to evaluate material quality and monitor in-service condition. This paper reports on research to determine the effectiveness of ultrasonic testing for determining the elastic properties of RPC. Comparison between static modulus of elasticity and ultrasonic modulus measurements is presented. A system for determining elastic moduli as a quality control tool is discussed. The effect of curing conditions on ultrasonic velocities and resulting calculated moduli values is presented and compared with traditional measurement methods.

  4. Nondestructive tests of regenerative chambers. [evaluating nondestructive methods of determining metal bond integrity

    NASA Technical Reports Server (NTRS)

    Malone, G. A.; Vecchies, L.; Wood, R.

    1974-01-01

    The capabilities and limitations of nondestructive evaluation methods were studied to detect and locate bond deficiencies in regeneratively cooled thrust chambers for rocket engines. Flat test panels and a cylinder were produced to simulate regeneratively cooled thrust chamber walls. Planned defects with various bond integrities were produced in the panels to evaluate the sensitivity, accuracy, and limitations of nondestructive methods to define and locate bond anomalies. Holography, acoustic emission, and ultrasonic scan were found to yield sufficient data to discern bond quality when used in combination and in selected sequences. Bonding techniques included electroforming and brazing. Materials of construction included electroformed nickel bonded to Nickel 200 and OFHC copper, electroformed copper bonded to OFHC copper, and 300 series stainless steel brazed to OFHC copper. Variations in outer wall strength, wall thickness, and defect size were evaluated for nondestructive test response.

  5. Nondestructive evaluation of composite materials - A design philosophy

    NASA Technical Reports Server (NTRS)

    Duke, J. C., Jr.; Henneke, E. G., II; Stinchcomb, W. W.; Reifsnider, K. L.

    1984-01-01

    Efficient and reliable structural design utilizing fiber reinforced composite materials may only be accomplished if the materials used may be nondestructively evaluated. There are two major reasons for this requirement: (1) composite materials are formed at the time the structure is fabricated and (2) at practical strain levels damage, changes in the condition of the material, that influence the structure's mechanical performance is present. The fundamental basis of such a nondestructive evaluation capability is presented. A discussion of means of assessing nondestructively the material condition as well as a damage mechanics theory that interprets the material condition in terms of its influence on the mechanical response, stiffness, strength and life is provided.

  6. Guided wave nuances for ultrasonic nondestructive evaluation.

    PubMed

    Rose, J L

    2000-01-01

    Recent developments in guided wave generation, reception, and mode control show that increased penetration power and sensitivity are possible. A tone burst function generator and appropriate signal processing are generally used. Variable angle beam and comb-type transducers are the key to this effort. Problems in tubing, piping, hidden corrosion detection in aging aircraft, adhesive and diffusion bonding, and ice detection are discussed. Additionally, sample configurations, inspection objectives, and logic are being developed for such sample problems as defect detection and analysis in lap splice joints, tear straps, cracks in a second layer, hidden corrosion in multiple layers, cracks from rivet holes, transverse cracking in a beam, and cracks in landing gear assembly. Theoretical and experimental aspects of guided wave analysis include phase velocity, group velocity, and attenuation dispersion curves; boundary element model analysis for reflection and transmission factor analysis; use of wave structure for defect detection sensitivity; source influence on the phase velocity spectrum, and the use of angle beam and comb transducer technology. Probe design and modeling considerations are being explored. Utilization of in-plane and out-of-plane displacement patterns on the surface and longitudinal power distribution across the structural cross-section are considered for improved sensitivity, penetration power, and resolution in nondestructive evaluation. Methods of controlling the phase velocity spectrum for mode and frequency selection are available. Such features as group velocity change, mode cut-off measurements, mode conversion, amplitude ratios of transmission, and reflection factors of specific mode and frequency as input will be introduced for their ability to be used in flaw and material characterization analysis. PMID:18238584

  7. Cryogenic Storage Tank Non-Destructive Evaluation

    NASA Technical Reports Server (NTRS)

    Arens, Ellen

    2010-01-01

    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

  8. Nondestructive Evaluation Methodologies Developed for Certifying Composite Flywheels

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

    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.

  9. Quantitative nondestructive evaluation of materials and structures

    NASA Technical Reports Server (NTRS)

    Smith, Barry T.

    1991-01-01

    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.

  10. Proceedings: Eleventh annual EPRI nondestructive evaluation information meeting

    SciTech Connect

    Avioli, M.J. Jr.; Behravesh, M.M.; Gehl, S.M.; Lang, J.; McCloskey, T.; Stein, J.; Viswanathan, R.; Welty, C.S.

    1991-08-01

    In increasing cost of equipment for power generating plants and the potential increases in productivity and safety available through rapidly developing nondestructive evaluation (NDE) technology led EPRI to begin a Nondestructive Evaluation Program in 1974. The major focus has been on light water reactor (LWR) inspection problems; however, increased application to other systems is now under way. This report, NP7047-M, presents a summary of companion report NP7047- SD Nondestructive Evaluation Research Progress in 1990: Proceedings from the Eleventh Annual EPRI NDE Information Meeting.'' NP7047-SD presents EPRI's effort in the NDE area. Most of the report consists of contractor-supplied progress reports on current NDE projects. In addition, organization plans of the program are presented from different perspectives; in-service inspection vendor, R D engineer, and utility owner. 1 fig., 1 tab.

  11. In-process nondestructive evaluation of the pultrusion process

    NASA Astrophysics Data System (ADS)

    Fecko, David L.; Heider, Dirk; Gillespie, John W., Jr.; Steiner, Karl V.

    1995-07-01

    Substantial growth potential for composite materials exists in the private sector, where high volume, low cost production is required. Post processing inspection can represent a significant percentage of the cost of composite products. Alternate ways of assuring quality must be examined. In-process inspection can be easily adapted to continuous composite manufacturing techniques such as the pultrusion process, enabling 100% inspection. Recent research efforts at the Center for Composite Materials has focused on ways of evaluating pultruded composites on-line by using ultrasonic non-destructive evaluation (NDE) techniques. The most accurate method to date is based upon Lamb wave velocity measurements. This inspection technique uses two transducers positioned at normal incidence to the composite in a through-transmission mode to generate and receive ultrasonic waves which propagate through the sample. Careful processing of the waveform data reveals the degree of porosity in the composite samples. A series of tests were performed in-situ on an actual laboratory scale pultrusion process which accurately predicted the porosity in a 6.4 mm multiplied by 3.2 mm (0.25' multiplied by 0.125') cross-section pultruded rod over a range of 0.5% to 12% void volume fraction.

  12. Aging aircraft NDI Development and Demonstration Center (AANC): An overview. [nondestructive inspection

    NASA Technical Reports Server (NTRS)

    Walter, Patrick L.

    1992-01-01

    A major center with emphasis on validation of nondestructive inspection (NDI) techniques for aging aircraft, the Aging Aircraft NDI Development and Demonstration Center (AANC), has been funded by the FAA at Sandia National Laboratories. The Center has been assigned specific tasks in developing techniques for the nondestructive inspection of static engine parts, assessing inspection reliability (POD experiments), developing testbeds for NDI validation, maintaining a FAA library of characterized aircraft structural test specimens, and leasing a hangar to house a high flight cycle transport aircraft for use as a full scale test bed.

  13. Airborne Ultrasonics for Nondestructive Evaluation of Leather Quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our recent research has shown that besides Acoustic Emission (AE), Airborne Ultrasonics (AU) can also be applied for the nondestructive evaluation (NDE) of leather quality. Implementation of these methods in the manufacturing process could save a considerable amount of money, decrease the use of ch...

  14. Evaluation of methods for nondestructive testing of brazed joints

    NASA Technical Reports Server (NTRS)

    Kanno, A.

    1968-01-01

    Evaluation of nondestructive methods of testing brazed joints reveals that ultrasonic testing is effective in the detection of nonbonds in diffusion bonded samples. Radiography provides excellent resolutions of void or inclusion defects, and the neutron radiographic technique shows particular advantage for brazing materials containing cadmium.

  15. Automated Non-Destructive Testing Array Evaluation System

    SciTech Connect

    Wei, T; Zavaljevski, N; Bakhtiari, S; Miron, A; Kupperman, D

    2004-12-24

    Automated Non-Destructive Testing Array Evaluation System (ANTARES) sofeware alogrithms were developed for use on X-probe(tm) data. Data used for algorithm development and preliminary perfomance determination was obtained for USNRC mock-up at Argone and data from EPRI.

  16. Quantitative non-destructive evaluation of composite materials based on ultrasonic parameters

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1987-01-01

    Research into the nondestructive evaluation of advanced reinforced composite laminates is summarized. The applicability of the Framers-Kronig equations to the nondestructive evaluation of composite materials is described.

  17. Hyperspectral imaging for nondestructive evaluation of tomatoes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Machine vision methods for quality and defect evaluation of tomatoes have been studied for online sorting and robotic harvesting applications. We investigated the use of a hyperspectral imaging system for quality evaluation and defect detection for tomatoes. Hyperspectral reflectance images were a...

  18. Materials and Nondestructive Evaluation Laboratoriers: User Test Planning Guide

    NASA Technical Reports Server (NTRS)

    Schaschl, Leslie

    2011-01-01

    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.

  19. The use of infrared thermography for nondestructive evaluation of joints

    NASA Astrophysics Data System (ADS)

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

    2004-12-01

    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.

  20. Aging management of major LWR components with nondestructive evaluation

    SciTech Connect

    Shah, V.N.; MacDonald, P.E.; Akers, D.W.; Sellers, C.; Murty, K.L.; Miraglia, P.Q.; Mathew, M.D.; Haggag, F.M.

    1997-12-31

    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.

  1. Nondestructive evaluation of critical composite material structural elements

    NASA Astrophysics Data System (ADS)

    Duke, John C., Jr.; Lesko, John J.; Weyers, R.

    1996-11-01

    A small span bridge that has suffered corrosive deterioration of a number of the steel structural members is in the process of being rehabilitated with glass and carbon fiber reinforced, pultruded polymer structural beams. As part of a comprehensive research program to develop methods for modeling long term durability of the composite material, nondestructive evaluation if being used to provide a preliminary assessment of the initial condition of the beams as well as to monitor the deterioration of the beams during service.

  2. Nondestructive Evaluation of Ceramic Candle Filters Using Vibration Response

    SciTech Connect

    Chen, Roger H. L.; Kiriakidis, Alejandro C.; Peng, Steve W.

    1997-07-01

    This study aims at the development of an effective nondestructive evaluation technique to predict the remaining useful life of a ceramic candle filter during a power plant's annual maintenance shutdown. The objective of the present on-going study is to establish the vibration signatures of ceramic candle filters at varying degradation levels due to different operating hours, and to study the various factors involving the establishment of the signatures.

  3. Non-destructive evaluation of composite materials using ultrasound

    NASA Technical Reports Server (NTRS)

    Miller, J. G.

    1984-01-01

    Investigation of the nondestructive evaluation of advanced composite-laminates is summarized. Indices derived from the measurement of fundamental acoustic parameters are used in order to quantitatively estimate the local material properties of the laminate. The following sections describe ongoing studies of phase insensitive attenuation measurements, and discuss several phenomena which influences the previously reported technique of polar backscatter. A simple and effective programmable gate circuit designed for use in estimating attenuation from backscatter is described.

  4. Nondestructive Evaluation of the VSC-17 Cask

    SciTech Connect

    Sheryl Morton; Al Carlson; Cecilia Hoffman; James Rivera; Phil Winston; Koji Shirai; Shin Takahashi; Masaharo Tanaka

    2006-01-01

    In 2003, representatives from the Central Research Institute of Electric Power Industry (CRIEPI) requested development of a project with the objective of determining the performance of a concrete spent nuclear fuel storage cask. Radiation and environmental effects may cause chemical alteration of the concrete that could result in excessive cracking, spalling, and loss of compressive strength. The Idaho National Laboratory (INL) project team and CRIEPI representatives identified the Ventilated Storage Cask (VSC 17) spent nuclear fuel storage cask, originally located at the INL Test Area North, as a candidate to study cask performance because it had been used to store fuel as part of a dry cask storage demonstration project for over 15 years. The project involved investigating the properties of the concrete shield. INL performed a survey of the cask in the summers of 2003 and 2004. The INL team met with the CRIEPI representatives in December of 2004 to discuss the next steps. As a result of that meeting, CRIEPI requested that in the summer 2005 INL perform additional surveys on the VSC 17 cask with participation of CRIEPI scientists. This document summarizes the evaluation methods used on the VSC 17 to evaluate the cask for compressive strength, concrete cracking, concrete thickness, and temperature distribution.

  5. Dual-band infrared thermography for quantitative nondestructive evaluation

    SciTech Connect

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

    1993-04-01

    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 authors clarify interpretation of subsurface flaws. To accomplish this, the authors ratio images recorded at two infrared bands, centered near 5 microns and 10 microns. These image ratios are used to decouple temperature patterns associated with interior flaw sites from spatially varying surface emissivity noise. They also discuss three-dimensional (3D) dynamic thermal imaging of structural flaws using dual-band infrared (DBIR) computed tomography. Conventional thermography provides single-band infrared images which are difficult to interpret. Standard procedures yield imprecise (or qualitative) information about subsurface flaw sites which are typically masked by surface clutter. They use a DBIR imaging technique pioneered at LLNL to capture the time history of surface temperature difference patterns for flash-heated targets. They relate these patterns to the location, size, shape and depth of subsurface flaws. They have demonstrated temperature accuracies of 0.2{degree}C, timing synchronization of 3 ms (after onset of heat flash) and intervals of 42 ms, between images, during an 8 s cooling (and heating) interval characterizing the front (and back) surface temperature-time history of an epoxy-glue disbond site in a flash-heated aluminum lap joint.

  6. Rapid Prototyping Integrated With Nondestructive Evaluation and Finite Element Analysis

    NASA Technical Reports Server (NTRS)

    Abdul-Aziz, Ali; Baaklini, George Y.

    2001-01-01

    Most reverse engineering approaches involve imaging or digitizing an object then creating a computerized reconstruction that can be integrated, in three dimensions, into a particular design environment. Rapid prototyping (RP) refers to the practical ability to build high-quality physical prototypes directly from computer aided design (CAD) files. Using rapid prototyping, full-scale models or patterns can be built using a variety of materials in a fraction of the time required by more traditional prototyping techniques (refs. 1 and 2). Many software packages have been developed and are being designed to tackle the reverse engineering and rapid prototyping issues just mentioned. For example, image processing and three-dimensional reconstruction visualization software such as Velocity2 (ref. 3) are being used to carry out the construction process of three-dimensional volume models and the subsequent generation of a stereolithography file that is suitable for CAD applications. Producing three-dimensional models of objects from computed tomography (CT) scans is becoming a valuable nondestructive evaluation methodology (ref. 4). Real components can be rendered and subjected to temperature and stress tests using structural engineering software codes. For this to be achieved, accurate high-resolution images have to be obtained via CT scans and then processed, converted into a traditional file format, and translated into finite element models. Prototyping a three-dimensional volume of a composite structure by reading in a series of two-dimensional images generated via CT and by using and integrating commercial software (e.g. Velocity2, MSC/PATRAN (ref. 5), and Hypermesh (ref. 6)) is being applied successfully at the NASA Glenn Research Center. The building process from structural modeling to the analysis level is outlined in reference 7. Subsequently, a stress analysis of a composite cooling panel under combined thermomechanical loading conditions was performed to validate

  7. A versatile nondestructive evaluation imaging workstation

    NASA Technical Reports Server (NTRS)

    Chern, E. James; Butler, David W.

    1994-01-01

    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.

  8. Evaluation of an electric field sensor for nondestructive material inspection

    NASA Astrophysics Data System (ADS)

    Kalyanasundaram, Kayatri; Arunachalam, Kavitha

    2013-01-01

    An electric field sensor is fabricated on a 125 micron thick flexible dielectric substrate for electromagnetic (EM) nondestructive material inspection at 915 MHz. The sensor consists of an electrically short dipole antenna and a radio frequency (RF) diode detector connected to a pair of high impedance screen printed carbon lines. The DC component of the rectified diode voltage conveyed across the high impedance lines is measured using a data acquisition circuit. Sensor measurements are validated with simulated data for a conformal patch antenna operating at 915 MHz. Sensor performance for EM nondestructive testing (NDT) is evaluated using phantom defects in low loss dielectric slabs. Preliminary results indicate sensor utility for EM NDT and support further testing on realistic defects.

  9. Nondestructive Damage Evaluation in Ceramic Matrix Composites for Aerospace Applications

    PubMed Central

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

    2013-01-01

    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. PMID:23935428

  10. Evaluation of Nondestructive Assay/Nondestructive Examination Capabilities for Department of Energy Spent Nuclear Fuel

    SciTech Connect

    Luptak, A.J.; Bulmahn, K.D.

    1998-09-01

    This report summarizes an evaluation of the potential use of nondestructive assay (NDA) and nondestructive examination (NDE) technologies on DOE spent nuclear fuel (SNF). It presents the NDA/NDE information necessary for the National Spent Nuclear Fuel Program (NSNFP) and the SNF storage sites to use when defining that role, if any, of NDA/NDE in characterization and certification processes. Note that the potential role for NDA/NDE includes confirmatory testing on a sampling basis and is not restricted to use as a primary, item-specific, data collection method. The evaluation does not attempt to serve as a basis for selecting systems for development or deployment. Information was collected on 27 systems being developed at eight DOE locations. The systems considered are developed to some degree, but are not ready for deployment on the full range of DOE SNF and still require additional development. The system development may only involve demonstrating performance on additional SNF, packaging the system for deployment, and developing calibration standards, or it may be as extensive as performing additional basic research. Development time is considered to range from one to four years. We conclude that NDA/NDE systems are capable of playing a key role in the characterization and certification of DOE SNF, either as the primary data source or as a confirmatory test. NDA/NDE systems will be able to measure seven of the nine key SNF properties and to derive data for the two key properties not measured directly. The anticipated performance goals of these key properties are considered achievable except for enrichment measurements on fuels near 20% enrichment. NDA/NDE systems can likely be developed to measure the standard canisters now being considered for co-disposal of DOE SNF. This ability would allow the preparation of DOE SNF for storage now and the characterization and certification to be finalize later.

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

    NASA Astrophysics Data System (ADS)

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

    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.

  12. Nondestructive evaluation of Ni-Ti shape memory alloy

    SciTech Connect

    Meir, S.; Gordon, S.; Karsh, M.; Ayers, R.; Olson, D. L.; Wiezman, A.

    2011-06-23

    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.

  13. Efficient Nondestructive Evaluation of Prototype Carbon Fiber Reinforced Structures

    NASA Technical Reports Server (NTRS)

    Russell, Samuel S.; Walker, James L.; Workman, Gary; Thom, Robert (Technical Monitor)

    2002-01-01

    Thermography inspection is an optic based technology that can reduce the time and cost required to inspect propellant tanks or aero structures fabricated from composite materials. Usually areas identified as suspect in the thermography inspection are examined with ultrasonic methods to better define depth, orientation and the nature of the anomaly. This combination of nondestructive evaluation techniques results in a rapid and comprehensive inspection of composite structures. Examples of application of this inspection philosophy to prototype will be presented. Methods organizing the inspection and evaluating the results will be considered.

  14. Nondestructive Evaluation Quality Procedure: Personnel Qualification and Certification Radiographic Testing-Levels I& II

    SciTech Connect

    Dolan, K; Rikard, R D; Rodriquez, J

    2003-07-01

    This Operational Procedure establishes the minimum requirements for the qualification and certification/recertification of Nondestructive Evaluation (NDE) personnel in the nondestructive testing (NDT) radiographic testing (RT) method. This document is in accordance with the American Society for Nondestructive Testing Recommended Practice SNT-TC-1A, 1996, except as amended herein.

  15. Potential techniques for non-destructive evaluation of cable materials

    NASA Astrophysics Data System (ADS)

    Gillen, Kenneth T.; Clough, Roger L.; Mattson, Bengt; Stenberg, Bengt; Oestman, Erik

    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.

  16. Liberty Bell 7 Recovery Evaluation and Nondestructive Testing

    NASA Technical Reports Server (NTRS)

    Madaras, Eric I.; Smith, William L.

    1999-01-01

    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.

  17. Experimental implementation of reverse time migration for nondestructive evaluation applications.

    PubMed

    Anderson, Brian E; Griffa, Michele; Bas, Pierre-Yves Le; Ulrich, Timothy J; Johnson, Paul A

    2011-01-01

    Reverse time migration (RTM) is a commonly employed imaging technique in seismic applications (e.g., to image reservoirs of oil). Its standard implementation cannot account for multiple scattering/reverberation. For this reason it has not yet found application in nondestructive evaluation (NDE). This paper applies RTM imaging to NDE applications in bounded samples, where reverberation is always present. This paper presents a fully experimental implementation of RTM, whereas in seismic applications, only part of the procedure is done experimentally. A modified RTM imaging condition is able to localize scatterers and locations of disbonding. Experiments are conducted on aluminum samples with controlled scatterers. PMID:21302980

  18. Nondestructive Degradation Evaluation of Ceramic Candle Filters Using Vibration Signatures

    SciTech Connect

    Chen, R.H.L.; Parthasarathy, B.

    1996-12-31

    The structural integrity of ceramic candle filters is a key element for hot gas cleanup systems, They protect the heat exchanger and gas turbine components from getting clogged and also prevent erosion. Ceramic candle filters used in the recent demonstration plant have experienced degradation and fracturing. Preliminary examination of these ceramic filters indicated that damage of the filters may have resulted from strength degradation at consistent high temperature operation, thermal transient events, excessive ash accumulation and bridging and pulse cleaning. The ceramic candle filter is a slender structure made of layers of porous materials. The structure has high acoustic attenuation which has greatly limited the conventional ultrasonic detection capability. In general, stiffness reduction of a structure will cause the change of the modal parameters of the structure. This study proposes a nondestructive approach for evaluating the structural properties of the ceramic filters using dynamic characterization method. The vibration signatures of the ceramic filters at different degradation levels are established using transient impact-response technique. Results from this study indicate that the vibration signatures of the filters can be used as an index to quantify the darnage condition of the filters. The results also indicate the feasibility of using the vibration mode shapes to predict the damage location. The application of this study can be implemented to develop a nondestructive evaluation method for future in-situ inspection of the ceramic filters.

  19. The Nuclear Renaissance — Implications on Quantitative Nondestructive Evaluations

    NASA Astrophysics Data System (ADS)

    Matzie, Regis A.

    2007-03-01

    The world demand for energy is growing rapidly, particularly in developing countries that are trying to raise the standard of living for billions of people, many of whom do not even have access to electricity. With this increased energy demand and the high and volatile price of fossil fuels, nuclear energy is experiencing resurgence. This so-called nuclear renaissance is broad based, reaching across Asia, the United States, Europe, as well as selected countries in Africa and South America. Some countries, such as Italy, that have actually turned away from nuclear energy are reconsidering the advisability of this design. This renaissance provides the opportunity to deploy more advanced reactor designs that are operating today, with improved safety, economy, and operations. In this keynote address, I will briefly present three such advanced reactor designs in whose development Westinghouse is participating. These designs include the advanced passive PWR, AP1000, which recently received design certification for the US Nuclear Regulatory Commission; the Pebble Bed Modular reactor (PBMR) which is being demonstrated in South Africa; and the International Reactor Innovative and Secure (IRIS), which was showcased in the US Department of Energy's recently announced Global Nuclear Energy Partnership (GNEP), program. The salient features of these designs that impact future requirements on quantitative nondestructive evaluations will be discussed. Such features as reactor vessel materials, operating temperature regimes, and new geometric configurations will be described, and mention will be made of the impact on quantitative nondestructive evaluation (NDE) approaches.

  20. Acoustic wave generation by microwaves and applications to nondestructive evaluation.

    PubMed

    Hosten, Bernard; Bacon, Christophe; Guilliorit, Emmanuel

    2002-05-01

    Although acoustic wave generation by electromagnetic waves has been widely studied in the case of laser-generated ultrasounds, the literature on acoustic wave generation by thermal effects due to electromagnetic microwaves is very sparse. Several mechanisms have been suggested to explain the phenomenon of microwave generation, i.e. radiation pressure, electrostriction or thermal expansion. Now it is known that the main cause is the thermal expansion due to the microwave absorption. This paper will review the recent advances in the theory and experiments that introduce a new way to generate ultrasonic waves without contact for the purpose of nondestructive evaluation and control. The unidirectional theory based on Maxwell's equations, heat equation and thermoviscoelasticity predicts the generation of acoustic waves at interfaces and inside stratified materials. Acoustic waves are generated by a pulsed electromagnetic wave or a burst at a chosen frequency such that materials can be excited with a broad or narrow frequency range. Experiments show the generation of acoustic waves in water, viscoelastic polymers and composite materials shaped as rod and plates. From the computed and measured accelerations at interfaces, the viscoelastic and electromagnetic properties of materials such as polymers and composites can be evaluated (NDE). Preliminary examples of non-destructive testing applications are presented. PMID:12159977

  1. Evaluating NPS Visitor Centers

    ERIC Educational Resources Information Center

    Zube, E. H.; And Others

    1976-01-01

    The recent efforts of the National Park Service to assess the quality of their design programs through a comprehensive evaluation of twelve visitor centers are detailed. Overall findings provide strong support for the design programs employed by the National Park Service. (BT)

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

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

    McBurney, Sean

    1995-01-01

    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.

  4. Nondestructive Evaluation of Thick Concrete Using Advanced Signal Processing Techniques

    SciTech Connect

    Clayton, Dwight A; Barker, Alan M; Santos-Villalobos, Hector J; Albright, Austin P; Hoegh, Kyle; Khazanovich, Lev

    2015-09-01

    The purpose of the U.S. Department of Energy Office of Nuclear Energy’s Light Water Reactor Sustainability (LWRS) Program is to develop technologies and other solutions that can improve the reliability, sustain the safety, and extend the operating lifetimes of nuclear power plants (NPPs) beyond 60 years [1]. Since many important safety structures in an NPP are constructed of concrete, inspection techniques must be developed and tested to evaluate the internal condition. In-service containment structures generally do not allow for the destructive measures necessary to validate the accuracy of these inspection techniques. This creates a need for comparative testing of the various nondestructive evaluation (NDE) measurement techniques on concrete specimens with known material properties, voids, internal microstructure flaws, and reinforcement locations.

  5. Application of Raman Spectroscopy for Nondestructive Evaluation of Composite Materials

    NASA Technical Reports Server (NTRS)

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

    2007-01-01

    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.

  6. Theory and experimental technique for nondestructive evaluation of ceramic composites

    NASA Technical Reports Server (NTRS)

    Generazio, Edward R.

    1990-01-01

    The important ultrasonic scattering mechanisms for SiC and Si3N4 ceramic composites were identified by examining the interaction of ultrasound with individual fibers, pores, and grains. The dominant scattering mechanisms were identified as asymmetric refractive scattering due to porosity gradients in the matrix material, and symmetric diffractive scattering at the fiber-to-matrix interface and at individual pores. The effect of the ultrasonic reflection coefficient and surface roughness in the ultrasonic evaluation was highlighted. A new nonintrusive ultrasonic evaluation technique, angular power spectrum scanning (APSS), was presented that is sensitive to microstructural variations in composites. Preliminary results indicate that APSS will yield information on the composite microstructure that is not available by any other nondestructive technique.

  7. Induction thermography for non-destructive evaluation of adhesive bonds

    NASA Astrophysics Data System (ADS)

    Balaji, L.; Balasubramaniam, Krishnan; Krishnamurthy, C. V.

    2013-01-01

    Adhesive bonding is widely used in automotive industry in the recent times. One of the major problems with adhesive bonds is the lack of a suitable non-destructive evaluation technique for assessing bonding. In this paper, an experimental study was carried out to apply induction thermography technique to evaluate adhesively bonded steel plates. Samples were fabricated with artificial defects such as air gap, foreign material, and improper adhesive filling. Induction thermography technique was found to detect defects and foreign inclusions. The sample specimen was also inspected using standard techniques such as Ultrasonic testing and Radiography testing. Defect detecting capabilities of the three techniques are compared. Induction thermography heating was FE modelled in 3D using COMSOL 3.5a. The simulated Induction thermography model was compared and validated with experimental results.

  8. Nerva fuel nondestructive evaluation and characterization equipment and facilities

    NASA Astrophysics Data System (ADS)

    Caputo, Anthony J.

    1993-01-01

    Nuclear Thermal Propulsion (NTP) is one of the technologies that the Space Exploration Initiative (SEI) has identified as essential for a manned mission to Mars. A base or prior work is available upon which to build in the development of nuclear rockets. From 1955 to 1973, the U.S Atomic Energy Commission (AEC) sponsored development and testing of a nuclear rocket engine under Project Rover. The rocket engine, called the Nuclear Engine for Rocket Vehicle Application (NERVA), used a graphite fuel element incorporating coated particle fuel. Much of the NERVA development and manufacturing work was performed at the Oak Ridge Y-12 Plant. This paper gives a general review of that work in the area of nondestructive evaluation and characterization. Emphasis is placed on two key characteristics: uranium content and distribution and thickness profile of metal carbide coatings deposited in the gas passage holes.

  9. Primary Water Stress Corrosion Crack Morphology and Nondestructive Evaluation Reliability

    SciTech Connect

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

    2004-12-01

    A research program on primary stress corrosion crack (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 compling a knowledge base on all cracking in nickel based materials at all degradation sites in nuclear power plants, assessing NDE methods using mockups to quantify the detection, sizing, and using mockups to quantify the detection sizing and characterization of tight cracks, and determining the role of welding processes in degradation. In this paper, the resuts of the initial literature searchs are presented. The relevant data on crack properties such as shape and orientation are presented and their impace on nondestructive evaluation (NDE) reliability is discussed.

  10. Nondestructive Evaluation (NDE) for Inspection of Composite Sandwich Structures

    NASA Technical Reports Server (NTRS)

    Zalameda, Joseph N.; Parker, F. Raymond

    2014-01-01

    Composite honeycomb structures are widely used in aerospace applications due to their low weight and high strength advantages. Developing nondestructive evaluation (NDE) inspection methods are essential for their safe performance. Flash thermography is a commonly used technique for composite honeycomb structure inspections due to its large area and rapid inspection capability. Flash thermography is shown to be sensitive for detection of face sheet impact damage and face sheet to core disbond. Data processing techniques, using principal component analysis to improve the defect contrast, are discussed. Limitations to the thermal detection of the core are investigated. In addition to flash thermography, X-ray computed tomography is used. The aluminum honeycomb core provides excellent X-ray contrast compared to the composite face sheet. The X-ray CT technique was used to detect impact damage, core crushing, and skin to core disbonds. Additionally, the X-ray CT technique is used to validate the thermography results.

  11. Physical model assisted probability of detection in nondestructive evaluation

    SciTech Connect

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

    2011-06-23

    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.

  12. Microwave Nondestructive Evaluation of Dielectric Materials with a Metamaterial Lens

    NASA Technical Reports Server (NTRS)

    Shreiber, Daniel; Gupta, Mool; Cravey, Robin L.

    2008-01-01

    A novel microwave Nondestructive Evaluation (NDE) sensor was developed in an attempt to increase the sensitivity of the microwave NDE method for detection of defects small relative to a wavelength. The sensor was designed on the basis of a negative index material (NIM) lens. Characterization of the lens was performed to determine its resonant frequency, index of refraction, focus spot size, and optimal focusing length (for proper sample location). A sub-wavelength spot size (3 dB) of 0.48 lambda was obtained. The proof of concept for the sensor was achieved when a fiberglass sample with a 3 mm diameter through hole (perpendicular to the propagation direction of the wave) was tested. The hole was successfully detected with an 8.2 cm wavelength electromagnetic wave. This method is able to detect a defect that is 0.037 lambda. This method has certain advantages over other far field and near field microwave NDE methods currently in use.

  13. Development of nondestructive evaluation methods for ceramic coatings.

    SciTech Connect

    Sun, J. G.

    2007-01-01

    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.

  14. Non-destructive evaluation method employing dielectric electrostatic ultrasonic transducers

    NASA Technical Reports Server (NTRS)

    Yost, William T. (Inventor); Cantrell, Jr., John H. (Inventor)

    2003-01-01

    An acoustic nonlinearity parameter (.beta.) measurement method and system for Non-Destructive Evaluation (NDE) of materials and structural members novelly employs a loosely mounted dielectric electrostatic ultrasonic transducer (DEUT) to receive and convert ultrasonic energy into an electrical signal which can be analyzed to determine the .beta. of the test material. The dielectric material is ferroelectric with a high dielectric constant .di-elect cons.. A computer-controlled measurement system coupled to the DEUT contains an excitation signal generator section and a measurement and analysis section. As a result, the DEUT measures the absolute particle displacement amplitudes in test material, leading to derivation of the nonlinearity parameter (.beta.) without the costly, low field reliability methods of the prior art.

  15. Infrared non-destructive evaluation method and apparatus

    DOEpatents

    Baleine, Erwan; Erwan, James F; Lee, Ching-Pang; Stinelli, Stephanie

    2014-10-21

    A method of nondestructive evaluation and related system. The method includes arranging a test piece (14) having an internal passage (18) and an external surface (15) and a thermal calibrator (12) within a field of view (42) of an infrared sensor (44); generating a flow (16) of fluid characterized by a fluid temperature; exposing the test piece internal passage (18) and the thermal calibrator (12) to fluid from the flow (16); capturing infrared emission information of the test piece external surface (15) and of the thermal calibrator (12) simultaneously using the infrared sensor (44), wherein the test piece infrared emission information includes emission intensity information, and wherein the thermal calibrator infrared emission information includes a reference emission intensity associated with the fluid temperature; and normalizing the test piece emission intensity information against the reference emission intensity.

  16. Process-interactive nondestructive evaluation for metal-matrix composites

    NASA Astrophysics Data System (ADS)

    Liaw, P. K.; Shannon, R. E.; Clark, W. G., Jr.; Harrigan, W. C., Jr.

    Nondestructive evaluation (NDE) has been conducted on composite products at various stages of fabrication processes including raw powders, powder mixtures, billets and final product extrusions. Eddy current was found to be effective in identifying matrix powder alloy chemistry and particle size, and in determining the mix ratio of silicon carbide (SiC) reinforcement particles in aluminum matrix alloy powders. Ultrasonic techniques were capable of identifying SiC clusters in large-scale, consolidated powder metallurgy (P/M) metal matrix composite (MMC) billets, while eddy current methods could be used to determine near-surface density variations in the billets. Multiple NDE techniques (eddy current, ultrasonics and resistivity) could be employed to quantify microstructural characteristics of composite extrusions. These results suggest that NDE methods can be integrated into manufacturing processes to provide online, closed-loop control of fabrication parameters.

  17. Advanced quantitative magnetic nondestructive evaluation methods - Theory and experiment

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

    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.

  18. Remote monitoring and nondestructive evaluation of wind turbine towers

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

    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.

  19. Physical Model Assisted Probability of Detection in Nondestructive Evaluation

    NASA Astrophysics Data System (ADS)

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

    2011-06-01

    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.

  20. Nondestructive evaluation of environmental barrier coatings in CFCC combustor liners.

    SciTech Connect

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

    2007-01-01

    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.

  1. Physical Principles Underlying Ultrasonic Nondestructive Evaluation of Anisotropic Media

    NASA Astrophysics Data System (ADS)

    Blodgett, Earl Daniel

    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

  2. High resolution ultrasonic spectroscopy system for nondestructive evaluation

    NASA Technical Reports Server (NTRS)

    Chen, C. H.

    1991-01-01

    With increased demand for high resolution ultrasonic evaluation, computer based systems or work stations become essential. The ultrasonic spectroscopy method of nondestructive evaluation (NDE) was used to develop a high resolution ultrasonic inspection system supported by modern signal processing, pattern recognition, and neural network technologies. The basic system which was completed consists of a 386/20 MHz PC (IBM AT compatible), a pulser/receiver, a digital oscilloscope with serial and parallel communications to the computer, an immersion tank with motor control of X-Y axis movement, and the supporting software package, IUNDE, for interactive ultrasonic evaluation. Although the hardware components are commercially available, the software development is entirely original. By integrating signal processing, pattern recognition, maximum entropy spectral analysis, and artificial neural network functions into the system, many NDE tasks can be performed. The high resolution graphics capability provides visualization of complex NDE problems. The phase 3 efforts involve intensive marketing of the software package and collaborative work with industrial sectors.

  3. Research in nondestructive evaluation techniques for nuclear reactor concrete structures

    SciTech Connect

    Clayton, Dwight; Smith, Cyrus

    2014-02-18

    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 and 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.

  4. Nondestructive evaluation of ceramic candle filter with various boundary conditions

    SciTech Connect

    Chen, H.L.; Kiriakidis, A.C.

    2005-06-01

    Nondestructive evaluation (NDE) using a dynamic characterization technique was conducted to study ceramic candle filters. Ceramic candle filters are hollow cylindrical structures made of porous ceramic materials used to protect gas turbine in coal-fired power plants. Deterioration and failure of ceramic filters occurs after being exposed to high-temperature and high-pressure operational environment over a period of time. This paper focuses on the development of an NDE method that can predict the in-situ structural stiffness of the candle filters while still being attached to the plenum. A combination of laboratory testing, theoretical analysis, and finite element method (FEM) simulations are presented. The candle filters were tested using a laser vibrometer/accelerometer setup with variable boundary restraints. A variable end-restraint Timoshenko beam equation was derived to determine the dynamic response of the candle filters with simulated in-situ boundary conditions. Results from the FEM simulation were verified with the analysis to determine the stiffness degradation of the candle filters as well as the boundary conditions. Results from this study show that the vibration characteristics can be used effectively to evaluate both the structural stiffness and the in-situ boundary restraints of the ceramic candle filters during field inspections.

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

    NASA Technical Reports Server (NTRS)

    Walker, James L.

    1998-01-01

    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.

  6. Incorporation of nondestructive evaluation in Pontis Bridge Management System

    NASA Astrophysics Data System (ADS)

    Hadavi, Ahmad

    1998-03-01

    The highway system in the United States includes nearly 577,000 bridges, the majority of which were built during two major bridge building periods -- just before World War II (1930s) and in the first two decades of the Cold War (1950s and 1960s). Given the age and increased usage of these bridges over the years, many now require substantial maintenance to satisfy their desired level of service. The complex task of allocating scarce funds for the repair, maintenance, and rehabilitation of this large number of bridges led to the development of several optimization studies and two major bridge management system, namely BRIDGIT and Pontis. Pontis has emerged as the system of choice for all states in the Nation. At this time over 40 highway agencies continue to license, evaluate and implement the current AASHTOWARE Program, Pontis V. 3.2. However, all data currently required by Pontis to assess the structural stability and resulting suggestions for repair and maintenance of bridges are based on visual inspection and judgement. Consequently, all suggestions are based on that visual inspection. This paper discusses development of a plan for how non-destructive evaluation (NDE) data can be used to provide more information than visual inspection.

  7. Research in nondestructive evaluation techniques for nuclear reactor concrete structures

    NASA Astrophysics Data System (ADS)

    Clayton, Dwight; Smith, Cyrus

    2014-02-01

    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.

  8. Nondestructive evaluation techniques for nickel-cadmium aerospace battery cells

    NASA Technical Reports Server (NTRS)

    Haak, R.; Tench, D.

    1982-01-01

    The ac impedance characteristics of Ni-Cd cells as an in-situ, nondestructive means of determining cell lifetime, particularly with respect to the probability of premature failure were evaluated. Emphasis was on evaluating Ni-Cd cell impedance over a wide frequency range (10,000 to 0.0004 Hz) as the cells were subjected to charge/discharge cycle testing. The results indicate that cell degradation is reflected in the low frequency (Warburg) impedance characteristics associated with diffusion processes. The Warburg slope (W) was found to steadily increase as a function of cell aging for completely discharged cells. In addition, based on data for two cells, a high or rapidly increasing value for W signals imminent cell failure by one mechanism. Degradation by another mechanism is apparently reflected in a fall-off (roll-over) of W at lower frequencies. As a secondary result, the frequency dependence of the absolute cell impedance at low frequencies (5 - 500 mHz) was found to be a good indication of the cell state-of-charge.

  9. Optical coherence tomography for nondestructive evaluation of fuel rod degradation

    SciTech Connect

    Renshaw, Jeremy B.; Jenkins, Thomas P. Buckner, Benjamin D.; Friend, Brian

    2015-03-31

    Nuclear power plants regularly inspect fuel rods to ensure safe and reliable operation. Excessive corrosion can cause fuel failures which can have significant repercussions for the plant, including impacts on plant operation, worker exposure to radiation, and the plant's INPO rating. While plants typically inspect for fuel rod corrosion using eddy current techniques, these techniques have known issues with reliability in the presence of tenacious, ferromagnetic crud layers that can deposit during operation, and the nondestructive evaluation (NDE) inspection results can often be in error by a factor of 2 or 3. For this reason, alternative measurement techniques, such as Optical Coherence Tomography (OCT), have been evaluated that are not sensitive to the ferromagnetic nature of the crud. This paper demonstrates that OCT has significant potential to characterize the thickness of crud layers that can deposit on the surfaces of fuel rods during operation. Physical trials have been performed on simulated crud samples, and the resulting data show an apparent correlation between the crud layer thickness and the OCT signal.

  10. Optical coherence tomography for nondestructive evaluation of fuel rod degradation

    NASA Astrophysics Data System (ADS)

    Renshaw, Jeremy B.; Jenkins, Thomas P.; Buckner, Benjamin D.; Friend, Brian

    2015-03-01

    Nuclear power plants regularly inspect fuel rods to ensure safe and reliable operation. Excessive corrosion can cause fuel failures which can have significant repercussions for the plant, including impacts on plant operation, worker exposure to radiation, and the plant's INPO rating. While plants typically inspect for fuel rod corrosion using eddy current techniques, these techniques have known issues with reliability in the presence of tenacious, ferromagnetic crud layers that can deposit during operation, and the nondestructive evaluation (NDE) inspection results can often be in error by a factor of 2 or 3. For this reason, alternative measurement techniques, such as Optical Coherence Tomography (OCT), have been evaluated that are not sensitive to the ferromagnetic nature of the crud. This paper demonstrates that OCT has significant potential to characterize the thickness of crud layers that can deposit on the surfaces of fuel rods during operation. Physical trials have been performed on simulated crud samples, and the resulting data show an apparent correlation between the crud layer thickness and the OCT signal.

  11. Non-destructive evaluation of anchorage zones by ultrasonics techniques.

    PubMed

    Kharrat, M; Gaillet, L

    2015-08-01

    This work aims to evaluate the efficiency and reliability of two Non-Destructive Testing (NDT) methods for damage assessment in bridges' anchorages. The Acousto-Ultrasonic (AU) technique is compared to classical Ultrasonic Testing (UT) in terms of defect detection and structural health classification. The AU technique is firstly used on single seven-wire strands damaged by artificial defects. The effect of growing defects on the waves traveling through the strands is evaluated. Thereafter, three specimens of anchorages with unknown defects are inspected by the AU and UT techniques. Damage assessment results from both techniques are then compared. The structural health conditions of the specimens can be then classified by a damage severity criterion. Finally, a damaged anchorage socket with mastered defects is controlled by the same techniques. The UT allows the detection and localization of damaged wires. The AU technique is used to bring out the effect of defects on acoustic features by comparing a healthy and damaged anchorage sockets. It is concluded that the UT method is suitable for local and crack-like defects, whereas the AU technique enables the assessment of the global structural health of the anchorage zones. PMID:25824342

  12. Synchronized Electronic Shutter System (SESS) for Thermal Nondestructive Evaluation

    NASA Technical Reports Server (NTRS)

    Zalameda, Joseph N.

    2001-01-01

    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.

  13. Non-Destructive Evaluation of Materials via Ultraviolet Spectroscopy

    NASA Technical Reports Server (NTRS)

    Pugel, Betsy

    2008-01-01

    A document discusses the use of ultraviolet spectroscopy and imaging for the non-destructive evaluation of the degree of cure, aging, and other properties of resin-based composite materials. This method can be used in air, and is portable for field use. This method operates in reflectance, absorbance, and luminescence modes. The ultraviolet source is used to illuminate a composite surface of interest. In reflectance mode, the reflected response is acquired via the imaging system or via the spectrometer. The spectra are analyzed for organic compounds (conjugated organics) and inorganic compounds (semiconducting band-edge states; luminescing defect states such as silicates, used as adhesives for composite aerospace applications; and metal oxides commonly used as thermal coating paints on a wide range of spacecraft). The spectra are compared with a database for variation in conjugation, substitution, or length of molecule (in the case of organics) or band edge position (in the case of inorganics). This approach is useful in the understanding of material quality. It lacks the precision in defining the exact chemical structure that is found in other materials analysis techniques, but it is advantageous over methods such as nuclear magnetic resonance, infrared spectroscopy, and chromatography in that it can be used in the field to assess significant changes in chemical structure that may be linked to concerns associated with weaknesses or variations in structural integrity, without disassembly of or destruction to the structure of interest.

  14. Nondestructive Evaluation of Metal Fatigue Using Nonlinear Acoustics

    NASA Technical Reports Server (NTRS)

    Cantrell, John H., Jr.

    2008-01-01

    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.

  15. Synchronized electronic shutter system (SESS) for thermal nondestructive evaluation

    NASA Astrophysics Data System (ADS)

    Zalameda, Joseph N.

    2001-03-01

    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.

  16. Nondestructive evaluation of concrete dams and other structures

    NASA Astrophysics Data System (ADS)

    Olson, Larry D.; Sack, Dennis A.

    1995-05-01

    This paper presents an overview of several stress-wave based nondestructive testing methods which can be used to assess the condition of concrete structures such as dams, buildings, and foundations. The specific methods to be presented include the use of the impact echo (IE) and spectral analysis of surface waves (SASW) methods in the assessment of dam concrete condition (including freeze-thaw damage assessment), the use of ultrasonic pulse velocity tomography (UPV tomography) in the 2 dimensional imaging of concrete defects in walls and foundations, and the use of the crosshole sonic logging (CSL) method for rapid, accurate, and cost-effective quality assurance of drilled shaft foundations. Included in this paper are summary descriptions of each of the NDT methods used (including some underlying theory), along with brief case histories of the application of each of these methods to real-world problems. Case histories presented include the evaluation of the Rogers' Dam spillway for freeze-thaw damage and overall concrete condition, the use of the CSL method in quality assurance testing of foundations for the LA Metro Green Line, and the use of tomography for imaging a defect in a deep foundation.

  17. Non-Destructive Evaluation (NDE) Applications of THz Radiation

    NASA Astrophysics Data System (ADS)

    Zimdars, David

    2005-03-01

    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 resolution < 50 um. THz pulses can be analyzed spectroscopically to reveal chemical content. Recently, highly integrated turn-key THz imaging systems have been introduced commercially. We will demonstrate the detection of voids and disbonds intentionally incorporated within the sprayed on foam insulation of a space shuttle external tank mock-up segments. An industrially hardened THz scanning system which has been deployed to scan the space shuttle tank with small remote transceiver will be described. Additional terahertz security imaging applications for the detection of weapons and explosives will also be discussed, as well as the application of terahertz sensors for high speed industrial process monitoring and quality control.

  18. Development of nondestructive evaluation methods for structural ceramics.

    SciTech Connect

    Ellingson, W. A.

    1998-08-19

    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.

  19. Development of nondestructive evaluation methods for structural ceramics

    SciTech Connect

    Ellingson, W.A.; Koehl, R.D.; Wilson, J.A.; Stuckey, J.B.; Engel, H.P. |

    1996-04-01

    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.

  20. Nondestructive Evaluation Methods for the Ares I Common Bulkhead

    NASA Technical Reports Server (NTRS)

    Walker, James

    2010-01-01

    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.

  1. Low-frequency electromagnetic technique for nondestructive evaluation

    NASA Astrophysics Data System (ADS)

    Dalichaouch, Yacine; Singsaas, Alan L.; Putris, Firas; Perry, Alexander R.; Czipott, Peter V.

    2000-05-01

    We have developed a low frequency electromagnetic technique using sensitive room temperature magnetoresistive (MR) sensors for a variety of nondestructive evaluation (NDE) applications. These applications include the NDE of medical implants and aircraft structures, the detection of cracks and corrosion in metals, the detection of ferromagnetic foreign objects in the eye and the brain, and the noninvasive determination of iron content in the liver. Our technique consists of applying a low frequency ac magnetic field to the sample and detecting the sample response. The low excitation frequency enables us to probe deep into metal structures; the sensitivity of the MR sensor allows us to detect weak responses from the sample without applying too large an excitation field, particularly in the case of human tissue. The MR sensors are small and relatively inexpensive compared to other sensitive magnetic field sensors such as fluxgates and superconducting quantum interference devices or SQUIDs; hence the resulting NDE instrument will be compact and cost-efficient, enabling its commercialization for practical applications. In this paper, we focus primarily on NDE of orthopedic implants.

  2. Investigation of capacitively coupled ultrasonic transducer system for nondestructive evaluation.

    PubMed

    Zhong, Cheng Huan; Wilcox, Paul D; Croxford, Anthony J

    2013-12-01

    Capacitive coupling offers a simple solution to wirelessly probe ultrasonic transducers. This paper investigates the theory, feasibility, and optimization of such a capacitively coupled transducer system (CCTS) in the context of nondestructive evaluation (NDE) applications. The noncontact interface relies on an electric field formed between four metal plates-two plates are physically connected to the electrodes of a transducer, the other two are in a separate probing unit connected to the transmit/receive channel of the instrumentation. The complete system is modeled as an electric network with the measured impedance of a bonded piezoelectric ceramic disc representing a transducer attached to an arbitrary solid substrate. A transmission line model is developed which is a function of the physical parameters of the capacitively coupled system, such as the permittivity of the material between the plates, the size of the metal plates, and their relative positions. This model provides immediate prediction of electric input impedance, pulse-echo response, and the effect of plate misalignment. The model has been validated experimentally and has enabled optimization of the various parameters. It is shown that placing a tuning inductor and series resistor on the transmitting side of the circuit can significantly improve the system performance in terms of the signal-to-crosstalk ratio. Practically, bulk-wave CCTSs have been built and demonstrated for underwater and through-composite testing. It has been found that electrical conduction in the media between the plates limits their applications. PMID:24297024

  3. Eddy current nondestructive material evaluation based on HTS SQUIDs

    NASA Astrophysics Data System (ADS)

    Mück, M.; Kreutzbruck, M. v.; Baby, U.; Tröll, J.; Heiden, C.

    1997-08-01

    High Temperature Superconductor (HTS) Superconducting Quantum Interference Devices (SQUIDs) are promising sensors for applications in eddy current nondestructive evaluation (NDE). Due to their high field sensitivity at low frequencies, they are especially suitable for applications, where a large penetration depth is required. We have investigated two different SQUID-based NDE systems, one of which is optimised for testing felloes of aircraft wheels. The second system allows for testing planar structures using a motorised x-y-stage, which moves the cryostat above the planar samples. As sensors 3 GHz rf SQUIDs made from YBCO were used, having a field noise of about 1 pT/√Hz. This results in a dynamic range of our SQUID system of about 155 dB/√Hz. In most cases, the SQUIDs have been cooled by immersing them in liquid nitrogen. We have however also developed a cryosystem, which allows for cooling the sensors by a Ne-gas flow. In planar test structures we could detect flaws with lengths of 10 mm, having a height of 0.6 mm in a depth of 13 mm. In aircraft felloes, flaws located at the inner surface of the felloe (thickness 8 mm) were easily detectable despite a high static background field of up to 0.5 G caused by ferromagnetic structures inside the felloe. For flaws in a depth of 5 mm, the spatial resolution of both systems was about 8 mm without applying image postprocessing.

  4. Large Area Nondestructive Evaluation of a Fatigue Loaded Composite Structure

    NASA Technical Reports Server (NTRS)

    Zalameda, Joseph N.; Burke, Eric R.; Horne, Michael R.; Madaras, Eric I.

    2016-01-01

    Large area nondestructive evaluation (NDE) inspections are required for fatigue testing of composite structures to track damage initiation and growth. Of particular interest is the progression of damage leading to ultimate failure to validate damage progression models. In this work, passive thermography and acoustic emission NDE were used to track damage growth up to failure of a composite three-stringer panel. Fourteen acoustic emission sensors were placed on the composite panel. The signals from the array were acquired simultaneously and allowed for acoustic emission location. In addition, real time thermal data of the composite structure were acquired during loading. Details are presented on the mapping of the acoustic emission locations directly onto the thermal imagery to confirm areas of damage growth leading to ultimate failure. This required synchronizing the acoustic emission and thermal data with the applied loading. In addition, processing of the thermal imagery which included contrast enhancement, removal of optical barrel distortion and correction of angular rotation before mapping the acoustic event locations are discussed.

  5. Nondestructive Evaluation of Metal Fatigue Using Nonlinear Acoustics

    NASA Astrophysics Data System (ADS)

    Cantrell, John H.

    2009-03-01

    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 β extracted from acoustic harmonic generation measurements. The β 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 and 410 Cb stainless steel 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.

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

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

    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.

  7. Infrared thermal wave nondestructive testing for rotor blades in wind turbine generators non-destructive evaluation and damage monitoring

    NASA Astrophysics Data System (ADS)

    Zhao, Shi bin; Zhang, Cun-lin; Wu, Nai-ming; Duan, Yu-xia; Li, Hao

    2009-07-01

    The rotor blades are key components in wind turbine generators. A visual inspection of the laminated shells for delaminations, air pockets, missing/disoriented fabric etc. is in most cases also not possible due to the manufacturing process, so Non-destructive testing and evaluation (NDT & E) techniques for assessing the integrity of rotor blades structure are essential to both reduce manufacturing costs and out of service time of wind turbine generators due to maintenance. Nowadays, Infrared Thermal Wave Nondestructive Testing (Pulsed thermography) is commonly used for assessing composites. This research work utilizes Infrared Thermal Wave Nondestructive Testing system (EchoTherm, Thermal Wave Imaging, Inc.) to inspect a specimen with embedded defects (i.e. foreign matter and air inclusions) in different depth which is a part of rotor blades in wind turbine generators, we have successfully identified defects including foreign matter and air inclusions, and discovered a defective workmanship. The system software allows us to simultaneously view and analyze the results for an entire transition.

  8. Generation and complete nondestructive analysis of hyperentanglement assisted by nitrogen-vacancy centers in resonators

    NASA Astrophysics Data System (ADS)

    Liu, Qian; Zhang, Mei

    2015-06-01

    We present two efficient schemes for the deterministic generation and the complete nondestructive analysis of hyperentangled Bell states in both the polarization and spatial-mode degrees of freedom (DOFs) of two-photon systems, assisted by the nitrogen-vacancy (NV) centers in diamonds coupled to microtoroidal resonators as a result of cavity quantum electrodynamics. With the input-output process of photons, two-photon polarization-spatial hyperentangled Bell states can be generated in a deterministic way and their complete nondestructive analysis can be achieved. These schemes can be generalized to generate and analyze hyperentangled Greenberger-Horne-Zeilinger states of multiphoton systems as well. Compared with previous works, these two schemes relax the difficulty of their implementation in experiment as it is not difficult to obtain the π phase shift in single-sided NV-cavity systems, but difficult in single-sided quantum-dot-cavity systems. Moreover, our schemes do not require that the transmission for the uncoupled cavity is balanceable with the reflectance for the coupled cavity and they can be operated at room temperature. Our calculations show that these schemes can reach a high fidelity and efficiency with current technology, which may be a benefit to long-distance high-capacity quantum communication with two DOFs of photon systems.

  9. Development of nondestructive evaluation methods for structural ceramics

    SciTech Connect

    Ellingson, W.A.; Koehl, R.D.; Stuckey, J.B.; Sun, J.G.; Engel, H.P.; Smith, R.G.

    1997-06-01

    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.

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

    NASA Technical Reports Server (NTRS)

    Generazio, Edward R.

    1991-01-01

    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).

  11. Technologies for Nondestructive Evaluation of Surfaces and Thin Coatings

    NASA Technical Reports Server (NTRS)

    1999-01-01

    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

  12. a University Course on the Physical Principles of Ultrasound Nondestructive Evaluation

    NASA Astrophysics Data System (ADS)

    Genis, Vladimir

    2009-03-01

    The ultrasound nondestructive evaluation (NDE) of materials course was offered to Applied Engineering Technology (AET) students at Drexel University for last two years. The main objective of this three-credit (thirty-hour) course is to introduce students to physical principles of ultrasound measurements and to demonstrate the basic principles of ultrasound nondestructive evaluation of materials by combining hands-on laboratory experience with lectures. The work in the laboratory enhances the fundamentals taught in the classroom sessions.

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

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

    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.

  14. Nondestructive Evaluation of the Friction Weld Process on 2195/2219 Grade Aluminum

    NASA Technical Reports Server (NTRS)

    Suits, Michael W.; Clark, Linda S.; Cox, Dwight E.

    1999-01-01

    In 1996, NASA's Marshall Space Flight Center began an ambitious program designed to find alternative methods of repairing conventional TIG (Tungsten Inert Gas) welds and VPPA (Variable Polarity Plasma Arc) welds on the Space Shuttle External Tank without producing additional heat-related anomalies or conditions. Therefore, a relatively new method, invented by The Welding Institute (TWI) in Cambridge, England, called Friction Stir Welding (FSW), was investigated for use in this application, as well as being used potentially as an initial weld process. As with the conventional repair welding processes, nondestructive evaluation (NDE) plays a crucial role in the verification of these repairs. Since it was feared that conventional NDE might have trouble with this type of weld structure (due to shape of nugget, grain structure, etc.) it was imperative that a complete study be performed to address the adequacy of the NDE process. This paper summarizes that process.

  15. The eddy-current technique for nondestructive evaluation of generator retaining rings: Feasibility study: Interim report

    SciTech Connect

    Elmo, P.M.; Nottingham, L.D.

    1988-05-01

    An evaluation of the feasibility of using eddy current nondestructive inspection techniques to detect intergranular stress corrosion in generator rotor retaining rings was conducted by the EPRI NDE Center. Experiments were conducted using a bend-bar containing representative stress corrosion damage, a calibration block containing electrical discharge machined (EDM) notches, and four retired retaining rings containing EDM notches and stress corrosion damage. An eddy current transducer transport was designed and fabricated to interface with an existing computer-controlled, two-axis positioner and digital eddy current data acquisition system. Test results of experiments performed with this equipment on the retaining ring test-bed provided experimental validation of the eddy current method's feasibility as a retaining ring inspection method. Details are given of the system and its performance under laboratory and simulated service-inspection conditions. 9 refs., 47 figs.

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

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    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.

  18. Non-destructive evaluation of TBC by electrochemical impedance spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Jianqi

    suggested. An alternative electrolyte (trifluoroacetic acid) was investigated using EIS in order to be used as compatible or friendly solution to TBC. A similar characteristic EIS result was found using the alternative electrolyte compared with the commonly used electrolyte [Fe(CN)6]-3/[Fe(CN) 6]-4 in this work. It has indicated that a friendly electrolyte be viable for EIS technique to be used for non-destructive evaluation of TBC. Visualization of a flexible probe for EIS field detection has also been designed. (Abstract shortened by UMI.)

  19. Nondestructive evaluation of composite materials by electrical resistance measurement

    NASA Astrophysics Data System (ADS)

    Mei, Zhen

    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

  20. Recent advances in nondestructive evaluation made possible by novel uses of video systems

    NASA Technical Reports Server (NTRS)

    Generazio, Edward R.; Roth, Don J.

    1990-01-01

    Complex materials are being developed for use in future advanced aerospace systems. High temperature materials have been targeted as a major area of materials development. The development of composites consisting of ceramic matrix and ceramic fibers or whiskers is currently being aggressively pursued internationally. These new advanced materials are difficult and costly to produce; however, their low density and high operating temperature range are needed for the next generation of advanced aerospace systems. These materials represent a challenge to the nondestructive evaluation community. Video imaging techniques not only enhance the nondestructive evaluation, but they are also required for proper evaluation of these advanced materials. Specific research examples are given, highlighting the impact that video systems have had on the nondestructive evaluation of ceramics. An image processing technique for computerized determination of grain and pore size distribution functions from microstructural images is discussed. The uses of video and computer systems for displaying, evaluating, and interpreting ultrasonic image data are presented.

  1. Development of nondestructive evaluation methods for ceramic coatings.

    SciTech Connect

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

    2002-04-29

    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

  2. Nondestructive Evaluation of Ceramic Matrix Composite Combustor Components

    NASA Technical Reports Server (NTRS)

    Sun, Jiangang G.; Verrilli, Michael J.; Stephan, Robert R.; Barnett, Terry R.; Ojard, Greg C.

    2003-01-01

    Combustor liners fabricated from a SiC/SiC composite (silicon carbide fibers in a silicon carbide matrix) 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 correlated 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.

  3. Nondestructive Evaluation of Ceramic Matrix Composite Combustor Components

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

    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

  4. Nondestructive evaluation technique using infrared thermography and terahertz imaging

    NASA Astrophysics Data System (ADS)

    Sakagami, Takahide; Shiozawa, Daiki; Tamaki, Yoshitaka; Iwama, Tatsuya

    2016-05-01

    Nondestructive testing (NDT) techniques using pulse heating infrared thermography and terahertz (THz) imaging were developed for detecting deterioration of oil tank floor, such as blister and delamination of corrosion protection coating, or corrosion of the bottom steel plate under coating. Experimental studies were conducted to demonstrate the practicability of developed techniques. It was found that the pulse heating infrared thermography was utilized for effective screening inspection and THz-TDS imaging technique performed well for the detailed inspection of coating deterioration and steel corrosion.

  5. Nondestructive evaluation of concrete structures by nonstationary thermal wave imaging

    NASA Astrophysics Data System (ADS)

    Mulaveesala, Ravibabu; Panda, Soma Sekhara Balaji; Mude, Rupla Naik; Amarnath, Muniyappa

    2012-06-01

    Reinforced concrete structures (RCS) have potential application in civil engineering and with the advent of nuclear engineering RCS to be capable enough to withstanding a variety of adverse environmental conditions. However, failures/loss of durability of designed structures due to premature reinforcement corrosion of rebar is a major constrain. Growing concern of safety of structure due to pre-mature deterioration has led to a great demand for development of non-destructive and non-contact testing techniques for monitoring and assessing health of RCS. This paper presents an experimental investigation of rebar corrosion by non-stationary thermal wave imaging. Experimental results have been proven, proposed approach is an effective technique for identification of corrosion in rebar in the concrete samples.

  6. Nondestructive evaluation of a ceramic matrix composite material

    NASA Technical Reports Server (NTRS)

    Grosskopf, Paul P.; Duke, John C., Jr.

    1992-01-01

    Monolithic ceramic materials have proven their usefulness in many applications, yet, their potential for critical structural applications is limited because of their sensitivity to small imperfections. To overcome this extreme sensitivity to small imperfections, ceramic matrix composite materials have been developed that have the ability to withstand some distributed damage. A borosilicate glass reinforced with several layers of silicon-carbide fiber mat has been studied. Four-point flexure and tension tests were performed not only to determine some of the material properties, but also to initiate a controlled amount of damage within each specimen. Acousto-ultrasonic (AU) measurements were performed periodically during mechanical testing. This paper will compare the AU results to the mechanical test results and data from other nondestructive methods including acoustic emission monitoring and X-ray radiography. It was found that the AU measurements were sensitive to the damage that had developed within the material.

  7. Langley Research Center Standard for the Evaluation of Socket Welds

    NASA Technical Reports Server (NTRS)

    Berry, R. F., Jr.

    1985-01-01

    A specification utilized for the nondestructive evaluation of socket type pipe joints at Langley Research Center (LaRC) is discussed. The scope of hardware shall include, but is not limited to, all common pipe fittings: tees, elbows, couplings, caps, and so forth, socket type flanges, unions, and valves. In addition, the exterior weld of slip on flanges shall be inspected using this specification. At the discretion of the design engineer, standard practice engineer, Fracture Mechanics Engineering Section, Pressure Systems Committee, or other authority, four nondestructive evaluation techniques may be utilized exclusively, or in combination, to inspect socket type welds. These techniques are visual, radiographic, magnetic particle, and dye penetrant. Under special circumstances, other techniques (such as eddy current or ultrasonics) may be required and their application shall be guided by the appropriate sections of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (B&PVC).

  8. Low velocity impact testing and nondestructive evaluation of transparent materials

    SciTech Connect

    Brennan, R. E.; Green, W. H.

    2011-06-23

    Advanced transparent materials are used in protective systems for enhancing the survivability of ground vehicles, air vehicles, and personnel in applications such as face shields, riot gear, and vehicle windows. Low velocity impact damage can limit visibility and compromise the structural integrity of a transparent system, increasing the likelihood of further damage or penetration from a high velocity impact strike. For this reason, it is critical to determine damage tolerance levels of transparent systems to indicate whether or not a component should be replaced. In this study, transparent laminate systems will be tested by comparing baseline conditions to experimentally controlled damage states. Destructive testing including air gun and sphere impact testing will be used to replicate low velocity impacts in the field. Characterization of the damaged state will include basic visual inspection as well as nondestructive techniques including cross-polarization, x-ray, and ultrasound. The combination of destructive testing and characterization of the resulting damage can help to establish a damage acceptance criterion for materials used in protective systems.

  9. Nondestructive Evaluation (NDE) Research Progress in 1988, Proceedings From the Ninth Annual EPRI NDE Information Meeting

    SciTech Connect

    1989-05-01

    Nondestructive evaluation (NDE) research has led to improved technologies and new procedures for inspecting electric generating plant components. This review of 1988 EPRI research discusses NDE procedures for pressure vessel and containment weld examinations, assessments of the eddy-current technology for steam generators, and integrated ultrasonic techniques for examining cast austenitic stainless components.

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

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    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.

  11. Interdisciplinary program for quantitative nondestructive evaluation. Semi-annual report, October 1, 1982-February 28, 1983

    SciTech Connect

    Not Available

    1983-01-01

    Separate abstracts were prepared for the papers published in the following areas: (1) Application of Ultrasonic Quantitative Nondestructive Evaluation to Radio Frequency System Window Problems, (a) Improvements in Probability of Detection and (b) Sizing of Internal Flaws in Bore and Web Geometries; (2) Electromagnetic Detection and Sizing; (3) New Technical Opportunities; and (4) New Flaw Detection Techniques.

  12. A review of issues and strategies in nondestructive evaluation of fiber reinforced structural composites

    NASA Technical Reports Server (NTRS)

    Vary, A.

    1979-01-01

    Techniques for quantitative assessment of the mechanical strength and integrity of fiber composites during manufacture and service and following repair operations are presented. Problems and approaches are discussed relative to acceptance criteria, calibrating standards, and methods for nondestructive evaluation of composites in strength-critical applications. Acousto-ultrasonic techniques provide the methods of choice in this area.

  13. Nondestructive evaluation of internal maturity of tomatoes using spatially offset Raman spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This research explored the use of spatially offset Raman spectroscopy (SORS) for nondestructive evaluation of internal maturity of tomatoes. A Raman spectroscopy system using a 785 nm laser was developed to collect spatially-offset spectra in the wavenumber range of 200 – 2500. The SORS measuremen...

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

    NASA Technical Reports Server (NTRS)

    1972-01-01

    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.

  15. The thermographic nondestructive evaluation of iron aluminide green sheet

    NASA Astrophysics Data System (ADS)

    Watkins, Michael Lee

    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.

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

    NASA Technical Reports Server (NTRS)

    Leifeste, Mark R.

    2007-01-01

    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.

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

    SciTech Connect

    Gieske, J.H.

    1994-04-01

    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.

  18. Nondestructive spectroscopic and imaging techniques for quality evaluation and assessment of fish and fish products.

    PubMed

    He, Hong-Ju; Wu, Di; Sun, Da-Wen

    2015-01-01

    Nowadays, people have increasingly realized the importance of acquiring high quality and nutritional values of fish and fish products in their daily diet. Quality evaluation and assessment are always expected and conducted by using rapid and nondestructive methods in order to satisfy both producers and consumers. During the past two decades, spectroscopic and imaging techniques have been developed to nondestructively estimate and measure quality attributes of fish and fish products. Among these noninvasive methods, visible/near-infrared (VIS/NIR) spectroscopy, computer/machine vision, and hyperspectral imaging have been regarded as powerful and effective analytical tools for fish quality analysis and control. VIS/NIR spectroscopy has been widely applied to determine intrinsic quality characteristics of fish samples, such as moisture, protein, fat, and salt. Computer/machine vision on the other hand mainly focuses on the estimation of external features like color, weight, size, and surface defects. Recently, by incorporating both spectroscopy and imaging techniques in one system, hyperspectral imaging cannot only measure the contents of different quality attributes simultaneously, but also obtain the spatial distribution of such attributes when the quality of fish samples are evaluated and measured. This paper systematically reviews the research advances of these three nondestructive optical techniques in the application of fish quality evaluation and determination and discuss future trends in the developments of nondestructive technologies for further quality characterization in fish and fish products. PMID:24915393

  19. Nondestructive evaluation of a graphite/aluminum composite space radiator panel. Technical report

    SciTech Connect

    Feldman, N.M.; Foltz, J.V.

    1991-12-01

    Graphite aluminum composites which employ graphite fibers for mechanical reinforcement have applications in the aerospace industry. They are particularly attractive for spacecraft thermal management systems due to their ability to efficiently transport heat. The detection and evaluation of damage in structures fabricated from this material is necessary to the efficiency and application of these materials. This technical report presents research on a graphite fiber reinforced aluminum composite space radiator panel. The panel was evaluated after each of four fabrication stages by four nondestructive techniques: ultrasound, x-ray, dye penetrant, and visual inspection. The results illustrate the importance of nondestructive evaluation (NDE) from the time the composite is fabricated through the time it is implemented into the spacecraft. These NDE technologies will help detect external or internal irregularities (anomalies) at each increment of the fabrication and qualification testing of the composite radiator panel.

  20. Non-destructive evaluation of membrane lung gas exchange performance.

    PubMed

    Tallman, R D; Guardia, Z A; Gruber, M A

    1996-12-01

    This paper describes a method of evaluating the gas exchange effectiveness of hollow fiber oxygenators utilizing gas on both sides of the membrane. The goal of the study was to develop an evaluation technique which was accurate, reliable, and did not harm or contaminate a new, sterile oxygenator. Three pediatric oxygenators were tested and compared: the Medtronic Minimax Plus, the Terumo Capiox 320, and the Sorin Masterflo 34 (all with rated blood flows of 2-2.5 L/min). Gas entering the "blood" side was a mixture of CO2, O2, and N2 in a mixture matching typical venous blood partial pressures. The "blood" flows used were 0.5, 1, 1.5, or 2 L/min. Gas entering the gas port had an FiO2 of 0.4 flowing at 0.5, 1, 1.5, 2, 2.5, 3, or 3.5 L/min. Fractional contents of CO2 and O2 at all inlets and outlets were determined using a gas analyzer and converted to partial pressures. Efficacy indices and gas transfer rates were calculated and compared. Of the devices studied, the Masterflo 34 had the highest gas transport rates and effectiveness followed by the Minimax-Plus and the Capiox 320. Reversing the direction of the flow through the "blood" phase of the Minimax-Plus greatly changed its gas exchange effectiveness. The techniques described in this study should allow for a more uniform and consistent evaluation of gas exchange by membrane lungs which can be made inexpensively and relatively quickly. In addition, these methods should allow manufactures to evaluate gas exchange effectiveness and transfer rates of individual units during production as well as reduce the complexity involved when evaluating newly developed oxygenators. PMID:10164050

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

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

    Roberts, Mark J. (Compiler)

    1999-01-01

    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.

  3. Evaluation of Damage in Steels Subjected to Exploitation Loading - Destructive and Non-Destructive Methods

    NASA Astrophysics Data System (ADS)

    Kowalewski, Zbigniew L.; Mackiewicz, Sławomir; Szelążek, Jacek; Pietrzak, Krystyna; Augustyniak, Bolesław

    Damage due to creep and plastic flow is assessed using destructive and non-destructive methods in steels (40HNMA and P91). In the destructive methods the standard tension tests were carried out after prestraining and variations of the selected tension parameters were taken into account for damage identification. In order to assess a damage development during the creep and plastic deformation the tests for both steels were interrupted for a range of the selected strain magnitudes. The ultrasonic and magnetic techniques were used as the non-destructive methods for damage evaluation. The last step of the experimental programme contained microscopic observations. A very promising correlation between parameters of methods for damage development evaluation was achieved. It is well proved for the ultimate tensile stress and birefringence coefficient.

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

    SciTech Connect

    B. Mi; G. Zhao; R. Bayles

    2006-08-10

    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.

  5. Method and apparatus for non-destructive evaluation of composite materials with cloth surface impressions

    NASA Technical Reports Server (NTRS)

    Madras, Eric I. (Inventor)

    1995-01-01

    A method and related apparatus for nondestructive evaluation of composite materials by determination of the quantity known as Integrated Polar Backscatter, which avoids errors caused by surface texture left by cloth impressions by identifying frequency ranges associated with peaks in a power spectrum for the backscattered signal, and removing such frequency ranges from the calculation of Integrated Polar Backscatter for all scan sites on the composite material is presented.

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

    NASA Technical Reports Server (NTRS)

    Yolken, H. Thomas; Matzkanin, George A.

    2009-01-01

    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.

  7. A review of issues and strategies in nondestructive evaluation of fiber reinforced structural composites

    NASA Technical Reports Server (NTRS)

    Vary, A.

    1979-01-01

    The need for advanced nondestructive evaluation (NDE) techniques for quantitative assessment of the mechanical strength and integrity of fiber composites during manufacture and service and following repair operations is stressed. The discussion covers problems and different approaches in regard to acceptance criteria, calibration standards, and methods for NDE of composites in strength critical applications. Finally, it is concluded that acousto-ultrasonic techniques provide the 'methods of choice' in this area.

  8. Probabilistic nondestructive evaluation of bonded aluminum honeycomb structures

    NASA Astrophysics Data System (ADS)

    Schaefer, Lloyd A.

    1995-07-01

    Aluminum honeycomb panels fabricated in accordance with spacecraft fracture control guidelines must be evaluated to a 90/95 POD/CL (probability of detection/confidence) level for detection of the critical initial flaw (CIF) size. Severe weight limitations can drive the CIF to a size of one cell diameter, or smaller. Additionally, producibility (low or no type II errors) must be maintained, and inspection costs minimized. To assure these goals, a reliability demonstration program was undertaken on thin skin panels for the Space Station Electric Power System ORU (orbital replacement unit) enclosures. This paper examines the probabilistic NDE process in detail, including: analysis of the manufacturing methodology, expected flaw types, construction of the disbond flaw data base, and the subsequent evaluations and results using laser shearography. The experimental data is then reduced utilizing the statistical methodology outlined in a proposed military standard for NDE reliability demonstrations, and contrasted against conventional through transmission ultrasonic inspection. The effort revealed that substantial gains in system reliability and flaw type discrimination are possible with laser shearography, along with a nearly order of magnitude reduction in inspection time.

  9. Nondestructive evaluation of aircraft coatings with infrared diffuse reflectance spectra

    NASA Astrophysics Data System (ADS)

    Korth, Hans G.; Wilson, Kody A.; Gross, Kevin C.; Hawks, Michael R.; Zens, Timothy W. C.

    2015-05-01

    Aircraft coatings degrade over time, but aging can be difficult to detect before failure and delamination. We present a method to evaluate aircraft coatings in situ using infrared diffuse reflectance spectra. This method can detect and classify coating degradation much earlier than visual inspection. The method has been tested on two different types of coatings that were artificially aged in an autoclave. Spectra were measured using a hand-held diffuse reflectance infrared Fourier transform spectrometer (DRIFTS). One set of 72 samples can be classified as either aged or unaged with 100% accuracy. A second sample set contained samples that had been artificially aged for 0, 24, 48 or 96 hours. Several classification methods are compared, with accuracy better than 98% possible.

  10. Guided waves in a multilayered composite and ultrasonic nondestructive evaluation

    NASA Technical Reports Server (NTRS)

    Datta, S. K.; Karunasena, W. M.; Shah, A. H.

    1991-01-01

    Analysis of wave propagation in a laminated composite plate with many layers is made difficult by the anisotropy of the laminae, different lay-ups, many layers and defects in the fabricated plate. A good understanding of the wave field in such a plate without defects is a prerequisite for use of ultrasonic techniques to evaluate the various defects that can substantially reduce the strength and service life of this structure. Results of modeling studies of wave propagation and scattering in a multilayered composite plate are presented. The analysis technique combines the finite element discretization through the thickness with wave form representation along the plate in order to calculate the dispersive modes of propagation in the plate. To study scattering of these waves by a matrix crack that grows into delaminations, a hybrid finite element representation of the field near the crack and the modal representation of the scattered exterior field are used. Results are presented showing the dependence of the reflection and transmission coefficients on the size of the crack with delamination which can be used to size the defect using ultrasonic techniques.

  11. Infrared Contrast Analysis Technique for Flash Thermography Nondestructive Evaluation

    NASA Technical Reports Server (NTRS)

    Koshti, Ajay

    2014-01-01

    The paper deals with the infrared flash thermography inspection to detect and analyze delamination-like anomalies in nonmetallic materials. It provides information on an IR Contrast technique that involves extracting normalized contrast verses time evolutions from the flash thermography infrared video data. The paper provides the analytical model used in the simulation of infrared image contrast. The contrast evolution simulation is achieved through calibration on measured contrast evolutions from many flat bottom holes in the subject material. The paper also provides formulas to calculate values of the thermal measurement features from the measured contrast evolution curve. Many thermal measurement features of the contrast evolution that relate to the anomaly characteristics are calculated. The measurement features and the contrast simulation are used to evaluate flash thermography inspection data in order to characterize the delamination-like anomalies. In addition, the contrast evolution prediction is matched to the measured anomaly contrast evolution to provide an assessment of the anomaly depth and width in terms of depth and diameter of the corresponding equivalent flat-bottom hole (EFBH) or equivalent uniform gap (EUG). The paper provides anomaly edge detection technique called the half-max technique which is also used to estimate width of an indication. The EFBH/EUG and half-max width estimations are used to assess anomaly size. The paper also provides some information on the "IR Contrast" software application, half-max technique and IR Contrast feature imaging application, which are based on models provided in this paper.

  12. The FAA`s Aging Aircraft Nondestructive Inspection Validation Center at Sandia National Laboratories: An introduction

    SciTech Connect

    Walter, P.

    1995-07-01

    In these times of budget tightening for both government and private industry, this issue of Materials Evaluation is devoted to describing a cooperative relationship leveraging resources in the Department of Transportation`s Federal Aviation Administration (FAA) and the Department of Energy`s Sandia National Laboratories. This relationship resulted in a facility whose purpose is to assess technologies intended to enhance the reliability and cost effectiveness of inspection in the civil aviation industry. Eight articles are presented to describe this facility and its related activities. The center, located at the Albuquerque International Airport, has as its mission assessing and -- where justified -- encouraging the transfer of emerging inspection technologies to the civil aviation industry.

  13. Electromagnetic nondestructive evaluation of tempering process in AISI D2 tool steel

    NASA Astrophysics Data System (ADS)

    Kahrobaee, Saeed; Kashefi, Mehrdad

    2015-05-01

    The present paper investigates the potential of using eddy current technique as a reliable nondestructive tool to detect microstructural changes during the different stages of tempering treatment in AISI D2 tool steel. Five stages occur in tempering of the steel: precipitation of ɛ carbides, formation of cementite, retained austenite decomposition, secondary hardening effect and spheroidization of carbides. These stages were characterized by destructive methods, including dilatometry, differential scanning calorimetry, X-ray diffraction, scanning electron microscopic observations, and hardness measurements. The microstructural changes alter the electrical resistivity/magnetic saturation, which, in turn, influence the eddy current signals. Two EC parameters, induced voltage sensed by pickup coil and impedance point detected by excitation coil, were evaluated as a function of tempering temperature to characterize the microstructural features, nondestructively. The study revealed that a good correlation exists between the EC parameters and the microstructural changes.

  14. A systems approach of the nondestructive evaluation techniques applied to Scout solid rocket motors.

    NASA Technical Reports Server (NTRS)

    Oaks, A. E.

    1971-01-01

    Review and appraisal of the status of the nondestructive tests applied to Scout solid-propellant rocket motors, using analytical techniques to evaluate radiography for detecting internal discontinuities such as voids and unbonds. Information relating to selecting, performing, controlling, and evaluating the results of NDE tests was reduced to a common simplified format. With these data and the results of the analytical studies performed, it was possible to make the basic appraisals of the ability of a test to meet all pertinent acceptance criteria and, where necessary, provide suggestions to improve the situation.

  15. Non-destructive evaluation of cylindrical composite structures using photothermal radiometry

    NASA Astrophysics Data System (ADS)

    Wang, C.; Mandelis, A.; Liu, Y.

    2005-06-01

    Thermal-wave diagnostics by means of infrared photothermal radiometry (PTR) has been used for quantitative non-destructive evaluation of cylindrical composite structures. To quantitatively evaluate the thermal-wave field of a cylindrical composite material, the Green function corresponding to the composite structure has been developed and subsequently the thermal-wave field has been derived. Furthermore, the characteristics of the thermal-wave field for a cylindrical material with a surface coating are discussed. Experimental results from a stainless steel (AISI 302) tube are used to validate the theoretical model.

  16. Millimeter Wave Nondestructive Evaluation of Corrosion Under Paint in Steel Structures

    SciTech Connect

    Kharkovsky, S.; Zoughi, R.

    2006-03-06

    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.

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

    NASA Astrophysics Data System (ADS)

    Yu, Feng

    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

  18. Non-destructive Magnetic Evaluation of Laser Weld Quality in Hot Rolled Coils

    NASA Astrophysics Data System (ADS)

    Mohapatra, J. N.; Chakradhar, I.; Rao, K. R. C.; Rao, V. V. L.; Kaza, Marutiram

    2015-06-01

    Weld quality evaluation was conducted on laser welded thin sectsions (2 mm) of hot-rolled (HR) low-carbon steel coils during cold rolling process. The analysis revealed that the poor welds consisting of the weld defects like incomplete fusion, cluster of porosity, and large difference in hardness between the weld zone and base metal were responsible for the weld failures. Experiments were conducted by varying the welding parameters; laser power and welding speed to optimize the parameters for minimizing the weld defects. The optimized weld process parameters have helped elimination of weld defects and the results are verified with microscopy and microhardness measurements. As destructive evaluation techniques are time consuming and not always permitted in industrial applications, attempts have been made in the present investigation for the utilization of suitable non-destructive techniques for the evaluation of weld quality. Non-destructive magnetic techniques of magnetic hysteresis loop and magnetic Barkhausen emissions were used in the present investigation to establish possible correlations of magnetic properties across the weld seam with the mechanical property (microhardness) for evaluation of weld quality. It is inferred that the magnetic properties of coercivity and inverse of root mean square voltage can be effectively utilized to determine weld quality in HR steel coils.

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

    NASA Astrophysics Data System (ADS)

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

    2012-09-01

    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.

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

    NASA Technical Reports Server (NTRS)

    Martin, Richard E.

    2010-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

    Generazio, Edward R.

    1991-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2011-02-01

    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.

  3. Coupling Photon Monte Carlo Simulation and CAD Software. Application to X-ray Nondestructive Evaluation

    NASA Astrophysics Data System (ADS)

    Tabary, J.; Glière, A.

    A Monte Carlo radiation transport simulation program, EGS Nova, and a Computer Aided Design software, BRL-CAD, have been coupled within the framework of Sindbad, a Nondestructive Evaluation (NDE) simulation system. In its current status, the program is very valuable in a NDE laboratory context, as it helps simulate the images due to the uncollided and scattered photon fluxes in a single NDE software environment, without having to switch to a Monte Carlo code parameters set. Numerical validations show a good agreement with EGS4 computed and published data. As the program's major drawback is the execution time, computational efficiency improvements are foreseen.

  4. Non-Destructive Evaluation Method and Apparatus for Measuring Acoustic Material Nonlinearity

    NASA Technical Reports Server (NTRS)

    Yost, William T. (Inventor); Cantrell, John H. (Inventor)

    2002-01-01

    An acoustic non-linearity parameter (beta) measurement method and system for Non-Destructive Evaluation (NDE) of materials and structural members obviates the need for electronic calibration of the measuring equipment. Unlike known substitutional measuring techniques requiring elaborate calibration procedures, the electrical outputs of the capacitive detector of a sample with known beta and the test sample of unknown beta are compared to determine the unknown beta. In order to provide the necessary stability of the present-inventive reference-based approach, the bandpass filters of the measurement system are maintained in a temperature-controlled environment, and the line voltage supplied to said amplifiers is well-regulated.

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

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    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.

  6. Highly sensitive anisotropic magnetoresistance magnetometer for Eddy-current nondestructive evaluation.

    PubMed

    He, D F; Tachiki, M; Itozaki, H

    2009-03-01

    Using a commercially available anisotropic magnetoresistance (AMR) sensor of HMC1001, we developed a sensitive magnetometer. It could operate in amplifier mode or feedback mode. The magnetic field sensitivity of the AMR sensor was about 3.2 mV/V G. When the AMR sensor was biased by a voltage of 24 V, the magnetic field resolutions of the AMR magnetometer were about 12 pT/square root(Hz) at 1 kHz and 20 pT/square root(Hz) at 100 Hz. We used the AMR magnetometer for Eddy-current nondestructive evaluation in unshielded environment. PMID:19334957

  7. Nondestructive Evaluation of Foam Insulation for the External Tank Return to Flight

    NASA Technical Reports Server (NTRS)

    Walker, James L.; Richter, Joel D.

    2006-01-01

    Nondestructive evaluation methods have been developed to identify defects in the foam thermal protection system (TPS) of the Space Shuttle External Tank (ET). Terahertz imaging and backscatter radiography have been brought from prototype lab systems to production hardened inspection tools in just a few years. These methods have been demonstrated to be capable of detecting void type defects under many inches of foam which, if not repaired, could lead to detrimental foam loss. The evolution of these methods from lab tools to implementation on the ET will be discussed.

  8. Interdisciplinary program for quantitative nondestructive evaluation. Semiannual report, 1 October 1981-31 March 1982

    SciTech Connect

    Not Available

    1982-01-01

    This report constitutes the semiannual report of the Air Force/Defense Advanced Research Project Agency research program in quantitative nondestructive evaluation covering the period October 1, 1981 to March 31, 1982. It is organized by projects, each of which contains the reports of individual investigations. Because the goals of the projects are largely such that strong interdisciplinary interactions are necessary in order to achieve them, the individual reports reflect a close cooperation between various investigators. Projects included in this year's effort are: application of ultrasonic QNDE to RFC window problems; electromagnetic detection and sizing; new technical opportunities; and new flaw detection techniques. Twenty-three project reports are presented.

  9. Non-destructive evaluation of metal-to-metal adhesive joints using vibration analysis: experimental results

    NASA Astrophysics Data System (ADS)

    Pandurangan, Pradeep; Buckner, Gregory D.

    2006-03-01

    Vibration based non-destructive evaluation shows promise for damage detection in metal-to-metal adhesive joints. This research investigates an experimental technique to diagnose damage in single-lap adhesive joints subject to cyclical tensile loading. Vibration analysis reveals that damage can be correlated with changes in identified modal damping ratios. Constant amplitude forcing functions are employed to eliminate amplitude-dependent nonlinearities in the dynamic response profiles. Damping estimates obtained from time-domain analyses correlate well with damage magnitudes. Finite element modal analysis of the lap joints supports the experimental results.

  10. Evaluation of electroexplosive devices by nondestructive test techniques and impulsive waveform firings

    NASA Technical Reports Server (NTRS)

    Menichelli, V. J.

    1972-01-01

    Special requirements of the space industry for more detailed knowledge of the quality and reliability of each electroexplosive device (EED) selected for use aboard a spacecraft are described. Statistical methods do not practically demonstrate the high reliability needed. To close this gap, nondestructive test techniques and instrumentation for 1-W/1-A no-fire devices have been developed. Several lots of squibs have been evaluated using these techniques and instrumentation. They yield data as to the quality and normal behavior of each electroexplosive device without firing or degrading the unit. Performance data were obtained by initiating the EED's with an impulsive waveform and sensing the initiation characteristics, sensitivity, and output.

  11. Nondestructive Techniques to Evaluate the Characteristics and Development of Engineered Cartilage.

    PubMed

    Mansour, Joseph M; Lee, Zhenghong; Welter, Jean F

    2016-03-01

    In this review, methods for evaluating the properties of tissue engineered (TE) cartilage are described. Many of these have been developed for evaluating properties of native and osteoarthritic articular cartilage. However, with the increasing interest in engineering cartilage, specialized methods are needed for nondestructive evaluation of tissue while it is developing and after it is implanted. Such methods are needed, in part, due to the large inter- and intra-donor variability in the performance of the cellular component of the tissue, which remains a barrier to delivering reliable TE cartilage for implantation. Using conventional destructive tests, such variability makes it near-impossible to predict the timing and outcome of the tissue engineering process at the level of a specific piece of engineered tissue and also makes it difficult to assess the impact of changing tissue engineering regimens. While it is clear that the true test of engineered cartilage is its performance after it is implanted, correlation of pre and post implantation properties determined non-destructively in vitro and/or in vivo with performance should lead to predictive methods to improve quality-control and to minimize the chances of implanting inferior tissue. PMID:26817458

  12. Non-Destructive Evaluation of Thermal Spray Coating Interface Quality by Eddy Current Method

    SciTech Connect

    B.Mi; X. Zhao; R. Bayles

    2006-05-26

    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 different surface preparation conditions before applying the coating, e.g., grit-blasted surface, wire-brush cleaned surface, and a dirty surface. A quad-frequency eddy current probe was used to manually scan over the coating surface to evaluate the bonding quality. Experimental results show that the three surface preparation conditions can be successfully differentiated by looking into the impedance difference observed from the eddy current probe. The measurement is fairly robust and consistent. More specimens are also prepared with variations of process parameters, such as spray angle, stand-off distance, and application of corrosion protective sealant, etc. They are blindly tested to evaluate the reliability of the eddy current system. Quantitative relations between the coating bond strength and the eddy current response are also established with the support of destructive testing. This non-contact, non-destructive, easy to use technique has the potential for evaluating the coating quality immediately after its application so that any defects can be corrected immediately.

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

    NASA Astrophysics Data System (ADS)

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

    2012-01-01

    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.

  14. Assessing Primary Water Stress Corrosion Crack Morphology and Nondestructive Evaluation Reliability

    SciTech Connect

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

    2005-12-01

    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.

  15. Nondestructive Evaluation (NDE) research progress in 1988: Proceedings from the ninth annual EPRI NDE information meeting

    SciTech Connect

    Avioli, M.J. Jr.; Dau, G.J.; Liu, S.N.; Stein, J.; Welty, C.S.

    1989-05-01

    The increasing cost of equipment for power generating plants and the potential increases in productivity and safety analysis through rapidly developing Nondestructive Evaluation (NDE) technology led EPRI to initiate a Nondestructive Evaluation Program in 1974. To date, the major focus has been on light water reactor inspection problems; however, increased application to other systems is now underway. This report presents a comprehensive review of the EPRI effort in the NDE area. Most of the report consists of contractor-supplied progress reports on each current project. An organizational plan of the program is presented in overview. In addition, organization from several viewpoints is presented, e.g., in-service inspection operators, R and D personnel, and utility representatives. As the tenth in a planned series of annual progress reports of EPRI-funded NDE activities, this report also serves as the proceedings of the Ninth Annual EPRI NDE Information Meeting held in Charlotte, North Carolina, on November 15--16, 1988. It summarizes significant progress made since the previous EPRI Special Report NP-5490-SR was issued in June 1988. Section 1 contains information about the program organization, and the sections that follow contain contractor-supplied progress reports on each current project. The progress reports are grouped by plant components -- pipe, pressure vessel, and steam generator and boiler tubes. In addition, Part 5 is devoted to discussions of technology transfer.

  16. Nondestructive evaluation research progress in 1989: Proceedings from the tenth annual EPRI NDE information meeting

    SciTech Connect

    Avioli, M.J. Jr.; Behravesh, M.M.; Gehl, S.M.; Liu, S.N.; Stein, J.; Welty, C.S. )

    1990-06-01

    The increasing cost of equipment for power generating plants and the potential increases in productivity and safety available through rapidity developing nondestructive evaluation (NDE) technology led EPRI to initiate a Nondestructive Evaluation Program in 1974. To date, the major focus has been on light water reactor (LWR) inspection problems; however, increased application to other systems is now under way. This report presents a comprehensive review of the EPRI effort in the NDE area. Most of the report consists of contractor-supplied progress reports on each current project. An organizational plan of the program is presented in overview. In addition, organization from several viewpoints is presented, e.g., in-service inspection operators, R D personnel, and utility representatives. As the eleventh in a planned series of annual progress reports of EPRI-funded NDE activities, this report also serves as the proceedings of the Tenth Annual EPRI NDE Information Meeting held in Palo Alto, California, on November 14-15, 1989. It summarizes significant progress made since the previous EPRI Special Report NP-6075-SR was issued in May 1989. Section 1 contains information about the program organization, and the sections that follow contain contractor-supplied progress reports on each current project. The progress reports are grouped by plant components -- pipe and nozzle, pressure vessel, and boilers and steam generators. In addition, Part 5 is devoted to discussions of technology transfer. The individual papers have been cataloged separately.

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

    NASA Astrophysics Data System (ADS)

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

    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.

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

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1997-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

    Roberts, Mark J. (Compiler)

    1999-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

    Generazio, Edward R.

    1992-01-01

    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.

  1. Nondestructive analysis and development

    NASA Technical Reports Server (NTRS)

    Moslehy, Faissal A.

    1993-01-01

    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.

  2. An Electromagnetic Sensor with a Metamaterial Lens for Nondestructive Evaluation of Composite Materials

    PubMed Central

    Savin, Adriana; Steigmann, Rozina; Bruma, Alina; Šturm, Roman

    2015-01-01

    This paper proposes the study and implementation of a sensor with a metamaterial (MM) lens in electromagnetic nondestructive evaluation (eNDE). Thus, the use of a new type of MM, named Conical Swiss Rolls (CSR) has been proposed. These structures can serve as electromagnetic flux concentrators in the radiofrequency range. As a direct application, plates of composite materials with carbon fibers woven as reinforcement and polyphenylene sulphide as matrix with delaminations due to low energy impacts were examined. The evaluation method is based on the appearance of evanescent modes in the space between carbon fibers when the sample is excited with a transversal magnetic along z axis (TMz) polarized electromagnetic field. The MM lens allows the transmission and intensification of evanescent waves. The characteristics of carbon fibers woven structure became visible and delaminations are clearly emphasized. The flaws can be localized with spatial resolution better than λ/2000. PMID:26151206

  3. Non-destructive evaluation of depth of surface cracks using ultrasonic frequency analysis.

    PubMed

    Her, Shiuh-Chuan; Lin, Sheng-Tung

    2014-01-01

    Ultrasonic is one of the most common uses of a non-destructive evaluation method for crack detection and characterization. The effectiveness of the acoustic-ultrasound Structural Health Monitoring (SHM) technique for the determination of the depth of the surface crack was presented. A method for ultrasonic sizing of surface cracks combined with the time domain and frequency spectrum was adopted. The ultrasonic frequency spectrum was obtained by Fourier transform technique. A series of test specimens with various depths of surface crack ranging from 1 mm to 8 mm was fabricated. The depth of the surface crack was evaluated using the pulse-echo technique. In this work, three different longitudinal waves with frequencies of 2.25 MHz, 5 MHz and 10 MHz were employed to investigate the effect of frequency on the sizing detection of surface cracks. Reasonable accuracies were achieved with measurement errors less than 7%. PMID:25225875

  4. Electromagnetic Thermography Nondestructive Evaluation: Physics-based Modeling and Pattern Mining

    PubMed Central

    Gao, Bin; Woo, Wai Lok; Tian, Gui Yun

    2016-01-01

    Electromagnetic mechanism of Joule heating and thermal conduction on conductive material characterization broadens their scope for implementation in real thermography based Nondestructive testing and evaluation (NDT&E) systems by imparting sensitivity, conformability and allowing fast and imaging detection, which is necessary for efficiency. The issue of automatic material evaluation has not been fully addressed by researchers and it marks a crucial first step to analyzing the structural health of the material, which in turn sheds light on understanding the production of the defects mechanisms. In this study, we bridge the gap between the physics world and mathematical modeling world. We generate physics-mathematical modeling and mining route in the spatial-, time-, frequency-, and sparse-pattern domains. This is a significant step towards realizing the deeper insight in electromagnetic thermography (EMT) and automatic defect identification. This renders the EMT a promising candidate for the highly efficient and yet flexible NDT&E. PMID:27158061

  5. Non-Destructive Evaluation of Depth of Surface Cracks Using Ultrasonic Frequency Analysis

    PubMed Central

    Her, Shiuh-Chuan; Lin, Sheng-Tung

    2014-01-01

    Ultrasonic is one of the most common uses of a non-destructive evaluation method for crack detection and characterization. The effectiveness of the acoustic-ultrasound Structural Health Monitoring (SHM) technique for the determination of the depth of the surface crack was presented. A method for ultrasonic sizing of surface cracks combined with the time domain and frequency spectrum was adopted. The ultrasonic frequency spectrum was obtained by Fourier transform technique. A series of test specimens with various depths of surface crack ranging from 1 mm to 8 mm was fabricated. The depth of the surface crack was evaluated using the pulse-echo technique. In this work, three different longitudinal waves with frequencies of 2.25 MHz, 5 MHz and 10 MHz were employed to investigate the effect of frequency on the sizing detection of surface cracks. Reasonable accuracies were achieved with measurement errors less than 7%. PMID:25225875

  6. Use of an ultrasonic-acoustic technique for nondestructive evaluation of fiber composite strength

    NASA Technical Reports Server (NTRS)

    Vary, A.; Bowles, K. J.

    1978-01-01

    This report describes the ultrasonic-acoustic technique used to measure a 'Stress Wave Factor'. In a prior study this factor was found effective in evaluating the interlaminar shear strength of fiber-reinforced composites. Details of the method used to measure the stress wave factor are described. In addition, frequency spectra of the stress waves are analyzed in order to clarify the nature of the wave phenomena involved. The stress wave factor can be measured with simple contact probes requiring only one-side access to a part. This is beneficial in nondestructive evaluations because the waves can run parallel to fiber directions and thus measure material properties in directions assumed by actual loads. Moreover, the technique can be applied where conventional through transmission techniques are impractical or where more quantitative data are required. The stress wave factor was measured for a series of graphite/polyimide composite panels and results obtained are compared with through transmission immersion ultrasonic scans.

  7. Evaluation of thermal cameras for non-destructive thermal testing applications

    NASA Astrophysics Data System (ADS)

    Chrzanowski, K.; Park, S. N.

    2001-04-01

    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 very general guidelines about the use of the measured MRTD and MDTD values for evaluation of thermal cameras for NDTT applications. Precise methods that enable evaluation of a thermal imager for NDTT application on the basis of measurement results of the MRTD and the MDTD are presented in this paper. The methods enable estimation of probabilities of detection, orientation, recognition and identification of thermal anomalies generated by flaws in the materials imaged.

  8. Electromagnetic Thermography Nondestructive Evaluation: Physics-based Modeling and Pattern Mining

    NASA Astrophysics Data System (ADS)

    Gao, Bin; Woo, Wai Lok; Tian, Gui Yun

    2016-05-01

    Electromagnetic mechanism of Joule heating and thermal conduction on conductive material characterization broadens their scope for implementation in real thermography based Nondestructive testing and evaluation (NDT&E) systems by imparting sensitivity, conformability and allowing fast and imaging detection, which is necessary for efficiency. The issue of automatic material evaluation has not been fully addressed by researchers and it marks a crucial first step to analyzing the structural health of the material, which in turn sheds light on understanding the production of the defects mechanisms. In this study, we bridge the gap between the physics world and mathematical modeling world. We generate physics-mathematical modeling and mining route in the spatial-, time-, frequency-, and sparse-pattern domains. This is a significant step towards realizing the deeper insight in electromagnetic thermography (EMT) and automatic defect identification. This renders the EMT a promising candidate for the highly efficient and yet flexible NDT&E.

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

    SciTech Connect

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

    1989-06-01

    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)

  10. Electromagnetic Thermography Nondestructive Evaluation: Physics-based Modeling and Pattern Mining.

    PubMed

    Gao, Bin; Woo, Wai Lok; Tian, Gui Yun

    2016-01-01

    Electromagnetic mechanism of Joule heating and thermal conduction on conductive material characterization broadens their scope for implementation in real thermography based Nondestructive testing and evaluation (NDT&E) systems by imparting sensitivity, conformability and allowing fast and imaging detection, which is necessary for efficiency. The issue of automatic material evaluation has not been fully addressed by researchers and it marks a crucial first step to analyzing the structural health of the material, which in turn sheds light on understanding the production of the defects mechanisms. In this study, we bridge the gap between the physics world and mathematical modeling world. We generate physics-mathematical modeling and mining route in the spatial-, time-, frequency-, and sparse-pattern domains. This is a significant step towards realizing the deeper insight in electromagnetic thermography (EMT) and automatic defect identification. This renders the EMT a promising candidate for the highly efficient and yet flexible NDT&E. PMID:27158061

  11. Thermal-wave nondestructive evaluation of cylindrical composite structures using frequency-domain photothermal radiometry

    NASA Astrophysics Data System (ADS)

    Wang, Chinhua; Mandelis, Andreas; Liu, Yue

    2005-01-01

    In this paper, thermal-wave diagnostics by means of laser infrared photothermal radiometry (PTR) have been used for quantitative nondestructive evaluation of cylindrical composite structures. To quantitatively evaluate the thermal-wave field of a cylindrical composite material, the Green function corresponding to the composite structure and the PTR measurement scheme has been developed and subsequently the thermal-wave field has been derived. Furthermore, the characteristics of the thermal-wave field for two cases of practical interest, i.e., a cylindrical material with a surface coating and a cylindrical tube filled with a low thermal-conductivity fluid medium inside, are discussed. Experimental results from a stainless-steel (AISI 302) cylinder are used to validate the theoretical model.

  12. Non-Destructive Evaluation of Grain Structure Using Air-Coupled Ultrasonics

    SciTech Connect

    Belvin, A. D.; Burrell, R. K.; Cole, E.G.

    2009-08-01

    Cast material has a grain structure that is relatively non-uniform. There is a desire to evaluate the grain structure of this material non-destructively. Traditionally, grain size measurement is a destructive process involving the sectioning and metallographic imaging of the material. Generally, this is performed on a representative sample on a periodic basis. Sampling is inefficient and costly. Furthermore, the resulting data may not provide an accurate description of the entire part's average grain size or grain size variation. This project is designed to develop a non-destructive acoustic scanning technique, using Chirp waveforms, to quantify average grain size and grain size variation across the surface of a cast material. A Chirp is a signal in which the frequency increases or decreases over time (frequency modulation). As a Chirp passes through a material, the material's grains reduce the signal (attenuation) by absorbing the signal energy. Geophysics research has shown a direct correlation with Chirp wave attenuation and mean grain size in geological structures. The goal of this project is to demonstrate that Chirp waveform attenuation can be used to measure grain size and grain variation in cast metals (uranium and other materials of interest). An off-axis ultrasonic inspection technique using air-coupled ultrasonics has been developed to determine grain size in cast materials. The technique gives a uniform response across the volume of the component. This technique has been demonstrated to provide generalized trends of grain variation over the samples investigated.

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

    PubMed

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

    2013-07-01

    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

  14. Nondestructive evaluation of notched cracks in mortars by nonlinear ultrasonic technique

    NASA Astrophysics Data System (ADS)

    Chen, Jun; Ren, Jun; Yin, Tingyuan

    2016-04-01

    In this paper, a nonlinear ultrasonic technique is used to nondestructively characterise concentrated defects in cement-based materials. Cracks are artificially notched in mortar samples and five different crack widths are used to simulate increased damage of samples. The relative ratio of second harmonic amplitude to the square of fundamental ultrasonic signal amplitude is defined as the damage indicator of the nonlinear ultrasonic technique, which is measured for mortar samples in conjunction with a typical linear nondestructive evaluation parameter - ultrasonic pulse velocity. It is found that both linear and nonlinear damage parameters have a good correlation with the change of crack width, while the nonlinearity parameter shows a better sensitivity to the width increase. In addition, the nonlinearity parameter presents an exponential increase with the crack growth, indicating an accelerating nonlinear ultrasonic response of materials to increased internal damage in the late phase. The results demonstrate that the nonlinear ultrasonic technique based on the second harmonic principle keeps the high sensitivity to the isolated cracks in cement-based materials, similarly to the case of distributed cracks in previous studies. The developed technique could thus be a useful experimental tool for the assessment of concentrated damage of concrete structures.

  15. Acoustic diagnosis for nondestructive evaluation of ceramic coatings on steel substrates

    SciTech Connect

    Aizawa, Tatsuhiko; Kihara, Junji; Ito, Manabu

    1995-11-01

    New methodology is proposed and developed to make quantitative nondestructive evaluation of TiN coated SKH steel substrates. Since the measured acoustic structure is in precise correspondence with the multi-layered elastic media, change of elastic properties by degradation and damage can be easily distinguished by the acoustic spectro microscopy. In particular, rather complex acoustic structure can be measured by the present method for ceramic coated steel substrate system, but it is completely described by the two-layer model in two dimensional elasticity. Typical example is the cut-off phenomenon where the dispersion curve for the leaky surface wave velocity is forced to be terminated by alternative activation of shear wave instead of it. The quantitative nondestructive diagnosis was developed on the basis of this predictable acoustic structure. Furthermore, the effect of coating conditions on the acoustic structure is also discussed to make residual stress distribution analysis in coating by the acoustic spectro microscopy with reference to the X-ray stress analysis. Some comments are made on further advancement of the present acoustic spectro microscopy adaptive to precise characterization of ceramic coatings and practical sensing system working in practice.

  16. 78 FR 14549 - National Contact Center; Information Collection; National Contact Center Customer Evaluation Survey

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-06

    ... ADMINISTRATION National Contact Center; Information Collection; National Contact Center Customer Evaluation Survey AGENCY: Contact Center Services, Federal Citizen Information Center, Office of Citizen Services... requirement regarding the National Contact Center customer evaluation surveys. In this request, the...

  17. 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)

    Waller, Jess; Saulsberry, Regor

    2012-01-01

    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

  18. Development of nondestructive-evaluation techniques for high-temperature ceramic heat-exchanger components

    NASA Astrophysics Data System (ADS)

    Kupperman, D. S.; Yuhas, D.; Michaels, T. E.; Michaels, J. E.

    1982-01-01

    An assessment was made of ultrasonic techniques developed to date for nondestructive evaluation of SiC heat exchanger tubes. The results suggest that ultrasonic inspection is a useful and valuable technique for inspecting these tubes, including ceramic butt joints. However, this method alone is currently not sufficiently effective to detect all critical flaws because of (1) the difficulties in following the surface of an out of round tube; (2) the high velocity and thus the large angle of refraction of sound in SiC, which for small diameter tubes leads to significant beam distortion; and (3) insuffient resolution, relative to the small critical flaw size in ceramics, at conventional ultrasonic testing frequencies. The experiments show that higher frequencies (up to 35 MHz) are required for effective wall thickness measurements and detection of laminar type flaws.

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

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

    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.

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

    SciTech Connect

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

    2011-10-03

    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.

  1. Risk assessment of turbine rotor failure using probabilistic ultrasonic non-destructive evaluations

    SciTech Connect

    Guan, Xuefei; Zhang, Jingdan; Zhou, S. Kevin; Rasselkorde, El Mahjoub; Abbasi, Waheed A.

    2014-02-18

    The study presents a method and application of risk assessment methodology for turbine rotor fatigue failure using probabilistic ultrasonic nondestructive evaluations. A rigorous probabilistic modeling for ultrasonic flaw sizing is developed by incorporating the model-assisted probability of detection, and the probability density function (PDF) of the actual flaw size is derived. Two general scenarios, namely the ultrasonic inspection with an identified flaw indication and the ultrasonic inspection without flaw indication, are considered in the derivation. To perform estimations for fatigue reliability and remaining useful life, uncertainties from ultrasonic flaw sizing and fatigue model parameters are systematically included and quantified. The model parameter PDF is estimated using Bayesian parameter estimation and actual fatigue testing data. The overall method is demonstrated using a realistic application of steam turbine rotor, and the risk analysis under given safety criteria is provided to support maintenance planning.

  2. High-resolution thermal imaging methodology for non-destructive evaluation of historic structures

    NASA Astrophysics Data System (ADS)

    Hess, Michael; Vanoni, David; Petrovic, Vid; Kuester, Falko

    2015-11-01

    This paper presents a methodology for automated, portable thermography, for the acquisition of high-resolution thermal image mosaics supporting the non-destructive evaluation of historic structures. The presented approach increases the spatial resolution of thermal surveys to a level of detail needed for building scale analysis. The integration of a robotic camera platform enables automated alignment of multiple images into a high-resolution thermal image mosaic giving a holistic view of the structure while maintaining a level of detail equaling or exceeding that of traditional spot surveys using existing cameras. Providing a digital workflow for automated data and metadata recording increases the consistency and accuracy of surveys regardless of the location or operator. An imaging workflow and instrumentation are shown for a case-study on buildings in Florence, Italy demonstrating the effectiveness of this methodology for structural diagnostics.

  3. Neural network-based inversion algorithms in magnetic flux leakage nondestructive evaluation

    NASA Astrophysics Data System (ADS)

    Ramuhalli, Pradeep; Udpa, Lalita; Udpa, Satish S.

    2003-05-01

    Magnetic flux leakage (MFL) methods are commonly used in the nondestructive evaluation (NDE) of ferromagnetic materials. An important problem in MFL NDE is the determination of flaw parameters such as the flaw length, depth, and shape (profile) from the measured values of the flux density B. Commonly used methods use a forward model in a loop to determine B for a given set of flaw parameters. This approach iteratively adjusts the flaw parameters to minimize the error between the measured and predicted values of B. This article proposes the use of neural networks as forward models. The proposed approach uses two neural networks in feedback configuration—a forward network and an inverse network. The second network is used to predict the profile given the measured value of B, and acts to constrain the solution space. Results of applying these methods to MFL data obtained from a two-dimensional finite-element model, with rectangular flaws of various dimensions, are presented.

  4. Process for Nondestructive Evaluation of the Quality of a Crimped Wire Connector

    NASA Technical Reports Server (NTRS)

    Yost, William T. (Inventor); Cramer, Karl E. (Inventor); Perey, Daniel F. (Inventor); Williams, Keith A. (Inventor)

    2014-01-01

    A process and apparatus for collecting data for nondestructive evaluation of the quality of a crimped wire connector are provided. The process involves providing a crimping tool having an anvil and opposing jaw for crimping a terminal onto a stranded wire, moving the jaw relative to the anvil to close the distance between the jaw and the anvil and thereby compress the terminal against the wire, while transmitting ultrasonic waves that are propagated through the terminal-wire combination and received at a receiving ultrasonic transducer as the jaw is moved relative to the anvil, and detecting and recording the position of the jaw relative to the anvil as a function of time and detecting and recording the amplitude of the ultrasonic wave that is received at the receiving ultrasonic transducer as a function of time as the jaw is moved relative to the anvil.

  5. Nondestructive evaluation of braided carbon fiber composites with artificial defect using HTS-SQUID gradiometer

    NASA Astrophysics Data System (ADS)

    Shinyama, Y.; Yamaji, T.; Hatsukade, Y.; Takai, Y.; Aly-Hassan, M. S.; Nakai, A.; Hamada, H.; Tanaka, S.

    2011-11-01

    Braided carbon fiber reinforced plastics (CFRPs) are one of multifunctional materials with superior properties such as mechanical strength to normal CFRPs since the braided CFRPs have continuous fiber bundles. In this paper, we applied the current-injection-based nondestructive evaluation (NDE) method using a HTS-SQUID gradiometer to the braided CFRP for the detection of the breakage of the bundles. We prepared planar braided CFRP samples with and without artificial cracks of 1 and 2 mm lengths, and measured the current density distribution above the samples using the NDE method. In the measurement results, not only a few completely-cut bundles but also the additional partially-cut bundles were detected from decrease in the measured current density along the cut bundle around the cracks. From these results, we showed that it is possible to inspect a few partially-cut bundles in the braided CFRPs by the NDE method.

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

    SciTech Connect

    Dr. Shreekanth Mandayam; Dr. Robi Polikar; Dr. John C. Chen

    2003-06-01

    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 fabricated test specimens with simulated defects for nondestructive evaluation (NDE); designed and developed two versions of a test platform for performing multi-sensor interrogation of test specimens under loaded conditions simulating pressurized gas pipelines; and performed acoustic emission (AE) NDE on the test specimens. The data resulting from this work will be employed for designing multi-sensor data fusion algorithms during the next reporting period.

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

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    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.

  8. Evaluation and correction of readout artifacts from flat panel detectors for non-destructive testing purposes

    NASA Astrophysics Data System (ADS)

    Burtzlaff, S.; Voland, V.; Salamon, M.; Hofmann, Th.; Uhlmann, N.

    2009-08-01

    Flat panel detectors are commonly used for non-destructive testing purposes using X-ray technology. During a series of measurements with high absorbing objects, we observed an unknown kind of artifacts especially apparent with high contrast edges. These artifacts lead to unwanted results in radioscopic and computed tomography inspection. Given the object is fully occupying the lower part and half of the upper part of the detector. Looking at the image with high contrast visualization, it can be seen that the covered upper part of the detector is brighter than the covered lower half. The horizontal border of the detector tile is clearly recognizable. Furthermore, the uncovered area directly above the object is darker than next to the edge. In this area the vertical border of the edge below can be localized. We examined and evaluated the effect and developed a correction algorithm. The effect and its correction results are presented.

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

    SciTech Connect

    Shreekanth Mandayam; Robi Polikar; John C. Chen

    2004-04-01

    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 fabricated test specimens with simulated defects for nondestructive evaluation (NDE); designed and developed two versions of a test platform for performing multi-sensor interrogation of test specimens under loaded conditions simulating pressurized gas pipelines; and performed magnetic flux leakage (MFL), ultrasonic testing (UT), thermal imaging and acoustic emission (AE) NDE on the test specimens. The data resulting from this work will be employed for designing multi-sensor data fusion algorithms.

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

    NASA Technical Reports Server (NTRS)

    Walker, James L.; Richter, Joel D.

    2006-01-01

    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.

  11. Nondestructive Evaluation of Carbon Fiber Reinforced Polymer Composites Using Reflective Terahertz Imaging

    PubMed Central

    Zhang, Jin; Li, Wei; Cui, Hong-Liang; Shi, Changcheng; Han, Xiaohui; Ma, Yuting; Chen, Jiandong; Chang, Tianying; Wei, Dongshan; Zhang, Yumin; Zhou, Yufeng

    2016-01-01

    Terahertz (THz) time-domain spectroscopy (TDS) imaging is considered a nondestructive evaluation method for composite materials used for examining various defects of carbon fiber reinforced polymer (CFRP) composites and fire-retardant coatings in the reflective imaging modality. We demonstrate that hidden defects simulated by Teflon artificial inserts are imaged clearly in the perpendicular polarization mode. The THz TDS technique is also used to measure the thickness of thin fire-retardant coatings on CFRP composites with a typical accuracy of about 10 micrometers. In addition, coating debonding is successfully imaged based on the time-delay difference of the time-domain waveforms between closely adhered and debonded sample locations. PMID:27314352

  12. A sparse digital signal model for ultrasonic nondestructive evaluation of layered materials.

    PubMed

    Bochud, N; Gomez, A M; Rus, G; Peinado, A M

    2015-09-01

    Signal modeling has been proven to be an useful tool to characterize damaged materials under ultrasonic nondestructive evaluation (NDE). In this paper, we introduce a novel digital signal model for ultrasonic NDE of multilayered materials. This model borrows concepts from lattice filter theory, and bridges them to the physics involved in the wave-material interactions. In particular, the proposed theoretical framework shows that any multilayered material can be characterized by a transfer function with sparse coefficients. The filter coefficients are linked to the physical properties of the material and are analytically obtained from them, whereas a sparse distribution naturally arises and does not rely on heuristic approaches. The developed model is first validated with experimental measurements obtained from multilayered media consisting of homogeneous solids. Then, the sparse structure of the obtained digital filter is exploited through a model-based inverse problem for damage identification in a carbon fiber-reinforced polymer (CFRP) plate. PMID:26092090

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

    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.

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

    DOEpatents

    Jiles, David C.; Sipahi, Levent B.

    1994-05-17

    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.

  15. Nondestructive evaluation of explosively welded clad rods by resonance acoustic spectroscopy.

    PubMed

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

    2003-07-01

    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 cladding into the aluminum core. Excellent agreement is achieved between measured and calculated values of the resonant frequencies of the system, through appropriate adjustment of the interfacial mass and spring constants used in the wave scattering calculations. Destructive analysis of the interface in the experimental specimens confirms that key features of the interfacial profile may be inferred from resonance acoustic spectroscopy analysis applied to ultrasonic measurements. PMID:12788219

  16. Nondestructive Evaluation of Carbon Fiber Reinforced Polymer Composites Using Reflective Terahertz Imaging.

    PubMed

    Zhang, Jin; Li, Wei; Cui, Hong-Liang; Shi, Changcheng; Han, Xiaohui; Ma, Yuting; Chen, Jiandong; Chang, Tianying; Wei, Dongshan; Zhang, Yumin; Zhou, Yufeng

    2016-01-01

    Terahertz (THz) time-domain spectroscopy (TDS) imaging is considered a nondestructive evaluation method for composite materials used for examining various defects of carbon fiber reinforced polymer (CFRP) composites and fire-retardant coatings in the reflective imaging modality. We demonstrate that hidden defects simulated by Teflon artificial inserts are imaged clearly in the perpendicular polarization mode. The THz TDS technique is also used to measure the thickness of thin fire-retardant coatings on CFRP composites with a typical accuracy of about 10 micrometers. In addition, coating debonding is successfully imaged based on the time-delay difference of the time-domain waveforms between closely adhered and debonded sample locations. PMID:27314352

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

    NASA Technical Reports Server (NTRS)

    Temple, Enoch C.

    1994-01-01

    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.

  18. Risk assessment of turbine rotor failure using probabilistic ultrasonic non-destructive evaluations

    NASA Astrophysics Data System (ADS)

    Guan, Xuefei; Zhang, Jingdan; Zhou, S. Kevin; Rasselkorde, El Mahjoub; Abbasi, Waheed A.

    2014-02-01

    The study presents a method and application of risk assessment methodology for turbine rotor fatigue failure using probabilistic ultrasonic nondestructive evaluations. A rigorous probabilistic modeling for ultrasonic flaw sizing is developed by incorporating the model-assisted probability of detection, and the probability density function (PDF) of the actual flaw size is derived. Two general scenarios, namely the ultrasonic inspection with an identified flaw indication and the ultrasonic inspection without flaw indication, are considered in the derivation. To perform estimations for fatigue reliability and remaining useful life, uncertainties from ultrasonic flaw sizing and fatigue model parameters are systematically included and quantified. The model parameter PDF is estimated using Bayesian parameter estimation and actual fatigue testing data. The overall method is demonstrated using a realistic application of steam turbine rotor, and the risk analysis under given safety criteria is provided to support maintenance planning.

  19. Quantitative broadband ultrasonic backscatter - An approach to nondestructive evaluation in acoustically inhomogeneous materials

    NASA Technical Reports Server (NTRS)

    Odonnell, M.; Miller, J. G.

    1981-01-01

    The use of a broadband backscatter technique to obtain the frequency dependence of the longitudinal-wave ultrasonic backscatter coefficient from a collection of scatterers in a solid is investigated. Measurements of the backscatter coefficient were obtained over the range of ultrasonic wave vector magnitude-glass sphere radius product between 0.1 and 3.0 from model systems consisting of dilute suspensions of randomly distributed crown glass spheres in hardened polyester resin. The results of these measurements were in good agreement with theoretical prediction. Consequently, broadband measurements of the ultrasonic backscatter coefficient may represent a useful approach toward characterizing the physical properties of scatterers in intrinsically inhomogeneous materials such as composites, metals, and ceramics, and may represent an approach toward nondestructive evaluation of these materials.

  20. Review of nonlinear ultrasonic guided wave nondestructive evaluation: theory, numerics, and experiments

    NASA Astrophysics Data System (ADS)

    Chillara, Vamshi Krishna; Lissenden, Cliff J.

    2016-01-01

    Interest in using the higher harmonic generation of ultrasonic guided wave modes for nondestructive evaluation continues to grow tremendously as the understanding of nonlinear guided wave propagation has enabled further analysis. The combination of the attractive properties of guided waves with the attractive properties of higher harmonic generation provides a very unique potential for characterization of incipient damage, particularly in plate and shell structures. Guided waves can propagate relatively long distances, provide access to hidden structural components, have various displacement polarizations, and provide many opportunities for mode conversions due to their multimode character. Moreover, higher harmonic generation is sensitive to changing aspects of the microstructures such as to the dislocation density, precipitates, inclusions, and voids. We review the recent advances in the theory of nonlinear guided waves, as well as the numerical simulations and experiments that demonstrate their utility.

  1. Nondestructive evaluation techniques for development and characterization of carbon nanotube based superstructures

    NASA Astrophysics Data System (ADS)

    Wincheski, Buzz; Kim, Jae-Woo; Sauti, Godfrey; Wainwright, Elliot; Williams, Phillip; Siochi, Emile J.

    2015-03-01

    Recently, multiple commercial vendors have developed capability for the production of large-scale quantities of high-quality carbon nanotube sheets and yarns [1]. While the materials have found use in electrical shielding applications, development of structural systems composed of a high volume fraction of carbon nanotubes is still lacking [2]. A recent NASA program seeks to address this by prototyping a structural nanotube composite with strength-to-weight ratio exceeding current state-of-the-art carbon fiber composites. Commercially available carbon nanotube sheets, tapes, and yarns are being processed into high volume fraction carbon nanotube-polymer nanocomposites. Nondestructive evaluation techniques have been applied throughout this development effort for material characterization and process control. This paper will report on the progress of these efforts, including magnetic characterization of residual catalyst content, Raman scattering characterization of nanotube diameter and nanotube strain, and polarized Raman scattering for characterization of nanotube alignment.

  2. Gigahertz time-domain spectroscopy and imaging for non-destructive materials research and evaluation

    NASA Astrophysics Data System (ADS)

    Bulgarevich, Dmitry S.; Shiwa, Mitsuharu; Furuya, Takashi; Tani, Masahiko

    2016-06-01

    By using optical sampling with repetition frequency modulation of pump/probe laser pulses on photoconductive emitter/detector antennas, the high-speed time/frequency domain gigahertz imaging is reported due to the absence of opto-mechanical delay line in this optical scheme. The clear contrast for a 3-cm wide metal plate, which was placed behind a 5-cm thick concrete block, was observed with a 1 × 1 mm image pixilation. On average, it took only ~0.75 s per pixel/waveform acquisition/assignment with a 675 ps time-domain window. This could become a valuable non-destructive evaluation technique in gigahertz spectral range with all benefits of time-domain spectroscopy.

  3. Gigahertz time-domain spectroscopy and imaging for non-destructive materials research and evaluation.

    PubMed

    Bulgarevich, Dmitry S; Shiwa, Mitsuharu; Furuya, Takashi; Tani, Masahiko

    2016-01-01

    By using optical sampling with repetition frequency modulation of pump/probe laser pulses on photoconductive emitter/detector antennas, the high-speed time/frequency domain gigahertz imaging is reported due to the absence of opto-mechanical delay line in this optical scheme. The clear contrast for a 3-cm wide metal plate, which was placed behind a 5-cm thick concrete block, was observed with a 1 × 1 mm image pixilation. On average, it took only ~0.75 s per pixel/waveform acquisition/assignment with a 675 ps time-domain window. This could become a valuable non-destructive evaluation technique in gigahertz spectral range with all benefits of time-domain spectroscopy. PMID:27302877

  4. Evaluation of nondestructive testing techniques for the space shuttle nonmetallic thermal protection system

    NASA Technical Reports Server (NTRS)

    Tiede, D. A.

    1972-01-01

    A program was conducted to evaluate nondestructive analysis techniques for the detection of defects in rigidized surface insulation (a candidate material for the Space Shuttle thermal protection system). Uncoated, coated, and coated and bonded samples with internal defects (voids, cracks, delaminations, density variations, and moisture content), coating defects (holes, cracks, thickness variations, and loss of adhesion), and bondline defects (voids and unbonds) were inspected by X-ray radiography, acoustic, microwave, high-frequency ultrasonic, beta backscatter, thermal, holographic, and visual techniques. The detectability of each type of defect was determined for each technique (when applicable). A possible relationship between microwave reflection measurements (or X-ray-radiography density measurements) and the tensile strength was established. A possible approach for in-process inspection using a combination of X-ray radiography, acoustic, microwave, and holographic techniques was recommended.

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

    NASA Technical Reports Server (NTRS)

    Generazio, Ed

    2005-01-01

    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.

  6. High-speed terahertz reflection three-dimensional imaging for nondestructive evaluation.

    PubMed

    Jin, Kyong Hwan; Kim, Young-Gil; Cho, Seung Hyun; Ye, Jong Chul; Yee, Dae-Su

    2012-11-01

    We demonstrate high-speed terahertz (THz) reflection three-dimensional (3D) imaging based on electronically controlled optical sampling (ECOPS). ECOPS enables scanning of an axial range of 9 mm in free space at 1 kHz. It takes 80 s to scan a transverse range of 100 mm × 100 mm along a zigzag trajectory that consists of 200 lines using translation stages. To show applicability of the imaging system to nondestructive evaluation, a THz reflection 3D image of an artificially made sample is obtained, which is made of glass fiber reinforced polymer composite material and has defects such as delamination and inclusion, and is compared with an ultrasonic reflection 3D image of the sample. PMID:23187360

  7. Gigahertz time-domain spectroscopy and imaging for non-destructive materials research and evaluation

    PubMed Central

    Bulgarevich, Dmitry S.; Shiwa, Mitsuharu; Furuya, Takashi; Tani, Masahiko

    2016-01-01

    By using optical sampling with repetition frequency modulation of pump/probe laser pulses on photoconductive emitter/detector antennas, the high-speed time/frequency domain gigahertz imaging is reported due to the absence of opto-mechanical delay line in this optical scheme. The clear contrast for a 3-cm wide metal plate, which was placed behind a 5-cm thick concrete block, was observed with a 1 × 1 mm image pixilation. On average, it took only ~0.75 s per pixel/waveform acquisition/assignment with a 675 ps time-domain window. This could become a valuable non-destructive evaluation technique in gigahertz spectral range with all benefits of time-domain spectroscopy. PMID:27302877

  8. An Assessment of Nondestructive Evaluation Capability for Complex Additive Manufacturing Aerospace Components

    NASA Technical Reports Server (NTRS)

    Walker, James; Beshears, Ron; Lambert, Dennis; Tilson, William

    2016-01-01

    The primary focus of this work is to investigate some of the fundamental relationships between processing, mechanical testing, materials characterization, and NDE for additively manufactured (AM) components using the powder bed fusion direct melt laser sintered process. The goal is to understand the criticality of defects unique to the AM process and then how conventional nondestructive evaluation methods as well as some of the more non-traditional methods such as computed tomography, are effected by the AM material. Specific defects including cracking, porosity and partially/unfused powder will be addressed. Besides line-of-site NDE, as appropriate these inspection capabilities will be put into the context of complex AM geometries where hidden features obscure, or inhibit traditional NDE methods.

  9. Ultrasonic guided waves for nondestructive evaluation/structural health monitoring of trusses

    NASA Astrophysics Data System (ADS)

    'Peter'Zhu, Xuan; Rizzo, Piervincenzo; Marzani, Alessandro; Bruck, Jerry

    2010-04-01

    Ultrasonic guided waves (UGWs) are particularly effective in those nondestructive evaluation and structural health monitoring applications that benefit from built-in transduction, moderately large inspection ranges and high sensitivity to small flaws. This paper describes a method to detect cracks in large trusses that combines the advantages of UGWs with the extraction of defect-sensitive features to perform a multivariate diagnosis of damage. The proposed algorithm was applied to the guided waves propagating along one of the main chords of a dismantled overhead sign support structure. The probing hardware consisted of a data acquisition system that controlled the generation and detection of ultrasonic signals by means of piezoelectric transducers made of lead zirconate titanate. The effectiveness of the proposed approach to diagnose the presence of an artificial defect around the welded joint between one main chord and a diagonal member of the truss structure is explained.

  10. Integrated Nondestructive Evaluation and Finite Element Analysis Predicts Crack Location and Shape

    NASA Technical Reports Server (NTRS)

    Abdul-Azia, Ali; Baaklini, George Y.; Trudell, Jeffrey J.

    2002-01-01

    This study describes the finite-element analyses and the NDE modality undertaken on two flywheel rotors that were spun to burst speed. Computed tomography and dimensional measurements were used to nondestructively evaluate the rotors before and/or after they were spun to the first crack detection. Computed tomography data findings of two- and three-dimensional crack formation were used to conduct finite-element (FEA) and fracture mechanics analyses. A procedure to extend these analyses to estimate the life of these components is also outlined. NDE-FEA results for one of the rotors are presented in the figures. The stress results, which represent the radial stresses in the rim, clearly indicate that the maximum stress region is within the section defined by the computed tomography scan. Furthermore, the NDE data correlate well with the FEA results. In addition, the measurements reported show that the NDE and FEA data are in parallel.

  11. C/C composite brake disk nondestructive evaluation by IR thermography

    NASA Astrophysics Data System (ADS)

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

    2012-06-01

    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.

  12. Nondestructive evaluation of the preservation state of stone columns in the Hospital Real of Granada

    NASA Astrophysics Data System (ADS)

    Moreno de Jong van Coevorden, C.; Cobos Sánchez, C.; Rubio Bretones, A.; Fernández Pantoja, M.; García, Salvador G.; Gómez Martín, R.

    2012-12-01

    This paper describes the results of the employment of two nondestructive evaluation methods for the diagnostic of the preservation state of stone elements. The first method is based on ultrasonic (US) pulses while the second method uses short electromagnetic pulses. Specifically, these methods were applied to some columns, some of them previously restored. These columns are part of the architectonic heritage of the University of Granada, in particular they are located at the patio de la capilla del Hospital Real of Granada. The objective of this work was the application of systems based on US pulses (in transmission mode) and the ground-penetrating radar systems (electromagnetic tomography) in the diagnosis and detection of possible faults in the interior of columns.

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

    SciTech Connect

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

    1998-04-01

    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.

  14. Nanomanipulation and Lithography for Carbon Nanotube Based Nondestructive Evaluation Sensor Development

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    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.

  15. Nondestructive Evaluation of Additive Manufacturing State-of-the-Discipline Report

    NASA Technical Reports Server (NTRS)

    Waller, Jess M.; Parker, Bradford H.; Hodges, Kenneth L.; Burke, Eric R.; Walker, James L.

    2014-01-01

    This report summarizes the National Aeronautics and Space Administrations (NASA) state of the art of nondestructive evaluation (NDE) for additive manufacturing (AM), or "3-D printed", hardware. NASA's unique need for highly customized spacecraft and instrumentation is suited for AM, which offers a compelling alternative to traditional subtractive manufacturing approaches. The Agency has an opportunity to push the envelope on how this technology is used in zero gravity, an enable in-space manufacturing of flight spares and replacement hardware crucial for long-duration, manned missions to Mars. The Agency is leveraging AM technology developed internally and by industry, academia, and other government agencies for its unique needs. Recent technical interchange meetings and workshops attended by NASA have identified NDE as a universal need for all aspects of additive manufacturing. The impact of NDE on AM is cross cutting and spans materials, processing quality assurance, testing and modeling disciplines. Appropriate NDE methods are needed before, during, and after the AM production process.

  16. VibroSim: A hybrid computational/empirical model of vibrothermography nondestructive evaluation

    NASA Astrophysics Data System (ADS)

    Holland, Stephen D.; Koester, Lucas; Vaddi, Jyani; Lesthaeghe, Tyler; Meeker, William Q.; Schiefelbein, Bryan

    2016-02-01

    Vibrothermography is a nondestructive evaluation technique that finds cracks through vibration-induced heating of contacting crack surfaces. Because there are multiple phenomena involved: vibration, vibration-induced heating, and heat flow, all three processes must be accurately represented in individually tested components in order to create a meaningful model of the entire process. Finite element models are suitable for the well-understood vibrational and heat flow modeling components. With the phenomenology of the heat generation component still unclear, an empirical model was used to relate the dynamic engineering strain from the vibration to the crack heating itself. All three components are integrated into a single COMSOL model generated by a collection of MATLAB scripts.

  17. Nondestructive Evaluation Techniques for Development and Characterization of Carbon Nanotube Based Superstructures

    NASA Technical Reports Server (NTRS)

    Wincheski, Buzz; Kim, Jae-Woo; Sauti, Godfrey; Wainwright, Elliot; Williams, Phillip; Siochi, Emile J.

    2014-01-01

    Recently, multiple commercial vendors have developed capability for the production of large-scale quantities of high-quality carbon nanotube sheets and yarns. While the materials have found use in electrical shielding applications, development of structural systems composed of a high volume fraction of carbon nanotubes is still lacking. A recent NASA program seeks to address this by prototyping a structural nanotube composite with strength-toweight ratio exceeding current state-of-the-art carbon fiber composites. Commercially available carbon nanotube sheets, tapes, and yarns are being processed into high volume fraction carbon nanotube-polymer nanocomposites. Nondestructive evaluation techniques have been applied throughout this development effort for material characterization and process control. This paper will report on the progress of these efforts, including magnetic characterization of residual catalyst content, Raman scattering characterization of nanotube diameter, defect ratio, and nanotube strain, and polarized Raman scattering for characterization of nanotube alignment.

  18. Nondestructive Evaluation of Advanced Materials with X-ray Phase Mapping

    NASA Technical Reports Server (NTRS)

    Hu, Zhengwei

    2005-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

    Goldsby, Jon C.

    1998-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

    1995-01-01

    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.

  1. Shearographic and thermographic nondestructive evaluation of the space shuttle structure and thermal protection systems (TPS)

    NASA Astrophysics Data System (ADS)

    Davis, Christopher K.

    1996-11-01

    Shearography and thermography have shown promising results on orbiter structure and external tank (ET) and solid rocket booster (SRB) thermal protection systems (TPS). The orbiter uses a variety of composite structure, the two most prevalent materials being aluminum and graphite-epoxy honeycomb. Both techniques have detected delaminations as small at 0.25 inches diameter in the orbiter payload bay doors graphite-epoxy honeycomb structure. Other applications include the robotic manipulator system (RMS) and the rudder speed brake structure. The ET uses spray-on foam insulation (SOFI) as the TPS and the SRB forward section uses marshall sprayable ablative as the TPS. Debonding SOFI damage to the orbiter 'belly' tile and exposes the ET to thermal loading. Voids in SOFI test panels as small as 0.375 inch were detected in 1.75 inch thick foam using a pressure reduction of not more than 10 inches of water or 0.4 pounds per square inch. Preliminary results of the X33 metallic TPS are presented. Ultrasonic testing approved for orbiter bond integrity testing, is time consuming and problematic. No current non-destructive inspection technique is approved for inspection of ET/SRB TPS or the orbiter RMS honeycomb at Kennedy Space Center. Only visual inspections are routinely performed on orbiter structure. The various successes of these two techniques make them good candidates for the aforementioned applications.

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

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1998-01-01

    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.

  3. A time-domain finite element boundary integration method for ultrasonic nondestructive evaluation.

    PubMed

    Shi, Fan; Choi, Wonjae; Skelton, Elizabeth A; Lowe, Michael J S; Craster, Richard V

    2014-12-01

    A 2-D and 3-D numerical modeling approach for calculating the elastic wave scattering signals from complex stress-free defects is evaluated. In this method, efficient boundary integration across the complex boundary of the defect is coupled with a time-domain finite element (FE) solver. The model is designed to simulate time-domain ultrasonic nondestructive evaluation in bulk media. This approach makes use of the hybrid concept of linking a local numerical model to compute the near-field scattering behavior and theoretical mathematical formulas for postprocessing to calculate the received signals. It minimizes the number of monitoring signals from the FE calculation so that the computation effort in postprocessing decreases significantly. In addition, by neglecting the conventional regular monitoring box, the region for FE calculation can be made smaller. In this paper, the boundary integral method is implemented in a commercial FE code, and it is validated by comparing the scattering signals with results from corresponding full FE models. The coupled method is then implemented in real inspection scenarios in both 2-D and 3-D, and the accuracy and the efficiency are demonstrated. The limitations of the proposed model and future works are also discussed. PMID:25474780

  4. Non-destructive evaluation of spiral-welded pipes using flexural guided waves

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaowei; Tang, Zhifeng; Lü, Fuzai; Pan, Xiaohong

    2016-02-01

    Millions of miles of pipes are being used in both civil and industrial fields. Spiral-welded pipes, which are widely applied in fields such as drainage, architecture as well as oil and gas storage and transportation, are difficult to inspect due to their complex geometry. Guided waves have shown a great potential in Non-Destructive Evaluation (NDE) and Structural Health Monitoring (SHM) for such cases. Flexural guided waves that propagate at a helix angle relative to the axial direction of pipe, are the most appropriate modes for inspecting spiral-welded pipes. The classical Normal Mode Expansion method (NME) is adopted to disseminate the forced response and perturbation analysis of a steel pipe with respect to a time delay circular loading. A time delay circular array transducer (TDCAT) is proposed for the purpose of exciting pure flexural mode in pipes. Pure flexural mode can be excited when the time delay parameter is specifically designed. The theoretical prediction is verified by finite element numerical evaluation and spiral-welded pipe inspection experiment.

  5. Phenomenological and mechanics aspects of nondestructive evaluation and characterization by sound and ultrasound of material and fracture properties

    NASA Technical Reports Server (NTRS)

    Fu, L. S. W.

    1982-01-01

    Developments in fracture mechanics and elastic wave theory enhance the understanding of many physical phenomena in a mathematical context. Available literature in the material, and fracture characterization by NDT, and the related mathematical methods in mechanics that provide fundamental underlying principles for its interpretation and evaluation are reviewed. Information on the energy release mechanism of defects and the interaction of microstructures within the material is basic in the formulation of the mechanics problems that supply guidance for nondestructive evaluation (NDE).

  6. Nondestructive Evaluation of Stiffness and Stresses of Ceramic Candle Filters at Elevated Temperature under Vibrational Environment

    SciTech Connect

    Chen, R.H.L.; Kiriakidia, A.

    2002-09-19

    In recent years a significant amount of effort has been devoted to develop damage-tolerant hot gas filter elements, which can withstand chemical, high pressure and extreme thermal cyclic loading in the coal-based environment (Alvin 1999, Spain and Starrett 1999). Ceramic candle filters have proven to be an effective filter for the ash laden gas streams, protecting the gas turbine components from exposure to particulate matter (Lippert et al. 1994). Ceramic candle filters need to sustain extreme thermal environment and vibration-induced stresses over a great period of time. Destructive tests have been used to describe physical, mechanical and thermal properties of the filters and to relate these properties and behaviors to in-service performance, and ultimately to predict the useful life of the filter materials (Pontius and Starrett 1994, Alvin et al. 1994). Nondestructive evaluation (NDE) techniques have been developed to determine the deterioration or the presence of damage and to estimate the remaining stiffness of ceramic candle filters (Chen and Kiriakidis 2001). This paper presents a study of parameters involved in the prediction of remaining life of ceramic candle filters under service conditions. About one hundred ceramic candle filters from previous studies (Chen and Kiriakidis 2000) and forty-six filters received during this project have been nondestructively evaluated. They are divided in Pall Vitropore, Schumacher and Coors filters. Forty-six of these filters were used having various in-service exposure times at the PSDF and the rest were unused filters. Dynamic characterization tests were employed to investigate the material properties of ceramic candle filters. The vibration frequency changes due to exposure hours, dust cake accumulation, candle's axisymmetry, boundary conditions and elevated temperatures are studied. Investigations on fatigue stresses of the filters due to vibration of the plenum and back pulse shaking are also studied. Finite element

  7. Pulsed Bremsstrahlung Interrogation with Photoneutron - Gamma-Ray Spectrometry for Nondestructive Evaluation

    NASA Astrophysics Data System (ADS)

    Jones, James Litton

    A novel photoneutron-based nondestructive evaluation (NDE) technique which does not require a radioactive neutron source is presented. Some unique features of this technique include: 1) pulsed interrogation neutron production within, or very near, an inspected object, 2) spectrum tailoring of the source neutrons, and 3) compatibility with many existing high-energy, commercial x-ray inspection devices. Basic concept feasibility was first established by numerical methods. The pulsed photoneutron inspection technique performs nondestructive elemental analysis using gamma-ray spectrometry. Highly penetrating bremsstrahlung photons are produced by a pulsed electron accelerator capable of producing up to 16-MeV electrons. The photoneutrons are generated by the bremsstrahlung photons interacting with an inspected object and near-by beryllium metal. The interactions of the neutrons within an inspected item result in the emission of elemental characteristic gamma-rays. Spectrometry is performed by analyzing the gamma -rays acquired between accelerator pulses. A unique fast detection and acquisition system, using two 5.08 x 5.08 -cm organic scintillators, acquires gamma-ray emissions within 100 ns of each accelerator pulse. The fast system is capable of processing individual gamma-ray signals at count rates up to 40 MHz between accelerator pulses with a repetition rate up to 1 kHz. The system incorporates a unique x-ray flash recovery method which allows individual gamma-ray detection as soon as 75 ns after the start of each x-ray flash occurring within the detector. Conventional detection and data acquisition systems are used to acquire gamma-ray spectra for the time period between 1000 ns and the next accelerator pulse. Operational tests using a 30-ps pulse width, electron accelerator demonstrated the x-ray flash recovery methodology, gamma-ray detection, and data acquisition. Although, gamma -ray spectrometry performance was limited by x-ray flash -induced gain shifts in

  8. Fast solver for large scale eddy current non-destructive evaluation problems

    NASA Astrophysics Data System (ADS)

    Lei, Naiguang

    Eddy current testing plays a very important role in non-destructive evaluations of conducting test samples. Based on Faraday's law, an alternating magnetic field source generates induced currents, called eddy currents, in an electrically conducting test specimen. The eddy currents generate induced magnetic fields that oppose the direction of the inducing magnetic field in accordance with Lenz's law. In the presence of discontinuities in material property or defects in the test specimen, the induced eddy current paths are perturbed and the associated magnetic fields can be detected by coils or magnetic field sensors, such as Hall elements or magneto-resistance sensors. Due to the complexity of the test specimen and the inspection environments, the availability of theoretical simulation models is extremely valuable for studying the basic field/flaw interactions in order to obtain a fuller understanding of non-destructive testing phenomena. Theoretical models of the forward problem are also useful for training and validation of automated defect detection systems. Theoretical models generate defect signatures that are expensive to replicate experimentally. In general, modelling methods can be classified into two categories: analytical and numerical. Although analytical approaches offer closed form solution, it is generally not possible to obtain largely due to the complex sample and defect geometries, especially in three-dimensional space. Numerical modelling has become popular with advances in computer technology and computational methods. However, due to the huge time consumption in the case of large scale problems, accelerations/fast solvers are needed to enhance numerical models. This dissertation describes a numerical simulation model for eddy current problems using finite element analysis. Validation of the accuracy of this model is demonstrated via comparison with experimental measurements of steam generator tube wall defects. These simulations generating two

  9. Nondestructive evaluation of planar defects in plates using low-frequency shear horizontal waves

    NASA Astrophysics Data System (ADS)

    Fortunko, C. M.; King, R. B.; Tan, M.

    1982-05-01

    An ultrasonic technique is described that allows the determination of the through-thickness dimension and limited localization of planar defects (cracks) in an isotropic metal plate. The scattering of horizontally polarized shear (SH) plate waves by edge and buried planar defects is investigated using a variational integral expression. Numerical results are presented that allow the calculation of the SH plate wave signal amplitudes as a function of defect through-thickness dimension and location within a plate for two-dimensional cracks. It is shown that SH waves are particularly useful for detecting and sizing of crack-like defects. In addition, it is demonstrated that in plates, which can support a number of propagating SH plate waves, it is also possible to determine the relative position of a defect from interference phenomena. The numerical results are confirmed experimentally using an electromagnetic-acoustic transducer system to generate and detect 454-kHz SH wave signals along the normal to the circumference of a 1.22-m-diam steel pipe with a 15.9-mm wall thickness. The experimental results demonstrate the efficacy of using SH wave signals in quantitative nondestructive evaluation of butt welds.

  10. Modeling of Resonant Ultrasound Spectroscopy Based Nondestructive Evaluation Using the "XYZ-Algorithm"

    SciTech Connect

    Ahmed, Salahuddin; Bond, Leonard J.

    2007-05-03

    Resonant ultrasound spectroscopy (RUS) is employed as a nondestructive evaluation (NDE) tool in a number of metal/ceramic forming industries [1]. The presence of volumetric defects in an otherwise flaw-free object affects the resonance characteristics of the object. The changes in resonance behavior depend on the number, locations, volume, and material properties of the defects. Since the normal modes of an object depend on its geometry and the position-dependent material properties, namely the density and the complex elastic stiffness tensor, by accurate measurement of a specimen’s resonance frequencies and amplitudes, one can detect and characterize flaws embedded within it. A correct forward mathematical model to predict resonance characteristics is vital to the required analyses. In this paper, we present several computational results depicting the influence of the presence of embedded flaws/defects in a test specimen having simple geometrical shape. The mathematical model is based on the computationally efficient “XYZ Algorithm” of Visscher et al.

  11. X-ray and gamma-ray computed tomography for industrial nondestructive testing and evaluation

    NASA Astrophysics Data System (ADS)

    Costello, Ian; Wells, Peter; Davis, John R.; Benci, Nino; Skerrett, David; Davies, D. R.

    1994-03-01

    This paper presents an overview of two recently constructed computed tomography (CT) scanners that have been designed to provide structural information for industrially relevant materials and components. CT enables cross-sectional slices of an object to be nondestructively imaged and represented as a map of linear attenuation coefficient. As linear attenuation is the product of mass attenuation and density, this usually enables a straightforward interpretation of the image in terms of density. The two instruments are a transportable scanner using a 160 kV(peak) powered x-ray tube for the inspection of wooden power poles up to 450 mm in diameter, and an industrial scanning system designed around an Ir-192 gamma-ray source for materials characterization and the testing and evaluation of castings, ceramics, and composites. The images presented in this paper have generally been reconstructed using the summation convolution back-projection (SCBP) method, and this technique is outlined. Direct Fourier reconstruction is also used and compared with the SCBP method. A brief discussion is offered on incorporating edge detection methods into the image reconstruction process for the improved identification of defects such as cracks and voids.

  12. Non-Destructive Evaluation of Wind Turbine Blades Using an Infrared Camera

    SciTech Connect

    Beattie, A.G.; Rumsey, M.

    1998-12-17

    The use of a digital infrared as a non-destructive evaluation thermography camera (NDE) tool was ex- plored in two separate wind turbine blade fatigue tests. The fwst test was a fatigue test of part of a 13.1 meter wood-epoxy-composite blade. The second test was on a 4.25 meter pultruded fiber glass blade section driven at several mechanical resonant frequencies. The digital infrared camera can produce images of either the static temperature distribution on the surface of the specimen, or the dynamic temperature distribution that is in phase with a specific frequency on a vibrating specimen. The dynamic temperature distribution (due to thermoplastic effects) gives a measure of the sum of the principal stresses at each point on the surface. In the wood- epoxy-composite blade fatigue test, the point of ultimate failure was detected long before failure occurred. The mode shapes obtained with the digital infrared camera, from the resonant blade tests, were in very good agree- ment with the finite-element calculations. In addition, the static temperature images of the resonating blade showed two areas that contained cracks. Close-up dy- namic inf%red images of these areas showed the crack structure that agreed with subsequent dye-penetrant analysis.

  13. A knowledge-based shell for selecting a nondestructive evaluation technique

    SciTech Connect

    Roberge, P.R.

    1995-02-01

    The complexity of planning a nondestructive evaluation (NDE) program or an inspection schedule for specific problems and available NDE techniques can be drastically reduced by the creation of a knowledge based system that would balance the advantages and limitations of each technique for specific problems. Such a system could incorporate the fundamental knowledge derived from failure analysis and cover topics such as materials vs. defect size and type, probability of failure, and basic reliability information. In order to efficiently organize knowledge of materials degradation, the parameters that control various forms of failure must first be rationalized in a general framework. This framework and their factors would then constitute a quantitative and easily programmable description of the independent variables controlling the intensity of a failure. This article describes such a framework, which could guide the general selection of NDE for materials failure with a particular emphasis on corrosion related failures. The framework architecture itself was constructed using an object-oriented methodology for maximum flexibility because it was anticipated that the materials parameters could easily be described as multidimensional objects.

  14. PHOTOACOUSTIC NON-DESTRUCTIVE EVALUATION AND IMAGING OF CARIES IN DENTAL SAMPLES

    SciTech Connect

    Li, T.; Dewhurst, R. J.

    2010-02-22

    Dental caries is a disease wherein bacterial processes damage hard tooth structure. Traditional dental radiography has its limitations for detecting early stage caries. In this study, a photoacoustic (PA) imaging system with the near-infrared light source has been applied to postmortem dental samples to obtain 2-D and 3-D images. Imaging results showed that the PA technique can be used to image human teeth caries. For non-destructive photoacoustic evaluation and imaging, the induced temperature and pressure rises within biotissues should not cause physical damage to the tissue. For example, temperature rises above 5 deg. C within live human teeth will cause pulpal necrosis. Therefore, several simulations based on the thermoelastic effect have been applied to predict temperature and pressure fields within samples. Predicted temperature levels are below corresponding safety limits, but care is required to avoid nonlinear absorption phenomena. Furthermore, PA imaging results from the phantom provide evidence for high sensitivity, which shows the imaging potential of the PA technique for detecting early stage disease.

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

    NASA Technical Reports Server (NTRS)

    Grygler, Micheal S.

    1994-01-01

    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.

  16. Non-destructive Evaluation of Bonds Between Fiberglass Composite and Metal

    NASA Technical Reports Server (NTRS)

    Zhao, Selina; Sonta, Kestutis; Perey, Daniel F.; Cramer, K. E.; Berger, Libby

    2015-01-01

    To assess the integrity and reliability of an adhesive joint in an automotive composite component, several non-destructive evaluation (NDE) methodologies are correlated to lap shear bond strengths. A glass-fabric-reinforced composite structure was bonded to a metallic structure with a two-part epoxy adhesive. Samples were subsequently cut and tested in shear, and flaws were found in some areas. This study aims to develop a reliable and portable NDE system for service-level adhesive inspection in the automotive industry. The results of the experimental investigation using several NDE methods are presented and discussed. Fiberglass-to-metal bonding is the ideal configuration for NDE via thermography using excitation with induction heating, due to the conductive metal and non-conductive glass-fiber-reinforced composites. Excitation can be either by a research-grade induction heater of highly defined frequency and intensity, or by a service-level heater, such as would be used for sealing windshields in a body shop. The thermographs thus produced can be captured via a high-resolution infrared camera, with principal component analysis and 2D spatial Laplacian processing. Alternatively, the thermographs can be captured by low resolution thermochromic microencapsulated liquid crystal film imaging, which needs no post-processing and can be very inexpensive. These samples were also examined with phased-array ultrasound. The NDE methods are compared to the lap shear values and to each other for approximate cost, accuracy, and time and level of expertise needed.

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

    SciTech Connect

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

    2002-06-03

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2009-07-01

    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.

  19. Stochastic-integral models for propagation-of-uncertainty problems in nondestructive evaluation

    NASA Astrophysics Data System (ADS)

    Sabbagh, Elias H.; Murphy, R. Kim; Sabbagh, Harold A.; Aldrin, John C.; Knopp, Jeremy; Blodgett, Mark P.

    2013-01-01

    Generalized polynomical chaos (gPC), the probabilistic collocation method (PCM), and analysis of variance (ANOVA) are finding considerable application to problems of interest to engineers in which random parameters are an essential feature of the mathematical model. So far the applications have been mainly to stochastic partial differential equations, but we extend the method to volume-integral equations, which have met great success in electromagnetic nondestructive evaluation (NDE), especially with eddy-currents. The problems of main interest to the NDE community in this connection are concerned with the issue of `propagation of uncertainty' when the relevant parameters are not well characterized, or are known simply as random variables. We demonstrate the ideas by considering a metallic surface that has undergone a shot-peening treatment to reduce residual stresses, and has, therefore, become a random conductivity field. In particular, we show how ANOVA becomes a very promising method for high-dimensional model representation (HDMR) when there are a large number of random variables present in the problem.

  20. Contemporary ultrasonic signal processing approaches for nondestructive evaluation of multilayered structures

    NASA Astrophysics Data System (ADS)

    Zhang, Guang-Ming; Harvey, David M.

    2012-03-01

    Various signal processing techniques have been used for the enhancement of defect detection and defect characterisation. Cross-correlation, filtering, autoregressive analysis, deconvolution, neural network, wavelet transform and sparse signal representations have all been applied in attempts to analyse ultrasonic signals. In ultrasonic nondestructive evaluation (NDE) applications, a large number of materials have multilayered structures. NDE of multilayered structures leads to some specific problems, such as penetration, echo overlap, high attenuation and low signal-to-noise ratio. The signals recorded from a multilayered structure are a class of very special signals comprised of limited echoes. Such signals can be assumed to have a sparse representation in a proper signal dictionary. Recently, a number of digital signal processing techniques have been developed by exploiting the sparse constraint. This paper presents a review of research to date, showing the up-to-date developments of signal processing techniques made in ultrasonic NDE. A few typical ultrasonic signal processing techniques used for NDE of multilayered structures are elaborated. The practical applications and limitations of different signal processing methods in ultrasonic NDE of multilayered structures are analysed.

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

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

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

    2009-01-01

    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.

  3. Laser Doppler technique for nondestructive evaluation of mechanical heart valves kinematics

    NASA Astrophysics Data System (ADS)

    Grigioni, Mauro; Daniele, Carla; Morbiducci, U.; Del Gaudio, C.; D'Avenio, Giuseppe; Di Meo, D.; Barbaro, Vincenzo

    2004-06-01

    Laser techniques for vibration measurement, due to their non-contact nature, represents an interesting alternative investigational tool to be tested in biomedical and clinic fields. A particular application could be as evaluation method in design and quality control of artificial organs. Aim of this study is to investigate the application of laser vibrometry to the study of mechanical heart valves in-vitro, with an ad hoc set-up. A heterodyne laser Doppler vibrometry system, which allows the measurement of both vibrational velocity and displacement was used. Three different approaches have been carried out, in order to stress the limits of the laser vibrometry technique for testing heart valve prostheses. Critical points and difficulties to build up experimental studies in this field were clearly pointed out. In the present study only one laser head was used, the aim of the authors being to test the feasibility of a simplified approach on mechanical cardiac valves. Starting from that analysis a comparison could be made to assess the capability to discriminate between normal and malfunctioning devices. The advantage of the proposed test bench is that it could provide a non-contact, non-destructive analysis of the valve under the same working conditions as those upon implantation. The proposed method could furnish a typical "fingerprint" characterizing each valve behavior in repeatable experimental conditions.

  4. Application of laser ultrasonic non-destructive evaluation technique to additive manufacturing

    NASA Astrophysics Data System (ADS)

    Manzo, Anthony J.; Kenderian, Shant; Helvajian, Henry

    2016-04-01

    The change in properties of a propagating ultrasonic wave has been a mainstay characterization tool of the nondestructive evaluation (NDE) industry for identifying subsurface defects (e.g. damage). A variant of this concept could be applicable to 3D additive manufacturing where the existence of defects (e.g. pores) within a sub-layer could mark a product as non-qualifying. We have been exploring the utility of pulsed laser ultrasonic excitation coupled with CW laser heterodyne detection as an all optical scheme for characterizing sub surface layer properties. The all-optical approach permits a straight forward integration into a laser additive processing tool. To test the concept, we have developed an experimental system that generates pulsed ultrasonic waves (the probe) with high bandwidth (<<10MHz) and a surface displacement sensor that can capture the ultrasonic "return" signal with bandwidth close to 300 MHz. The use of high frequencies enables the detection of smaller defect sites. The technique is time resolved with the sensor and probe as point (>>30-200 microns) beams. Current tests include characterizing properties of spot weld joints between two thin stainless steel plates. The long term objective is to transition the technique into a laser additive manufacturing tool.

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

    PubMed

    Li, Minghui; Hayward, Gordon

    2012-01-01

    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

  6. Photoacoustic Non-Destructive Evaluation and Imaging of Caries in Dental Samples

    NASA Astrophysics Data System (ADS)

    Li, T.; Dewhurst, R. J.

    2010-02-01

    Dental caries is a disease wherein bacterial processes damage hard tooth structure. Traditional dental radiography has its limitations for detecting early stage caries. In this study, a photoacoustic (PA) imaging system with the near-infrared light source has been applied to postmortem dental samples to obtain 2-D and 3-D images. Imaging results showed that the PA technique can be used to image human teeth caries. For non-destructive photoacoustic evaluation and imaging, the induced temperature and pressure rises within biotissues should not cause physical damage to the tissue. For example, temperature rises above 5 °C within live human teeth will cause pulpal necrosis. Therefore, several simulations based on the thermoelastic effect have been applied to predict temperature and pressure fields within samples. Predicted temperature levels are below corresponding safety limits, but care is required to avoid nonlinear absorption phenomena. Furthermore, PA imaging results from the phantom provide evidence for high sensitivity, which shows the imaging potential of the PA technique for detecting early stage disease.

  7. Compensation electronics for larger dynamic range of a SQUID based nondestructive evaluation system

    NASA Astrophysics Data System (ADS)

    Kreutzbruck, M. v.; Theiss, A.; Mück, M.; Heiden, C.

    1999-09-01

    We have developed a compensation system for any given SQUID sensor which allows sensitive eddy current measurements above 100 Hz in the presence of strong and slowly varying background fields. High Tc SQUIDs have been used successfully in nondestructive evaluation (NDE) systems based on eddy current excitation when searching for defects in conductive samples such as aircraft parts. Due to their high and frequency independent field resolution and their excellent spatial resolution, SQUIDs provide in the case of deep lying defects—compared to other conventional electromagnetic NDE systems—a more reliable crack detection. Fast readout electronics having an unsurpassed dynamic range of up to eight orders of magnitude enabled us to perform measurements in an environment polluted with electromagnetic noise, e.g., an aircraft hangar. Nevertheless, test objects containing ferromagnetic structures with a high remanent magnetization, such as aircraft wheels or steel bolts in an aircraft wing, very often cause instabilities of the flux-locked loop operation of the SQUID. To prevent unlocking, we have developed a new background field compensation scheme. Special compensation electronics take care of slowly varying magnetic fields of up to 1 mT/s and allow us to perform eddy current measurements in the presence of slow (<30 Hz) background field variations of up to 5 mT.

  8. Image Analysis, Modeling, Enhancement, Restoration, Feature Extraction and Their Applications in Nondestructive Evaluation and Radio Astronomy.

    NASA Astrophysics Data System (ADS)

    Zheng, Yi.

    The principal topic of this dissertation is the development and application of signal and image processing to Nondestructive Evaluation (NDE) and radio astronomy. The dissertation consists of nine papers published or submitted for publication. Each of them has a specific and unique topic related to signal processing or image processing in NDE or radio astronomy. Those topics are listed in the following. (1) Time series analysis and modeling of Very Large Array (VLA) phase data. (2) Image analysis, feature extraction and various applied enhancement methods for industrial NDE X-ray radiographic images. (3) Enhancing NDE radiographic X-ray images by adaptive regional Kalman filtering. (4) Robotic image segmentation, modeling, and restoration with a rule based expert system. (5) Industrial NDE radiographic X-ray image modeling and Kalman filtering considering signal-dependent colored noise. (6) Computational study of Kalman filtering VLA phase data and its computational performance on a supercomputer. (7) A practical and fast maximum entropy deconvolution method for de-blurring industrial NDE X-ray and infrared images. (8) Local feature enhancement of synthetic radio images by adaptive Kalman filtering. (9) A new technique for correcting phase data of a synthetic -aperture antenna array.

  9. A multi-inspection non-destructive testing method for quality evaluation of composite riveted structure

    NASA Astrophysics Data System (ADS)

    Wang, Weihan; He, Jingjing; Yang, Jingsong; Liu, Shengwang; Zhang, Weifang

    2015-03-01

    Carbon fiber composites have excellent mechanical properties, which are widely used in aerospace industry. However, 60% to 80% damages in composite occur in riveted structures. This research focuses on the quality evaluation of three major riveted structures used in mechanical connection: pressure riveted connection, hammer riveted connection and pull riveted connection. The non-destructive testing results show that the pull riveting technology introduces minimal damage to the composite, but the hammer riveted structure can be seriously damaged by the riveting technology. The pull riveted structure is an interference fit, which makes the composite plate firmly fixed. However, the fix is weak in the pressure riveted structure and the hammer riveted structure, due to the small gap between the rivets and plate. The results show that the pull riveted structure has a higher tensile strength compared with the pressure riveted structure and hammer riveted structure. The hammer riveted structure has a large dispersion in mechanical properties caused by the impact loading used in the hammer riveting technology.

  10. An Analysis of Nondestructive Evaluation Techniques for Polymer Matrix Composite Sandwich Materials

    NASA Technical Reports Server (NTRS)

    Cosgriff, Laura M.; Roberts, Gary D.; Binienda, Wieslaw K.; Zheng, Diahua; Averbeck, Timothy; Roth, Donald J.; Jeanneau, Philippe

    2006-01-01

    Structural sandwich materials composed of triaxially braided polymer matrix composite material face sheets sandwiching a foam core are being utilized for applications including aerospace components and recreational equipment. Since full scale components are being made from these sandwich materials, it is necessary to develop proper inspection practices for their manufacture and in-field use. Specifically, nondestructive evaluation (NDE) techniques need to be investigated for analysis of components made from these materials. Hockey blades made from sandwich materials and a flat sandwich sample were examined with multiple NDE techniques including thermographic, radiographic, and shearographic methods to investigate damage induced in the blades and flat panel components. Hockey blades used during actual play and a flat polymer matrix composite sandwich sample with damage inserted into the foam core were investigated with each technique. NDE images from the samples were presented and discussed. Structural elements within each blade were observed with radiographic imaging. Damaged regions and some structural elements of the hockey blades were identified with thermographic imaging. Structural elements, damaged regions, and other material variations were detected in the hockey blades with shearography. Each technique s advantages and disadvantages were considered in making recommendations for inspection of components made from these types of materials.

  11. Laser optoacoustic method for quantitative nondestructive evaluation of the subsurface damage depth in ground silicon wafers

    NASA Astrophysics Data System (ADS)

    Podymova, N. B.; Karabutov, A. A.; Cherepetskaya, E. B.

    2014-08-01

    This paper is a report on the novel laser optoacoustic method for nondestructive evaluation of the depth of the subsurface damage in ground single-crystal silicon wafers. It is based on different mechanisms of laser excitation of ultrasound by absorption of Q-switched Nd:YAG laser pulses at the fundamental wavelength: the concentration-deformation mechanism in the undamaged single-crystal silicon and the thermoelastic one in the subsurface damaged layer. Due to the uniform heating of the whole damaged layer during the laser pulse action the amplitude of the compression phase of the laser-induced ultrasonic signal is proportional to the damaged depth. The rarefaction phase of this signal arises by absorption of the remaining laser energy in the single-crystal silicon beneath the damaged layer. The empirical relation between the depth of the subsurface damage and the ratio of the amplitudes of compression and rarefaction phases of the laser-induced ultrasonic signal can be fitted by a linear function within the depth variation and the corresponding spread of the signal amplitudes. The proposed method attracts some interest for in situ control of the solid surface condition that is important in different tasks of linear and nonlinear optics.

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

    NASA Technical Reports Server (NTRS)

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

    2007-01-01

    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.

  13. Evaluation of an Extended Autocorrelation Phase Estimator for Ultrasonic Velocity Profiles Using Nondestructive Testing Systems.

    PubMed

    Ofuchi, César Yutaka; Coutinho, Fabio Rizental; Neves, Flávio; de Arruda, Lucia Valéria Ramos; Morales, Rigoberto Eleazar Melgarejo

    2016-01-01

    In this paper the extended autocorrelation velocity estimator is evaluated and compared using a nondestructive ultrasonic device. For this purpose, three velocity estimators are evaluated and compared. The autocorrelation method (ACM) is the most used and well established in current ultrasonic velocity profiler technology, however, the technique suffers with phase aliasing (also known as the Nyquist limit) at higher velocities. The cross-correlation method (CCM) is also well known and does not suffer with phase aliasing as it relies on time shift measurements between emissions. The problem of this method is the large computational burden due to several required mathematical operations. Recently, an extended autocorrelation method (EAM) which combines both ACM and CCM was developed. The technique is not well known within the fluid engineering community, but it can measure velocities beyond the Nyquist limit without the ACM phase aliasing issues and with a lower computational cost than CCM. In this work, all three velocity estimation methods are used to measure a uniform flow of the liquid inside a controlled rotating cylinder. The root-mean-square deviation variation coefficient (CVRMSD) of the velocity estimate and the reference cylinder velocity was used to evaluate the three different methods. Results show that EAM correctly measures velocities below the Nyquist limit with less than 2% CVRMSD. Velocities beyond the Nyquist limit are only measured well by EAM and CCM, with the advantage of the former of being computationally 15 times faster. Furthermore, the maximum value of measurable velocity is also investigated considering the number of times the velocity surpasses the Nyquist limit. The combination of number of pulses and number of samples, which highly affects the results, are also studied in this work. Velocities up to six times the Nyquist limit could be measurable with CCM and EAM using a set of parameters as suggested in this work. The results validate

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

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1993-01-01

    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.

  15. Dynamic laser speckle for non-destructive quality evaluation of bread

    NASA Astrophysics Data System (ADS)

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

    2010-10-01

    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 μm) 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.

  16. Nondestructive Evaluation of Adhesively Bonded Joints by Acousto-Ultrasonic Technique and Acoustic Emission

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

    Reliable applications of adhesively bonded joints require an effective nondestructive evaluation technique for their bond strength prediction. To properly evaluate factors affecting bond strength, effects of defects such as voids and disbonds on stress distribution in the overlap region must be understood. At the same time, in order to use acousto-ultrasonic (AU) technique to evaluate bond quality, the effect of these defects on dynamic response of single lap joints must be clear. The stress distribution in a single lap joint with and without defects (void or disbond) is analyzed. A bar-Theta parameter which contains adherend and adhesive thickness and properties is introduced. It is shown for bonded joints with bar-Theta greater than 10, that a symmetric void or disbond in the middle of overlap up to the 70 percent of overlap length has negligible effect on bond strength. In contrast frequency response analyses by a finite element technique showed that the dynamic response is affected significantly by the presence of voids or disbonds. These results have direct implication in the interpretations of AU results. Through transmission attenuation and a number of AU parameters for various specimens with and without defects are evaluated. It is found that although void and disbond have similar effects on bond strength (stress distribution), they have completely different effects on wave propagation characteristics. For steel-adhesive-steel specimens with voids, the attenuation changes are related to the bond strength. However, the attenuation changes for specimens with disbond are fairly constant over a disbond range. In order to incorporate the location of defects in AU parameters, a weighting function is introduced. Using an immersion system with focused transducers, a number of AU parameters are evaluated. It is found that by incorporating weighting functions in these parameters better sensitivities (AU parameters vs. bond strength) are achieved. Acoustic emission

  17. Learning Resources Center Conference: Proceedings and Evaluation.

    ERIC Educational Resources Information Center

    Mikan, Kathleen

    This report includes both a collection of 16 papers presented at a national conference on learning resource centers (LRC's) in nursing schools and the results of a survey of participants conducted to evaluate the impact of the conference. Designed to increase the participants' knowledge and awareness of how they might better utilize an LRC to…

  18. Client Outcome Evaluation in Mental Health Centers.

    ERIC Educational Resources Information Center

    Southern Regional Education Board, Atlanta, GA.

    Outcome evaluation assesses the results or benefits of mental health services received by clients or communities by comparing descriptive data on the mental health status of clients at different points in time. It aids clinicians and managers in planning programs and managing clinical services. A mental health center should establish goal-oriented…

  19. Nondestructive Test Probe

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Under the Aircraft Structural Integrity program, Langley Research Center invented a device to detect fatigue cracks in aluminum alloy plates. Krautkramer Branson obtained an exclusive license and commercialized a hand-held device, the "CrackFinder," an electromagnetic probe for nondestructive evaluation, used to scan aircraft skins for surface breaks. The technology involves an eddy current, which is an electrical current induced by an alternating magnetic field. The CrackFinder also employs an innovative self-nulling feature, where the device automatically recalibrates to zero so that each flaw detected produces a reading. Compared to conventional testing systems, the CrackFinder is affordable, small, simple to use, and needs no calibration.

  20. Application of Near-Field Microwave and Millimeter Wave Nondestructive Testing for Evaluation of Fiber Breakage and Orientation Evaluation in CFRP Composite Patches

    NASA Astrophysics Data System (ADS)

    Kharkovsky, S.; Zoughi, R.

    2005-04-01

    Near-field microwave and millimeter wave nondestructive testing and evaluation techniques have been successfully used for detecting defects such as disbond and delamination in complex composite structures. This paper presents the results of fiber breakage detection and fiber orientation determination in carbon fiber reinforced polymer patches which are used in aerospace industry and civil infrastructure.

  1. The effect of variation in phased array element performance for Non-Destructive Evaluation (NDE).

    PubMed

    Duxbury, David; Russell, Jonathan; Lowe, Michael

    2013-08-01

    This paper reports the results of an investigation into the effects of phased array element performance on ultrasonic beam integrity. This investigation has been performed using an array beam model based on Huygens' principle to independently investigate the effects of element sensitivity and phase, and non-functioning elements via Monte Carlo simulation. The purpose of this work is to allow a new method of array calibration for Non-Destructive Evaluation (NDE) to be adopted that focuses on probe integrity rather than beam integrity. This approach is better suited to component inspections that utilise Full Matrix Capture (FMC) to record data as the calibration routine is uncoupled from the beams that the array is required to produce. For this approach to be adopted specifications must be placed on element performance that guarantee beam quality without carrying out any beam forming. The principal result of this investigation is that the dominant outcome following variations in array element performance is the introduction of beam artefacts such as main beam broadening, raising of the noise floor of the ultrasonic field, and the enlargement or creation of side lobes. Specifications for practical allowable limits of element sensitivity, element phase, and the number of non-functioning elements have been suggested based on a minimum amplitude difference between beam artefacts and the main beam peak of 8 dB. Simulation at a number of centre frequencies has led to a recommendation that the product of transducer bandwidth and maximum phase error should be kept below 0.051 and 0.035 for focused and plane beams respectively. Element sensitivity should be within 50% of mean value of the aperture, and no more than 9% of the elements should be non-functioning. PMID:23337826

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

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

    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

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

    NASA Astrophysics Data System (ADS)

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

    2007-01-01

    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

  4. Non-Destructive Evaluation of Kissing Bonds using Local Defect Resonance (LDR) Spectroscopy: A Simulation Study

    NASA Astrophysics Data System (ADS)

    Delrue, S.; Tabatabaeipour, M.; Hettler, J.; Van Den Abeele, K.

    With the growing demand from industry to optimize and further develop existing Non-Destructive Testing & Evaluation (NDT&E) techniques or new methods to detect and characterize incipient damage with high sensitivity and increased quality, ample efforts have been devoted to better understand the typical behavior of kissing bonds, such as delaminations and cracks. Recently, it has been shown experimentally that the nonlinear ultrasonic response of kissing bonds could be enhanced by using Local Defect Resonance (LDR) spectroscopy. LDR spectroscopy is an efficient NDT technique that takes advantage of the characteristic fre- quencies of the defect (defect resonances) in order to provide maximum acoustic wave-defect interaction. In fact, for nonlinear methodologies, the ultrasonic excitation of the sample should occur at either multiples or integer ratios of the characteristic defect resonance frequencies, in order to obtain the highest signal-to-noise response in the nonlinear LDR spectroscopy. In this paper, the potential of using LDR spectroscopy for the detection, localization and characterization of kissing bonds is illustrated using a 3D simulation code for elastic wave propagation in materials containing closed but dynamically active cracks or delaminations. Using the model, we are able to define an appropriate method, based on the Scaling Subtraction Method (SSM), to determine the local defect resonance frequencies of a delamination in a composite plate and to illustrate an increase in defect nonlinearity due to LDR. The simulation results will help us to obtain a better understanding of the concept of LDR and to assist in the further design and testing of LDR spectroscopy for the detection, localization and characterization of kissing bonds.

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

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

    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.

  6. Application of nondestructive testing in underwater evaluation of bridges and related structures

    NASA Astrophysics Data System (ADS)

    Garlich, Michael J.

    1995-05-01

    Determining a bridge structure's existing conditions and load carrying capacity often requires more complete data than can be gathered by visual observation and simple measurements. This is true below water as well as above. Various nondestructive testing techniques may be utilized underwater to gather such detailed data. Techniques to be addressed in this paper include ultrasonic nondestructive testing of timber and correlation to destructive and partially destructive testing, pulse velocity of concrete, ultrasonics in steel inspection, and an example of the underwater usage of diver-carried ground penetrating radar.

  7. The development of ultrasonic techniques for nondestructive evaluation of adhesive bonds

    NASA Astrophysics Data System (ADS)

    Chapman, Gilbert B., II

    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

  8. Development of nondestructive evaluation methods to characterize anomalous microstructures in titanium-6aluminum-4vanadium

    NASA Astrophysics Data System (ADS)

    Blodgett, Mark Patrick

    The main objective of this dissertation is to confirm through research the following hypothesis: "The use of nondestructive evaluation tools allows the detection of different microstructure types and allows the identification of microstructure anomalies (interior and surface) in metals and alloys." The work was conducted on Ti-6A1-4V forged bar stock, presenting a case study for a high performance structural alloy. Ti-6A1-4V is a good model material, which cannot tolerate microstructure anomalies in demanding applications. The alloy is well established with extensive documentation on physical, chemical, and mechanical properties. It is also available in many different microstructures, readily generated by heat treating. This dissertation addresses issues concerning microstructure characterization and the identification of microstructural anomalies. Specifically, this work includes (i) background research on the identification of ultrasonic and electrical characteristics of five different TP6A1-4V microstructures; (ii) an application of ultrasonic backscattering measurements to detect diffusion bonded Ti-6A1-4V microstructure changes, to simulate locally isolated remnant cast structure for billet NDI; (iii) original research on laser interferometric detection for ultrasonic phase mapping to characterize macroscopic texture in Ti-6A1-4V; and (iv) original research on eddy current electrical conductivity mapping in titanium alloys. Three original NDE methods were developed to evaluate microstructure and microstructure anomalies in Ti-6A1-4V. First, a forward scattering measurement technique was developed to spatially map the incoherent grain scattering in the forward propagation direction. These results showed, for the first time, that mapping of the forward scatter provides a basis for characterization of texture in polycrystalline titanium alloys. Second, a laser interferometric system was developed to map the signal amplitude and phase of the transmitted acoustic

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

    NASA Astrophysics Data System (ADS)

    Saleh, Tarik Adel

    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

  10. An evaluation of leaf biomass : length ratio as a tool for nondestructive assessment in eelgrass (Zostera marina L.).

    PubMed

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

    2012-01-01

    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. PMID:22645432

  11. Usability evaluation of centered time cartograms

    NASA Astrophysics Data System (ADS)

    Ullah, Rehmat; Mengistu, Eskedar Zelalem; van Elzakker, C. P. J. M.; Kraak, Menno-Jan

    2016-06-01

    A time cartogram visualizes travelling-times between locations. It replaces the geographic distance by time distance and distorts the underlyingmap accordingly. By distorting themap, time cartogramsmay give a more intuitive and clear picture of travelling-times. The distortion of the map, however, can make time cartograms harder to recognize and use. Although cartograms are becoming widespread in use, very little is known about their usability. This study focuses on the usability of centered time cartograms: time cartograms that visualize travellingtimes from a fixed starting location to other destinations in a region. We created several centered time cartograms to answer spatio-temporal questions related to the Dutch railway network. Two experiments were performed: a laboratory test and an online survey. In the laboratory test, we used eye-tracking, thinking aloud, and video-recording to compare four different designs of centered time cartograms to find out which one (or combination) of these performs better in answering spatiotemporal questions and thus, to establish a favorable design strategy for these cartograms. In the online survey, centered time cartograms were evaluated against a geographic and schematic map for accuracy, response time, and preference. The first experiment suggested that among various designs, the centered time cartogram with emphasized railroads is the most preferred design and the centered time cartogram without railroads is the least preferred. The second experiment indicated that overall, centered time cartograms perform better than the two other solutions in performing spatio-temporal tasks, particularly when the task has a dominant time-related component.

  12. Industrial Assessment Center Program Impact Evaluation

    SciTech Connect

    Martin, M.A.

    2000-01-26

    This report presents the results of an evaluation of the U.S. Department of Energy's Industrial Assessment Center (IAC) Program. The purpose of this program is to conduct energy, waste, and productivity assessments for small to medium-sized industrial firms. Assessments are conducted by 30 university-based industrial assessment centers. The purpose of this project was to evaluate energy and cost savings attributable to the assessments, the trained alumni, and the Websites sponsored by this program. How IAC assessments, alumni, and Web-based information may influence industrial energy efficiency decision making was also studied. It is concluded that appreciable energy and cost savings may be attributed to the IAC Program and that the IAC Program has resulted in more active and improved energy-efficiency decision making by industrial firms.

  13. Structural Anomalies Detected in Ceramic Matrix Composites Using Combined Nondestructive Evaluation and Finite Element Analysis (NDE and FEA)

    NASA Technical Reports Server (NTRS)

    Abdul-Aziz, Ali; Baaklini, George Y.; Bhatt, Ramakrishna T.

    2003-01-01

    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

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

    NASA Technical Reports Server (NTRS)

    Decker, Arthur J.

    2004-01-01

    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

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

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1997-01-01

    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

  16. Litchi freshness rapid non-destructive evaluating method using electronic nose and non-linear dynamics stochastic resonance model

    PubMed Central

    Ying, Xiaoguo; Liu, Wei; Hui, Guohua

    2015-01-01

    In this paper, litchi freshness rapid non-destructive evaluating method using electronic nose (e-nose) and non-linear stochastic resonance (SR) was proposed. EN responses to litchi samples were continuously detected for 6 d Principal component analysis (PCA) and non-linear stochastic resonance (SR) methods were utilized to analyze EN detection data. PCA method could not totally discriminate litchi samples, while SR signal-to-noise ratio (SNR) eigen spectrum successfully discriminated all litchi samples. Litchi freshness predictive model developed using SNR eigen values shows high predictive accuracy with regression coefficients R2 = 0 .99396. PMID:25920547

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

    PubMed Central

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

    2014-01-01

    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. PMID:24932051

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

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1992-01-01

    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.

  19. Evaluation of damage evolution and material behavior in a sigma/Ti-6242 composite using nondestructive methods

    SciTech Connect

    Benson, D.; Karpur, P.; Stubbs, D.A.; Matikas, T.E.

    1997-12-31

    Correlations between damage, as it evolves under simulated service conditions, and the results produced from nondestructive evaluation (NDE) techniques are useful in establishing successful life prediction methodologies in metal-matrix composites. Traditional characterization techniques provide limited information on the failure mechanisms in metal-matrix composites because of the complexities caused by the inhomogeneous, anisotropic nature of these materials. In addition, the currently used destructive techniques yield only qualitative information on the internal damage of composites. Very little quantitative information exists correlating the internal damage with property changes in the material such as stiffness, elongation, and residual strength. This research effort correlated NDE results with the residual tensile strength of a six-ply, unidirectional BP Sigma-1240 SiC/Ti-6Al-2Sn-4Zr-2Mo composite after being isothermally fatigued. Information obtained from these tests was used to pinpoint load levels and interruption points for subsequent interrupted fatigue tests. The following nondestructive evaluation techniques were used to evaluate the test specimens before and after fatigue testing: (1) scanning acoustic microscopy, (2) oblique incidence shear wave scanning, (3) reflector plate ultrasonic scanning, (4) immersion surface wave scanning, (5) in situ surface and longitudinal waves and, (6) X-ray radiography. This paper presents the results from each of the NDE techniques and examines the correlation among the techniques, other destructive methods, and the residual tensile strength.

  20. Nondestructive evaluation of progressive neuronal changes in organotypic rat hippocampal slice cultures using ultrahigh-resolution optical coherence microscopy

    PubMed Central

    Li, Fengqiang; Song, Yu; Dryer, Alexandra; Cogguillo, William; Berdichevsky, Yevgeny; Zhou, Chao

    2014-01-01

    Abstract. Three-dimensional tissue cultures have been used as effective models for studying different diseases, including epilepsy. High-throughput, nondestructive techniques are essential for rapid assessment of disease-related processes, such as progressive cell death. An ultrahigh-resolution optical coherence microscopy (UHR-OCM) system with ∼1.5  μm axial resolution and ∼2.3  μm transverse resolution was developed to evaluate seizure-induced neuronal injury in organotypic rat hippocampal cultures. The capability of UHR-OCM to visualize cells in neural tissue was confirmed by comparison of UHR-OCM images with confocal immunostained images of the same cultures. In order to evaluate the progression of neuronal injury, UHR-OCM images were obtained from cultures on 7, 14, 21, and 28 days in vitro (DIVs). In comparison to DIV 7, statistically significant reductions in three-dimensional cell count and culture thickness from UHR-OCM images were observed on subsequent time points. In cultures treated with kynurenic acid, significantly less reduction in cell count and culture thickness was observed compared to the control specimens. These results demonstrate the capability of UHR-OCM to perform rapid, label-free, and nondestructive evaluation of neuronal death in organotypic hippocampal cultures. UHR-OCM, in combination with three-dimensional tissue cultures, can potentially prove to be a promising tool for high-throughput screening of drugs targeting various disorders. PMID:25750928

  1. Nondestructive Evaluation of Foam Insulation on the Space Shuttle External Tank

    NASA Technical Reports Server (NTRS)

    Richter, Joel; Walker, James L.

    2006-01-01

    Foam loss on the External Tank (ET) during launch can be caused by a number of factors. Voids are the best understood mechanism of foam loss, although it is known that delaminations, cracks and crushed foam can also lead to liberation of foam. Shortly after the Columbia accident, work began on non-destructive evaluation of foam targeted at finding voids and delaminations. After several months of searching for candidate methods capable of inspecting ET foam, the five most promising techniques were taken through a blind test and narrowed down to two methods to develop and use for inspection of the ET. These methods were backscatter radiography and terahertz imaging. The backscatter radiography system measures a test part by detecting Compton backscattered x-ray energy generated by a collimated beam of x-rays directed at the test subject. This collimated beam is scanned across the subject, recording scatter intensity data one pixel at a time until the area of interest is covered. The resulting data can be used to generate an image similar to a radiograph. Some depth information can be gathered utilizing apertures or collimation on the detectors. The detectors are located around the collimated source, making this a single sided inspection. The void detection limit with the currently utilized system is around 0.5 inches in diameter by 0.2 inches high. The terahertz imaging system inspects a test part by utilizing a transceiver to emit a pulse focused at the aluminum skin of the ET, which reflects it back to the transceiver where it is analyzed. The transceiver is scanned across the area of interest until a measurement has been taken at every location. Amplitude, time delay and frequency content are examined to note any discontinuities which may be the result of a void or other type of defect. The pulse currently utilized is in the millimeter wave regime. The void detection limit with this system is around 0.5 inches in diameter by 0.2 inches high. With increased

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

    NASA Astrophysics Data System (ADS)

    Gavrilov, Dmitry J.

    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

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

    NASA Astrophysics Data System (ADS)

    Khatri, Devvrath

    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.

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

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1988-01-01

    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.

  5. Photothermal radiometry apparatus using pseudorandom excitation for nondestructive evaluation of layered materials

    SciTech Connect

    Merienne, E.; Hakem, K.; Egee, M. . Faculte des Sciences de Reims)

    1994-02-01

    The characterization of thermal system under unsteady regime is mostly carried out under pulsed or sinusoidal excitation, as they are easier to produce, analyze, and model. The new means of study offered by optics and computers now allow us to operate and exploit other modes of thermal analysis of systems. The equipment presented uses random type excitation and is to be applied to nondestructive testing. Yet, the scope of this method can be enhanced. In fact, it can be tied to different means of thermal stimulation as well as to various types of sensors. It can be more generally used for the analysis of different thermal systems under unsteady regime.

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

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

    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.

  7. Application of Advanced Nondestructive Evaluation Techniques for Cylindrical Composite Test Samples

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

    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.

  8. Non-destructive high-resolution thermal imaging techniques to evaluate wildlife and delicate biological samples

    NASA Astrophysics Data System (ADS)

    Lavers, C.; Franklin, P.; Franklin, P.; Plowman, A.; Sayers, G.; Bol, J.; Shepard, D.; Fields, D.

    2009-07-01

    Thermal imaging cameras now allows routine monitoring of dangerous yet endangered wildlife in captivity. This study looks at the potential applications of radiometrically calibrated thermal data to wildlife, as well as providing parameters for future materials applications. We present a non-destructive active testing technique suitable for enhancing imagery contrast of thin or delicate biological specimens yielding improved thermal contrast at room temperature, for analysis of sample thermal properties. A broad spectrum of animals is studied with different textured surfaces, reflective and emissive properties in the infra red part of the electromagnetic spectrum. Some surface features offer biomimetic materials design opportunities.

  9. Metrological evaluation of a flaw detector used in non-destructive testing by ultrasound

    NASA Astrophysics Data System (ADS)

    Mayworm, R. C.; Alvarenga, A. V.; Costa-Felix, R. P. B.

    2016-07-01

    Nondestructive tests are widely used in various sectors of industry, and its main techniques are based on the use of ultrasound. The flaw detector is a device used in ultrasonic testing. In this article, it is studied the influence of the flaw detection settings on the measurement result. It was observed that when the speed of sound and the thickness of the standard block are known, the equipment gives the best results, with a maximum error of 08%. The results show the importance of having a standard block calibrated in order to minimize errors.

  10. Photothermal Analysis Applied To Non-Destructive Evaluation Of Paint On Polymer Substrates

    NASA Astrophysics Data System (ADS)

    Vergne, D.; Busse, G.

    1988-10-01

    The decoration and protection quality of coatings on polymers is of considerable interest for industrial applications. However, at present there is no non-destructive (NDE) method to monitor the quality of these coatings during the manufacturing process or while they are in use. As an approach for such a method we use photothermal analysis where the propagation and reflection of optically generated thermal waves is investigated. We found that one can monitor the drying process, the effect of surface temperature treatment, and coating thickness (accuracy + 2 μm in 50 μm thickness). The information obtained with this remote NDE method is adequate for most industrial applications, eg car manufacturing.

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

    NASA Astrophysics Data System (ADS)

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

    2009-09-01

    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.

  12. A study of active thermography approaches for the non-destructive testing and evaluation of aerospace structures

    NASA Astrophysics Data System (ADS)

    Avdelidis, Nicolas P.; Ibarra-Castanedo, Clemente; Marioli-Riga, Zaira P.; Bendada, Abdelhakim; Maldague, Xavier P. V.

    2008-03-01

    The prerequisite for more competent and cost effective aircraft has led to the evolution of innovative testing and evaluation procedures. Non-destructive testing and evaluation (NDT & E) techniques for assessing the integrity of an aircraft structure are essential to both reduce manufacturing costs and out of service time of aircraft due to maintenance. Nowadays, active - transient thermal NDT & E (i.e. thermography) is commonly used for assessing aircraft composites. This research work evaluates the potential of pulsed thermography (PT) and/or pulsed phase thermography (PPT) for assessing defects (i.e. impact damage and inclusions for delaminations) on GLARE and GLARE type composites. Finally, in the case of the detection of inserts - delaminations C-Scan ultrasonic testing was also used with the intention of providing supplementary results.

  13. Residual Detergent Detection Method for Nondestructive Cytocompatibility Evaluation of Decellularized Whole Lung Scaffolds.

    PubMed

    Zvarova, Barbora; Uhl, Franziska E; Uriarte, Juan J; Borg, Zachary D; Coffey, Amy L; Bonenfant, Nicholas R; Weiss, Daniel J; Wagner, Darcy E

    2016-05-01

    The development of reliable tissue engineering methods using decellularized cadaveric or donor lungs could potentially provide a new source of lung tissue. The vast majority of current lung decellularization protocols are detergent based and incompletely removed residual detergents may have a deleterious impact on subsequent scaffold recellularization. Detergent removal and quality control measures that rigorously and reliably confirm removal, ideally utilizing nondestructive methods, are thus critical for generating optimal acellular scaffolds suitable for potential clinical translation. Using a modified and optimized version of a methylene blue-based detergent assay, we developed a straightforward, noninvasive method for easily and reliably detecting two of the most commonly utilized anionic detergents, sodium deoxycholate (SDC) and sodium dodecyl sulfate (SDS), in lung decellularization effluents. In parallel studies, we sought to determine the threshold of detergent concentration that was cytotoxic using four different representative human cell types utilized in the study of lung recellularization: human bronchial epithelial cells, human pulmonary vascular endothelial cells (CBF12), human lung fibroblasts, and human mesenchymal stem cells. Notably, different cells have varying thresholds for either SDC or SDS-based detergent-induced cytotoxicity. These studies demonstrate the importance of reliably removing residual detergents and argue that multiple cell lines should be tested in cytocompatibility-based assessments of acellular scaffolds. The detergent detection assay presented here is a useful nondestructive tool for assessing detergent removal in potential decellularization schemes or for use as a potential endpoint in future clinical schemes, generating acellular lungs using anionic detergent-based decellularization protocols. PMID:26905643

  14. Development of Non-destructive Evaluation System Using an HTS-SQUID Gradiometer with an External Pickup Coil

    NASA Astrophysics Data System (ADS)

    Kawano, J.; Kawauchi, S.; Ishikawa, F.; Tanabe, K.

    We are developing a new eddy-current non-destructive evaluation (NDE) system using a high-temperature superconducting quantum interference device (HTS-SQUID) gradiometer with the aim of applying it to power plants. Electric power facilities such as ducts and vessels are generally untransportable because of their size, and thus it is difficult to apply a conventional SQUID NDE system. The new NDE system employs an external Cu pickup coil which is supposed to be driven flexibly by a robot arm at room temperature and an HTS-SQUID chip which is placed in a magnetically shielded vessel. In the present research, we investigated the performance of an HTS-SQUID sensor connected with external pickup coils before mounting them to a robot arm. By varying the Cu coil conditions such as their sizes, the number of turns, and the diameter of wire, we qualitatively evaluated the frequency dependence of the effective area and the cutoff frequency.

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

    SciTech Connect

    Day, R.A.

    1988-12-31

    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.

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

    NASA Astrophysics Data System (ADS)

    Weischedel, Herbert R.; Hoehle, Hans-Werner

    1995-05-01

    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.

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

    USGS Publications Warehouse

    Whitbeck, M.; Grace, J.B.

    2006-01-01

    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.

  18. Electromagnetic Nondestructive Evaluation of Wire Insulation and Models of Insulation Material Properties

    NASA Technical Reports Server (NTRS)

    Bowler, Nicola; Kessler, Michael R.; Li, Li; Hondred, Peter R.; Chen, Tianming

    2012-01-01

    Polymers have been widely used as wiring electrical insulation materials in space/air-craft. The dielectric properties of insulation polymers can change over time, however, due to various aging processes such as exposure to heat, humidity and mechanical stress. Therefore, the study of polymers used in electrical insulation of wiring is important to the aerospace industry due to potential loss of life and aircraft in the event of an electrical fire caused by breakdown of wiring insulation. Part of this research is focused on studying the mechanisms of various environmental aging process of the polymers used in electrical wiring insulation and the ways in which their dielectric properties change as the material is subject to the aging processes. The other part of the project is to determine the feasibility of a new capacitive nondestructive testing method to indicate degradation in the wiring insulation, by measuring its permittivity.

  19. Rapid, non-destructive evaluation of ultrathin WSe{sub 2} using spectroscopic ellipsometry

    SciTech Connect

    Eichfeld, Sarah M.; Lin, Yu-Chuan; Hossain, Lorraine; Eichfeld, Chad M.; Robinson, Joshua A.

    2014-09-01

    The utilization of tungsten diselenide (WSe{sub 2}) in electronic and optoelectronic devices depends on the ability to understand and control the process-property relationship during synthesis. We demonstrate that spectroscopic ellipsometry is an excellent technique for accurate, non-destructive determination of ultra-thin (<30 nm) WSe{sub 2} properties. The refractive index (n) and extinction coefficient (k) were found to be independent of thickness down to 1.3 nm, and were used to determine film thickness, which was confirmed to be within 9% of values found via atomic force microscopy. Finally, the optical bandgap was found to closely correlate with thickness, ranging from 1.2 to 1.55 eV as the WSe{sub 2} is thinned to the equivalent of 2 atomic layers.

  20. Test and Evaluation of the Magnograph (TM) unit, a nondestructive wire rope tester

    NASA Astrophysics Data System (ADS)

    Underbakke, L. D.; Haynes, H. H.

    1982-07-01

    The nondestructive wire rope test device, a unitized AC/DC Magnograph, was tested for operational characteristics prior to acquisition by Naval field activities and start of inspection programs. The Magnograph was tested for loss of metallic area (LMA) and local fault (LF) detection accuracy. Wire ropes 1/2, 3/4, 1-1/8, 1-1/2, 2, and 2-1/2 inches in diameter were tested on a wire rope test track to find the accuracy of the unit. Two mining wire ropes, guy wires of a 1,000-ft-tall tower, and wire rope for 400-, 250-, and 30-ton cranes were used to determine operational characteristics of the Magnograph.

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

    NASA Astrophysics Data System (ADS)

    Pérez-Benitez, J. A.; Padovese, L. R.

    2012-04-01

    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.

  2. 78 FR 30303 - National Contact Center; Submission for OMB Review; National Contact Center Customer Evaluation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-22

    ... in the Federal Register at 78 FR 14549, on March 6, 2013. No comments were received. DATES: Submit... ADMINISTRATION National Contact Center; Submission for OMB Review; National Contact Center Customer Evaluation Survey AGENCY: Contact Center Services, Federal Citizen Information Center, Office of Citizen...

  3. 3D Ultrasonic Non-destructive Evaluation of Spot Welds Using an Enhanced Total Focusing Method

    NASA Astrophysics Data System (ADS)

    Jasiuniene, Elena; Samaitis, Vykintas; Mazeika, Liudas; Sanderson, Ruth

    2015-02-01

    Spot welds are used to join sheets of metals in the automotive industry. When spot weld quality is evaluated using conventional ultrasonic manual pulse-echo method, the reliability of the inspection is affected by selection of the probe diameter and the positioning of the probe in the weld center. The application of a 2D matrix array is a potential solution to the aforementioned problems. The objective of this work was to develop a signal processing algorithm to reconstruct the 3D spot weld volume showing the size of the nugget and the defects in it. In order to achieve this, the conventional total focusing method was enhanced by taking into account the directivities of the single elements of the array and the divergence of the ultrasonic beam due to the propagation distance. Enhancements enabled a reduction in the background noise and uniform sensitivity at different depths to be obtained. The proposed algorithm was verified using a finite element model of ultrasonic wave propagation simulating three common spot weld conditions: a good weld, an undersized weld, and a weld containing a pore. The investigations have demonstrated that proposed method enables the determination of the size of the nugget and detection of discontinuities.

  4. High temperature ultrasonic transducers for the generation of guided waves for non-destructive evaluation of pipes

    SciTech Connect

    Sinding, K.; Searfass, C.; Malarich, N.; Reinhardt, B.; Tittmann, B. R.

    2014-02-18

    Applications for non-destructive evaluation and structural health monitoring of steam generators require ultrasonic transducers capable of withstanding the high temperatures of the pipes and heat exchangers. These applications require a strong coupling of the transducer to the heat exchanger’s complex geometry at the elevated temperatures. Our objective is to use spray-on piezo-electrics for depositing comb transducers onto the curved surfaces. This paper shows results for composite transducers such as lead zirconate titanate/ bismuth titanate and bismuth titanate/ lithium niobate. The comb transducers were prepared by precision laser ablation. The feasibility of producing second harmonic waves in rods with these spay-on comb transducers was demonstrated and paves the way toward measuring material degradation early-on before crack initiation occurs.

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

    NASA Technical Reports Server (NTRS)

    Suits, Michael W.; Bryson, Craig C.

    2006-01-01

    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.

  6. Non-destructive evaluation of the cladding thickness in LEU fuel plates by accurate ultrasonic scanning technique

    SciTech Connect

    Borring, J.; Gundtoft, H.E.; Borum, K.K.; Toft, P.

    1997-08-01

    In an effort to improve their ultrasonic scanning technique for accurate determination of the cladding thickness in LEU fuel plates, new equipment and modifications to the existing hardware and software have been tested and evaluated. The authors are now able to measure an aluminium thickness down to 0.25 mm instead of the previous 0.35 mm. Furthermore, they have shown how the measuring sensitivity can be improved from 0.03 mm to 0.01 mm. It has now become possible to check their standard fuel plates for DR3 against the minimum cladding thickness requirements non-destructively. Such measurements open the possibility for the acceptance of a thinner nominal cladding than normally used today.

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

    DOEpatents

    Thompson, Donald O.; Wormley, Samuel J.

    1989-03-28

    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.

  8. Non-Destructive Evaluation for Corrosion Monitoring in Concrete: A Review and Capability of Acoustic Emission Technique

    PubMed Central

    Zaki, Ahmad; Chai, Hwa Kian; Aggelis, Dimitrios G.; Alver, Ninel

    2015-01-01

    Corrosion of reinforced concrete (RC) structures has been one of the major causes of structural failure. Early detection of the corrosion process could help limit the location and the extent of necessary repairs or replacement, as well as reduce the cost associated with rehabilitation work. Non-destructive testing (NDT) methods have been found to be useful for in-situ evaluation of steel corrosion in RC, where the effect of steel corrosion and the integrity of the concrete structure can be assessed effectively. A complementary study of NDT methods for the investigation of corrosion is presented here. In this paper, acoustic emission (AE) effectively detects the corrosion of concrete structures at an early stage. The capability of the AE technique to detect corrosion occurring in real-time makes it a strong candidate for serving as an efficient NDT method, giving it an advantage over other NDT methods. PMID:26251904

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

    NASA Technical Reports Server (NTRS)

    Vary, A.

    1980-01-01

    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.

  10. Non-Destructive Evaluation for Corrosion Monitoring in Concrete: A Review and Capability of Acoustic Emission Technique.

    PubMed

    Zaki, Ahmad; Chai, Hwa Kian; Aggelis, Dimitrios G; Alver, Ninel

    2015-01-01

    Corrosion of reinforced concrete (RC) structures has been one of the major causes of structural failure. Early detection of the corrosion process could help limit the location and the extent of necessary repairs or replacement, as well as reduce the cost associated with rehabilitation work. Non-destructive testing (NDT) methods have been found to be useful for in-situ evaluation of steel corrosion in RC, where the effect of steel corrosion and the integrity of the concrete structure can be assessed effectively. A complementary study of NDT methods for the investigation of corrosion is presented here. In this paper, acoustic emission (AE) effectively detects the corrosion of concrete structures at an early stage. The capability of the AE technique to detect corrosion occurring in real-time makes it a strong candidate for serving as an efficient NDT method, giving it an advantage over other NDT methods. PMID:26251904

  11. High temperature ultrasonic transducers for the generation of guided waves for non-destructive evaluation of pipes

    NASA Astrophysics Data System (ADS)

    Sinding, K.; Searfass, C.; Malarich, N.; Reinhardt, B.; Tittmann, B. R.

    2014-02-01

    Applications for non-destructive evaluation and structural health monitoring of steam generators require ultrasonic transducers capable of withstanding the high temperatures of the pipes and heat exchangers. These applications require a strong coupling of the transducer to the heat exchanger's complex geometry at the elevated temperatures. Our objective is to use spray-on piezo-electrics for depositing comb transducers onto the curved surfaces. This paper shows results for composite transducers such as lead zirconate titanate/ bismuth titanate and bismuth titanate/ lithium niobate. The comb transducers were prepared by precision laser ablation. The feasibility of producing second harmonic waves in rods with these spay-on comb transducers was demonstrated and paves the way toward measuring material degradation early-on before crack initiation occurs.

  12. Criteria for Evaluation of Teacher Education Center Programs.

    ERIC Educational Resources Information Center

    Setranjiwalla, Zohra K.; Drummond, William H.

    In compliance with the Teacher Education Center Act of 1973 (Section 231.608, Florida Statutes), a select group of Florida educators, Department of Education members, and State Council on Teacher Education Centers (TEC's) representatives developed proposed criteria for both the evaluation of teacher centers and evaluation of the evaluation…

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

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1994-01-01

    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.

  14. Wavelet-based subsurface defect characterization in pulsed phase thermography for non-destructive evaluation

    NASA Astrophysics Data System (ADS)

    Zauner, G.; Mayr, G.; Hendorfer, G.

    2009-02-01

    Active infrared thermography is a method for non-destructive testing (NDT) of materials and components. In pulsed thermography (PT), a brief and high intensity flash is used to heat the sample. The decay of the sample surface temperature is detected and recorded by an infrared camera. Any subsurface anomaly (e.g. inclusion, delamination, etc.) gives rise to a local temperature increase (thermal contrast) on the sample surface. Conventionally, in Pulsed Phase Thermography (PPT) the analysis of PT time series is done by means of Discrete Fourier Transform producing phase images which can suppress unwanted physical effects (due to surface emissivity variations or non-uniform heating). The drawback of the Fourier-based approach is the loss of temporal information, making quantitative inversion procedures tricky (e.g. defect depth measurements). In this paper the complex Morlet-Wavelet transform is used to preserve the time information of the signal and thus provides information about the depth of a subsurface defect. Additionally, we propose to use the according phase contrast value to derive supplementary information about the thermal reflection properties at the defect interface. This provides additional information (e.g. about the thermal mismatch factor between the specimen and the defect) making interpretation of PPT results easier and perhaps unequivocal.

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

    NASA Astrophysics Data System (ADS)

    Lopez, Richard Daniel

    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.

  16. First-year evaluation of a nondestructive assay system for the examination of ORNL TRU waste

    SciTech Connect

    Schultz, F.J.; Haff, K.W.; Coffey, D.E.; Norris, L.B.; Caldwell, J.T.; Close, D.A.; Kuckertz, T.H.; Kunz, W.E.; Pratt, J.C.

    1984-04-01

    The Oak Ridge National Laboratory has been selected as the demonstration site for a new transuranic neutron assay system (NAS) developed at the Los Alamos National Laboratory. In addition, in order to meet specific ORNL program objectives, an upgraded segmented gamma-ray drum scanner has been integrated into the nondestructive assay (NDA) system to serve as a radioisotope identifier and as a quantitative assay backup to the NAS. A verification study, wherein selected waste drums will be emptied into glove boxes and their contents sampled and subsequently gamma-ray assayed, will take place in FY 1984. Results will be compared to those obtained from the NDA techniques. The NAS uses pulsed-neutron interrogation (differential- dieaway technique) and passive neutron measurements to determine fissile component and an upper-limit estimate of the total TRU activity contained in each waste drum. Of the 171 waste drums assayed to date, nine drums were determined to contain less than 10 nCi/g TRU isotopes. An additional number of drums (approximately 20%) are expected to be categorized as non-TRU, which is presently defined as less than 100 nCi/g TRU concentration. This requires a detailed analysis of the data which includes waste matrix compensation, systematic qualitative and quantitative gamma-ray analyses, and interpretation of neutron multiplicity data. Reproducibility of the active assay measurements on a single waste drum indicate agreement to +-3% relative error. 14 references, 24 figures, 8 tables.

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

    NASA Astrophysics Data System (ADS)

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

    2013-01-01

    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 α'-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.

  18. Large area detector based computed tomography system for production nondestructive evaluation.

    SciTech Connect

    Keating, S. C.; Davis, A. A.; Claytor, T. N.

    2001-01-01

    We present a system for industrial x-ray computed tomography that has been optimized for all phases of nondestructive component inspection. Data acquisition is greatly enhanced by the use of high resolution, large area, flat-panel amorphous-silicon detectors. The detectors have proven, over several years, to be a robust alternative to CCD-optics and image intensifier CT systems. In addition to robustness, these detectors provide the advantage of area detection as compared with the single slice geometry of linear array systems. Parallel processing provides significant speed improvements for data reconstruction, and is implemented for parallel-beam, fan-beam and Feldkamp conebeam reconstruction algorithms. By clustering ten or more equal-speed computers, reconstruction times are reduced by an order of magnitude. We have also developed interactive software for visualization and interrogation of the full three-dimensional dataset. Inspection examples presented in this paper include an electro-mechanical device, nonliving biological specimens and a turbo-machinery component. We also present examples of everyday items for the benefit of the layperson.

  19. Theoretical prediction of remote-field eddy current response for the nondestructive evaluation of metallic tubes

    NASA Astrophysics Data System (ADS)

    Palanisamy, R.

    1987-04-01

    The remote-field eddy current effect refers to low-frequency eddy current nondestructive testing (NDT) phenomenon in tubular conductors in which the behavior of both amplitude and phase of induced magnetic field are in apparent contradiction to the well-known ``skin-effect'' theory. Near-equal detection sensitivity across the wall thickness, the ability to measure wall thickness, and the absence of lift-off problems are some of the attractive features of this technique. Despite its early recognition and useful application in down-hole inspection of oil-well casing, no development of adequate scientific basis that could explain this phenomenon has been reported in the open literature. Modeling of the remote-field eddy current phenomenon using the axisymmetric finite element computer code is described in this paper. The results presented show that the finite element numerical technique originally developed for the computation of fields in electrical and magnetic devices can be used as well for the modeling of remote-field eddy current NDT problems.

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

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    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.

  1. Evaluating the Radiation From Accidental Exposure During a Nondestructive Testing Event.

    PubMed

    Ting, Chien-Yi; Wang, Hsin-Ell; Lin, Jao-Perng; Lin, Chun-Chih

    2015-08-01

    Industrial radiography is a common nondestructive testing (NDT) method used in various industries. An investigation was conducted for a 1999 incident in Taiwan where two workers (Operators A and B) were accidently exposed to an unshielded Ir source while conducting industrial radiography. Operators A and B experienced acute close-range radiation exposure to a source of Ir for 3 h at a strength of 2.33 × 10 Bq. The health of mammary glands, bone marrow, thyroid glands, eyes, and genital organs of these two workers after radiation exposure was examined. Subsequently, Operator A experienced severe radiation injury, including tissue necrosis and keratinization in the fingers, chromosomal abnormalities, reduced blood cell count, diffuse hyperplasia of the thyroid gland, opaque spots in the crystalline lens, and related radiation effects. The results showed that the left index finger and thumb, eyes, and gonads of Operator A were exposed to a radiation dose of about 369-1,070, 23.1-67.4, 2.4-5.3, and 4.2-11.6 Gy, respectively. Effective dose for Operator A was estimated to range from 6.9 to 18.9 Sv. The left fingers, thumb, eyes, and gonads of Operator B were exposed to a radiation dose of 184.9-646.2, 11.8-40.7, 0.49-3.33, and 0.72-7.18 Gy, respectively, and his effective dose was between 2.5 and 11.5 Sv. This accident indicated a major flaw in the control and regulation of radiation safety for conducting NDT industrial radiography in 1999; however, similar problems still exist. Modifications of the Ionizing Radiation Protection Act in Taiwan are suggested in this study to regulate the management of NDT industries, continually educate the NDT workers in radiation safety, and enact notification provisions for medical care systems toward acute radiation exposure events. PMID:26107437

  2. 75 FR 6032 - National Contact Center; Submission for OMB Review; National Contact Center Customer Evaluation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-05

    ... renewal of a previously approved information collection requirement regarding the National Contact Center customer evaluation survey. A request for public comments was published in the Federal Register at 74 FR... ADMINISTRATION National Contact Center; Submission for OMB Review; National Contact Center Customer...

  3. 13 CFR 306.7 - Performance evaluations of University Centers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... one (1) other University Center in the performance evaluation on a cost-reimbursement basis. ... University Centers. 306.7 Section 306.7 Business Credit and Assistance ECONOMIC DEVELOPMENT ADMINISTRATION, DEPARTMENT OF COMMERCE TRAINING, RESEARCH AND TECHNICAL ASSISTANCE INVESTMENTS University Center...

  4. Summary of Activities for Nondestructive Evaluation of Insulation in Cryogenic Tanks

    NASA Technical Reports Server (NTRS)

    Arens, Ellen

    2012-01-01

    This project was undertaken to investigate methods to non-intrusively determine the existence and density of perlite insulation in the annular region of the cryogenic storage vessels, specifically considering the Launch Complex 39 hydrogen tanks at Kennedy Space Center. Lack of insulation in the tanks (as existed in the pad B hydrogen tank at Kennedy Space Center) results in an excessive loss of commodity and can pose operational and safety risks if precautions are not taken to relieve the excessive gas build-up. Insulation with a density that is higher than normal (due to settling or compaction) may also pose an operational and safety risk if the insulation prevents the system from moving and responding to expansions and contractions as fluid is removed and added to the tank.

  5. Ultrasonic Nondestructive Evaluation of PRSEUS Pressure Cube Article in Support of Load Test to Failure

    NASA Technical Reports Server (NTRS)

    Johnston, Patrick H.

    2013-01-01

    The PRSEUS Pressure Cube Test was a joint development effort between the Boeing Company and NASA Langley Research Center, sponsored in part by the Environmentally Responsible Aviation Project and Boeing internal R&D. This Technical Memorandum presents the results of ultrasonic inspections in support of the PRSEUS Pressure Cube Test, and is a companion document with the NASA test report and a report on the acoustic emission measurements made during the test.

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

    SciTech Connect

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

    2012-04-30

    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.

  7. A model-based method for the characterisation of stress in magnetic materials using eddy current non-destructive evaluation

    NASA Astrophysics Data System (ADS)

    Dahia, Abla; Berthelot, Eric; Le Bihan and, Yann; Daniel, Laurent

    2015-03-01

    A precise knowledge of the distribution of internal stresses in materials is key to the prediction of magnetic and mechanical performance and lifetime of many industrial devices. This is the reason why many efforts have been made to develop and enhance the techniques for the non-destructive evaluation of stress. In the case of magnetic materials, the use of eddy current (EC) techniques is a promising pathway to stress evaluation. The principle is based on the significant changes in magnetic permeability of magnetic materials subjected to mechanical stress. These modifications of magnetic permeability affect in turn the signal obtained from an EC probe inspecting the material. From this principle, a numerical tool is proposed in this paper to predict the EC signal obtained from a material subjected to stress. This numerical tool is a combination of a 3D finite element approach with a magneto-mechanical constitutive law describing the effect of stress on the magnetic permeability. The model provides the variations of impedance of an EC probe as a function of stress. An experimental setup in which a magnetic material subjected to a tension stress is inspected using EC techniques is tailored in order to validate the model. A very good agreement is found between experimental and modelling results. For the Iron-Cobalt alloy tested in this study, it is shown that a uniaxial tensile stress can be detected with an error lower than 3 MPa in the range from 0 to 100 MPa.

  8. Application of low-coherence interferometry for in situ nondestructive evaluation of thin and thick multilayered transparent composites

    NASA Astrophysics Data System (ADS)

    Khomenko, Anton; Cloud, Gary Lee; Haq, Mahmoodul

    2015-12-01

    Multilayered transparent composites having laminates with polymer interlayers and backing sheets are commonly used in a wide range of applications where visibility, transparency, impact resistance, and safety are essential. Manufacturing flaws or damage during operation can seriously compromise both safety and performance. Most fabrication defects are not discernible until after the entire multilayered transparent composite assembly has been completed, and in-the-field inspection for damage is a problem not yet solved. A robust and reliable nondestructive evaluation (NDE) technique is needed to evaluate structural integrity and identify defects that result from manufacturing issues as well as in-service damage arising from extreme environmental conditions in addition to normal mechanical and thermal loads. Current optical techniques have limited applicability for NDE of such structures. This work presents a technique that employs a modified interferometer utilizing a laser diode or femtosecond fiber laser source to acquire in situ defect depth location inside a thin or thick multilayered transparent composite, respectively. The technique successfully located various defects inside examined composites. The results show great potential of the technique for defect detection, location, and identification in multilayered transparent composites.

  9. Reference Specimen for Nondestructive Evaluation: Characterization of the Oxide Layer of a Cold Shot in Inconel 600

    NASA Astrophysics Data System (ADS)

    Saletes, I.; Filleter, T.; Goldbaum, D.; Chromik, R. R.; Sinclair, A. N.

    2015-02-01

    The presence of a cold shot in an aircraft turbine blade can lead to the catastrophic failure of the blade and ultimately to the failure of the power plant. Currently, no nondestructive evaluation (NDE) method exists to detect this kind of defect. This deficiency is primarily due to the fact that the only known cold shot defects in existence are those found in failed blades. Therefore, in order to develop effective NDE methods, reference specimens are needed which mimic the embedded oxide layer that is a primary distinguishing feature of a cold shot. Here, we present a procedure to synthetically reproduce the features of a real cold shot in Inconel 600 and the precise characterization of this oxide layer as a reference specimen suitable for NDE evaluation. As a first step to develop a suitable NDE technique, high-frequency ultrasound simulations are considered. A theoretical 1-D model is developed in order to quantify the multiple reflection-transmission trajectory of the acoustic wave in the reference specimen. This paper also presents an experimental determination of the density and the Young's modulus of the Inconel 600 oxide, which are required as inputs to calculate the acoustic impedance used in the theoretical model.

  10. Innovative non-destructive evaluation methods on HTR fuel at AREVA NP: towards a 100% non invasive control strategy

    SciTech Connect

    Banchet, J.; Tisseur, D.; Hermosilla Lara, S.; Piriou, M.; Bargain, R.; Guillermier, P.

    2007-07-01

    High Temperature Reactor (HTR) fuel consists in millimetric multilayered particles called TRISO, embedded, depending on the reactor design, in a pebble or cylinder-shaped graphite matrix called compact. Particles are typically composed of a 500 {mu}m fissile material kernel, a 95 {mu}m porous carbon layer called buffer, a 40 {mu}m dense pyrolytic carbon layer, a 35 {mu}m silicon carbide layer and another 40 {mu}m dense pyrolytic carbon layer. In order to ensure fuel qualification, as well as reactor safety, particles and compacts need to satisfy specifications concerning their physical characteristics and their integrity. In particular, geometrical parameters such as particle diameter and sphericity as well as layers thickness, but also layers density and the absence of structural defects such as cracks or de-cohesions need to be detected and characterized. In the past, a huge R and D work was carried out to build a TRISO particle characterization quality control plan, mainly based on particle sampling as well as destructive characterization methods. However, since then, development of industrial non-destructive evaluation techniques and devices contributed to envisage not only a non invasive control of HTR fuel, but also a 100% production control strategy. Since 2004, AREVA NP is engaged in a R and D program aiming at the development of innovative industrial nondestructive evaluation methods for HTR fuel. After investigating a number of potential techniques, some of them were selected based on their performances and/or their industrial potential. In particular, development has been carried out on high resolution X-Ray imaging allowing accurate layer thickness, layer density and structural defects characterization, X-Ray tomography offering the possibility to characterize fuel element homogeneity and determine the number of in-contact particles contained in a fuel element, infrared thermal imaging (ITI) allowing cracks detection, eddy currents (EC) enabling

  11. A Review of the Chinese Higher Education Evaluation Center

    ERIC Educational Resources Information Center

    Luo, Laura Pan; Dehai, Wang

    2007-01-01

    The authors discuss the Higher Education Evaluation Center, the administrative body under the auspices of the Chinese Ministry of Education responsible for organizing and conducting evaluation of baccalaureate and associate degree programs offered at different universities and colleges in China. The Center also conducts research on regulations and…

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

    SciTech Connect

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

    2006-03-06

    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.

  13. Development of nondestructive evaluation techniques for high-temperature ceramic heat exchanger components. Ninth quarterly report, October-December 1979

    SciTech Connect

    Not Available

    1980-01-01

    Progress in developing and evaluating nondestructive methods for testing ceramic components for high-temperature heat exchangers is reported. The sensitivity of the ultrasonic bore-side probe was demonstrated for detection of 125-..mu..m-deep circumferential EDM notches on ID and OD surfaces of sintered and siliconized tubes. The signal to noise ratios for the ultrasonic echoes are better than 10 to 1, beyond the initial expectations for detection of small reflectors. This results from focussing of the beam in the tube wall. Preliminary data were presented on microprocessor-controlled operation of the ultrasonic probe. Some problems involving the computer interfacing have to be resolved, but detection and recording of an EDM notch located was demonstrated. The acoustic microscope was modified to handle 30-MHz sound waves. This was done to improve the penetration ability of the sound in SiC tube walls. The modification results in less acoustic noise. The ability to detect a notch only 75 ..mu..m in width was demonstrated.

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

    NASA Astrophysics Data System (ADS)

    Miller, James G.

    1995-03-01

    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.

  15. Design and preliminary results from a high temperature superconducting SQUID milliscope used for non-destructive evaluation

    SciTech Connect

    Espy, M.A.; Atencio, L.; Flynn, E.R.; Kraus, R.H. Jr.; Matlashov, A.

    1998-12-31

    The authors present the design and preliminary results from a SQUID milliscope. The device was designed for nondestructive evaluation (NDE) as part of the Enhanced Surveillance Program at Los Alamos National Laboratory and uses a high temperature superconducting (HTS) SQUID sensor to map magnetic fields induced in the sample. Eddy currents are induced in the conducting sample by a wire coil designed to produce minimal magnetic field at the SQUID when no sample is present. The features of interest are characterized by anomalies in the induced magnetic field. The goal of the instrument is sensitivity to small features generally buried under several intervening layers ({approximately}1--10 mm) of conducting and/or non-conducting materials and robustness of design (i.e., the ability to operate in a noisy, unshielded environment). The device has primarily focused on specific NDE problems such as the ability to detect buried seams in conducting materials and quantify the width of these seams. The authors present the design of the instrument, and some data to demonstrate its capabilities.

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

    SciTech Connect

    Smith, Cyrus M; Nanstad, Randy K; Clayton, Dwight A; Matlack, Katie; Ramuhalli, Pradeep; Light, Glenn

    2012-09-01

    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.

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

    NASA Astrophysics Data System (ADS)

    Flattum, Richard Y.; Cooney, Adam T.

    2013-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1995-01-01

    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.

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

    SciTech Connect

    Flattum, Richard Y.; Cooney, Adam T.

    2013-01-25

    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.

  20. Shearography for Non-Destructive Evaluation with Applications to BAT Mask Tile Adhesive Bonding and Specular Surface Honeycomb Panels

    NASA Technical Reports Server (NTRS)

    Lysak, Daniel B.

    2003-01-01

    In this report we examine the applicability of shearography techniques for nondestructive inspection and evaluation in two unique application areas. In the first application, shearography is used to evaluate the quality of adhesive bonds holding lead tiles to the BAT gamma ray mask for the NASA Swift program. By exciting the mask with a vibration, the more poorly bonded tiles can be distinguished by their greater displacement response, which is readily identifiable in the shearography image. A quantitative analysis is presented that compares the shearography results with a destructive pull test measuring the force at bond failure. Generally speaking, the results show good agreement. Further investigation would be useful to optimize certain test parameters such as vibration frequency and amplitude. The second application is to evaluate the bonding between the skin and core of a honeycomb structure with a specular (mirror-like) surface. In standard shearography techniques, the object under test must have a diffuse surface to generate the speckle patterns in laser light, which are then sheared. A novel configuration using the specular surface as a mirror to image speckles from a diffuser is presented, opening up the use of shearography to a new class of objects that could not have been examined with the traditional approach. This new technique readily identifies large scale bond failures in the panel, demonstrating the validity of this approach. For the particular panel examined here, some scaling issues should be examined further to resolve the measurement scale down to the very small size of the core cells. In addition, further development should be undertaken to determine the general applicability of the new approach and to establish a firm quantitative foundation.

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

    NASA Astrophysics Data System (ADS)

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

    2009-03-01

    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.

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

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    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.

  3. Nondestructive Evaluation of Thermal Barrier Coatings by Mid-infrared Reflectance

    NASA Technical Reports Server (NTRS)

    Eldridge, Jeffrey I; Spuckler, Charles M.; Nesbitt, James A.; Martin, Richard E.

    2005-01-01

    The application of mid-infrared reflectance (MIR) imaging to monitor damage in thermal barrier coatings (TBCs) has been extended from a previously demonstrated area-averaged spectroscopic analysis tool to become a practical imaging tool that provides the spatial resolution needed to quickly identify localized regions of TBC damage by visual inspection, Illumination optics and image collection procedures were developed to produce illumination-normalized flatfield reflectance images after subtraction of the background thermal emission. MIR reflectance images were collected with a bandpass filter centered at a wavelength of 4 microns, which provided the optimum balance between good sensitivity to buried cracks and coating erosion, but with a desirable sensitivity to TBC sintering and absorption from ambient gases. Examples are presented of the application of MIR reflectance imaging to monitor damage progression in plasma-sprayed 8wt% yttria-stabilized zirconia (8YSZ) TBCs subjected to either furnace cycling or alumina particle jet erosion. These results show that MIR reflectance imaging can reliably track the progression of buried delamination cracks produced by thermal cycling and can also be used to determine when any local section of the TBC has eroded beyond an acceptable limit. Modeling of the effects of buried cracks and erosion on reflectance will be presented to show the dependence of damage sensitivity to TBC thickness.

  4. Nondestructive evaluation of loose assemblies using multi-frequency eddy currents and artificial neural networks

    NASA Astrophysics Data System (ADS)

    Vourc'h, Eric; Joubert, Pierre-Yves; Le Gac, Guillaume; larzabal, Pascal

    2013-12-01

    This paper considers the problem of the evaluation of metallic assemblies in an aeronautical context, by means of a non-invasive method. The problems lies in the estimation of the distance separating two aluminum plates representative of a loose assembly (up to 300 µm), the top plate being possibly of unknown thickness ranging from 1 to 8 mm. To do so, the eddy current (EC) method is chosen, because it allows non-contact evaluation of conducting media to be carried out, which is sensitive to electrical conductivity changes in the part under evaluation, and hence to the presence of an air gap between parts. The problem falls into the category of evaluation of a multilayered conductive structure starting from EC data, which is an ill-posed problem. In order to bypass these difficulties, as well as to deal with the uncertainties that may be introduced by the experimental set-up, a ‘non-model’ approach is implemented by means of an artificial neural network (ANN). The latter is elaborated in a statistical learning approach starting from the experimental EC data provided by a ferrite cored coil EC probe used to investigate an assembly mockup of adjustable configuration. Moreover, in order to build a learning database allowing a robust and accurate ANN to be elaborated, as well as to deal with assemblies of unknown thicknesses, we consider EC data obtained at different frequencies chosen in an adjusted frequency bandwidth, experimentally determined so as to optimize the sensitivity toward the presence of an air gap between parts. The implementation of the proposed approach for distances between parts ranging from 60 to 300 µm provided estimated root mean square errors ranging from 7 μm up to 50 µm for the estimation of the distance between parts, and ranging from 20 µm up to 1.4 mm for the estimation of the top plates, ranging from 1 to 8 mm, respectively.

  5. Image correlation nondestructive evaluation of impact damage in a glass fiber composite

    NASA Technical Reports Server (NTRS)

    Russell, Samuel S.

    1990-01-01

    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.

  6. Eddy current technique applied to the nondestructive evaluation of turbine blade wall thickness

    NASA Astrophysics Data System (ADS)

    Le Bihan, Yann; Joubert, Pierre-Yves; Placko, Dominique

    2000-05-01

    The high pressure turbine blades of jet engines show internal channels designed for air cooling. These recesses define the internal walls (partitions) and external walls of the blade. The external wall thickness is a critical parameter which has to be systematically checked in order to ensure the blade strength. The thickness evaluation is usually lead by ultrasonic technique or by X-ray tomography. Nevertheless, both techniques present some drawbacks related to measurement speed and automation capability. These drawbacks are bypassed by the eddy current (EC) technique, well known for its robustness and reliability. However, the wall thickness evaluation is made difficult because of the complexity of the blade geometry. In particular, some disturbances appear in the thickness evaluation because of the partitions, which exclude the use of classical EC probes such as cup-core probe. In this paper, we show the main advantages of probes creating an uniformly oriented magnetic field in order to reduce the partition disturbances. Furthermore, we propose a measurement process allowing to separate the wall thickness parameter from the EC signals. Finally, we present some experimental results validating the proposed technique.

  7. Non-destructive concrete strength evaluation using smart piezoelectric transducer—a comparative study

    NASA Astrophysics Data System (ADS)

    Lim, Yee Yan; Zee Kwong, Kok; Liew, Willey Yun Hsien; Kiong Soh, Chee

    2016-08-01

    Concrete strength monitoring, providing information related to the readiness of the structure for service, is important for the safety and resource planning in the construction industry. In this paper, a semi-analytical model of surface bonded piezoelectric (lead zirconate titanate) based wave propagation (WP) technique was developed for strength evaluation of mortar with different mix, throughout the curing process. Mechanical parameters of the mortar specimen were mathematically evaluated from the surface wave (R-wave) and pressure wave (P-wave) using elastic wave equations. These parameters were then empirically correlated to the strength. The model was found to be very robust as it could be generalized to account for different water to cement (W/C) ratio. The performance of the WP technique was then compared to the electromechanical impedance technique and other conventional techniques, such as the ultrasonic pulse velocity (UPV) test and the rebound hammer test. Results showed that the WP technique performed equally well as the conventional counterparts. The proposed technique is also advantageous over embedded WP technique and the UPV test, in terms of its capability to capture two types of waves for the evaluation of dynamic modulus of elasticity and Poisson’s ratio. A separate study was finally conducted to verify the applicability of this technique on heterogeneous concrete specimen. With the inherent capability of the WP technique in enabling autonomous, real-time, online and remote monitoring, it could potentially replace its conventional counterparts, in providing a more effective technique for the monitoring of concrete strength.

  8. Johnson Space Center Overview

    NASA Technical Reports Server (NTRS)

    Gafka, Tammy; Terrier, Doug; Smith, James

    2011-01-01

    This slide presentation is a review of the work of Johnson Space Center. It includes a section on technology development areas, (i.e., composite structures, non-destructive evaluation, applied nanotechnology, additive manufacturing, and fracture and fatigue analytical methods), a section on structural analysis capabilities within NASA/JSC and a section on Friction stir welding and laser peening.

  9. Composite Structures Repair Development at Kennedy Space Center

    NASA Technical Reports Server (NTRS)

    Cox, Sarah B.

    2015-01-01

    This presentation discusses the development and results of composite patch repair perfromed at Kennedy Space Center. This includes impact damage, patch repair methods, nondestructive evaluation, and edgewise compression testing.

  10. Two dimensional imaging of photoluminescence from rice for quick and non-destructive evaluation

    NASA Astrophysics Data System (ADS)

    Katsumata, T.; Suzuki, T.; Aizawa, H.; Matashige, E.

    2005-05-01

    The visible PL with broad peak at wavelength of λ=462 nm are observed from polished rice, flour and corn starch under illumination of ultra-violet (UV) light. PL peaking at λ=462 nm is excited effectively with UV light at λ=365 nm. Peak intensity is found to vary with the source and the breed of the rice specimens. PL images from rice also reveal the uniformity of the rice products. Two-dimensional images of PL, which reavealed the uniformity of rice under UV irradiation, are potentially useful for the evaluation and the quality control of the rice products.

  11. Portable microwave instrument for non-destructive evaluation of structural characteristics

    DOEpatents

    Bible, D.W.; Crutcher, R.I.; Sohns, C.W.; Maddox, S.R.

    1995-01-24

    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.

  12. Portable microwave instrument for non-destructive evaluation of structural characteristics

    DOEpatents

    Bible, Don W.; Crutcher, Richard I.; Sohns, Carl W.; Maddox, Stephen R.

    1995-01-01

    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.

  13. Analysis of Microstructure Using Thermoelectric Diagnostics for Non-Destructive Evaluation of Materials

    SciTech Connect

    Park, Y.D.; Kaydanov, V.I.; Mishra, B.; Olson, D.L.

    2005-04-09

    Measurements of Thermoelectric power (TEP) were used to evaluate microstructural analysis in HSLA steel weldments and retained austenite volume fraction for TRIP steel. First, the measurements of TEP for weld microstructure across weldment have shown good correlation with hardness profile. The different TEP values indicated that changes in weld microstructure can be correlated with TEP values measured. Second, it was demonstrated that retained austenite volume fraction were well correlated to TEP measurements for transformation induced plasticity (TRIP) steels. The results suggest that TEP measurements can be correlated to retained austenite volume fraction for TRIP steels, which do not have same chemical composition and thermal heat treatment processes. The retained austenite volume fraction also was measured by X-ray diffraction (XRD) method. With the introduction of these advanced TEP coefficient measurement techniques, the welding and steel industry will be using analytical tools similar to those instruments applied in the semiconductor industry.

  14. Analysis of Microstructure Using Thermoelectric Diagnostics for Non-Destructive Evaluation of Materials

    NASA Astrophysics Data System (ADS)

    Park, Y. D.; Kaydanov, V. I.; Mishra, B.; Olson, D. L.

    2005-04-01

    Measurements of Thermoelectric power (TEP) were used to evaluate microstructural analysis in HSLA steel weldments and retained austenite volume fraction for TRIP steel. First, the measurements of TEP for weld microstructure across weldment have shown good correlation with hardness profile. The different TEP values indicated that changes in weld microstructure can be correlated with TEP values measured. Second, it was demonstrated that retained austenite volume fraction were well correlated to TEP measurements for transformation induced plasticity (TRIP) steels. The results suggest that TEP measurements can be correlated to retained austenite volume fraction for TRIP steels, which do not have same chemical composition and thermal heat treatment processes. The retained austenite volume fraction also was measured by X-ray diffraction (XRD) method. With the introduction of these advanced TEP coefficient measurement techniques, the welding and steel industry will be using analytical tools similar to those instruments applied in the semiconductor industry.

  15. Comparison between beamforming and super resolution imaging algorithms for non-destructive evaluation

    SciTech Connect

    Fan, Chengguang; Drinkwater, Bruce W.

    2014-02-18

    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.

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

    NASA Technical Reports Server (NTRS)

    Waller, Jess M.; Saulsberry, Regor L.

    2012-01-01

    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.

  17. Evaluation of bonds in armor plate and other materials using infrared nondestructive testing techniques.

    PubMed

    Vogel, P E

    1968-09-01

    Reported here are the results of using an ir technique in evaluating the bond in hot-roll bonded armor plate, a coating bond, and the bonds in the three-layer construction of a small missile motor. When a specimen is exposed to heat, the heat flows into it at a rate that can be determined. If the flow is interrupted by a void, the inclusion of a material of different conductivity, or any similar thermal barrier, a difference in surface temperature will result that can be defined with an ir radiometer or thermograph. Lack of bond, while not presenting a gross void, is shown here to be a sufficient impediment to be distinguishable. PMID:20068876

  18. Comparison between beamforming and super resolution imaging algorithms for non-destructive evaluation

    NASA Astrophysics Data System (ADS)

    Fan, Chengguang; Drinkwater, Bruce W.

    2014-02-01

    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.

  19. Non-Destructive Evaluation of Fatigue Damage for SUS316 by Using Electromagnetic Methods

    NASA Astrophysics Data System (ADS)

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

    2009-03-01

    There are some fatigue damage estimation methods for an austenitic stainless steel that uses martensitic transformation. For instance, those are the remanent magnetization method, the excitation method using the differential pick-up coil, and so on. We are researching also those two methods in our laboratory now. In the remanent magnetization method, it is well known that the relationship between fatigue damage and the remanent magnetization is simple, clear, and reproducible. In addition, the excitation method can be easily used at the job site because the special magnetizer is unnecessary. But, these methods have some disadvantages shown as follows. For instance, the former needs a special magnetizer and the latter's output signal is small. On the other hand, it is well known that the inductance of a pancake type coil put on the metallic specimen changes according to the electromagnetic properties of the metallic specimen. In this paper, the assessment method of fatigue of an austenitic stainless steel (SUS316) that uses the change by fatigue of the inductance of the pancake type coil measured with the LCR meter is shown. In addition, the fatigue evaluation performance of this method is described.

  20. Nondestructive Evaluation of Friction Stir-Welded Aluminum Alloy to Coated Steel Sheet Lap Joint

    NASA Astrophysics Data System (ADS)

    Das, H.; Kumar, A.; Rajkumar, K. V.; Saravanan, T.; Jayakumar, T.; Pal, Tapan Kumar

    2015-11-01

    Dissimilar lap joints of aluminum sheet (AA 6061) of 2 mm thickness and zinc-coated steel sheet of 1 mm thickness were produced by friction stir welding with different combinations of rotational speed and travel speed. Ultrasonic C- and B-scanning, and radiography have been used in a complementary manner for detection of volumetric (cavity and flash) and planar (de bond) defects as the defects are in micron level. Advanced ultrasonic C-scanning did not provide any idea about the defects, whereas B-scanning cross-sectional image showed an exclusive overview of the micron-level defects. A digital x-ray radiography methodology is proposed for quality assessment of the dissimilar welds which provide three-fold increase in signal-to-noise ratio with improved defect detection sensitivity. The present study clearly shows that the weld tool rotational speed and travel speed have a decisive role on the quality of the joints obtained by the friction stir welding process. The suitability of the proposed NDE techniques to evaluate the joint integrity of dissimilar FSW joints is thus established.

  1. Non-destructive evaluation of adhesive layer using a planar array capacitive imaging technology

    NASA Astrophysics Data System (ADS)

    Zhang, Yuyan; Zhao, Limei; Wen, Yintang; Sun, Dongtao

    2016-04-01

    The thermal protection materials for aircraft are usually assembled on the substrate surface by means of adhesion agent. It is very necessary to evaluate the interface bonding quality which has great influence on heat preservation performance. At present, there is still no relatively satisfactory and reliable method for defect detection of cohesive coating. Planar array electrical capacitance tomography (ECT) is a suitable non-invasive imaging technique when there is only limited access to the targeted object. This research aims to investigate the feasibility of using planar array electrical capacitive tomography for bondline defect detection. In this paper, a planar array ECT system is developed consist of a planar array sensor of 12 electrodes, a capacitance acquisition system and image reconstruction software. The sensor development, simulation of sensitivity map, practical application and imaging reconstruction are discussed. A series of specimens of thermal protection material with man-made defects are tested by the proposed planar array ECT system. The experimental results show that the defect in cohesive coating can be effectively detected and the minimum size can be detected is 10mm×10mm.

  2. Evaluation of a center pivot variable rate irrigation system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Uniformity of water distribution of a variable rate center pivot irrigation system was evaluated. This 4-span center-pivot system was configured with 10 water application zones along its 766 ft-long lateral. Two experiments were conducted for the uniformity tests. In one test, a constant water appli...

  3. 14 CFR 142.55 - Training center evaluator requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Training center evaluator requirements. 142.55 Section 142.55 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SCHOOLS AND OTHER CERTIFICATED AGENCIES TRAINING CENTERS Personnel and Flight Training Equipment Requirements § 142.55 Training...

  4. Federally Sponsored Multidisciplinary Research Centers: Learning, Evaluation, and Vicious Circles

    ERIC Educational Resources Information Center

    Youtie, Jan; Corley, Elizabeth A.

    2011-01-01

    Despite the increasing investment in multi-year federally funded science and technology centers in universities, there are few studies of how these centers engage in learning and change based on information submitted from various agents in the oversight and evaluation process. One challenge is how to manage and respond to this evaluative…

  5. Nondestructive evaluation of residual stress in short-fiber reinforced plastics by x-ray diffraction

    NASA Astrophysics Data System (ADS)

    Tanaka, Keisuke; Tokoro, Syouhei; Akiniwa, Yoshiaki; Egami, Noboru

    2014-06-01

    The X-ray diffraction method is used to measure the residual stress in injection-molded plates of short-fiber reinforced plastics (SFRP) made of crystalline thermoplastics, polyphenylene sulphide (PPS), reinforced by carbon fibers with 30 mass%. Based on the orientation of carbon fibers, injection molded plates can be modeled as three-layered lamella where the core layer is sandwiched by skin layers. The stress in the matrix in the skin layer was measured using Cr-Kα radiation with the sin2Ψ method. Since the X-ray penetration depth is shallow, the state of stresses measured by X-rays in FRP can be assumed to be plane stress. The X-ray measurement of stress in carbon fibers was not possible because of high texture. A new method was proposed to evaluate the macrostress in SFRP from the measurement of the matrix stress. According to micromechanics analysis of SFRP, the matrix stresses in the fiber direction, σ1m, and perpendicular to the fiber direction, σ2m, and shear stress τ12m can be expressed as the functions of the applied (macro-) stresses, σ1A, σ2A , τ12A as follows: σ1m = α11σ1A +α12σ2A, σ2m = α21σ1A + α22σ2A, τ12m = α66τ12A, where α11 ,α12, α21, α22, α66 are stress-partitioning coefficients. Using skin-layer strips cut parallel, perpendicular and 45° to the molding direction, the stress in the matrix was measured under the uniaxial applied stress and the stress-partitioning coefficients of the above equations were determined. Once these relations are established, the macrostress in SFRP can be determined from the measurements of the matrix stresses by X-rays.

  6. Introduction to cadet center for advanced data evaluation technology

    NASA Technical Reports Server (NTRS)

    Schulbach, Cathy; Jorgensen, C.

    1991-01-01

    Viewgraphs on the Center for Advanced Data Evaluation Technology are presented. Topics covered include: technology problem; human problem; goals and objectives; key CADET focus; and elements of the modeling process.

  7. The nondestructive evaluation of high temperature conditioned concrete in conjunction with acoustic emission and x-ray computed tomography

    NASA Astrophysics Data System (ADS)

    Su, Yu-Min; Hou, Tsung-Chin; Lin, Li-Chiang; Chen, Gwan-Ying; Pan, Huang-Hsing

    2016-04-01

    Portland Cement Concrete plays a vital part of protecting structural rebars or steels when high-temperature fire incidents occur, that induces loss of evaporate water, dehydration of CH, and deconstruction of C-S-H. The objective of the study was to assess fire-damaged concrete in conjunction with nondestructive evaluation methods of acoustic emission, visual inspections, and X-ray computed tomography. The experimental program was to mix an Ordinary Portland Cement concrete firstly. Concrete cylinders with twenty-day moisture cure were treated in a furnace with 400 and 600°C for one hour. After temperature is cooled down, the concrete cylinders were brought to air or moisture re-curing for ten days. Due to the incident of the furnace, acoustic emission associated with splitting tensile strength test was not able to continue. Future efforts are planned to resume this unfinished task. However, two proposed tasks were executed and completed, namely visual inspections and voids analysis on segments obtained from X-ray CT facility. Results of visual inspections on cross-sectional and cylindrical length of specimens showed that both aggregates and cement pastes turned to pink or red at 600°C. More surface cracks were generated at 600°C than that at 400°C. On the other hand, voids analysis indicated that not many cracks were generated and voids were remedied at 400°C. However, a clear tendency was found that remedy by moisture curing may heal up to 2% voids of the concrete cylinder that was previously subject to 600°C of high temperature conditioning.

  8. Direct, non-destructive, and rapid evaluation of developmental cotton fibers by ATR FT-IR spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chemical, compositional, and structural differences within the fibers at different growth stages have been investigated considerably through a number of methodologies. Due to its direct, non-destructive, and rapid attribute, this study reports the utilization of attenuated total reflection Fourier t...

  9. The EPIC Brief: A Description of the EPIC Evaluation Center.

    ERIC Educational Resources Information Center

    EPIC Evaluation Center, Tucson, AZ.

    This initial issue describes the development, organization, staff, and facilities of the EPIC (Evaluative Programs for Innovative Curriculums) Evaluation Center, a cooperative effort of the U.S. Office of Education (under Title III of the Elementary and Secondary Education Act), the University of Arizona (College of Education), and the public and…

  10. Interactivity Centered Usability Evaluation (ICUE) for Course Management Systems

    ERIC Educational Resources Information Center

    Yoon, Sangil

    2010-01-01

    ICUE (Interactivity Centered Usability Evaluation) is an enhanced usability testing protocol created by the researcher. ICUE augments the facilitator's role for usability testing, and offers strategies in developing and presenting usability tasks during a testing session. ICUE was designed to address weaknesses found in the usability evaluation of…

  11. Evaluation of the Academic Empowerment Center at a Private University

    ERIC Educational Resources Information Center

    Edwards, James E., Jr.

    2009-01-01

    This applied dissertation described the evaluation of a program designed to provide students with the necessary academic and social skills needed to matriculate and graduate from the university. The problem was that there was no evidence of a formalized program evaluation to determine if the Academic Empowerment Center (AEC) was effective in…

  12. Best practices for evaluating the capability of nondestructive evaluation (NDE) and structural health monitoring (SHM) techniques for damage characterization

    NASA Astrophysics Data System (ADS)

    Aldrin, John C.; Annis, Charles; Sabbagh, Harold A.; Lindgren, Eric A.

    2016-02-01

    A comprehensive approach to NDE and SHM characterization error (CE) evaluation is presented that follows the framework of the `ahat-versus-a' regression analysis for POD assessment. Characterization capability evaluation is typically more complex with respect to current POD evaluations and thus requires engineering and statistical expertise in the model-building process to ensure all key effects and interactions are addressed. Justifying the statistical model choice with underlying assumptions is key. Several sizing case studies are presented with detailed evaluations of the most appropriate statistical model for each data set. The use of a model-assisted approach is introduced to help assess the reliability of NDE and SHM characterization capability under a wide range of part, environmental and damage conditions. Best practices of using models are presented for both an eddy current NDE sizing and vibration-based SHM case studies. The results of these studies highlight the general protocol feasibility, emphasize the importance of evaluating key application characteristics prior to the study, and demonstrate an approach to quantify the role of varying SHM sensor durability and environmental conditions on characterization performance.

  13. Nondestructive test of regenerative chambers

    NASA Technical Reports Server (NTRS)

    Malone, G. A.; Stauffis, R.; Wood, R.

    1972-01-01

    Flat panels simulating internally cooled regenerative thrust chamber walls were fabricated by electroforming, brazing and diffusion bonding to evaluate the feasibility of nondestructive evaluation techniques to detect bonds of various strength integrities. Ultrasonics, holography, and acoustic emission were investigated and found to yield useful and informative data regarding the presence of bond defects in these structures.

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

    NASA Astrophysics Data System (ADS)

    Whitney, Timothy Marvin

    1996-08-01

    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 function of temperature. Parts per million changes in specimen density, geometry, elastic moduli, temperature, and boundary conditions are detected with RUS. A novel apparatus is presented for driving and detecting the mechanical resonance of objects with major dimensions ranging from 0.1 cm to 33 cm. The noise floor of the apparatus is characterized using a high Q titanium alloy and a low Q graphite/epoxy composite. The apparatus is used to measure the amplitude/frequency resonance spectra of right rectangular parallelepiped (RRP) specimens of four different lay-ups of AS4/3501-6 carbon fiber reinforced epoxy (CFRE) composite material at room temperature and at one degree C intervals between -177^circC and 25 ^circC. It is important to know the mechanical properties of this material at low temperatures for underwater, polar, and space applications. The temperature dependence of the second order elastic moduli are calculated from the resonance spectra of the AS4/3501-6 RRPs. High power ultrasound is used to enhance the cure of AS4/3501-6 CFRE composite. Composite panels are insonified through the caul plate, by a high power ultrasonic horn, while curing. Stiffness enhancements of five percent are observed. The resonance spectrum of a steel caul plate is used to monitor the degree of cure of AS4/3501-6 CFRE composite panels in real time. Because the curing composite acts to change the boundary conditions, the resonance spectrum changes as the composite cures. RUS is used to screen a variety of high precision engineered parts for mechanical defects

  15. Evaluation of an Emerging Research Center: Lessons Learned.

    PubMed

    Nigg, C R; Qureshi, K; Inouye, J; Sy, A; Sullivan, K; Boland, M G

    2012-02-01

    PROBLEM STATEMENT: Rigorous evaluation assures that research endeavors meet their purpose and achieve stated goals. This is especially true for federally funded exploratory research centers, which tend to be more complex due to the involvement of multiple, interdisciplinary investigators. This study provides an overview of the approach used to develop an evaluation strategy and reports the lessons learned during the initial development of the Center for Ohana Self-Management of Chronic Illness (COSMCI) at the University of Hawai'i at Mānoa School of Nursing and Dental Hygiene. The COSMCI is composed of an interdisciplinary team of researchers and practitioners and aims to advance knowledge in the field of self management of chronic disease in the community setting. APPROACH: A systematic approach was utilized that included formative and summative strategies for ongoing evaluation. The problem was solved by addressing five key concerns: (1) development of research structure, (2) observing the process of the research pilot projects, (3) scholarly activity of COSMCI faculty, (4) dissemination and translation and (5) sustainability prospects. The method of research included formulating process strategies and determine if the plans for developing the Center were followed and whether these plans were effective. Interviews were also conducted at year one and at mid-point though the project. RESULTS: Themes that emerged from our evaluation included inclusion, timelines, realistic expectations, ongoing evaluation and preparing for changes in the team. This provided timely recognition of successes and challenges and facilitated a rapid response for interventions especially during the early development stage of the center. CONCLUSION/RECOMMENDATIONS: Effective development of a successful Center is highly dependent upon having a strong evaluation process in place that can inform ongoing development. An exploratory research center requires ongoing evaluation that allows for

  16. Strategies for Success: An Evaluation Handbook for Parent Training and Information Centers and Community Parent Resource Centers

    ERIC Educational Resources Information Center

    Godfrey, Gretchen

    2006-01-01

    This handbook is a basic "how-to" guide to help one's Parent Training and Information Center (PTI) or Community Parent Resource Center (CPRC) evaluate its programs. Evaluation may seem overwhelming, but a center already performs some steps of the evaluation process for the reports required by the Technical Assistance ALLIANCE for Parent Centers…

  17. Fast, quantitative, and nondestructive evaluation of hydrided LWR fuel cladding by small angle incoherent neutron scattering of hydrogen

    DOE PAGESBeta

    Yan, Y.; Qian, S.; Littrell, K.; Parish, C. M.; Plummer, L. K.

    2015-02-13

    A non-destructive neutron scattering method to precisely measure the uptake of hydrogen and the distribution of hydride precipitates in light water reactor (LWR) fuel cladding was developed. Zircaloy-4 cladding used in commercial LWRs was used to produce hydrided specimens. The hydriding apparatus consists of a closed stainless steel vessel that contains Zr alloy specimens and hydrogen gas. Following hydrogen charging, the hydrogen content of the hydrided specimens was measured using the vacuum hot extraction method, by which the samples with desired hydrogen concentration were selected for the neutron study. Optical microscopy shows that our hydriding procedure results in uniform distributionmore » of circumferential hydrides across the wall. Small angle neutron incoherent scattering was performed in the High Flux Isotope Reactor at Oak Ridge National Laboratory. This study demonstrates that the hydrogen in commercial Zircaloy-4 cladding can be measured very accurately in minutes by this nondestructive method over a wide range of hydrogen concentrations from a very small amount ( 20 ppm) to over 1000 ppm. The hydrogen distribution in a tube sample was obtained by scaling the neutron scattering rate with a factor determined by a calibration process using standard, destructive direct chemical analysis methods on the specimens. This scale factor will be used in future tests with unknown hydrogen concentrations, thus providing a nondestructive method for absolute hydrogen concentration determination.« less

  18. Fast, quantitative, and nondestructive evaluation of hydrided LWR fuel cladding by small angle incoherent neutron scattering of hydrogen

    SciTech Connect

    Yan, Y.; Qian, S.; Littrell, K.; Parish, C. M.; Plummer, L. K.

    2015-02-13

    A non-destructive neutron scattering method to precisely measure the uptake of hydrogen and the distribution of hydride precipitates in light water reactor (LWR) fuel cladding was developed. Zircaloy-4 cladding used in commercial LWRs was used to produce hydrided specimens. The hydriding apparatus consists of a closed stainless steel vessel that contains Zr alloy specimens and hydrogen gas. Following hydrogen charging, the hydrogen content of the hydrided specimens was measured using the vacuum hot extraction method, by which the samples with desired hydrogen concentration were selected for the neutron study. Optical microscopy shows that our hydriding procedure results in uniform distribution of circumferential hydrides across the wall. Small angle neutron incoherent scattering was performed in the High Flux Isotope Reactor at Oak Ridge National Laboratory. This study demonstrates that the hydrogen in commercial Zircaloy-4 cladding can be measured very accurately in minutes by this nondestructive method over a wide range of hydrogen concentrations from a very small amount ( 20 ppm) to over 1000 ppm. The hydrogen distribution in a tube sample was obtained by scaling the neutron scattering rate with a factor determined by a calibration process using standard, destructive direct chemical analysis methods on the specimens. This scale factor will be used in future tests with unknown hydrogen concentrations, thus providing a nondestructive method for absolute hydrogen concentration determination.

  19. Polynomials for evaluation of two-center overlap integrals

    NASA Astrophysics Data System (ADS)

    Petrov, Dimitar

    2016-05-01

    Expressions of products AkBk, where Ak and Bk are incomplete gamma functions, are given for evaluation of two-center overlap integrals (TCOIs) over unnormalized Slater-type orbitals (STOs). The polynomials of AkBk have been derived after the method proposed by Lofthus and pertain to two-center bonds of σ, π, δ, and φ axial symmetries. The functions of AkBk have been arranged in pairs of s, p, d, and f STOs with principal quantum numbers between 1 and 5. The contributions of these functions to various TCOIs have been evaluated and discussed. The formulae are applicable as input matrices for computations of TCOIs.

  20. An assessment of nondestructive testing technologies for chemical weapons monitoring

    SciTech Connect

    Taylor, T.T.

    1993-05-01

    The US Department of Energy (DOE), with the US Army Chemical Research, Development and Engineering Center (CRDEC) under the sponsorship of the Defense Nuclear Agency (DNA), completed testing of Nondestructive Evaluation (NDE) technology on live agent systems. The tests were conducted at Tooele Army Depot during August 1992. The Nondestructive Evaluation systems were tested for potential use in verifying chemical treaty requirements. Five technologies, two neutron and three acoustic, were developed at DOE laboratories. Two systems from the United Kingdom (one neutron and one acoustic) were also included in the field trials. All systems tested showed the ability to distinguish among the VX, GB, and Mustard. Three of the systems (two acoustic and one neutron) were used by On-Site Inspection Agency (OSIA) personnel.

  1. Evaluation and Research Center for Project Head Start, University of South Carolina. Interim Evaluation Report.

    ERIC Educational Resources Information Center

    Friedman, Myles I.

    This document is an interim evaluation report of language development curriculums in full year Head Start programs operating in the five state area the Research and Evaluation Center serves. One experimental study in language development carried on in cooperation with the Texas and Tulane centers is reported in depth. The study was implemented in…

  2. 14 CFR 142.55 - Training center evaluator requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... corrective action; and (4) If evaluating in qualified and approved flight training equipment must satisfactorily pass a written test and annual proficiency check in a flight simulator or aircraft in which the... (CONTINUED) SCHOOLS AND OTHER CERTIFICATED AGENCIES TRAINING CENTERS Personnel and Flight Training...

  3. Residential Environmental Education Center Program Evaluation: An Ongoing Challenge

    ERIC Educational Resources Information Center

    Bourke, Nicholas; Buskist, Connie; Herron, Julie

    2014-01-01

    Residential environmental education centers (REECs) have been criticized for their lack of quality program evaluation. However, the last national study done on the practices of REECs was Chenery and Hammerman's (1985) research. This article presents the results of a national survey of directors of REECs (n = 114) that gives insight into the…

  4. Usability Evaluation of the Student Centered e-Learning Environment

    ERIC Educational Resources Information Center

    Junus, Inas Sofiyah; Santoso, Harry Budi; Isal, R. Yugo K.; Utomo, Andika Yudha

    2015-01-01

    Student Centered e-Learning Environment (SCeLE) has substantial roles to support learning activities at Faculty of Computer Science, Universitas Indonesia (Fasilkom UI). Although it has been utilized for about 10 years, the usability aspect of SCeLE as an e-Learning system has not been evaluated. Therefore, the usability aspects of SCeLE Fasilkom…

  5. Evaluation of Teacher Training in a Title III Center.

    ERIC Educational Resources Information Center

    Reid, Ethna R.

    This study is a report on a series of exemplary and instructional reading programs conducted by the Exemplary Center for Reading Instruction and designed to improve reading instruction in kindergarten through grade 12. The following topics are included: (1) evaluation of beginning reading programs, including materials selection, materials…

  6. Evaluation of the Dade-Monroe Teacher Education Center.

    ERIC Educational Resources Information Center

    Gomez, Joseph J.

    The Dade-Monroe (Florida) Teacher Education Center (TEC) was evaluated. The TEC was founded in 1979 and serves the instructional personnel (teachers, teacher aides, and teacher assistants) in the public schools of Dade and Monroe counties. Program documents were reviewed and structured interviews were held with 7 TEC facilitators, 9 council…

  7. Current and future developments in civil aircraft non-destructive evaluation from an operator's point of view

    NASA Technical Reports Server (NTRS)

    Register, Jeff

    1992-01-01

    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.

  8. Infrared image processing devoted to thermal non-contact characterization-Applications to Non-Destructive Evaluation, Microfluidics and 2D source term distribution for multispectral tomography

    NASA Astrophysics Data System (ADS)

    Batsale, Jean-Christophe; Pradere, Christophe

    2015-11-01

    The cost of IR cameras is more and more decreasing. Beyond the preliminary calibration step and the global instrumentation, the infrared image processing is then one of the key step for achieving in very broad domains. Generally the IR images are coming from the transient temperature field related to the emission of a black surface in response to an external or internal heating (active IR thermography). The first applications were devoted to the so called thermal Non-Destructive Evaluation methods by considering a thin sample and 1D transient heat diffusion through the sample (transverse diffusion). With simplified assumptions related to the transverse diffusion, the in-plane diffusion and transport phenomena can be also considered. A general equation can be applied in order to balance the heat transfer at the pixel scale or between groups of pixels in order to estimate several fields of thermophysical properties (heterogeneous field of in-plane diffusivity, flow distributions, source terms). There is a lot of possible strategies to process the space and time distributed big amount of data (previous integral transformation of the images, compression, elimination of the non useful areas...), generally based on the necessity to analyse the derivative versus space and time of the temperature field. Several illustrative examples related to the Non-Destructive Evaluation of heterogeneous solids, the thermal characterization of chemical reactions in microfluidic channels and the design of systems for multispectral tomography, will be presented.

  9. An approach for relating the results of quantitative nondestructive evaluation to intrinsic properties of high-performance materials

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1990-01-01

    One of the most difficult problems the manufacturing community has faced during recent years has been to accurately assess the physical state of anisotropic high-performance materials by nondestructive means. In order to advance the design of ultrasonic nondestructive testing systems, a more fundamental understanding of how ultrasonic waves travel and interact within the anisotropic material is needed. The relationship between the ultrasonic and engineering parameters needs to be explored to understand their mutual dependence. One common denominator is provided by the elastic constants. The preparation of specific graphite/epoxy samples to be used in the experimental investigation of the anisotropic properties (through the measurement of the elastic stiffness constants) is discussed. Accurate measurements of these constants will depend upon knowledge of refraction effects as well as the direction of group velocity propagation. The continuing effort for the development of improved visualization techniques for physical parameters is discussed. Group velocity images are presented and discussed. In order to fully understand the relationship between the ultrasonic and the common engineering parameters, the physical interpretation of the linear elastic coefficients (the quantities that relate applied stresses to resulting strains) are discussed. This discussion builds a more intuitional understanding of how the ultrasonic parameters are related to the traditional engineering parameters.

  10. Transdisciplinary Evaluation of Children. Final Report of the Southwest Regional Resource Center's Involvement with the Central Arizona Child Evaluation Center.

    ERIC Educational Resources Information Center

    Renne, Diane J.; Moore, Jean J.

    Presented is the final report of a project to demonstrate educationally relevant approaches to assessment of and prescription for severely handicapped children (0 to 21 years old) within an existing multidisciplinary diagnostic facility, the Central Arizona Child Evaluation Center. Part I provides introductory information with a definition of…

  11. Evaluation of Reference Centers for Special Immunobiologicals implementation

    PubMed Central

    Nóbrega, Laura Andrade Lagôa; Novaes, Hillegonda Maria Dutilh; Sartori, Ana Marli Christovam

    2016-01-01

    ABSTRACT OBJECTIVE To describe the Reference Centers for Special Immunobiologicals and evaluate their implementation considering formal regulations. METHODS We conducted a program evaluation, of evaluative research type. From August 2011 to January 2012, a questionnaire was applied to the 42 Reference Centers for Special Immunobiologicals existing in the Country, approaching the structure, human resources, and developed activities dimensions. We conducted a descriptive analysis of data and used a clustering for binary data with the squared Euclidean distance, by the farthest neighbor method, to aggregate services with similar features. RESULTS We observed great diversity among the services in the three dimensions. The clustering resulted in five service profiles, named according to their characteristics. 1) Best structure: 12 Reference Centers for Special Immunobiologicals with the highest proportion of services with the minimum of rooms recommended, purpose-built vaccine refrigerators, preventive maintenance of the cold chain, and oxygen source. 2) Immunobiologicals distributor: six Reference Centers for Special Immunobiologicals that distributed more than applied immunogens; no doctor present for more than half of the working hours and no purpose-built vaccine refrigerators . 3) Incipient implementation: five Reference Centers for Special Immunobiologicals with inadequate structure, such as absence of purpose-built vaccine refrigerators, preventive maintenance of the cold chain and oxygen source; none had computer. 4) Vaccination rooms: 13 Reference Centers for Special Immunobiologicals, everyone did routine immunization, most participated in vaccination campaigns. 5) Teaching and research: six services, all inserted into teaching hospitals, developed researches and received trainees; most had doctors in more than half of the working hours. CONCLUSIONS The evaluation of the Reference Centers for Special Immunobiologicals implementation was based on the profiles

  12. Development of the Non-Destructive Evaluation System Using an Eddy Current Probe for Detection of Fatigue Damage in a Stainless Steel

    SciTech Connect

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

    2006-03-06

    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.

  13. Forensic neuropsychological evaluations in an academic medical center.

    PubMed

    Schwarz, Lauren; Schrift, Michael; Pliskin, Neil

    2009-01-01

    Within the expanding field of clinical neuropsychology, the subspecialty of forensic neuropsychology has developed. Currently, there is considerable diversity within the discipline as to how practitioners approach test selection, reports, and number of hours billed. How individuals handle these issues is subject to debate, but what is clear is that there are no specific guidelines as to how to conduct these evaluations. The current study provides an introduction to the issues faced by clinical neuropsychologists completing forensic evaluations. In addition, the authors present how the relevant issues are addressed in one neuropsychology service housed within a university-affiliated academic medical center. PMID:19333065

  14. Nondestructive biomarkers in ecotoxicology.

    PubMed Central

    Fossi, M C

    1994-01-01

    The aim of this article is to attempt a concise review of the state of the art of the nondestructive biomarkers approach in vertebrates, establishing a consensus on the most useful and sensitive nondestructive biomarker techniques, and proposing research priorities for the development and validation of this promising methodology. The following topics are discussed: the advantages of the use of nondestructive strategies in biomonitoring programs and the research fields in which nondestructive biomarkers can be applied; the biological materials suitable for nondestructive biomarkers and residue analysis in vertebrates; which biomarkers lend themselves to noninvasive techniques; and the validation and implementation strategy of the nondestructive biomarker approach. Examples of applications of this methodology in the hazard assessment of endangered species are also presented. Images Figure 1. C PMID:7713034

  15. Evaluating of NASA-Langley Research Center explosion seam welding

    NASA Technical Reports Server (NTRS)

    Otto, H. E.; Wittman, R.

    1977-01-01

    An explosion bonding technique to meet current fabrication requirements was demonstrated. A test program was conducted on explosion bonded joints, compared to fusion joints in 6061-T6 aluminum. The comparison was made in required fixtures, non-destructive testing, static strength and fatigue strength.

  16. Outcomes evaluation of St Petersburg Russia Women's Wellness Center.

    PubMed

    Callister, Lynn Clark; Getmanenko, Natalia; Garvrish, Natalia; Marakova, Olga Eugenevna; Zotina, Nataliya Vladimirovna; Turkina, Natalia

    2009-03-01

    Researchers demonstrate that investing in women's health yields great social and economic dividends, yet the health of women often receives little attention throughout the world. Women's wellness centers (WWCs) were established in the former Soviet Union beginning in 1992 under the sponsorship of the American International Health Alliance (AIHA) in conjunction with the United States Association for International Development (USAID) to provide a women-centered approach to primary care, providing access to a wide range of clinical services and educational outreach programs. Because the St Petersburg Women's Wellness Center (WWC) is considered one of the more advanced centers and represents a microcosm of opportunities and challenges in women's health care delivery in the Russian Federation, a descriptive qualitative outcomes evaluation of the clinic was conducted. In the spirit of continuous quality improvement, interviews were conducted with childbearing women. Findings are categorized into the dimensions of access, privacy and comfort, communication with providers, comprehensiveness of care, and follow-up care. Strengths of the clinic include the "woman friendly" environment and educational offerings. Suggestions also were made by study participants for improvement of clinic services. Qualitative research can be translated into clinical practice guidelines for WWCs in Eastern Europe. PMID:19191120

  17. Light Water Reactor Sustainability (LWRS) Program – Non-Destructive Evaluation (NDE) R&D Roadmap for Determining Remaining Useful Life of Aging Cables in Nuclear Power Plants

    SciTech Connect

    Simmons, Kevin L.; Ramuhalli, Pradeep; Brenchley, David L.; Coble, Jamie B.; Hashemian, Hash; Konnik, Robert; Ray, Sheila

    2012-09-14

    The purpose of the non-destructive evaluation (NDE) R&D Roadmap for Cables is to support the Materials Aging and Degradation (MAaD) R&D pathway. The focus of the workshop was to identify the technical gaps in detecting aging cables and predicting their remaining life expectancy. The workshop was held in Knoxville, Tennessee, on July 30, 2012, at Analysis and Measurement Services Corporation (AMS) headquarters. The workshop was attended by 30 experts in materials, electrical engineering, U.S. Nuclear Regulatory Commission (NRC), U.S. Department of Energy (DOE) National Laboratories (Oak Ridge National Laboratory, Pacific Northwest National Laboratory, Argonne National Laboratory, and Idaho National Engineering Laboratory), NDE instrumentation development, universities, commercial NDE services and cable manufacturers, and Electric Power Research Institute (EPRI). The motivation for the R&D roadmap comes from the need to address the aging management of in-containment cables at nuclear power plants (NPPs).

  18. Light Water Reactor Sustainability (LWRS) Program – Non-Destructive Evaluation (NDE) R&D Roadmap for Determining Remaining Useful Life of Aging Cables in Nuclear Power Plants

    SciTech Connect

    Simmons, K.L.; Ramuhali, P.; Brenchley, D.L.; Coble, J.B.; Hashemian, H.M.; Konnick, R.; Ray, S.

    2012-09-01

    Executive Summary [partial] The purpose of the non-destructive evaluation (NDE) R&D Roadmap for Cables is to support the Materials Aging and Degradation (MAaD) R&D pathway. A workshop was held to gather subject matter experts to develop the NDE R&D Roadmap for Cables. The focus of the workshop was to identify the technical gaps in detecting aging cables and predicting their remaining life expectancy. The workshop was held in Knoxville, Tennessee, on July 30, 2012, at Analysis and Measurement Services Corporation (AMS) headquarters. The workshop was attended by 30 experts in materials, electrical engineering, and NDE instrumentation development from the U.S. Nuclear Regulatory Commission (NRC), U.S. Department of Energy (DOE) National Laboratories (Oak Ridge National Laboratory, Pacific Northwest National Laboratory, Argonne National Laboratory, and Idaho National Engineering Laboratory), universities, commercial NDE service vendors and cable manufacturers, and the Electric Power Research Institute (EPRI).

  19. Nondestructive evaluation of ±45° flat-braided carbon-fiber-reinforced polymers with carbon nanofibers using HTS-SQUID gradiometer

    NASA Astrophysics Data System (ADS)

    Hatsukade, Y.; Shinyama, Y.; Yoshida, K.; Takai, Y.; Aly-Hassan, M. S.; Nakai, A.; Hamada, H.; Adachi, S.; Tanabe, K.; Tanaka, S.

    2013-01-01

    Step-by-step tensile tests were applied to flat-braided carbon-fiber-reinforced polymers with and without added dispersions of carbon nanofibers (CNFs) and with and without sample sides cut off to study their mechanical properties and destructive mechanisms by means of in situ observation and stress-strain measurements. An ex situ nondestructive evaluation technique, using a high-temperature superconductor superconducting quantum interference device gradiometer, was also applied to the samples to study their electrical properties; the relationships between the mechanical and electrical properties by visualizing current maps in the samples during ac current injection was also studied. Clear differences were observed in the mechanical and electrical properties and the destructive mechanisms between the samples with and without CNFs and with and without cut off sides. These differences were mainly attributed to the addition of CNFs, which enhanced the mechanical and electrical connections between the carbon fiber bundles.

  20. 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

    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

    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.

  1. Non-destructive evaluation of chlorophyll content in quinoa and amaranth leaves by simple and multiple regression analysis of RGB image components.

    PubMed

    Riccardi, M; Mele, G; Pulvento, C; Lavini, A; d'Andria, R; Jacobsen, S-E

    2014-06-01

    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

  2. Nondestructive testing potential evaluation of a terahertz frequency-modulated continuous-wave imager for composite materials inspection

    NASA Astrophysics Data System (ADS)

    Cristofani, Edison; Friederich, Fabian; Wohnsiedler, Sabine; Matheis, Carsten; Jonuscheit, Joachim; Vandewal, Marijke; Beigang, René

    2014-03-01

    The sub-terahertz (THz) frequency band has proved to be a noteworthy option for nondestructive testing (NDT) of nonmetal aeronautics materials. Composite structures or laminates can be inspected for foreign objects (water or debris), delaminations, debonds, etc., using sub-THz sensors during the manufacturing process or maintenance. Given the harmless radiation to the human body of this frequency band, no special security measures are needed for operation. Moreover, the frequency-modulated continuous-wave sensor used in this study offers a very light, compact, inexpensive, and high-performing solution. An automated two-dimensional scanner carrying three sensors partially covering the 70- to 320-GHz band is operated, using two complementary measurement approaches: conventional focused imaging, where focusing lenses are used; and synthetic aperture (SA) or unfocused wide-beam imaging, for which lenses are no longer needed. Conventional focused imagery offers finer spatial resolutions but imagery is depth-limited due to the beam waist effect, whereas SA measurements allow imaging of thicker samples with depth-independent but coarser spatial resolutions. The present work is a compendium of a much larger study and describes the key technical aspects of the proposed imaging techniques and reports on results obtained from human-made samples (A-sandwich, C-sandwich, solid laminates) which include diverse defects and damages typically encountered in aeronautics multilayered structures. We conclude with a grading of the achieved results in comparison with measurements performed by other NDT techniques on the same samples.

  3. Hypersonic Interceptor Performance Evaluation Center aero-optics performance predictions

    NASA Astrophysics Data System (ADS)

    Sutton, George W.; Pond, John E.; Snow, Ronald; Hwang, Yanfang

    1993-06-01

    This paper describes the Hypersonic Interceptor Performance Evaluation Center's (HIPEC) aerooptics performance predictions capability. It includes code results for three dimensional shapes and comparisons to initial experiments. HIPEC consists of a collection of aerothermal, aerodynamic computational codes which are capable of covering the entire flight regime from subsonic to hypersonic flow and include chemical reactions and turbulence. Heat transfer to the various surfaces is calculated as an input to cooling and ablation processes. HIPEC also has aero-optics codes to determine the effect of the mean flowfield and turbulence on the tracking and imaging capability of on-board optical sensors. The paper concentrates on the latter aspects.

  4. User-Centered Evaluation of Technosocial Predictive Analytics

    SciTech Connect

    Scholtz, Jean C.; Whiting, Mark A.

    2009-03-23

    In today’s technology filled world, it is absolutely essential to show the utility of new software, especially software that brings entirely new capabilities to potential users. In the case of technosocial predictive analytics, researchers are developing software capabilities to augment human reasoning and cognition. Getting acceptance and buy-in from analysts and decision makers will not be an easy task. In this position paper, we discuss an approach we are taking for user-centered evaluation that we believe will result in adoption of technosocial predictive software by the intelligence community.

  5. User-Centered Evaluation of Technosocial Predictive Analytic Systems

    SciTech Connect

    Scholtz, Jean; Whiting, Mark A.

    2009-03-23

    In today’s technology filled world, it is absolutely essential to show the utility of new software, especially software that brings entirely new capabilities to potential users. In the case of technosocial predictive analytics, researchers are developing software capabilities to augment human reasoning and cognition. Getting acceptance and buy-in from analysts and decision makers will not be an easy task. In this position paper, we discuss an approach we are taking for user-centered evaluation that we believe will result in facilitating the adoption of technosocial predictive software by the intelligence community.

  6. The Use of Information Based Evaluation in Evaluating the Diagnostic Teaching Center.

    ERIC Educational Resources Information Center

    Poteet, James A.

    Information Based Evaluation (IBE) is identified as a design procedure for assessing a variety of projects, programs, and educational changes. IBE was used to evaluate a Comprehensive Diagnostic Teaching Center (DTC) which, in addition to providing teacher training and services to handicapped pupils, would bring together and focus all of the…

  7. 78 FR 20924 - Center for Biologics Evaluation and Research eSubmitter Pilot Evaluation Program for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-08

    ...The Food and Drug Administration's (FDA's) Center for Biologics Evaluation and Research (CBER) is announcing an invitation to sponsors of investigational new drug (IND) applications to participate in a pilot evaluation program for CBER's eSubmitter Program (eSubmitter). CBER's eSubmitter is a computer-assisted automated program that has been customized to facilitate the creation of IND......

  8. Progress of Covariance Evaluation at the China Nuclear Data Center

    SciTech Connect

    Xu, R.; Zhang, Q.; Zhang, Y.; Liu, T.; Ge, Z.; Lu, H.; Sun, Z.; Yu, B.; Tang, G.

    2015-01-15

    Covariance evaluations at the China Nuclear Data Center focus on the cross sections of structural materials and actinides in the fast neutron energy range. In addition to the well-known Least-squares approach, a method based on the analysis of the sources of experimental uncertainties is especially introduced to generate a covariance matrix for a particular reaction for which multiple measurements are available. The scheme of the covariance evaluation flow is presented, and an example of n+{sup 90}Zr is given to illuminate the whole procedure. It is proven that the accuracy of measurements can be properly incorporated into the covariance and the long-standing small uncertainty problem can be avoided.

  9. 75 FR 34452 - Center for Drug Evaluation and Research Data Standards Plan; Availability for Comment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-17

    ... HUMAN SERVICES Food and Drug Administration Center for Drug Evaluation and Research Data Standards Plan... development of a comprehensive data standards program in the Center for Drug Evaluation and Research (CDER... Drug Information, Center for Drug Evaluation and Research, Food and Drug Administration, 10903...

  10. 76 FR 45268 - Center for Drug Evaluation and Research, Approach to Addressing Drug Shortage; Public Workshop

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-28

    ... HUMAN SERVICES Food and Drug Administration Center for Drug Evaluation and Research, Approach to... approach of the Center for Drug Evaluation and Research (CDER) to addressing drug shortages. This public... Benner, Center for Drug Evaluation and Research, Food and Drug Administration, 10903 New Hampshire...

  11. A new fiber-optic non-contact compact laser-ultrasound scanner for fast non-destructive testing and evaluation of aircraft composites.

    PubMed

    Pelivanov, Ivan; Buma, Takashi; Xia, Jinjun; Wei, Chen-Wei; O'Donnell, Matthew

    2014-03-21

    Laser ultrasonic (LU) inspection represents an attractive, non-contact method to evaluate composite materials. Current non-contact systems, however, have relatively low sensitivity compared to contact piezoelectric detection. They are also difficult to adjust, very expensive, and strongly influenced by environmental noise. Here, we demonstrate that most of these drawbacks can be eliminated by combining a new generation of compact, inexpensive fiber lasers with new developments in fiber telecommunication optics and an optimally designed balanced probe scheme. In particular, a new type of a balanced fiber-optic Sagnac interferometer is presented as part of an all-optical LU pump-probe system for non-destructive testing and evaluation of aircraft composites. The performance of the LU system is demonstrated on a composite sample with known defects. Wide-band ultrasound probe signals are generated directly at the sample surface with a pulsed fiber laser delivering nanosecond laser pulses at a repetition rate up to 76 kHz rate with a pulse energy of 0.6 mJ. A balanced fiber-optic Sagnac interferometer is employed to detect pressure signals at the same point on the composite surface. A- and B-scans obtained with the Sagnac interferometer are compared to those made with a contact wide-band polyvinylidene fluoride transducer. PMID:24737921

  12. A new fiber-optic non-contact compact laser-ultrasound scanner for fast non-destructive testing and evaluation of aircraft composites

    PubMed Central

    Pelivanov, Ivan; Buma, Takashi; Xia, Jinjun; Wei, Chen-Wei; O'Donnell, Matthew

    2014-01-01

    Laser ultrasonic (LU) inspection represents an attractive, non-contact method to evaluate composite materials. Current non-contact systems, however, have relatively low sensitivity compared to contact piezoelectric detection. They are also difficult to adjust, very expensive, and strongly influenced by environmental noise. Here, we demonstrate that most of these drawbacks can be eliminated by combining a new generation of compact, inexpensive fiber lasers with new developments in fiber telecommunication optics and an optimally designed balanced probe scheme. In particular, a new type of a balanced fiber-optic Sagnac interferometer is presented as part of an all-optical LU pump-probe system for non-destructive testing and evaluation of aircraft composites. The performance of the LU system is demonstrated on a composite sample with known defects. Wide-band ultrasound probe signals are generated directly at the sample surface with a pulsed fiber laser delivering nanosecond laser pulses at a repetition rate up to 76 kHz rate with a pulse energy of 0.6 mJ. A balanced fiber-optic Sagnac interferometer is employed to detect pressure signals at the same point on the composite surface. A- and B-scans obtained with the Sagnac interferometer are compared to those made with a contact wide-band polyvinylidene fluoride transducer. PMID:24737921

  13. Performance evaluation of the BostoMatic 300 machining center

    SciTech Connect

    Bryce, E.A.; Clingan, D.E.; Harwell, L.D.; Christensen, N.G.

    1996-01-01

    The BostoMatic 300 (BM300) machining center is an integral part of an ongoing Laboratory Directed Research and Development (LDRD) project at Sandia National Laboratories (SNL) titled ``Intelligent Tools for On-Machine Acceptance of Precision Machined Components``. On-Machine Acceptance (OMA) is a new agile manufacturing concept being developed for machine tools at SNL. The concept behind OMA is the integration of product design, fabrication, and qualification processes. To achieve the OMA integration of design, fabrication and qualification processes, the BM300 will function as a fabrication and inspection tool. The BM300 performance evaluation took place in July and August of 1994. Tests were conducted in the Advanced Manufacturing Process Laboratory (AMPL), Bldg 878, SNL/NM using a BM300 serial number MM-590. All testing was in accordance with ANSI/ASME B5.54-1992 ``Performance Evaluation of Numerically Controlled Machining Centers``, unless otherwise noted. The results of all tests were compiled and documented in Section 4.0. The ANSI B5.54 testing of the BM300 was divided into six areas. Those areas are linear displacement accuracy, angular displacement accuracy, axis of rotation (spindle), geometric accuracy, volumetric performance, and machine performance as a measuring tool. Details regarding the six tests and test equipment are documented in Section 4.0. As of August 1994 testing of the BM300 in the area of ``Machine Performance as a Measuring Tool`` had not been completed. Future testing in this area may incorporate the LDRD test part along with the appropriate ANSI B5.54 specification in determining the BM300 accuracy.

  14. Middleware Evaluation and Benchmarking for Use in Mission Operations Centers

    NASA Technical Reports Server (NTRS)

    Antonucci, Rob; Waktola, Waka

    2005-01-01

    Middleware technologies have been promoted as timesaving, cost-cutting alternatives to the point-to-point communication used in traditional mission operations systems. However, missions have been slow to adopt the new technology. The lack of existing middleware-based missions has given rise to uncertainty about middleware's ability to perform in an operational setting. Most mission architects are also unfamiliar with the technology and do not know the benefits and detriments to architectural choices - or even what choices are available. We will present the findings of a study that evaluated several middleware options specifically for use in a mission operations system. We will address some common misconceptions regarding the applicability of middleware-based architectures, and we will identify the design decisions and tradeoffs that must be made when choosing a middleware solution. The Middleware Comparison and Benchmark Study was conducted at NASA Goddard Space Flight Center to comprehensively evaluate candidate middleware products, compare and contrast the performance of middleware solutions with the traditional point- to-point socket approach, and assess data delivery and reliability strategies. The study focused on requirements of the Global Precipitation Measurement (GPM) mission, validating the potential use of middleware in the GPM mission ground system. The study was jointly funded by GPM and the Goddard Mission Services Evolution Center (GMSEC), a virtual organization for providing mission enabling solutions and promoting the use of appropriate new technologies for mission support. The study was broken into two phases. To perform the generic middleware benchmarking and performance analysis, a network was created with data producers and consumers passing data between themselves. The benchmark monitored the delay, throughput, and reliability of the data as the characteristics were changed. Measurements were taken under a variety of topologies, data demands

  15. 13 CFR 306.7 - Performance evaluations of University Centers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... University Centers. 306.7 Section 306.7 Business Credit and Assistance ECONOMIC DEVELOPMENT ADMINISTRATION, DEPARTMENT OF COMMERCE TRAINING, RESEARCH AND TECHNICAL ASSISTANCE INVESTMENTS University Center Economic... compete to receive Investment Assistance under the University Center Economic Development Program for...

  16. 13 CFR 306.7 - Performance evaluations of University Centers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... University Centers. 306.7 Section 306.7 Business Credit and Assistance ECONOMIC DEVELOPMENT ADMINISTRATION, DEPARTMENT OF COMMERCE TRAINING, RESEARCH AND TECHNICAL ASSISTANCE INVESTMENTS University Center Economic... compete to receive Investment Assistance under the University Center Economic Development Program for...

  17. 13 CFR 306.7 - Performance evaluations of University Centers.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... University Centers. 306.7 Section 306.7 Business Credit and Assistance ECONOMIC DEVELOPMENT ADMINISTRATION, DEPARTMENT OF COMMERCE TRAINING, RESEARCH AND TECHNICAL ASSISTANCE INVESTMENTS University Center Economic... compete to receive Investment Assistance under the University Center Economic Development Program for...

  18. 13 CFR 306.7 - Performance evaluations of University Centers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... University Centers. 306.7 Section 306.7 Business Credit and Assistance ECONOMIC DEVELOPMENT ADMINISTRATION, DEPARTMENT OF COMMERCE TRAINING, RESEARCH AND TECHNICAL ASSISTANCE INVESTMENTS University Center Economic... compete to receive Investment Assistance under the University Center Economic Development Program for...

  19. Social Network Analysis to Evaluate an Interdisciplinary Research Center

    ERIC Educational Resources Information Center

    Aboelela, Sally W.; Merrill, Jacqueline A.; Carley, Kathleen M.; Larson, Elaine

    2007-01-01

    We sought to examine the growth of an interdisciplinary center using social network analysis techniques. Specific aims were to examine the patterns of growth and interdisciplinary connectedness of the Center and to identify the social network characteristics of its productive members. The setting for this study was The Center for Interdisciplinary…

  20. Relative risk site evaluations for Yakima Training Center

    SciTech Connect

    Smith, R.M.; Whelan, G.

    1996-11-01

    All 20 U.S. Army Yakima Training Center (YTC) sites evaluated were given a `low` relative risk. At Solid Waste Management Unit (SWMU) 22, a `minimum` soils contaminant hazard factor was assigned even though 6,700 mg/kg TPH-diesel was found in surface soil. SWMU 22 is physically located on top of and with the fence surrounding Area of Concern (AOC) 4. Because the diesel is most likely associated with AOC 4, and plans are to clean up AOC 4, any further actions regarding these contaminated soils should be addressed as part of the planned actions for AOC 4. Contaminant hazard factors of `moderate` were assigned to the soil pathway for SWMUs 4 and 7 because dieldrin and arsenic, respectively, were found in surface soil samples at concentrations exceeding standards. A `moderate` contaminant hazard factor was also assigned to the sediment pathway for AOC 1 because arsenic detected in sediments in `Larry`s Swimming Pool` exceeded the standard. All other contaminant hazard factors were rated as minimal. The receptor factor for all sites and pathways was rated `limited,` except for SWMU 54 in which the groundwater receptor factor was rated `potential.` A `potential` rating was assigned to the groundwater pathway at this site to be conservative. The site is located on the south side of the syncline axis where the unconfined aquifer may be present and there are no monitoring wells at the site to confirm or deny the presence of groundwater contamination.

  1. Interim report task 3: immobilization process/equipment testing - task 3.4: non-destructive evaluation part 1 of 2 to Lawrence Livermore National Laboratory under contract b345772

    SciTech Connect

    Stewart, M W A; Vance E R; Day, R A; Lumpkin, G R

    2000-04-10

    This report contains a summary of the results generated for Task 3.4: Non-destructive Evaluation (a subtask of Task 3: Immobilization Process/Equipment Testing). The aim of this task was to carry out X-ray diffraction (XRD) on selected samples from previous Task 1: Form Development work. These XRD results were to be compared to the results obtained using quantitative scanning electron microscopy.

  2. Sensitivity and Calibration of Non-Destructive Evaluation Method That Uses Neural-Net Processing of Characteristic Fringe Patterns

    NASA Technical Reports Server (NTRS)

    Decker, Arthur J.; Weiland, Kenneth E.

    2003-01-01

    This paper answers some performance and calibration questions about a non-destructive-evaluation (NDE) procedure that uses artificial neural networks to detect structural damage or other changes from sub-sampled characteristic patterns. The method shows increasing sensitivity as the number of sub-samples increases from 108 to 6912. The sensitivity of this robust NDE method is not affected by noisy excitations of the first vibration mode. A calibration procedure is proposed and demonstrated where the output of a trained net can be correlated with the outputs of the point sensors used for vibration testing. The calibration procedure is based on controlled changes of fastener torques. A heterodyne interferometer is used as a displacement sensor for a demonstration of the challenges to be handled in using standard point sensors for calibration.

  3. Non-destructive evaluation of porosity and its effect on mechanical properties of carbon fiber reinforced polymer composite materials

    NASA Astrophysics Data System (ADS)

    Bhat, M. R.; Binoy, M. P.; Surya, N. M.; Murthy, C. R. L.; Engelbart, R. W.

    2012-05-01

    In this work, an attempt is made to induce porosity of varied levels in carbon fiber reinforced epoxy based polymer composite laminates fabricated using prepregs by varying the fabrication parameters such as applied vacuum, autoclave pressure and curing temperature. Different NDE tools have been utilized to evaluate the porosity content and correlate with measurable parameters of different NDE techniques. Primarily, ultrasonic imaging and real time digital X-ray imaging have been tried to obtain a measurable parameter which can represent or reflect the amount of porosity contained in the composite laminate. Also, effect of varied porosity content on mechanical properties of the CFRP composite materials is investigated through a series of experimental investigations. The outcome of the experimental approach has yielded interesting and encouraging trend as a first step towards developing an NDE tool for quantification of effect of varied porosity in the polymer composite materials.

  4. Staff Evaluation of the JCCC Success Center Model.

    ERIC Educational Resources Information Center

    Weglarz, Shirley G.

    This report describes a survey conducted at Johnson County Community College (JCCC) (Kansas) to measure staff perceptions, attitudes, and satisfaction with a variety of aspects of the Success Center/Student Services model, upon which the college's two-year old Success Center is based. Surveys were distributed in December 2001 to 107 Student Center…

  5. Evaluating the School Library Media Center. Analysis Techniques and Research Practices.

    ERIC Educational Resources Information Center

    Everhart, Nancy

    This book addresses two problems common to school library media specialists: the lack of time to conduct evaluations, and the lack of knowledge on how and what to evaluate in the school media center. The book contains research and evaluation techniques and studies that have been conducted in school library media centers. Many study results are…

  6. An Evaluation of the Alcoholism Rehabilitation Center Located at Fairbanks, Alaska.

    ERIC Educational Resources Information Center

    Grant, Claude W.; And Others

    At the request of the Alaska Bureau of Indian Affairs and the Alaska State Office of Alcoholism, the Alcoholism Rehabilitation Center at Fairbanks which serves Alaska Natives was evaluated in 1971. A three-member evaluation team evaluated the center's: (1) administrative structure and organization, (2) treatment program, and (3) relationship with…

  7. Nondestructive evaluation of crystallized-particle size in lactose-powder by terahertz time-domain spectroscopy

    NASA Astrophysics Data System (ADS)

    Yamauchi, Satoshi; Hatakeyama, Sakura; Imai, Yoh; Tonouchi, Masayoshi

    2014-03-01

    Transmission-type terahertz time-domain spectroscopy is applied to evaluate crystallized lactose particle of size below 30 μm, which is far too small compared to the wavelength of incident terahertz (THz)-wave. The THz-absorption spectrum of lactose is successfully deconvoluted by Lorentzian to two spectra with peaks at 17.1 cm-1 (0.53 THz) and 45.6 cm-1 (1.37 THz) derived from α-lactose monohydrate, and a spectrum at 39.7 cm-1 (1.19 THz) from anhydrous β-lactose after removal of the broad-band spectrum by polynomial cubic function. Lactose is mainly crystallized into α-lactose monohydrate from the supersaturated solution at room temperature with a small amount of anhydrous β-lactose below 4%. The absorption feature is dependent on the crystallized particle size and the integrated intensity ratio of the two absorptions due to α-lactose monohydrate is correlated in linear for the size.

  8. Visible and near-infrared light transmission: A hybrid imaging method for non-destructive meat quality evaluation

    NASA Astrophysics Data System (ADS)

    Ziadi, A.; Maldague, X.; Saucier, L.; Duchesne, C.; Gosselin, R.

    2012-09-01

    Visual inspection of the amount of external marbling (intramuscular fat) on the meat surface is the official method used to assign the quality grading level of meat. However, this method is based exclusively on the analysis of the meat surface without any information about the internal content of the meat sample. In this paper, a new method using visible (VIS) and near-infrared (NIR) light transmission is used to evaluate the quality of beef meat based on the marbling detection. It is demonstrated that using NIR light in transmission mode, it is possible to detect the fat not only on the surface, as in traditional methods, but also under the surface. Moreover, in combining the analysis of the two sides of the meat simple, it is possible to estimate the volumetric marbling which is not accessible by visual methods commonly proposed in computer vision. To the best of our knowledge, no similar work or method has been published or developed. The experimental results confirm the expected properties of the proposed method and illustrate the quality of the results obtained.

  9. In situ mobile subaquatic archaeometry evaluated by non-destructive Raman microscopy of gemstones lying under impure waters

    NASA Astrophysics Data System (ADS)

    Smith, David C.

    2003-08-01

    A series of laboratory simulations have been made in order to evaluate the credibility of carrying out physico-chemical analysis of cultural heritage items by Raman spectral fingerprinting using a mobile Raman microscope in situ under natural impure water in subaquatic or submarine conditions. Three different kinds of gemstone (zircon, microcline and sodalite) were successively placed under different kinds of impure water into which a low power microscope objective was immersed to eliminate the normal aerial pathway between the objective and the object to be analysed. According to the nature of the impurities (inorganic or organic, dissolved or suspended, transparent or coloured) the results obtained variously gave Raman band intensities stronger than, similar to or weaker than those of spectra obtained without water, i.e. in air. The significant point is that after only minor spectral treatment the less good spectra nevertheless yielded exploitable data with most, if not all, of the key Raman bands being detected. Thus the problems of fluorescence or peak absences under water are of a similar degree of magnitude to the other problems inherent with the Raman spectroscopic technique in aerial conditions, e.g. relative peak intensities varying with crystal orientation; peak positions varying with chemical composition. These results indicate that even if at certain sites of submerged cities or sunken ships, the combination of animal, vegetal, mineral and microbial impurities join together to inhibit or hinder the success of subaquatic or submarine archaeometry, there will certainly be other sites where such activity is indeed credible.

  10. In situ mobile subaquatic archaeometry evaluated by non-destructive Raman microscopy of gemstones lying under impure waters.

    PubMed

    Smith, David C

    2003-08-01

    A series of laboratory simulations have been made in order to evaluate the credibility of carrying out physico-chemical analysis of cultural heritage items by Raman spectral fingerprinting using a mobile Raman microscope in situ under natural impure water in subaquatic or submarine conditions. Three different kinds of gemstone (zircon, microcline and sodalite) were successively placed under different kinds of impure water into which a low power microscope objective was immersed to eliminate the normal aerial pathway between the objective and the object to be analysed. According to the nature of the impurities (inorganic or organic, dissolved or suspended, transparent or coloured) the results obtained variously gave Raman band intensities stronger than, similar to or weaker than those of spectra obtained without water, i.e. in air. The significant point is that after only minor spectral treatment the less good spectra nevertheless yielded exploitable data with most, if not all, of the key Raman bands being detected. Thus the problems of fluorescence or peak absences under water are of a similar degree of magnitude to the other problems inherent with the Raman spectroscopic technique in aerial conditions, e.g. relative peak intensities varying with crystal orientation; peak positions varying with chemical composition. These results indicate that even if at certain sites of submerged cities or sunken ships, the combination of animal, vegetal, mineral and microbial impurities join together to inhibit or hinder the success of subaquatic or submarine archaeometry, there will certainly be other sites where such activity is indeed credible. PMID:12909148

  11. Close infrared thermography using an intensified CCD camera: application in nondestructive high resolution evaluation of electrothermally actuated MEMS

    NASA Astrophysics Data System (ADS)

    Serio, B.; Hunsinger, J. J.; Conseil, F.; Derderian, P.; Collard, D.; Buchaillot, L.; Ravat, M. F.

    2005-06-01

    This communication proposes the description of an optical method for thermal characterization of MEMS devices. The method is based on the use of an intensified CCD camera to record the thermal radiation emitted by the studied device in the spectral domain from 600 nm to about 850 nm. The camera consists of an intensifier associated to a CCD sensor. The intensification allows for very low signal levels to be amplified and detected. We used a standard optical microscope to image the device with sub-micron resolution. Since, in close infrared, at very small scale and low temperature, typically 250°C for thermal MEMS (Micro-Electro-Mechanical Systems), the thermal radiation is very weak, we used image integration in order to increase the signal to noise ratio. Knowing the imaged materials emissivity, the temperature is given by using Planck"s law. In order to evaluate the system performances we have made micro-thermographies of a micro-relay thermal actuator. This device is an "U-shape" Al/SiO2 bimorph cantilever micro-relay with a gold-to-gold electrical contact, designed for secured harsh environment applications. The initial beam curvature resulting from residual stresses ensures a large gap between the contacts of the micro-relay. The current flow through the metallic layer heats the bimorph by Joule effect, and the differential expansion provides the vertical displacement for contact. The experimental results are confronted to FEM and analytical simulations. A good agreement was obtained between experimental results and simulations.

  12. Ultrasonic Nondestructive Evaluation of Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) During Large-Scale Load Testing and Rod Push-Out Testing

    NASA Technical Reports Server (NTRS)

    Johnston, Patrick H.; Juarez, Peter D.

    2016-01-01

    The Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) is a structural concept developed by the Boeing Company to address the complex structural design aspects associated with a pressurized hybrid wing body (HWB) aircraft configuration. The HWB has long been a focus of NASA's environmentally responsible aviation (ERA) project, following a building block approach to structures development, culminating with the testing of a nearly full-scale multi-bay box (MBB), representing a segment of the pressurized, non-circular fuselage portion of the HWB. PRSEUS is an integral structural concept wherein skins, frames, stringers and tear straps made of variable number of layers of dry warp-knit carbon-fiber stacks are stitched together, then resin-infused and cured in an out-of-autoclave process. The PRSEUS concept has the potential for reducing the weight and cost and increasing the structural efficiency of transport aircraft structures. A key feature of PRSEUS is the damage-arresting nature of the stitches, which enables the use of fail-safe design principles. During the load testing of the MBB, ultrasonic nondestructive evaluation (NDE) was used to monitor several sites of intentional barely-visible impact damage (BVID) as well as to survey the areas surrounding the failure cracks after final loading to catastrophic failure. The damage-arresting ability of PRSEUS was confirmed by the results of NDE. In parallel with the large-scale structural testing of the MBB, mechanical tests were conducted of the PRSEUS rod-to-overwrap bonds, as measured by pushing the rod axially from a short length of stringer.

  13. National Evaluation of the Comprehensive Technical Assistance Centers. Interim Report. NCEE 2010-4033

    ERIC Educational Resources Information Center

    Turnbull, Brenda J.; White, Richard N.; Sinclair, Elizabeth; Riley, Derek; Sipe, Cynthia L.; Pistorino, Carol

    2010-01-01

    This first of two reports presents early findings from the National Evaluation of the Comprehensive Technical Assistance Centers (Comprehensive Centers), a federally funded program that provides technical assistance to states in connection with the No Child Left Behind (NCLB) Act of 2001. The law authorizing the Comprehensive Centers, the…

  14. Educational ultrasound nondestructive testing laboratory.

    PubMed

    Genis, Vladimir; Zagorski, Michael

    2008-09-01

    The ultrasound nondestructive evaluation (NDE) of materials course was developed for applied engineering technology students at Drexel University's Goodwin College of Professional Studies. This three-credit, hands-on laboratory course consists of two parts: the first part with an emphasis on the foundations of NDE, and the second part during which ultrasound NDE techniques are utilized in the evaluation of parts and materials. NDE applications are presented and applied through real-life problems, including calibration and use of the latest ultrasonic testing instrumentation. The students learn engineering and physical principles of measurements of sound velocity in different materials, attenuation coefficients, material thickness, and location and dimensions of discontinuities in various materials, such as holes, cracks, and flaws. The work in the laboratory enhances the fundamentals taught during classroom sessions. This course will ultimately result in improvements in the educational process ["The greater expectations," national panel report, http://www.greaterexpectations.org (last viewed February, 2008); R. M. Felder and R. Brent "The intellectual development of Science and Engineering Students. Part 2: Teaching to promote growth," J. Eng. Educ. 93, 279-291 (2004)] since industry is becoming increasingly reliant on the effective application of NDE technology and the demand on NDE specialists is increasing. NDE curriculum was designed to fulfill levels I and II NDE in theory and training requirements, according to American Society for Nondestructive Testing, OH, Recommended Practice No. SNT-TC-1A (2006). PMID:19045633

  15. The Assess-and-Fix Approach: Using Non-Destructive Evaluations to Help Select Pipe Renewal Methods (WaterRF Report 4473)

    EPA Science Inventory

    Nondestructive examinations (NDE) can be easily performed as part of a typical water main rehabilitation project. Once a bypass water system has been installed and the water main has been cleaned, pulling a scanning tool through the main is very straightforward. An engineer can t...

  16. Nondestructive testing of brazed rocket engine components

    NASA Technical Reports Server (NTRS)

    Adams, C. J.; Hagemaier, D. J.; Meyer, J. A.

    1968-01-01

    Report details study made of nondestructive radiographic, ultrasonic, thermographic, and leak test methods used to inspect and evaluate the quality of the various brazed joints in liquid-propellant rocket engine components and assemblies. Descriptions of some of the unique equipment and methods developed are included.

  17. Nondestructive examination development and demonstration plan

    SciTech Connect

    Weber, J.R.

    1991-08-21

    Nondestructive examination (NDE) of waste matrices using penetrating radiation is by nature very subjective. Two candidate systems of examination have been identified for use in WRAP 1. This test plan describes a method for a comparative evaluation of different x-ray examination systems and techniques.

  18. BWR nondestructive evaluation source book

    SciTech Connect

    Neeley, V.I. ); Walker, S.M. ); Behravesh, M.M. )

    1990-06-01

    In response to increasing incidences of IGSCC in BWRs in the last decade, EPRI and the BWR Owners Group jointly developed and successfully implemented numerous projects relating to the use of NDE techniques to detect and size IGSCC. This report provides a brief summary of these various projects along with their historical perpectives in a single, condensed source. The various IGSCC problems of BWRs and the projects that were conducted to address them are more thoroughly described in many other EPRI reports referenced herein. 97 refs., 50 figs.

  19. 78 FR 16679 - Center for Drug Evaluation and Research Medical Policy Council; Request for Comments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-18

    ... HUMAN SERVICES Food and Drug Administration Center for Drug Evaluation and Research Medical Policy... interested organizations, on medical policy issues that may be considered by the CDER Medical Policy Council (Council) in FDA's Center for Drug Evaluation and Research (CDER). These comments will help the...

  20. Description, Evaluation, and Validation of a Pilot Developmental Assessment Center in a Military-Educational Environment.

    ERIC Educational Resources Information Center

    Butler, Richard P.; And Others

    The purpose of this report is to describe, evaluate, and validate a pilot assessment center (AC) established in the Center for Leadership and Personal Development at the U.S. Military Academy to develop cadets on job skills needed by newly commissioned officers in the U.S. Army. The AC programs employ a leadership evaluation development method…

  1. The Brave New World of GEC Evaluation: The Experience of the Rhode Island Geriatric Education Center

    ERIC Educational Resources Information Center

    Filinson, Rachel; Clark, Phillip G.; Evans, Joann; Padula, Cynthia; Willey, Cynthia

    2012-01-01

    In 2007, the Health Resources Services Administration introduced new mandates that raised the standards on program evaluation for Geriatric Education Centers. Described in this article are the primary and secondary evaluation efforts undertaken for one program within the Rhode Island Geriatric Education Center (RIGEC), the findings from these…

  2. Evaluating Center Pivot Distribution Uniformity from Catch Can Tests

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Center pivot irrigation is an important irrigation method in Missouri. However, only about half of the pivots in Missouri are the “typical”, full-circle, seven-span pivots. The other half are partial circles and/or have shorter or longer span lengths. Both items significantly impact the economics...

  3. Performance evaluation of a center pivot variable rate irrigation system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Variable Rate Irrigation (VRI) for center pivots offers potential to match specific application rates to non-uniform soil conditions along the length of the lateral. The benefit of such systems is influenced by the areal extent of these variations and the smallest scale to which the irrigation syste...

  4. Bilingual Early Childhood Centers. Final Evaluation Report 1978-79.

    ERIC Educational Resources Information Center

    Feingold, Jeffrey; And Others

    The bilingual Early Childhood Centers Program was established in three public and four non-public schools ln District 14 (Brooklyn, New York) as a response to the needs of children in grades K-2 with limited English proficiency. Participants were from Spanish or Yiddish dominant homes. The curriculum offered instruction in English as a Second…

  5. Evaluation of Merrimack Education Center's Project League 1972.

    ERIC Educational Resources Information Center

    Michel, Albert; Vaughn, John W.

    Individually Guided Education (IGE) is a system whereby change agents such as the Merrimack Education Center (MEC) work to effect innovative behavior in networks of schools. Thus, MEC undertook to form a League of Schools with the specific objectives of a) attainment by all member schools of peer support, b) creation of a communication network,…

  6. Teachers' Evaluation of Student-Centered Learning Environments

    ERIC Educational Resources Information Center

    Cubukcu, Zuhal

    2012-01-01

    Problem Statement: The student-centered teaching is the arrangement of the teaching experience focusing on the students' responsibilities and activities in the learning process which takes into consideration the students' interests, demands and needs. According to this approach, while teaching experiences are planned, different learning strategies…

  7. Evaluation of the Indian Education Technical Assistance Centers.

    ERIC Educational Resources Information Center

    Panton, Karen L. M.; And Others

    Six Indian Education Technical Assistance Centers (IETACs) provide technical assistance to American Indian and Alaska Native education programs funded by Title V grants from the Office of Indian Education (OIE). This study examines the services provided by the IETACs and identifies factors that influence their effectiveness. Data were collected…

  8. A User's Evaluation of a NASA Regional Dissemination Center.

    ERIC Educational Resources Information Center

    Sovel, M. Terry; Coddington, Dean C.

    Retrospective searches provided by a NASA Regional Dissemination Center (RDC) were found to be of substantial value to researchers during a six-month experimental period at the University of Denver's Research Institute (DRI). The purpose of the experiment was to gain a better understanding of the usefulness of an RDC to a user organization. DRI…

  9. Graphics Expression System Reading Center, Evaluation Period 1975-76.

    ERIC Educational Resources Information Center

    Hopkins, Thomas F.

    This paper describes the Graphics Expression System Reading Center Program, which provided students with limited learning motivation and with below norm achievement in reading, as well as those students reading on and above grade level with the opportunity to use the compact recording studio equipment in the production of television shows. The…

  10. Evaluative Study of the Neighborhood Information Center Project.

    ERIC Educational Resources Information Center

    Franklin, Hardy R.; Summers, F. William

    The 1972-1974 Neighborhood Information Center (NIC) Project was undertaken in Atlanta, Cleveland, Detroit, Houston, and Queens Borough to demonstrate that urban public libraries could be a vital force in daily living by providing free information and referrals to low income communities, and by adapting in non-traditional ways to meet neighborhood…

  11. User-Centered Evaluation of the Quality of Blogs

    ERIC Educational Resources Information Center

    Chuenchom, Sutthinan

    2011-01-01

    Blogs serve multiple purposes, resulting in several types of blogs that vary greatly in terms of quality and content. It is important to evaluate the quality of blogs, which requires appropriate evaluation criteria. Unfortunately, there are minimal studies on framework and the specific criteria and indicators for evaluating the quality of blogs.…

  12. Nondestructive testing techniques

    NASA Astrophysics Data System (ADS)

    Bray, Don E.; McBride, Don

    A comprehensive reference covering a broad range of techniques in nondestructive testing is presented. Based on years of extensive research and application at NASA and other government research facilities, the book provides practical guidelines for selecting the appropriate testing methods and equipment. Topics discussed include visual inspection, penetrant and chemical testing, nuclear radiation, sonic and ultrasonic, thermal and microwave, magnetic and electromagnetic techniques, and training and human factors. (No individual items are abstracted in this volume)

  13. In-Situ Nondestructive Evaluation of Kevlar(Registered Trademark)and Carbon Fiber Reinforced Composite Micromechanics for Improved Composite Overwrapped Pressure Vessel Health Monitoring

    NASA Technical Reports Server (NTRS)

    Waller, Jess; Saulsberry, Regor

    2012-01-01

    NASA has been faced with recertification and life extension issues for epoxy-impregnated Kevlar 49 (K/Ep) and carbon (C/Ep) composite overwrapped pressure vessels (COPVs) used in various systems on the Space Shuttle and International Space Station, respectively. Each COPV has varying criticality, damage and repair histories, time at pressure, and pressure cycles. COPVs are of particular concern due to the insidious and catastrophic burst-before-leak failure mode caused by stress rupture (SR) of the composite overwrap. SR life has been defined [1] as the minimum time during which the composite maintains structural integrity considering the combined effects of stress level(s), time at stress level(s), and associated environment. SR has none of the features of predictability associated with metal pressure vessels, such as crack geometry, growth rate and size, or other features that lend themselves to nondestructive evaluation (NDE). In essence, the variability or surprise factor associated with SR cannot be eliminated. C/Ep COPVs are also susceptible to impact damage that can lead to reduced burst pressure even when the amount of damage to the COPV is below the visual detection threshold [2], thus necessitating implementation of a mechanical damage control plan [1]. Last, COPVs can also fail prematurely due to material or design noncompliance. In each case (SR, impact or noncompliance), out-of-family behavior is expected leading to a higher probability of failure at a given stress, hence, greater uncertainty in performance. For these reasons, NASA has been actively engaged in research to develop NDE methods that can be used during post-manufacture qualification, in-service inspection, and in-situ structural health monitoring. Acoustic emission (AE) is one of the more promising NDE techniques for detecting and monitoring, in real-time, the strain energy release and corresponding stress-wave propagation produced by actively growing flaws and defects in composite

  14. Development of frequency and phase modulated thermal-wave methodologies for materials non-destructive evaluation and thermophotonic imaging of turbid media

    NASA Astrophysics Data System (ADS)

    Tabatabaei, Nima

    In frequency-domain photothermal radiometry (FD-PTR) a low-power intensity-modulated optical excitation generates thermal-wave field inside the sample and the subsequent infrared radiation from the sample is analyzed to detect material's inhomogeneities. The non-contact nature of FD-PTR makes it very suitable for non-destructive evaluation of broad range of materials. Moreover, the methodology is based on intrinsic contrast of light absorption which can be used as a diagnostic tool for inspection of malignancy in biological tissues. Nevertheless, the bottom line is that the physics of heat diffusion allows for a highly damped and dispersive propagation of thermal-waves. As a result, the current FD-PTR modalities suffer from limited inspection depth and poor axial/depth resolution. The main objective of this thesis is to show that using alternative types of modulation schemes (such as linear frequency modulation and binary phase coding) and radar matched filter signal processing, one can obtain localized responses from inherently diffuse thermal wave fields. In this thesis, the photothermal responses of turbid, transparent, and opaque media to linear frequency modulated and binary phase coded excitations are analytically derived. Theoretical simulations suggest that matched-filtering in diffusion-wave field acts as constructive interferometry, localizing the energy of the long-duty excitation under a narrow peak and allowing one to construct depth resolved images. The developed technique is the diffusion equivalent of optical coherence tomography and is named thermal coherence tomography. It was found that the narrow-band binary phase coded matched filtering yields optimal depth resolution, while the broad-band linear frequency modulation can be used to quantify material properties through the multi-parameter fitting of the experimental data to the developed theory. Thermophotonic detection of early dental caries is discussed in detail as a potential diagnostic

  15. On the practice of ignoring center-patient interactions in evaluating hospital performance.

    PubMed

    Varewyck, Machteld; Vansteelandt, Stijn; Eriksson, Marie; Goetghebeur, Els

    2016-01-30

    We evaluate the performance of medical centers based on a continuous or binary patient outcome (e.g., 30-day mortality). Common practice adjusts for differences in patient mix through outcome regression models, which include patient-specific baseline covariates (e.g., age and disease stage) besides center effects. Because a large number of centers may need to be evaluated, the typical model postulates that the effect of a center on outcome is constant over patient characteristics. This may be violated, for example, when some centers are specialized in children or geriatric patients. Including interactions between certain patient characteristics and the many fixed center effects in the model increases the risk for overfitting, however, and could imply a loss of power for detecting centers with deviating mortality. Therefore, we assess how the common practice of ignoring such interactions impacts the bias and precision of directly and indirectly standardized risks. The reassuring conclusion is that the common practice of working with the main effects of a center has minor impact on hospital evaluation, unless some centers actually perform substantially better on a specific group of patients and there is strong confounding through the corresponding patient characteristic. The bias is then driven by an interplay of the relative center size, the overlap between covariate distributions, and the magnitude of the interaction effect. Interestingly, the bias on indirectly standardized risks is smaller than on directly standardized risks. We illustrate our findings by simulation and in an analysis of 30-day mortality on Riksstroke. PMID:26303843

  16. Abnormal Nutritional Factors in Patients Evaluated at a Neuropathy Center.

    PubMed

    Latov, Norman; Vo, Mary L; Chin, Russell L; Carey, Bridget T; Langsdorf, Jennifer A; Feuer, Naomi T

    2016-06-01

    Abnormal concentrations of nutritional factors were found in 24.1% of 187 patients with neuropathy who were newly seen at our academic neuropathy referral center over a 1-year period. All patients presented with sensory axonal or small fiber neuropathy. In 7.3%, they were present in association with at least one other identifiable cause for neuropathy. Elevated levels of pyridoxal phosphate or mercury occurred more frequently than deficiencies in vitamins B1, B12, or B6. The nutritional abnormalities are amenable to correction by dietary intervention. PMID:27224436

  17. Nondestructive examination of the TRMM RCS propellant tanks

    NASA Technical Reports Server (NTRS)

    Free, James M.

    1993-01-01

    This paper assesses the feasibility of using eddy current nondestructive examination of determine flaw sizes in completely assembled hydrazine propellant tanks. The study was performed by the NASA Goddard Space Flight Center for the Tropical Rainfall Measuring Mission (TRMM) project to help determine whether existing propellant tanks could meet the fracture analysis requirements of the current pressure vessel specification, MIL-STD-1522A and, therefore be used on the TRMM spacecraft. After evaluating several nondestructive test methods, eddy current testing was selected as the most promising method for determining flaw sizes on external and internal surfaces of completely assembled tanks. Tests were conducted to confirm the detection capability of the eddy current NDE, procedures were developed to inspect two candidate tanks, and the test support equipment was designed. The non-spherical tank eddy current NDE test program was terminated when the decision was made to procure new tanks for the TRMM propulsion subsystem. The information on the development phase of this test program is presented in this paper as a reference for future investigation on the subject.

  18. Nondestructive examination of the TRMM RCS propellant tanks

    NASA Astrophysics Data System (ADS)

    Free, James M.

    1993-11-01

    This paper assesses the feasibility of using eddy current nondestructive examination of determine flaw sizes in completely assembled hydrazine propellant tanks. The study was performed by the NASA Goddard Space Flight Center for the Tropical Rainfall Measuring Mission (TRMM) project to help determine whether existing propellant tanks could meet the fracture analysis requirements of the current pressure vessel specification, MIL-STD-1522A and, therefore be used on the TRMM spacecraft. After evaluating several nondestructive test methods, eddy current testing was selected as the most promising method for determining flaw sizes on external and internal surfaces of completely assembled tanks. Tests were conducted to confirm the detection capability of the eddy current NDE, procedures were developed to inspect two candidate tanks, and the test support equipment was designed. The non-spherical tank eddy current NDE test program was terminated when the decision was made to procure new tanks for the TRMM propulsion subsystem. The information on the development phase of this test program is presented in this paper as a reference for future investigation on the subject.

  19. NON-DESTRUCTIVE TESTING METHODS FOR GEOTHERMAL PIPING.

    SciTech Connect

    BERNDT,M.L.

    2001-03-23

    Non-destructive testing is a key component of optimized plant inspection and maintenance programs. Risk based inspection, condition based maintenance and reliability centered maintenance systems all require detection, location and sizing of defects or flaws by non-destructive methods. Internal damage of geothermal piping by corrosion and erosion-corrosion is an ongoing problem requiring inspection and subsequent maintenance decisions to ensure safe and reliable performance. Conventional manual ultrasonic testing to determine remaining wall thickness has major limitations, particularly when damage is of a random and localized nature. Therefore, it is necessary to explore alternative non-destructive methods that offer potential benefits in terms of accurate quantification of size, shape and location of damage, probability of detection, ability to use on-line over long ranges, and economics. A review of non-destructive methods and their applicability to geothermal piping was performed. Based on this, ongoing research will concentrate on long range guided wave and dynamic methods.

  20. An evaluation of the Goddard Space Flight Center Library

    NASA Technical Reports Server (NTRS)

    Herner, S.; Lancaster, F. W.; Wright, N.; Ockerman, L.; Shearer, B.; Greenspan, S.; Mccartney, J.; Vellucci, M.

    1979-01-01

    The character and degree of coincidence between the current and future missions, programs, and projects of the Goddard Space Flight Center and the current and future collection, services, and facilities of its library were determined from structured interviews and discussions with various classes of facility personnel. In addition to the tabulation and interpretation of the data from the structured interview survey, five types of statistical analyses were performed to corroborate (or contradict) the survey results and to produce useful information not readily attainable through survey material. Conclusions reached regarding compatability between needs and holdings, services and buildings, library hours of operation, methods of early detection and anticipation of changing holdings requirements, and the impact of near future programs are presented along with a list of statistics needing collection, organization, and interpretation on a continuing or longitudinal basis.