Non-destructive evaluation on mechanical properties of nuclear graphite with porous structure

International Nuclear Information System (INIS)

Shibata, Taiju; Hanawa, Satoshi; Sumita, Junya; Tada, Tatsuya; Sawa, Kazuhiro; Iyoku, Tatsuo

2005-01-01

As a research subjects of 'Research and development for advanced high temperature gas cooled reactor fuels and graphite components,' we started the study of development of non-destructive evaluation methods for mechanical properties of graphite components. The micro-indentation and ultrasonic wave methods are focused to evaluate the degradation of graphite components in VHTR core. For the micro-indentation method, the test apparatus was designed for the indentation test on graphite specimens with some stress levels. It is expected the stress condition is evaluated by the indentation load-depth characteristics and hardness. For the ultrasonic wave method, ultrasonic wave testing machine and probes were prepared for experiments. It is expected that the stress and inner porous conditions are evaluated by the wave propagation characteristics with wave-pore interaction model. R and D plan to develop the non-destructive evaluation method for graphite is presented in this paper. (This study is the result of contract research in the fiscal year of 2004, Research and development for advanced high temperature gas cooled reactor fuels and graphite components,' which is entrusted to the Japan Atomic Energy Research Institute from the Ministry of Education, Culture, Sports, Science and Technology of Japan.) (author)

Enhancement of Spatial Resolution Using a Metamaterial Sensor in Nondestructive Evaluation

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Adriana Savin

2015-11-01

Full Text Available The current stage of non-destructive evaluation techniques imposes the development of new electromagnetic methods that are based on high spatial resolution and increased sensitivity. Printed circuit boards, integrated circuit boards, composite materials with polymeric matrix containing conductive fibers, as well as some types of biosensors are devices of interest in using such evaluation methods. In order to achieve high performance, the work frequencies must be either radiofrequencies or microwaves. At these frequencies, at the dielectric/conductor interface, plasmon polaritons can appear, propagating between conductive regions as evanescent waves. Detection of these waves, containing required information, can be done using sensors with metamaterial lenses. We propose in this paper the enhancement of the spatial resolution using electromagnetic methods, which can be accomplished in this case using evanescent waves that appear in the current study in slits of materials such as the spaces between carbon fibers in Carbon Fibers Reinforced Plastics or in materials of interest in the nondestructive evaluation field with industrial applications, where microscopic cracks are present. We propose herein a unique design of the metamaterials for use in nondestructive evaluation based on Conical Swiss Rolls configurations, which assure the robust concentration/focusing of the incident electromagnetic waves (practically impossible to be focused using classical materials, as well as the robust manipulation of evanescent waves. Applying this testing method, spatial resolution of approximately λ/2000 can be achieved. This testing method can be successfully applied in a variety of applications of paramount importance such as defect/damage detection in materials used in a variety of industrial applications, such as automotive and aviation technologies.

Nondestructive millimeter wave imaging and spectroscopy using dielectric focusing probes

International Nuclear Information System (INIS)

Hejase, Jose A.; Shane, Steven S.; Park, Kyoung Y.; Chahal, Premjeet

2014-01-01

A tool for interrogating objects over a wide band of frequencies with subwavelength resolution at small standoff distances (near field region) in the transmission mode using a single source and detector measurement setup in the millimeter wave band is presented. The design utilizes optics like principles for guiding electromagnetic millimeter waves from large cross-sectional areas to considerably smaller sub-wavelength areas. While plano-convex lenses can be used to focus waves to a fine resolution, they usually require a large stand-off distance thus resulting in alignment and spacing issues. The design procedure and simulation analysis of the focusing probes are presented in this study along with experimental verification of performance and imaging and spectroscopy examples. Nondestructive evaluation will find benefit from such an apparatus including biological tissue imaging, electronic package integrity testing, composite dielectric structure evaluation for defects and microfluidic sensing

Nondestructive millimeter wave imaging and spectroscopy using dielectric focusing probes

Energy Technology Data Exchange (ETDEWEB)

Hejase, Jose A.; Shane, Steven S.; Park, Kyoung Y.; Chahal, Premjeet [Terahertz Systems Laboratory (TeSLa) - Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI 48823 (United States)

2014-02-18

A tool for interrogating objects over a wide band of frequencies with subwavelength resolution at small standoff distances (near field region) in the transmission mode using a single source and detector measurement setup in the millimeter wave band is presented. The design utilizes optics like principles for guiding electromagnetic millimeter waves from large cross-sectional areas to considerably smaller sub-wavelength areas. While plano-convex lenses can be used to focus waves to a fine resolution, they usually require a large stand-off distance thus resulting in alignment and spacing issues. The design procedure and simulation analysis of the focusing probes are presented in this study along with experimental verification of performance and imaging and spectroscopy examples. Nondestructive evaluation will find benefit from such an apparatus including biological tissue imaging, electronic package integrity testing, composite dielectric structure evaluation for defects and microfluidic sensing.

Multi-Wave and Hybrid Imaging Techniques: A New Direction for Nondestructive Testing and Structural Health Monitoring

Directory of Open Access Journals (Sweden)

Yuhua Cheng

2013-11-01

Full Text Available In this article, the state-of-the-art multi-wave and hybrid imaging techniques in the field of nondestructive evaluation and structural health monitoring were comprehensively reviewed. A new direction for assessment and health monitoring of various structures by capitalizing the advantages of those imaging methods was discussed. Although sharing similar system configurations, the imaging physics and principles of multi-wave phenomena and hybrid imaging methods are inherently different. After a brief introduction of nondestructive evaluation (NDE , structure health monitoring (SHM and their related challenges, several recent advances that have significantly extended imaging methods from laboratory development into practical applications were summarized, followed by conclusions and discussion on future directions.

Diameter effect on stress-wave evaluation of modulus of elasticity of logs

Science.gov (United States)

Xiping Wang; Robert J. Ross; Brian K. Brashaw; John Punches; John R. Erickson; John W. Forsman; Roy E. Pellerin

2004-01-01

Recent studies on nondestructive evaluation (NDE) of logs have shown that a longitudinal stress-wave method can be used to nondestructively evaluate the modulus of elasticity (MOE) of logs. A strong relationship has been found between stress-wave MOE and static MOE of logs, but a significant deviation was observed between stress-wave and static values. The objective of...

Nondestructive evaluation of oriented strand board exposed to decay fungi.

Science.gov (United States)

Barbara L. Illman; Vina W. Yang; Robert J. Ross; William J. Nelson

2002-01-01

Stress wave nondestructive evaluation (NDE) technologies are being used in our laboratory to evaluate the performance properties of engineered wood. These techniques have proven useful in the inspection of timber structures to locate internal voids and decayed or deteriorated areas in large timbers. But no information exists concerning NDE and important properties of...

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

Energy Technology Data Exchange (ETDEWEB)

Lavers, C; Franklin, P; Franklin, P; Plowman, A; Sayers, G; Bol, J; Shepard, D; Fields, D, E-mail: brnc-radarcomms1@nrta.mod.u [Sensors Team, Plymouth University at Britannia Royal Naval College, Dartmouth, Devon (United Kingdom) and Paignton Zoological Park, Paignton, Devon (United Kingdom); Thermal Wave Imaging, Inc., 845 Livernoise St, Ferndale, MI (United States); Buckfast Butterfly and Otter Sanctuary, Buckfast, Devon (United Kingdom)

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.

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

International Nuclear Information System (INIS)

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

2009-01-01

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.

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

Science.gov (United States)

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.

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

International Nuclear Information System (INIS)

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.

Spatial and temporal control of thermal waves by using DMDs for interference based crack detection

Science.gov (United States)

Thiel, Erik; Kreutzbruck, Marc; Ziegler, Mathias

2016-02-01

Active Thermography is a well-established non-destructive testing method and used to detect cracks, voids or material inhomogeneities. It is based on applying thermal energy to a samples' surface whereas inner defects alter the nonstationary heat flow. Conventional excitation of a sample is hereby done spatially, either planar (e.g. using a lamp) or local (e.g. using a focused laser) and temporally, either pulsed or periodical. In this work we combine a high power laser with a Digital Micromirror Device (DMD) allowing us to merge all degrees of freedom to a spatially and temporally controlled heat source. This enables us to exploit the possibilities of coherent thermal wave shaping. Exciting periodically while controlling at the same time phase and amplitude of the illumination source induces - via absorption at the sample's surface - a defined thermal wave propagation through a sample. That means thermal waves can be controlled almost like acoustical or optical waves. However, in contrast to optical or acoustical waves, thermal waves are highly damped due to the diffusive character of the thermal heat flow and therefore limited in penetration depth in relation to the achievable resolution. Nevertheless, the coherence length of thermal waves can be chosen in the mmrange for modulation frequencies below 10 Hz which is perfectly met by DMD technology. This approach gives us the opportunity to transfer known technologies from wave shaping techniques to thermography methods. We will present experiments on spatial and temporal wave shaping, demonstrating interference based crack detection.

Experimental electro-thermal method for nondestructively testing welds in stainless steel pipes

International Nuclear Information System (INIS)

Green, D.R.

1979-01-01

Welds in austenitic stainless steel pipes are notoriously difficult to nondestructively examine using conventional ultrasonic and eddy current methods. Survace irregularities and microscopic variations in magnetic permeability cause false eddy current signal variations. Ultrasonic methods have been developed which use computer processing of the data to overcome some of the problems. Electro-thermal nondestructive testing shows promise for detecting flaws that are difficult to detect using other NDT methods. Results of a project completed to develop and demonstrate the potential of an electro-thermal method for nondestructively testing stainless steel pipe welds are presented. Electro-thermal NDT uses a brief pulse of electrical current injected into the pipe. Defects at any depth within the weld cause small differences in surface electrical current distribution. These cause short-lived transient temperature differences on the pipe's surface that are mapped using an infrared scanning camera. Localized microstructural differences and normal surface roughness in the welds have little effect on the surface temperatures

Nondestructive technique application for corrosion evaluation by hydrogen charging of stainless steel

Energy Technology Data Exchange (ETDEWEB)

Lee, Jin Kyung, E-mail: leejink@deu.ac.kr [Department of Mechanical Engineering, Dongeui University, Busan (Korea, Republic of); Bae, Dong Su [Department of Advanced Materials Engineering, Dongeui University, Busan (Korea, Republic of); Lee, Sang Pill; Hwang, Sung Guk [Department of Mechanical Engineering, Dongeui University, Busan (Korea, Republic of); Lee, Joon Hyun [School of Mechanical Engineering, Pusan National University, Busan (Korea, Republic of)

2016-11-01

Highlights: • We have studied on the nondestructive technique application for corrosion evaluation by hydrogen charging of stainless steel. An ultrasonic test (UT) is an useful method to evaluate the mechanical properties of material. By measuring the velocity and the attenuation of ultrasonic wave propagating the hydrogen charged stainless steel, the relation of ultrasonic wave and mechanical properties of hydrogen charged 316L stainless steel was discussed. However, in order to evaluate the dynamic behavior of materials, an acoustic emission (AE) technique was applied to investigate the corrosion characteristics of hydrogen charged specimen. Acoustic emission is one of elastic waves caused by dislocation, cracks initiation and propagation within material from loading outside. The waveform of the acoustic emission is different depending on the damage mechanism of material. Lots of AE parameters such as energy, duration time, event and amplitude were used to analyze the dynamic behavior of the hydrogen charged specimen. • A conventional 316L stainless steel was used in this study, and electrochemical treat system for hydrogen charging of the specimen. ASTM (G142) type tensile specimens (diameter 6.0 mm, gage length 28.6 mm) were prepared, and sulfuric acid(H{sub 2}SO{sub 4}) and arsenic trioxide(As{sub 2}O{sub 3}) were used as the electrolyte, and potentiostat(HA 151) supplied the current to platinum wire and specimen. • Tensile strength and attenuation coefficient has a relation to some extent. Therefore, we could estimate the tensile strength and the hydrogen charging time by measuring the attenuation coefficient using ultrasonic wave nondestructively. • Acoustic emission technique was useful to evaluate the dynamic damage because AE parameters of AE event, average energy and average frequency showed various change by external loading at the specimens with and without hydrogen. - Abstract: Caused corrosion by hydrogen on stainless steel using

Non-destructive thermal wave method applied to study thermal properties of fast setting time endodontic cement

Science.gov (United States)

Picolloto, A. M.; Mariucci, V. V. G.; Szpak, W.; Medina, A. N.; Baesso, M. L.; Astrath, N. G. C.; Astrath, F. B. G.; Santos, A. D.; Moraes, J. C. S.; Bento, A. C.

2013-11-01

The thermal wave method is applied for thermal properties measurement in fast endodontic cement (CER). This new formula is developed upon using Portland cement in gel and it was successfully tested in mice with good biocompatibility and stimulated mineralization. Recently, thermal expansion and setting time were measured, conferring to this material twice faster hardening than the well known Angelus Mineral trioxide aggregate (MTA) the feature of fast hardening (˜7 min) and with similar thermal expansion (˜12 μstrain/ °C). Therefore, it is important the knowledge of thermal properties like thermal diffusivity, conductivity, effusivity in order to match thermally the tissue environment upon its application in filling cavities of teeth. Photothermal radiometry technique based on Xe illumination was applied in CER disks 600 μm thick for heating, with prepared in four particle sizes (25, 38, 45, and 53) μm, which were added microemulsion gel with variation volumes (140, 150, 160, and 170) μl. The behavior of the thermal diffusivity CER disks shows linear decay for increase emulsion volume, and in contrast, thermal diffusivity increases with particles sizes. Aiming to compare to MTA, thermal properties of CER were averaged to get the figure of merit for thermal diffusivity as (44.2 ± 3.6) × 10-3 cm2/s, for thermal conductivity (228 ± 32) mW/cm K, the thermal effusivity (1.09 ± 0.06) W s0.5/cm2 K and volume heat capacity (5.2 ± 0.7) J/cm3 K, which are in excellent agreement with results of a disk prepared from commercial MTA-Angelus (grain size < 10 μm using 57 μl of distilled water).

Thermal shock resistance of ceramic fibre composites characterized by non-destructive methods

Directory of Open Access Journals (Sweden)

M. Dimitrijević

2008-12-01

Full Text Available Alumina based ceramic fibres and alumina based ceramic were used to produce composite material. Behaviour of composite ceramics after thermal shock treatments was investigated. Thermal shock of the samples was evaluated using water quench test. Surface deterioration level of samples was monitored by image analysis before and after a number of quenching cycles. Ultrasonic measurements were done on samples after quench tests. Dynamic Young modulus of elasticity and strength degradation were calculated using measured values of ultrasonic velocities. Strengths deterioration was calculated using the non-destructive measurements and correlated to degradation of surface area and number of quenches. The addition of small amount of ceramic fibres improves the strengths and diminishes the loss of mechanical properties of samples during thermal shock experiments.

Non-destructive thermal wave method applied to study thermal properties of fast setting time endodontic cement

Energy Technology Data Exchange (ETDEWEB)

Picolloto, A. M.; Mariucci, V. V. G.; Szpak, W.; Medina, A. N.; Baesso, M. L.; Astrath, N. G. C.; Astrath, F. B. G.; Bento, A. C., E-mail: acbento@uem.br [Departamento de Física, Grupo de Espectroscopia Fotoacústica e Fototérmica, Universidade Estadual de Maringá – UEM, Av. Colombo 5790, 87020-900 Maringá, Paraná (Brazil); Santos, A. D.; Moraes, J. C. S. [Departamento de Física e Química, Universidade Estadual Paulista Júlio de Mesquita Filho – UNESP, Av. Brasil 56, 15385-000 Ilha Solteira, SP (Brazil)

2013-11-21

The thermal wave method is applied for thermal properties measurement in fast endodontic cement (CER). This new formula is developed upon using Portland cement in gel and it was successfully tested in mice with good biocompatibility and stimulated mineralization. Recently, thermal expansion and setting time were measured, conferring to this material twice faster hardening than the well known Angelus Mineral trioxide aggregate (MTA) the feature of fast hardening (∼7 min) and with similar thermal expansion (∼12 μstrain/ °C). Therefore, it is important the knowledge of thermal properties like thermal diffusivity, conductivity, effusivity in order to match thermally the tissue environment upon its application in filling cavities of teeth. Photothermal radiometry technique based on Xe illumination was applied in CER disks 600 μm thick for heating, with prepared in four particle sizes (25, 38, 45, and 53) μm, which were added microemulsion gel with variation volumes (140, 150, 160, and 170) μl. The behavior of the thermal diffusivity CER disks shows linear decay for increase emulsion volume, and in contrast, thermal diffusivity increases with particles sizes. Aiming to compare to MTA, thermal properties of CER were averaged to get the figure of merit for thermal diffusivity as (44.2 ± 3.6) × 10{sup −3} cm{sup 2}/s, for thermal conductivity (228 ± 32) mW/cm K, the thermal effusivity (1.09 ± 0.06) W s{sup 0.5}/cm{sup 2} K and volume heat capacity (5.2 ± 0.7) J/cm{sup 3} K, which are in excellent agreement with results of a disk prepared from commercial MTA-Angelus (grain size < 10 μm using 57 μl of distilled water)

Non-destructive thermal wave method applied to study thermal properties of fast setting time endodontic cement

International Nuclear Information System (INIS)

Picolloto, A. M.; Mariucci, V. V. G.; Szpak, W.; Medina, A. N.; Baesso, M. L.; Astrath, N. G. C.; Astrath, F. B. G.; Bento, A. C.; Santos, A. D.; Moraes, J. C. S.

2013-01-01

The thermal wave method is applied for thermal properties measurement in fast endodontic cement (CER). This new formula is developed upon using Portland cement in gel and it was successfully tested in mice with good biocompatibility and stimulated mineralization. Recently, thermal expansion and setting time were measured, conferring to this material twice faster hardening than the well known Angelus Mineral trioxide aggregate (MTA) the feature of fast hardening (∼7 min) and with similar thermal expansion (∼12 μstrain/ °C). Therefore, it is important the knowledge of thermal properties like thermal diffusivity, conductivity, effusivity in order to match thermally the tissue environment upon its application in filling cavities of teeth. Photothermal radiometry technique based on Xe illumination was applied in CER disks 600 μm thick for heating, with prepared in four particle sizes (25, 38, 45, and 53) μm, which were added microemulsion gel with variation volumes (140, 150, 160, and 170) μl. The behavior of the thermal diffusivity CER disks shows linear decay for increase emulsion volume, and in contrast, thermal diffusivity increases with particles sizes. Aiming to compare to MTA, thermal properties of CER were averaged to get the figure of merit for thermal diffusivity as (44.2 ± 3.6) × 10 −3 cm 2 /s, for thermal conductivity (228 ± 32) mW/cm K, the thermal effusivity (1.09 ± 0.06) W s 0.5 /cm 2 K and volume heat capacity (5.2 ± 0.7) J/cm 3 K, which are in excellent agreement with results of a disk prepared from commercial MTA-Angelus (grain size < 10 μm using 57 μl of distilled water)

Infrared thermography non-destructive evaluation of lithium-ion battery

Science.gov (United States)

Wang, Zi-jun; Li, Zhi-qiang; Liu, Qiang

2011-08-01

The power lithium-ion battery with its high specific energy, high theoretical capacity and good cycle-life is a prime candidate as a power source for electric vehicles (EVs) and hybrid electric vehicles (HEVs). Safety is especially important for large-scale lithium-ion batteries, especially the thermal analysis is essential for their development and design. Thermal modeling is an effective way to understand the thermal behavior of the lithium-ion battery during charging and discharging. With the charging and discharging, the internal heat generation of the lithium-ion battery becomes large, and the temperature rises leading to an uneven temperature distribution induces partial degradation. Infrared (IR) Non-destructive Evaluation (NDE) has been well developed for decades years in materials, structures, and aircraft. Most thermographic methods need thermal excitation to the measurement structures. In NDE of battery, the thermal excitation is the heat generated from carbon and cobalt electrodes in electrolyte. A technique named "power function" has been developed to determine the heat by chemical reactions. In this paper, the simulations of the transient response of the temperature distribution in the lithium-ion battery are developed. The key to resolving the security problem lies in the thermal controlling, including the heat generation and the internal and external heat transfer. Therefore, three-dimensional modelling for capturing geometrical thermal effects on battery thermal abuse behaviour is required. The simulation model contains the heat generation during electrolyte decomposition and electrical resistance component. Oven tests are simulated by three-dimensional model and the discharge test preformed by test system. Infrared thermography of discharge is recorded in order to analyze the security of the lithium-ion power battery. Nondestructive detection is performed for thermal abuse analysis and discharge analysis.

Feasibility on fiber orientation detection on unidirectional CFRP composite laminates using nondestructive evaluation techniques

Science.gov (United States)

Yang, In-Young; Kim, Ji-Hoon; Cha, Cheon-Seok; Lee, Kil-Sung; Hsu, David K.; Im, Kwang-Hee

2007-07-01

In particular, CFRP (carbon fiber reinforced plastics) composite materials have found wide applicability because of their inherent design flexibility and improved material properties. CFRP composites were manufactured from uni-direction prepreg sheet in this paper. It is important to assess fiber orientation, material properties and part defect in order to ensure product quality and structural integrity of CFRP because strength and stiffness of composites depend on fiber orientation. It is desirable to perform nondestructive evaluation which is very beneficial. An new method for nondestructively determining the fiber orientation in a composite laminate is presented. A one-sided pitch-catch setup was used in the detection and evaluation of flaws and material anomalies in the unidirectional CFRP composite laminates. Two Rayleigh wave transducers were joined head-to-head and used in the pitch-catch mode on the surface of the composites. The pitch-catch signal was found to be more sensitive than normal incidence backwall echo of longitudinal wave to subtle flaw conditions in the composite. Especially, ultrasonic waves were extensively characterized in the CFRP composite laminates both normal to fiber and along to fiber with using a one-sided direction of Rayleigh wave transducers. Also, one-sided ultrasonic measurement was made with using a Rayleigh wave transducers and a conventional scanner was used in an immersion tank for extracting fiber orientation information from the ultrasonic reflection in the unidirectional laminate. Therefore, it is thought that the proposed method is useful to evaluate integrity of CFRP laminates.

Nondestructive evaluation using dipole model analysis with a scan type magnetic camera

Science.gov (United States)

Lee, Jinyi; Hwang, Jiseong

2005-12-01

Large structures such as nuclear power, thermal power, chemical and petroleum refining plants are drawing interest with regard to the economic aspect of extending component life in respect to the poor environment created by high pressure, high temperature, and fatigue, securing safety from corrosion and exceeding their designated life span. Therefore, technology that accurately calculates and predicts degradation and defects of aging materials is extremely important. Among different methods available, nondestructive testing using magnetic methods is effective in predicting and evaluating defects on the surface of or surrounding ferromagnetic structures. It is important to estimate the distribution of magnetic field intensity for applicable magnetic methods relating to industrial nondestructive evaluation. A magnetic camera provides distribution of a quantitative magnetic field with a homogeneous lift-off and spatial resolution. It is possible to interpret the distribution of magnetic field when the dipole model was introduced. This study proposed an algorithm for nondestructive evaluation using dipole model analysis with a scan type magnetic camera. The numerical and experimental considerations of the quantitative evaluation of several sizes and shapes of cracks using magnetic field images of the magnetic camera were examined.

A Novel Complementary Method for the Point-Scan Nondestructive Tests Based on Lamb Waves

Directory of Open Access Journals (Sweden)

Rahim Gorgin

2014-01-01

Full Text Available This study presents a novel area-scan damage identification method based on Lamb waves which can be used as a complementary method for point-scan nondestructive techniques. The proposed technique is able to identify the most probable locations of damages prior to point-scan test which lead to decreasing the time and cost of inspection. The test-piece surface was partitioned with some smaller areas and the damage probability presence of each area was evaluated. A0 mode of Lamb wave was generated and collected using a mobile handmade transducer set at each area. Subsequently, a damage presence probability index (DPPI based on the energy of captured responses was defined for each area. The area with the highest DPPI value highlights the most probable locations of damages in test-piece. Point-scan nondestructive methods can then be used once these areas are found to identify the damage in detail. The approach was validated by predicting the most probable locations of representative damages including through-thickness hole and crack in aluminum plates. The obtained experimental results demonstrated the high potential of developed method in defining the most probable locations of damages in structures.

Nondestructive materials evaluation and imaging by higher harmonics

International Nuclear Information System (INIS)

Kawashima, Koichiro

2012-01-01

Nondestructive detection of material anormalities, degradation and tight cracks, in which the acoustic impedance mismatch is low, is rather difficult by conventional ultrasonic testing. A novel nonlinear ultrasonic technique, in particular, higher harmonic technique, utilizes the waveform distortion, which results from the interaction between anormalities and large amplitude tone-burst waves. This technique is not affected by acoustic impedance mismatch, therefore, it has possibility to detect such anormalities, degradation and tight cracks. A novel higher harmonic imaging technique is proposed and applied to detect and visualize local plastic deformation of SUS 304 plates, plastic zone in front of crack tip, weld bond contour of carbon steel, small inclusions in ODS steel fuel tubes, pitting damage of SUS 316 plates in mercury, shallow fatigue cracks of SUS 316 plates introduced by thermal fatigue, and inter-granular stress corrosion cracking, IGSCC, in welded plates simulated safe-ends for bonding dissimilar metals. (author)

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

Science.gov (United States)

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.

Nondestructive testing of thin films using surface acoustic waves and laser ultrasonics

Science.gov (United States)

Jenot, Frédéric; Fourez, Sabrina; Ouaftouh, Mohammadi; Duquennoy, Marc

2018-04-01

Thin films are widely used in many fields such as electronics, optics or materials science. For example, they find applications in thermal or mechanical sensors design. They are also very useful as protective or reinforcement layers for many structures. However, some coating defects such as thickness variations, microfissuring or poor adhesion are common problems. Therefore, nondestructive testing of these structures using acoustic waves generated and detected by lasers represents a major interest. Indeed, in comparison with conventional methods based on the use of piezoelectric transducers, laser ultrasonics leads to non-contact investigations with a large bandwidth. Usually, bulk acoustic waves are used and a pulse-echo technique is considered that needs high frequencies and implies local measurements. In order to avoid this limitation, we propose to use surface acoustic waves in a frequency range up to 45 MHz. The samples consist of a micrometric gold layer deposited on silicon substrates. In a first part, using dispersion analysis, theoretical and experimental results clearly reveal that the first Rayleigh mode allows the detection of film thickness variations and open cracks. In a second part, a localized adhesion defect is introduced in a similar sample. The effects of such a flaw on the Rayleigh modes dispersion curves are theoretically described. Finally, we experimentally show that the first Rayleigh mode allows the defect detection only under specific conditions.

Nondestructive evaluation ultrasonic methods for construction materials

International Nuclear Information System (INIS)

Chilibon, I.; Zisu, T.; Raetchi, V.

2002-01-01

The paper presents some ultrasonic methods for evaluation of physical-mechanical properties of construction materials (bricks, concrete, BCA), such as: pulse method, examination methods, and direct measurement of the propagation velocity and impact-echo method. Utilizing these nondestructive evaluation ultrasonic methods it can be determined the main material parameters and material characteristics (elasticity coefficients, density, propagation velocity, ultrasound attenuation, etc.) of construction materials. These method are suitable for construction materials because the defectoscopy methods for metallic materials cannot be utilized, due to its rugged and non-homogeneous structures and grate attenuation coefficients of ultrasound propagation through materials. Also, the impact-echo method is a technique for flaw detection in concrete based on stress wave propagation. Studies have shown that the impact-echo method is effective for locating voids, honeycombing, delaminating, depth of surface opening cracks, and measuring member thickness

Feasibility of Residual Stress Nondestructive Estimation Using the Nonlinear Property of Critical Refraction Longitudinal Wave

Directory of Open Access Journals (Sweden)

Yu-Hua Zhang

2017-01-01

Full Text Available Residual stress has significant influence on the performance of mechanical components, and the nondestructive estimation of residual stress is always a difficult problem. This study applies the relative nonlinear coefficient of critical refraction longitudinal (LCR wave to nondestructively characterize the stress state of materials; the feasibility of residual stress estimation using the nonlinear property of LCR wave is verified. The nonlinear ultrasonic measurements based on LCR wave are conducted on components with known stress state to calculate the relative nonlinear coefficient. Experimental results indicate that the relative nonlinear coefficient monotonically increases with prestress and the increment of relative nonlinear coefficient is about 80%, while the wave velocity only decreases about 0.2%. The sensitivity of the relative nonlinear coefficient for stress is much higher than wave velocity. Furthermore, the dependence between the relative nonlinear coefficient and deformation state of components is found. The stress detection resolution based on the nonlinear property of LCR wave is 10 MPa, which has higher resolution than wave velocity. These results demonstrate that the nonlinear property of LCR wave is more suitable for stress characterization than wave velocity, and this quantitative information could be used for residual stress estimation.

Laser induced purely-thermal-wave interferometry (PTWI) using a novel photopyroelectric (PPE) instrument

Science.gov (United States)

Wang, Chinhua

A novel purely thermal-wave interferometric technique and its applications to non-contact and non-destructive evaluation of Ti:sapphire laser crystals, high-precision measurement of thermal diffusivity of gases, and high- sensitivity gas (hydrogen) sensors have been successfully developed both theoretically and experimentally. A comprehensive theoretical and experimental analysis of the system noise and detectivity has been conducted to consolidate the basis of the technique. Unlike the conventional single-ended photopyroelectric(PPE) technique, different thermal-wave interference patterns can be obtained by adjusting two incident beams (relative intensity and phase shift) and two thermal-wave cavities on both sides of a pyroelectric detector. It is found that the large base-line signal and large optical noise, which are encountered in the single- ended PPE scheme, can be coherently and completely suppressed in the fully destructive interferometric measurement. Differential surface absorptance, differential and absolute bulk absorption coefficient of Ti:sapphire laser crystals have been separately measured using an extended PPE-interference (PPEI) theory. Unlike the single-ended PPE method, in which thermal contributions from several optical parameters are always coupled together, the destructive interferometric: method provides a unique method for extracting precise values of one of these coupled parameters, without the need of equally precise knowledge of the values of others. The comparison measurement of thermal diffusivity of air using the single-ended PPE method and the PPEI method shows that the PPEI method enhances the measuring precision by one significant figure when compared with the single-beam method. The conventionally used concept of ``thermal-wave reflection coefficient'' has been extended to a more general case that is sample- thickness dependent. A novel hydrogen gas sensor has been initialized and developed based on the PPEI technique. It is

Study of Lamb Waves for Non-Destructive Testing Behind Screens

Science.gov (United States)

Kauffmann, P.; Ploix, M.-A.; Chaix, J.-F.; Gueudré, C.; Corneloup, G.; Baqué, F. AF(; )

2018-01-01

The inspection and control of sodium-cooled fast reactors (SFR) is a major issue for the nuclear industry. Ultrasonic solutions are under study because of the opacity of liquid sodium. In this paper, the use of leaky Lamb waves is considered for non-destructive testing (NDT) on parallel and immersed structures assimilated as plates. The first phase of our approach involved studying the propagation properties of leaky Lamb waves. Equations that model the propagation of Lamb waves in an immersed plate were solved numerically. The phase velocity can be experimentally measured using a two dimensional Fourier transform. The group velocity can be experimentally measured using a short-time Fourier transform technique. Attenuation of leaky Lamb waves is mostly due to the re-emission of energy into the surrounding fluid, and it can be measured by these two techniques.

Active spectral imaging nondestructive evaluation (SINDE) camera

Energy Technology Data Exchange (ETDEWEB)

Simova, E.; Rochefort, P.A., E-mail: eli.simova@cnl.ca [Canadian Nuclear Laboratories, Chalk River, Ontario (Canada)

2016-06-15

A proof-of-concept video camera for active spectral imaging nondestructive evaluation has been demonstrated. An active multispectral imaging technique has been implemented in the visible and near infrared by using light emitting diodes with wavelengths spanning from 400 to 970 nm. This shows how the camera can be used in nondestructive evaluation to inspect surfaces and spectrally identify materials and corrosion. (author)

Numerical modeling for the electromagnetic non-destructive evaluation: application to the non-destructive evaluation of concrete

International Nuclear Information System (INIS)

Travassos, L.

2007-06-01

Concrete is the most common building material and accounts for a large part of the systems that are necessary for a country to operate smoothly including buildings, roads, and bridges. Nondestructive testing is one of the techniques that can be used to assess the structural condition. It provides non perceptible information that conventional techniques of evaluation unable to do. The main objective of this work is the numerical simulation of a particular technique of nondestructive testing: the radar. The numerical modeling of the radar assessment of concrete structures make it possible to envisage the behavior of the system and its capacity to detect defects in various configurations. To achieve this objective, it was implemented electromagnetic wave propagation models in concrete structures, by using various numerical techniques to examine different aspects of the radar inspection. First of all, we implemented the finite-difference time-domain method in 3D which allows to take into account concrete characteristics such as porosity, salt content and the degree of saturation of the mixture by using Debye models. In addition, a procedure to improve the radiation pattern of bow-tie antennas is presented. This approach involves the Moment Method in conjunction with the Multi objective Genetic Algorithm. Finally, we implemented imaging algorithms which can perform fast and precise characterization of buried targets in inhomogeneous medium by using three different methods. The performance of the proposed algorithms is confirmed by numerical simulations. (author)

Application of golay complementary coded excitation schemes for non-destructive testing of sandwich structures

Science.gov (United States)

Arora, Vanita; Mulaveesala, Ravibabu

2017-06-01

In recent years, InfraRed Thermography (IRT) has become a widely accepted non-destructive testing technique to evaluate the structural integrity of composite sandwich structures due to its full-field, remote, fast and in-service inspection capabilities. This paper presents a novel infrared thermographic approach named as Golay complementary coded thermal wave imaging is presented to detect disbonds in a sandwich structure having face sheets from Glass/Carbon Fibre Reinforced (GFR/CFR) laminates and core of the wooden block.

Thermal wave propagation in the pulsed laser irradiation of media with thermal memory

International Nuclear Information System (INIS)

Galovic, S.; Kostoski, D.; Stamboliev, G.; Suljovrujic, E.

2002-01-01

Complete text of publication follows. If a sample is exposed to the influence of laser radiation part of its energy is absorbed and converted in heat. The heat generated in this way is transferred through the sample as heat waves, resulting in various effects (so called photothermal effects). A large number of nondestructive diagnostic methods are based on recording of these effects. It is necessary to create a good model in order to understand and correctly describe the measured results of heat transfer in different media. In a certain number of materials and structures, such as complex biological materials, polymers, metals excited by very short laser pulses etc., the property of thermal memory has been experimentally observed. Starting with the hyperbolic equation that describes heat transfer processes of such media, in this paper has been developed a model of laser-excited heat waves propagation in order to enable application of photothermal techniques in characterization of these media. The cases of optically opaque and transparent samples are considered. The influence of various backings on photothermal waves has also been analyzed. The results are compared to the previous models

Nondestructive evaluation of dissipative behavior of reinforced concrete structure

Energy Technology Data Exchange (ETDEWEB)

Luong, M.P. [Ecole Polytechnique, LMS, CNRS, 91 - Palaiseau (France)

2001-07-01

Current technological developments tend toward increased exploitation of materials strengths and toward tackling extreme loads and environmental actions such as offshore structures subject to wind and wave loading, or buildings in seismic area. Concrete is widely used as a construction material because of its high strength-cost ratio in many applications. Experience of earthquakes and laboratory tests has shown that well designed and detailed reinforced concrete is suitable for earthquake resistant structures. The most severe likely earthquake can be survived if the members are sufficiently ductile to absorb and dissipate seismic energy by inelastic deformation. This requires a designer to assess realistically the acceptable levels of strength and to ensure adequate dissipation. This paper proposes the use of infrared thermography as a nondestructive, noncontact and real-time technique to examine diverse mechanisms of dissipation and to illustrate the onset of damage process, stress concentration and heat dissipation localization in loaded zone. In addition, this technique can be used as a nondestructive method for evaluating the fatigue limit of concrete structure subject to repeated loading.

Nondestructive evaluation of dissipative behavior of reinforced concrete structure

International Nuclear Information System (INIS)

Luong, M.P.

2001-01-01

Current technological developments tend toward increased exploitation of materials strengths and toward tackling extreme loads and environmental actions such as offshore structures subject to wind and wave loading, or buildings in seismic area. Concrete is widely used as a construction material because of its high strength-cost ratio in many applications. Experience of earthquakes and laboratory tests has shown that well designed and detailed reinforced concrete is suitable for earthquake resistant structures. The most severe likely earthquake can be survived if the members are sufficiently ductile to absorb and dissipate seismic energy by inelastic deformation. This requires a designer to assess realistically the acceptable levels of strength and to ensure adequate dissipation. This paper proposes the use of infrared thermography as a nondestructive, noncontact and real-time technique to examine diverse mechanisms of dissipation and to illustrate the onset of damage process, stress concentration and heat dissipation localization in loaded zone. In addition, this technique can be used as a nondestructive method for evaluating the fatigue limit of concrete structure subject to repeated loading

Nondestructive quality evaluation technology of agricultural products

International Nuclear Information System (INIS)

Noh, Sang Ha

1997-01-01

Quality evaluation of agricultural products has been interested to many researchers for many years and as the result, several nondestructive techniques and so many papers have been reported for quality evaluation of agricultural products. These nondestructive techniques are based on the detection of mechanical, optical, electrical, electro-magnetical, dielectric and vibrational properties of agricultural products that are well correlated with certain quality factors of the products such as color, shape, firmness, sugar content, external or internal defects, moisture content, etc. The sophistication of nondestructive methods has evolved rapidly with modem technologies. In this paper an emphasis was put on reviewing some of those papers and techniques which could be led to on-line measurement for practical use.

Non-destructive techniques in the conservation field in the USA

Directory of Open Access Journals (Sweden)

Berta de Miguel

2015-12-01

Full Text Available Nondestructive evaluation techniques are extensively used in the field of architectural heritage conservation in the United States. This paper outlines the most used techniques, classifying them in visual assessment techniques, and techniques based on wave propagation. Depending on the type of wave, the latter group is subdivided in electromagnetic and acoustic techniques. The final section includes a two nondestructive techniques facilitators: unmanned aerial vehicles and Tablet PC Annotation System.

Infrared image processing devoted to thermal non-contact characterization-Applications to Non-Destructive Evaluation, Microfluidics and 2D source term distribution for multispectral tomography

International Nuclear Information System (INIS)

Batsale, Jean-Christophe; Pradere, Christophe

2015-01-01

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. (paper)

Proceedings CORENDE: Regional congress on nondestructive and structural evaluation

International Nuclear Information System (INIS)

1997-01-01

Works are presented at the CORENDE: Regional Congress on Nondestructive and Structural Evaluation organized by the National Atomic Energy Commission and the National Technological University (Mendoza). This congress wants to be the forum where people from research, industry and marketing might meet and discuss ideas towards the fostering of these new cultural habits. Papers covering all disciplines contributing to the evaluation of components, systems and structures are welcome: nondestructive evaluation methods and techniques (ultrasound, eddy currents and other electromagnetic methods, acoustic emission, radiography, thermography, leak testing, dye-penetrants, visual inspection, etc.), personnel certification, welding inspection, nondestructive metallography, optics and lasers, fluid-structure interaction, vibrations, extensometry, modelling of structures [es

Thermal gravitational waves in accelerating universe

Directory of Open Access Journals (Sweden)

B Ghayour

2013-10-01

Full Text Available Gravitational waves are considered in thermal vacuum state. The amplitude and spectral energy density of gravitational waves are found enhanced in thermal vacuum state compared to its zero temperature counterpart. Therefore, the allowed amount of enhancement depends on the upper bound of WMAP-5 and WMAP-7 for the amplitude and spectral energy density of gravitational waves. The enhancement of amplitude and spectral energy density of the waves in thermal vacuum state is consistent with current accelerating phase of the universe. The enhancement feature of amplitude and spectral energy density of the waves is independent of the expansion model of the universe and hence the thermal effect accounts for it. Therefore, existence of thermal gravitational waves is not ruled out

Non-destructive evaluation of UV pulse laser-induced damage performance of fused silica optics.

Science.gov (United States)

Huang, Jin; Wang, Fengrui; Liu, Hongjie; Geng, Feng; Jiang, Xiaodong; Sun, Laixi; Ye, Xin; Li, Qingzhi; Wu, Weidong; Zheng, Wanguo; Sun, Dunlu

2017-11-24

The surface laser damage performance of fused silica optics is related to the distribution of surface defects. In this study, we used chemical etching assisted by ultrasound and magnetorheological finishing to modify defect distribution in a fused silica surface, resulting in fused silica samples with different laser damage performance. Non-destructive test methods such as UV laser-induced fluorescence imaging and photo-thermal deflection were used to characterize the surface defects that contribute to the absorption of UV laser radiation. Our results indicate that the two methods can quantitatively distinguish differences in the distribution of absorptive defects in fused silica samples subjected to different post-processing steps. The percentage of fluorescence defects and the weak absorption coefficient were strongly related to the damage threshold and damage density of fused silica optics, as confirmed by the correlation curves built from statistical analysis of experimental data. The results show that non-destructive evaluation methods such as laser-induced fluorescence and photo-thermal absorption can be effectively applied to estimate the damage performance of fused silica optics at 351 nm pulse laser radiation. This indirect evaluation method is effective for laser damage performance assessment of fused silica optics prior to utilization.

Proceedings: 19th International Nondestructive Testing and Evaluation of Wood Symposium

Science.gov (United States)

Robert J. Ross; Raquel Gonçalves; Xiping Wang

2015-01-01

The 19th International Nondestructive Testing and Evaluation of Wood Symposium was hosted by the University of Campinas, College of Agricultural Engineering (FEAGRI/UNICAMP), and the Brazilian Association of Nondestructive Testing and Evaluation (ABENDI) in Rio de Janeiro, Brazil, on September 22–25, 2015. This Symposium was a forum for those involved in nondestructive...

Non-destructive characterization using pulsed fast-thermal neutrons

International Nuclear Information System (INIS)

Womble, P.C.

1995-01-01

Explosives, illicit drugs, and other contraband materials contain various chemical elements in quantities and ratios that differentiate them from each other and from innocuous substances. Furthermore, the major chemical elements in coal can provide information about various parameters of importance to the coal industry. In both examples, the non-destructive identification of chemical elements can be performed using pulsed fast-thermal neutrons that, through nuclear reactions, excite the nuclei of the various elements. This technique is being currently developed for the dismantling of nuclear weapons classified as trainers, and for the on-line coal bulk analysis. (orig.)

Study on thermal wave based on the thermal mass theory

Institute of Scientific and Technical Information of China (English)

无

2009-01-01

The conservation equations for heat conduction are established based on the concept of thermal mass.We obtain a general heat conduction law which takes into account the spatial and temporal inertia of thermal mass.The general law introduces a damped thermal wave equation.It reduces to the well-known CV model when the spatial inertia of heat flux and temperature and the temporal inertia of temperature are neglected,which indicates that the CV model only considers the temporal inertia of heat flux.Numerical simulations on the propagation and superposition of thermal waves show that for small thermal perturbation the CV model agrees with the thermal wave equation based on the thermal mass theory.For larger thermal perturbation,however,the physically impossible phenomenon pre-dicted by CV model,i.e.the negative temperature induced by the thermal wave superposition,is eliminated by the general heat conduction law,which demonstrates that the present heat conduction law based on the thermal mass theory is more reasonable.

Study on thermal wave based on the thermal mass theory

Institute of Scientific and Technical Information of China (English)

HU RuiFeng; CAO BingYang

2009-01-01

The conservation equations for heat conduction are established based on the concept of thermal mass. We obtain a general heat conduction law which takes into account the spatial and temporal inertia of thermal mass. The general law introduces a damped thermal wave equation. It reduces to the well-known CV model when the spatial inertia of heat flux and temperature and the temporal inertia of temperature are neglected, which indicates that the CV model only considers the temporal inertia of heat flux. Numerical simulations on the propagation and superposition of thermal waves show that for small thermal perturbation the CV model agrees with the thermal wave equation based on the thermal mass theory. For larger thermal perturbation, however, the physically impossible phenomenon pre-dicted by CV model, i.e. the negative temperature induced by the thermal wave superposition, is eliminated by the general heat conduction law, which demonstrates that the present heat conduction law based on the thermal mass theory is more reasonable.

Oxidation damage evaluation by non-destructive method for graphite components in high temperature gas-cooled reactor

International Nuclear Information System (INIS)

Shibata, Taiju; Tada, Tatsuya; Sumita, Junya; Sawa, Kazuhiro

2008-01-01

To develop non-destructive evaluation methods for oxidation damage on graphite components in High Temperature Gas-cooled Reactors (HTGRs), the applicability of ultrasonic wave and micro-indentation methods were investigated. Candidate graphites, IG-110 and IG-430, for core components of Very High Temperature Reactor (VHTR) were used in this study. These graphites were oxidized uniformly by air at 500degC. The following results were obtained from this study. (1) Ultrasonic wave velocities with 1 MHz can be expressed empirically by exponential formulas to burn-off, oxidation weight loss. (2) The porous condition of the oxidized graphite could be evaluated with wave propagation analysis with a wave-pore interaction model. It is important to consider the non-uniformity of oxidized porous condition. (3) Micro-indentation method is expected to determine the local oxidation damage. It is necessary to assess the variation of the test data. (author)

Thermographic Non-Destructive Evaluation for Natural Fiber-Reinforced Composite Laminates

Directory of Open Access Journals (Sweden)

Hai Zhang

2018-02-01

Full Text Available Natural fibers, including mineral and plant fibers, are increasingly used for polymer composite materials due to their low environmental impact. In this paper, thermographic non-destructive inspection techniques were used to evaluate and characterize basalt, jute/hemp and bagasse fibers composite panels. Different defects were analyzed in terms of impact damage, delaminations and resin abnormalities. Of particular interest, homogeneous particleboards of sugarcane bagasse, a new plant fiber material, were studied. Pulsed phase thermography and principal component thermography were used as the post-processing methods. In addition, ultrasonic C-scan and continuous wave terahertz imaging were also carried out on the mineral fiber laminates for comparative purposes. Finally, an analytical comparison of different methods was given.

Thermal Aging Evaluation of Mod. 9Cr-1Mo Steel using Nonlinear Rayleigh Waves

Energy Technology Data Exchange (ETDEWEB)

Joo, Young-Sang; Kim, Hoe-Woong; Kim, Jong-Bum [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Marino, Daniel; Kim, Jin-Yeon; Jacobs, L.J [Georgia Institute of Technology, Atlanta (United States); Ruiz, Alberto [UMSNH, Morelia (Mexico)

2014-10-15

Thermal aging can pose a high risk to decreases in the mechanical properties such as strength or creep resistance. This can lead to an unexpected failure during long term operation. Nonlinear NDE techniques are preferred over conventional NDE techniques (linear ultrasonic measurements) because nonlinear ultrasonic techniques have shown their capability to detect a microstructural damage in the structures undergoing fatigue and creep. These nonlinear ultrasonic techniques make use of the fact that the dislocation density increases, which will create a nonlinear distortion of an ultrasonic wave; this damage causes the generation of measurable higher harmonic components in an initially mono-chromatic ultrasonic signal. This study investigates the recently developed non-contact nonlinear ultrasonic technique to detect the microstructural damage of mod. 9Cr-1Mo steel based on nonlinear Rayleigh wave with varying propagation distances. Nonlinear Rayleigh surface wave measurements using a non-contact, air-coupled ultrasonic transducer have been applied for the thermal aging evaluation of modified 9Cr-1Mo ferritic-martensitic steel. Thermal aging for various heat treatment times of mod.. 9Cr-1Mo steel specimens is performed to obtain the nucleation and growth of precipitated particles in specimens. The amplitudes of the first and second harmonics are measured along the propagation distance and the relative nonlinearity parameter is obtained from these amplitudes. The relative nonlinearity parameter shows a similar trend with the Rockwell C hardness.

Nondestructive characterization of low-level transuranic waste

International Nuclear Information System (INIS)

Barna, B.A.; Reinhardt, W.W.

1981-10-01

The use of nondestructive evaluation (NDE) methods is proposed for characterization of transuranic (TRU) waste stored at the Radioactive Waste Management Complex. These NDE methods include real-time x-ray radiography, real-time neutron radiography, x-ray and neutron computed tomography, thermal imaging, container weighing, visual examination, and acoustic measurements. An integrated NDE system is proposed for characterization and certification of TRU waste destined for eventual shipment to the Waste Isolation Pilot Plant in New Mexico. Methods for automating both the classification waste and control of a complete nondestructive evaluation/nondestructive assay system are presented. Feasibility testing of the different NDE methods, including real-time x-ray radiography, and development of automated waste classification techniques are covered as part of a five year effort designed to yield a production waste characterization system

Nondestructive analysis and development

Science.gov (United States)

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.

Non-destructive testing and evaluation for structural integrity

International Nuclear Information System (INIS)

Baldev Raj; Jayakumar, T.; Rao, B.P.C.

1995-01-01

In this paper, a brief description of the physical concepts of non-destructive evaluation (NDE) methods and the physical/derived parameters that are used for assessing defects, stresses and microstructures are given. A few case studies highlighting the importance of non-destructive testing and evaluation for structural integrity assessment are also discussed based on the investigations carried out. Emerging concepts like intelligent processing of materials, expert systems, neural networks, use of multisensors with fusion of data and exploitation of signal analysis and imaging approaches are also addressed in this paper. (author). 92 refs., 1 tab

Newly developed non-destructive testing method for evaluation of irradiation brittleness of structural materials using ultrasonic

International Nuclear Information System (INIS)

Ishii, Toshimitsu; Ooka, Norikazu; Kato, Yoshiaki; Saito, Junichi; Hoshiya, Taiji; Shibata, Saburo; Kobayashi, Hideo

1999-01-01

Surveillance testing is important to evaluate neutron irradiation embrittlement of reactor pressure vessel material for long life operation. An alternative test method for evaluating the irradiation embrittlement of the pressure vessel material will have to be proposed to support the limited number of surveillance test specimens in order to manage the plant life to be extended. In this study, ultrasonic testing for irradiated A533B-1 steel and weld metal was applied to examine material degradation nondestructively. With increasing the shift of Charpy 41 J transition temperature, ultrasonic velocity decreased and attenuation coefficient of ultrasonic wave increased. Especially, the difference of ultrasonic velocity for 5 MHz shear wave between as-received and irradiated material is corresponding to the shift of transition temperature showing material degradation. (author)

Artificial intelligence to maximise contributions of nondestructive evaluation to materials science and technology

International Nuclear Information System (INIS)

Baldev Raj; Rajagopalan, C.

1996-01-01

The paper reviews the current status of Nondestructive Testing and Evaluation (NDT and E), in relation to materials science and technology. It suggests a path of growth for Nondestructive Testing and Evaluation, taking into account the increase in data and knowledge. We recommend Artificial Intelligence (AI) concepts for maximising the contributions of and benefits from, Nondestructive Testing and Evaluation. (author)

Lamb Wave Assessment of Fatigue and Thermal Damage in Composites

Science.gov (United States)

Seale, Michael D.; Smith, Barry T.; Prosser, W. H.

2004-01-01

Among the various techniques available, ultrasonic Lamb waves offer a convenient method of evaluating composite materials. Since the Lamb wave velocity depends on the elastic properties of a structure, an effective tool exists to monitor damage in composites by measuring the velocity of these waves. Lamb wave measurements can propagate over long distances and are sensitive to the desired in-plane elastic properties of the material. This paper describes two studies which monitor fatigue damage and two studies which monitor thermal damage in composites using Lamb waves. In the fatigue studies, the Lamb wave velocity is compared to modulus measurements obtained using strain gage measurements in the first experiment and the velocity is monitored along with the crack density in the second. In the thermal damage studies, one examines samples which were exposed to varying temperatures for a three minute duration and the second includes rapid thermal damage in composites by intense laser beams. In all studies, the Lamb wave velocity is demonstrated to be an excellent method to monitor damage in composites.

Pattern recognition approach to nondestructive evaluation of materials

International Nuclear Information System (INIS)

Chen, C.H.

1987-01-01

In this paper, a pattern recognition approach to the ultrasonic nondestructive evaluation of materials is examined. Emphasis is placed on identifying effective features from time and frequency domains, correlation functions and impulse responses to classify aluminum plate specimens into three major defect geometry categories: flat, angular cut and circular hole defects. A multi-stage classification procedure is developed which can further determine the angles and sizes for defect characterization and classification. The research clearly demonstrates that the pattern recognition approach can significantly improve the nondestructive material evaluation capability of the ultrasonic methods without resorting to the solution of highly complex mathematical inverse problems

A Review of Microwave Thermography Nondestructive Testing and Evaluation

Directory of Open Access Journals (Sweden)

Hong Zhang

2017-05-01

Full Text Available Microwave thermography (MWT has many advantages including strong penetrability, selective heating, volumetric heating, significant energy savings, uniform heating, and good thermal efficiency. MWT has received growing interest due to its potential to overcome some of the limitations of microwave nondestructive testing (NDT and thermal NDT. Moreover, during the last few decades MWT has attracted growing interest in materials assessment. In this paper, a comprehensive review of MWT techniques for materials evaluation is conducted based on a detailed literature survey. First, the basic principles of MWT are described. Different types of MWT, including microwave pulsed thermography, microwave step thermography, microwave pulsed phase thermography, and microwave lock-in thermography are defined and introduced. Then, MWT case studies are discussed. Next, comparisons with other thermography and NDT methods are conducted. Finally, the trends in MWT research are outlined, including new theoretical studies, simulations and modelling, signal processing algorithms, internal properties characterization, automatic separation and inspection systems. This work provides a summary of MWT, which can be utilized for material failures prevention and quality control.

A Review of Microwave Thermography Nondestructive Testing and Evaluation.

Science.gov (United States)

Zhang, Hong; Yang, Ruizhen; He, Yunze; Foudazi, Ali; Cheng, Liang; Tian, Guiyun

2017-05-15

Microwave thermography (MWT) has many advantages including strong penetrability, selective heating, volumetric heating, significant energy savings, uniform heating, and good thermal efficiency. MWT has received growing interest due to its potential to overcome some of the limitations of microwave nondestructive testing (NDT) and thermal NDT. Moreover, during the last few decades MWT has attracted growing interest in materials assessment. In this paper, a comprehensive review of MWT techniques for materials evaluation is conducted based on a detailed literature survey. First, the basic principles of MWT are described. Different types of MWT, including microwave pulsed thermography, microwave step thermography, microwave pulsed phase thermography, and microwave lock-in thermography are defined and introduced. Then, MWT case studies are discussed. Next, comparisons with other thermography and NDT methods are conducted. Finally, the trends in MWT research are outlined, including new theoretical studies, simulations and modelling, signal processing algorithms, internal properties characterization, automatic separation and inspection systems. This work provides a summary of MWT, which can be utilized for material failures prevention and quality control.

Research of the elastic waves generated by a pulse laser. Excitation mechanism of elastic waves and application to nondestructive testing; Pulse laser de reikishita danseiha ni kansuru kenkyu. Danseiha reiki no mechanism to hihakai kensa eno oyo

Energy Technology Data Exchange (ETDEWEB)

Cho, H.; Takemoto, M. [Aoyama Gakuin University, Tokyo (Japan). College of Science and Engineering

1994-07-20

A bulk wave is generated when a pulse laser is irradiated to the material, and the characteristics of a Young`s modulus and Poisson`s ratio can be nondestructively estimated from the bulk wave. The generation mechanism of laser ultrasonic waves must be first clarified for such application. In this paper, fundamental research was conducted to study the generation mechanism of the elastic waves excited by a Q-switched Nd-YAG laser, and the generation method and characteristics of Rayleigh waves. The following result was obtained. A bulk wave is generated by the disk-like adiabatic expansion near the surface if the laser power is small when a spot-shape pulse laser was irradiated. A bulk wave is generated by the thin disk-like adiabatic expansion beneath the surface due to the thermal diffusion in the depth direction of a base material when the laser power becomes large. Moreover, a bulk wave is generated by the impact force due to abrasion and plasma when the power becomes still larger. The information on the bulk wave characteristics and Rayleigh wave was also obtained. 25 refs., 15 figs., 1 tab.

National seminar on non-destructive evaluation techniques: proceedings cum souvenir

International Nuclear Information System (INIS)

Dutta, N.G.; Kulkarni, P.G.; Purushotham, D.S.C.

1994-01-01

This volume contains selected papers presented at the National Seminar on Non-Destructive Evaluation Techniques held at Bhabha Atomic Research Centre, Mumbai during December 8-9, 1994. The papers covered a wide spectrum of non-destructive evaluation activities including that for quality assurance of various nuclear components and structures with the focal theme being computerization and robotics. The papers relevant to INIS are indexed separately

Applying thermal neutron radiography to non-destructive assays of dynamic systems

International Nuclear Information System (INIS)

Silvani, Maria I.; Almeida, Gevaldo L. de; Goncalves, Marcelo J.; Lopes, Ricardo T.

2008-01-01

Dynamic processes or systems frequently can not have their behavior directly analyzed due to safety reasons or because they require destructive assays, which can not be always afforded when high-cost equipment, devices and components are involved. Under these circumstances, some kind of non-destructive technique should be applied to preserve the safety of the personnel performing the assay, as well as the integrity of the piece being inspected. Thermal neutrons are specially suited as a tool for this purpose, thanks to their capability to pass through metallic materials, which could be utterly opaque to X-rays. This paper describes the accomplishments achieved at the Instituto de Engenharia Nuclear / CNEN, Brazil, aiming at the development of an Image Acquisition System capable to perform non-destructive assays using thermal neutrons. It is comprised of a thermal neutron source provided by the Argonauta research reactor, a converter-scintillating screen, and a CCD-based video camera optically coupled to the screen through a dark chamber equipped with a mirror. The developed system has been used to acquire 2D neutron radiographic images of static devices to reveal their inner structure, as well as movies of running systems and working devices to verify its functioning and soundness. Radiographic images of objects taken at different angles would be later on used as projections to retrieve - through a proper unfolding software - their 3D images expressed as attenuation coefficients for thermal neutrons. A quantitative performance of the system has been assessed through its Modulation Transfer Function - MTF. In order to determine this curve, unique collimators designed to simulate different spatial frequencies have been manufactured. Besides that, images of some objects have been acquired with the system being developed as well as using the conventional radiographic film, allowing thus a qualitative comparison between them. (author)

Non-destructive testing of rocket fuse by thermal neutron radiography

International Nuclear Information System (INIS)

An Fulin; Li Furong

1999-01-01

A neutron radiography system in reactor horizontal hole of Tsinghua University was introduced, and its capability of neutron radiography was evaluated by theory and experiment, the non-destructive testing for rocket fuse is successful

Nondestructive Testing of Advanced Concrete Structure during Lifetime

Directory of Open Access Journals (Sweden)

Lubos Pazdera

2015-01-01

Full Text Available The paper reports on measurements and analysis of the measurements during hardening and drying of specimens using selected acoustic nondestructive testing techniques. An integrated approach was created for better understanding of the relations between the lifetime cycle and the development of the mechanical properties of concrete. Acoustic emission, impact echo, and ultrasonic techniques were applied simultaneously to the same mixtures. These techniques and results are presented on alkali-activated slag mortars. The acoustic emission method detects transient elastic waves within the material, caused by the release of cumulated stress energy, which can be mechanical, thermal, or chemical. Hence, the cause is a phenomenon which releases elastic energy into the material, which then spreads in the form of an elastic wave. The impact echo method is based on physical laws of elastic stress wave propagation in solids generated by mechanical impulse. Ultrasonic testing is commonly used to find flaws in materials or to assess wave velocity spreading.

Development of PZT-excited stroboscopic shearography for full-field nondestructive evaluation.

Science.gov (United States)

Asemani, Hamidreza; Park, Jinwoo; Lee, Jung-Ryul; Soltani, Nasser

2017-05-01

Nondestructive evaluation using shearography requires a way to stress the inspection target. This technique is able to directly measure the displacement gradient distribution on the object surface. Shearography visualizes the internal structural damages as the anomalous pattern in the shearograpic fringe pattern. A piezoelectric (PZT) excitation system is able to generate loadings in the vibrational, acoustic, and ultrasonic regimes. In this paper, we propose a PZT-excited stroboscopic shearography. The PZT excitation could generate vibrational loading, a stationary wavefield, and a nonstationary propagation wave to fulfill the external loading requirement of shearography. The sweeping of the PZT excitation frequency, the formation of a standing wave, and a small shearing to suppress the incident wave were powerful controllable tools to detect the defects. The sweeping of the PZT excitation frequency enabled us to determine one of the defect-sensitive frequencies almost in real time. In addition, because the defect sensitive frequencies always existed in wide and plural ranges, the risk of the defect being overlooked by the inspector could be alleviated. The results of evaluation using stroboscopic shearography showed that an artificial 20 mm-diameter defect could be visualized at the excitation frequencies of 5-8 kHz range and 12.5-15.5 kHz range. This technique provided full field reliable and repeatable inspection results. Additionally, the proposed method overcame the important drawback of the time-averaged shearography, being required to identify the resonance vibration frequency sensitive to the defect.

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

Energy Technology Data Exchange (ETDEWEB)

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 designed, developed and exercised multisensor data fusion algorithms for identifying defect related information present in magnetic flux leakage, ultrasonic testing and thermal imaging nondestructive evaluation signatures of a test-specimen suite representative of benign and anomalous indications in gas transmission pipelines.

Analytical nondestructive evaluation for materials characterization

International Nuclear Information System (INIS)

Raj, Baldev

1993-01-01

Science and technology of nondestructive testing and evaluation has contributed immensely to the safety and productivity of industrial plants. In recent years, nondestructive evaluation (NDE) has emerged as a frontline research area of equal if not greater technological relevance, for materials characterization as well. A comprehensive range of techniques from qualitative nondestructive testing for quality control of engineering products and materials to quantitative NDE for materials characterization is being used by the engineering industry and materials researchers, for better understanding of the manufacturing practices and materials behaviour. Quantitative NDE is considered essential for ensuring fitness for purpose at the start of the life in case the component has been designed using fracture mechanics parameters. Quantitative NDE is also vital for assessing degradation of material during service. Moreover, quantitative NDE enables characterization of dynamics of certain phenomenon (not achievable by destructive test methodologies) leading to better understanding of the performance of materials in relation to unavoidable defects in the materials. As the next logical step, the need for an analytical approach to NDE is felt. The need and motivation for such an approach is addressed and the means to achieve this objective are identified. It is argued that analytical NDE is essential to meet the challenges of characterization, intelligent processing of materials and life prediction of components and plants. These requirements are of significant importance in the context of recent developments in materials engineering, and for enhancing the competitive advantage of Indian engineering industry in the international market. (author). 9 refs., 3 figs

Nondestructive evaluation of creep-fatigue damage: an interim report

International Nuclear Information System (INIS)

Nickell, R.E.

1977-02-01

In view of the uncertainties involved in designing against creep-fatigue failure and the consequences of such failures in Class 1 nuclear components that operate at elevated temperature, the possibility of intermittent or even continuous non-destructive examination of these components has been considered. In this interim report some preliminary results on magnetic force and ultrasonic evaluation of creep-fatigue damage in an LMFBR steam generator material are presented. These results indicate that the non-destructive evaluation of pure creep damage will be extremely difficult. A set of biaxial creep-fatigue tests that are designed to discriminate between various failure theories is also described

Nerva fuel nondestructive evaluation and characterization equipment and facilities

International Nuclear Information System (INIS)

Caputo, A.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

Nondestructive Evaluation Program: Progress in 1986

International Nuclear Information System (INIS)

1987-07-01

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 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. The report summarizes significant progress made since the previous EPRI Special Report NP-4315-SR was issued in May 1986. Section 1 contains information about the program organization, and the sections that follow contain 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

Nondestructive analysis of alkali-silica reaction damage in concrete slabs using shear waves

Science.gov (United States)

Khazanovich, Lev; Freeseman, Katelyn; Salles, Lucio; Clayton, Dwight

2018-04-01

Alkali-silica reaction (ASR) is the chemical reaction that occurs in concrete. It is caused by the interaction of alkalis in Portland cement and silica in aggregates and results in microcracks within the material. This type of damage has been the focus of nondestructive evaluation efforts in recent history, but no work was done on in-situ structures or large-scale samples. To address these limitations, an ultrasonic linear array device, MIRA, was utilized for this research. An experimental investigation was performed on four slabs with various levels of alkali-silica reaction at the Electric Power Research Institute (EPRI) [1]. One-period impulses with a target of 50kHz center frequency were selected in this study. We propose the use of the Hilbert Transform Indicator (HTI) for quantification of ASR damage [2]. A higher HTI value would be indicative of damaged concrete, while a low value represents sound concrete. In general, values below 90 are regarded as an indicator of sound concrete while values above 100 indicate the presence of damage [3]. The ability of the HTI values to distinguish between areas of damaged concrete was evident via the production of color intensity maps. The maps show that the control specimen, was in good condition, while other slabs exhibited higher levels of damage as indicated by the HTI values. It should be noted that extreme damage conditions were not present in any of the slabs. Evaluation of migration-based reconstructions can give a qualitative characterization of large scale or excessive subsurface damage. However, for detection of stochastic damage mechanisms such as freeze-thaw damage, evaluation of the individual time-history data can provide additional information. A comparison of the spatially diverse measurements on several concrete slabs with varying freeze-thaw damage levels is given in this study. Signal characterization scans of different levels of freeze-thaw damage at various transducer spacing is investigated. The

Innovative technology transfer of nondestructive evaluation research

Science.gov (United States)

Brian Brashaw; Robert J. Ross; Xiping Wang

2008-01-01

Technology transfer is often an afterthought for many nondestructive evaluation (NDE) researchers. Effective technology transfer should be considered during the planning and execution of research projects. This paper outlines strategies for using technology transfer in NDE research and presents a wide variety of technology transfer methods used by a cooperative...

New technologies in electromagnetic non-destructive testing

CERN Document Server

Huang, Songling

2016-01-01

This book introduces novel developments in the field of electromagnetic non-destructive testing and evaluation (NDT/E). The topics include electromagnetic ultrasonic guided wave testing, pulsed eddy current testing, remote field eddy current testing, low frequency eddy current testing, metal magnetic memory testing, and magnetic flux leakage testing. Considering the increasing concern about the safety maintenance of critical structures in various industries and everyday life, these topics presented here will be of particular interest to the readers in the NDT/E field. This book covers both theoretical researches and the engineering applications of the electromagnetic NDT technology. It could serve as a valuable reference for college students and relevant NDT technicians. It is also a useful material for qualification training and higher learning for nondestructive testing professionals.

Selection of Shear Horizontal Wave Transducers for Robotic Nondestructive Inspection in Harsh Environments

Directory of Open Access Journals (Sweden)

Sungho Choi

2016-12-01

Full Text Available Harsh environments and confined spaces require that nondestructive inspections be conducted with robotic systems. Ultrasonic guided waves are well suited for robotic systems because they can provide efficient volumetric coverage when inspecting for various types of damage, including cracks and corrosion. Shear horizontal guided waves are especially well suited for robotic inspection because they are sensitive to cracks oriented perpendicular or parallel to the wave propagation direction and can be generated with electromagnetic acoustic transducers (EMATs and magnetostrictive transducers (MSTs. Both types of transducers are investigated for crack detection in a stainless steel plate. The MSTs require the robot to apply a compressive normal force that creates frictional force coupling. However, the coupling is observed to be very dependent upon surface roughness and surface debris. The EMATs are coupled through the Lorentz force and are thus noncontact, although they depend on the lift off between transducer and substrate. After comparing advantages and disadvantages of each transducer for robotic inspection the EMATs are selected for application to canisters that store used nuclear fuel.

Nondestructive evaluation of LWR spent fuel shipping casks

International Nuclear Information System (INIS)

Ballard, D.W.

1978-02-01

An analysis of nondestructive testing (NDT) methods currently being used to evaluate the integrity of Light Water Reactor (LWR) spent fuel shipping casks is presented. An assessment of anticipated NDT needs related to breeder reactor cask requirements is included. Specific R and D approaches to probable NDT problem areas such as the evaluation of austenitic stainless steel weldments are outlined

Research process of nondestructive testing pitting corrosion in metal material

Directory of Open Access Journals (Sweden)

Bo ZHANG

2017-12-01

Full Text Available Pitting corrosion directly affects the usability and service life of metal material, so the effective nondestructive testing and evaluation on pitting corrosion is of great significance for fatigue life prediction because of data supporting. The features of pitting corrosion are elaborated, and the relation between the pitting corrosion parameters and fatigue performance is pointed out. Through introducing the fundamental principles of pitting corrosion including mainly magnetic flux leakage inspection, pulsed eddy current and guided waves, the research status of nondestructive testing technology for pitting corrosion is summarized, and the key steps of nondestructive testing technologies are compared and analyzed from the theoretical model, signal processing to industrial applications. Based on the analysis of the signal processing specificity of different nondestructive testing technologies in detecting pitting corrosion, the visualization combined with image processing and signal analysis are indicated as the critical problems of accurate extraction of pitting defect information and quantitative characterization for pitting corrosion. The study on non-contact nondestructive testing technologies is important for improving the detection precision and its application in industries.

Mathematical modelling of ultrasonic non-destructive evaluation

Directory of Open Access Journals (Sweden)

Larissa Ju Fradkin

2001-01-01

Full Text Available High-frequency asymptotics have been used at our Centre to develop codes for modelling pulse propagation and scattering in the near-field of the ultrasonic transducers used in NDE (Non-Destructive Evaluation, particularly of walls of nuclear reactors. The codes are hundreds of times faster than the direct numerical codes but no less accurate.

Tone burst generator for a Non-Destructive Testing system based on ultrasonic guided waves

OpenAIRE

Jiménez Sánchez, Daniel

2011-01-01

English: This PFC provides a design of a tested and specific tone-burst generator circuit for a Non-Destructive System based on ultrasonid guided waves. This circuit includes a complementary protection circuit for the NDT system working in a pulse-echo configuration. In this paper, a brief state f art about different driving circuits employed in distinct NDE systems is presented. Castellano: El PFC proporciona un diseño electrónico específico y probado de un circuito excitador de salvas (C...

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

Directory of Open Access Journals (Sweden)

Adriana Savin

2015-07-01

Full Text Available 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.

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

Science.gov (United States)

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

2015-07-03

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.

Evolution of supernova remnants. III. Thermal waves

International Nuclear Information System (INIS)

Chevalier, R.A.

1975-01-01

The effect of heat conduction on the evolution of supernova remnants is investigated. A thermal wave, or electron conduction front, can travel more rapidly than a shock wave during the first thousand years of the remnant's evolution. A self-similar solution describing this phase has been found by Barenblatt. Numerical computations verify the solution and give the evolution past the thermal wave phase. While shell formation is not impeded, the interior density and temperature profiles are smoothed by the action of conduction

Analysis of pulse thermography using similarities between wave and diffusion propagation

Science.gov (United States)

Gershenson, M.

2017-05-01

Pulse thermography or thermal wave imaging are commonly used as nondestructive evaluation (NDE) method. While the technical aspect has evolve with time, theoretical interpretation is lagging. Interpretation is still using curved fitting on a log log scale. A new approach based directly on the governing differential equation is introduced. By using relationships between wave propagation and the diffusive propagation of thermal excitation, it is shown that one can transform from solutions in one type of propagation to the other. The method is based on the similarities between the Laplace transforms of the diffusion equation and the wave equation. For diffusive propagation we have the Laplace variable s to the first power, while for the wave propagation similar equations occur with s2. For discrete time the transformation between the domains is performed by multiplying the temperature data vector by a matrix. The transform is local. The performance of the techniques is tested on synthetic data. The application of common back projection techniques used in the processing of wave data is also demonstrated. The combined use of the transform and back projection makes it possible to improve both depth and lateral resolution of transient thermography.

Non-Destructive Inspection of Impact Damage in Composite Aircraft Panels by Ultrasonic Guided Waves and Statistical Processing.

Science.gov (United States)

Capriotti, Margherita; Kim, Hyungsuk E; Scalea, Francesco Lanza di; Kim, Hyonny

2017-06-04

This paper discusses a non-destructive evaluation (NDE) technique for the detection of damage in composite aircraft structures following high energy wide area blunt impact (HEWABI) from ground service equipment (GSE), such as heavy cargo loaders and other heavy equipment. The test structures typically include skin, co-cured stringers, and C-frames that are bolt-connected onto the skin with shear ties. The inspection exploits the waveguide geometry of these structures by utilizing ultrasonic guided waves and a line scan approach. Both a contact prototype and a non-contact prototype were developed and tested on realistic test panels subjected to impact in the laboratory. The results are presented in terms of receiver operating characteristic curves that show excellent probability of detection with low false alarm rates for defects located in the panel skin and stringers.

Single frequency thermal wave radar: A next-generation dynamic thermography for quantitative non-destructive imaging over wide modulation frequency ranges.

Science.gov (United States)

Melnikov, Alexander; Chen, Liangjie; Ramirez Venegas, Diego; Sivagurunathan, Koneswaran; Sun, Qiming; Mandelis, Andreas; Rodriguez, Ignacio Rojas

2018-04-01

Single-Frequency Thermal Wave Radar Imaging (SF-TWRI) was introduced and used to obtain quantitative thickness images of coatings on an aluminum block and on polyetherketone, and to image blind subsurface holes in a steel block. In SF-TWR, the starting and ending frequencies of a linear frequency modulation sweep are chosen to coincide. Using the highest available camera frame rate, SF-TWRI leads to a higher number of sampled points along the modulation waveform than conventional lock-in thermography imaging because it is not limited by conventional undersampling at high frequencies due to camera frame-rate limitations. This property leads to large reduction in measurement time, better quality of images, and higher signal-noise-ratio across wide frequency ranges. For quantitative thin-coating imaging applications, a two-layer photothermal model with lumped parameters was used to reconstruct the layer thickness from multi-frequency SF-TWR images. SF-TWRI represents a next-generation thermography method with superior features for imaging important classes of thin layers, materials, and components that require high-frequency thermal-wave probing well above today's available infrared camera technology frame rates.

Single frequency thermal wave radar: A next-generation dynamic thermography for quantitative non-destructive imaging over wide modulation frequency ranges

Science.gov (United States)

Melnikov, Alexander; Chen, Liangjie; Ramirez Venegas, Diego; Sivagurunathan, Koneswaran; Sun, Qiming; Mandelis, Andreas; Rodriguez, Ignacio Rojas

2018-04-01

Single-Frequency Thermal Wave Radar Imaging (SF-TWRI) was introduced and used to obtain quantitative thickness images of coatings on an aluminum block and on polyetherketone, and to image blind subsurface holes in a steel block. In SF-TWR, the starting and ending frequencies of a linear frequency modulation sweep are chosen to coincide. Using the highest available camera frame rate, SF-TWRI leads to a higher number of sampled points along the modulation waveform than conventional lock-in thermography imaging because it is not limited by conventional undersampling at high frequencies due to camera frame-rate limitations. This property leads to large reduction in measurement time, better quality of images, and higher signal-noise-ratio across wide frequency ranges. For quantitative thin-coating imaging applications, a two-layer photothermal model with lumped parameters was used to reconstruct the layer thickness from multi-frequency SF-TWR images. SF-TWRI represents a next-generation thermography method with superior features for imaging important classes of thin layers, materials, and components that require high-frequency thermal-wave probing well above today's available infrared camera technology frame rates.

Nondestructive evaluation of incipient decay in hardwood logs

Science.gov (United States)

Xiping Wang; Jan Wiedenbeck; Robert J. Ross; John W. Forsman; John R. Erickson; Crystal Pilon; Brian K. Brashaw

2005-01-01

Decay can cause significant damage to high-value hardwood timber. New nondestructive evaluation (NDE) technologies are urgently needed to effectively detect incipient decay in hardwood timber at the earliest possible stage. Currently, the primary means of inspecting timber relies on visual assessment criteria. When visual inspections are used exclusively, they provide...

The impact of thermal wave characteristics on thermal dose distribution during thermal therapy: A numerical study

International Nuclear Information System (INIS)

Shih, T.-C.; Kou, H.-S.; Liauh, C.-T.; Lin, W.-L.

2005-01-01

The aim of this study was to investigate the effects of the propagation speed of a thermal wave in terms of the thermal relaxation time on the temperature/thermal dose distributions in living tissue during thermal therapies. The temperature field in tissue was solved by the finite difference method, and the thermal dose was calculated from the formulation proposed by Sapareto and Dewey [Int. J. Radiat. Oncol. Biol. Phys. 10, 787-800 (1984)]. Under the same total deposited energy, for a rapid heating process the time lagging behavior of the peak temperature became pronounced and the level of the peak temperature was decreased with increasing the thermal relaxation time. When the heating duration was longer than the thermal relaxation time of tissues, there was no significant difference between the thermal dose distributions with/without considering the effect of the thermal relaxation time. In other words, when the heating duration is comparable to or shorter than the thermal relaxation time of tissue, the results of the wave bioheat transfer equation (WBHTE) are fully different from that of the Pennes' bioheat transfer equation (PBHTE). Besides, for a rapid heating process the dimension of thermal lesion was still significantly affected by perfusion, because this is what is predicted by the WBHTE but not by the PBHTE, i.e., the wave feature of the temperature field cannot fully be predicted by the PBHTE

Handbook of nondestructive evaluation

National Research Council Canada - National Science Library

Hellier, Charles

2013-01-01

"Fully revised to cover the latest nondestructive testing (NDT) procedures, this practical resource reviews established and emerging methods for examining materials without destroying them or altering their structure...

Designing a highly sensitive Eddy current sensor for evaluating damage on thermal barrier coating

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong Min; Kim, Hak Joon; Song, Sung Jin; Seok, Chang Seong; Lee, Yeong Ze [Dept. of Mechanical Engineering, Sungkyunkwan University, Suwon (Korea, Republic of); Lee, Seul Gi [LG Electronics, Seoul (Korea, Republic of)

2016-06-15

A thermal barrier coating (TBC) has been widely applied to machine components working under high temperature as a thermal insulator owing to its critical financial and safety benefits to the industry. However, the nondestructive evaluation of TBC damage is not easy since sensing of the microscopic change that occurs on the TBC is required during an evaluation. We designed an eddy current probe for evaluating damage on a TBC based on the finite element method (FEM) and validated its performance through an experiment. An FEM analysis predicted the sensitivity of the probe, showing that impedance change increases as the TBC thermally degrades. In addition, the effect of the magnetic shield concentrating magnetic flux density was also observed. Finally, experimental validation showed good agreement with the simulation result.

Online Preventative Non-Destructive Evaluation in Automated Fibre Placement

NARCIS (Netherlands)

Tonnaer, R.; Shroff, S.; Groves, R.M.

2016-01-01

The strict quality requirements for aerospace composite struc- tures give rise to costly quality control procedures. In automated bre placement (AFP) these procedures rely heavily on manual work and inspection. This research aims at performing preventative non-destructive evaluation of composite

Visualization of Tooth for Non-Destructive Evaluation from CT Images

Energy Technology Data Exchange (ETDEWEB)

Gao, Hui; Chae, Ok Sam [Kyung Hee University, Seoul (Korea, Republic of)

2009-06-15

This paper reports an effort to develop 3D tooth visualization system from CT sequence images as a part of the non-destructive evaluation suitable for the simulation of endodontics, orthodontics and other dental treatments. We focus on the segmentation and visualization for the individual tooth. In dental CT images teeth are touching the adjacent teeth or surrounded by the alveolar bones with similar intensity. We propose an improved level set method with shape prior to separate a tooth from other teeth as well as the alveolar bones. Reconstructed 3D model of individual tooth based on the segmentation results indicates that our technique is a very conducive tool for tooth visualization, evaluation and diagnosis. Some comparative visualization results validate the non-destructive function of our method.

Nondestructive evaluation of nuclear-grade graphite

Science.gov (United States)

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

2012-05-01

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.

Non-Destructive Inspection of Impact Damage in Composite Aircraft Panels by Ultrasonic Guided Waves and Statistical Processing

Directory of Open Access Journals (Sweden)

Margherita Capriotti

2017-06-01

Full Text Available This paper discusses a non-destructive evaluation (NDE technique for the detection of damage in composite aircraft structures following high energy wide area blunt impact (HEWABI from ground service equipment (GSE, such as heavy cargo loaders and other heavy equipment. The test structures typically include skin, co-cured stringers, and C-frames that are bolt-connected onto the skin with shear ties. The inspection exploits the waveguide geometry of these structures by utilizing ultrasonic guided waves and a line scan approach. Both a contact prototype and a non-contact prototype were developed and tested on realistic test panels subjected to impact in the laboratory. The results are presented in terms of receiver operating characteristic curves that show excellent probability of detection with low false alarm rates for defects located in the panel skin and stringers.

Fluctuation and thermal energy balance for drift-wave turbulence

International Nuclear Information System (INIS)

Kim, Chang-Bae; Horton, W.

1990-05-01

Energy conservation for the drift-wave system is shown to be separated into the wave-energy power balance equation and an ambient thermal-energy transport equation containing the anomalous transport fluxes produced by the fluctuations. The wave energy equation relates the wave energy density and wave energy flux to the anomalous transport flux and the dissipation of the fluctuations. The thermal balance equation determines the evolution of the temperature profiles from the divergence of the anomalous heat flux, the collisional heating and cooling mechanisms and the toroidal pumping effect. 16 refs., 1 tab

Fluctuation and thermal energy balance for drift-wave turbulence

International Nuclear Information System (INIS)

Changbae Kim; Horton, W.

1991-01-01

Energy conservation for the drift-wave system is shown to be separated into the wave-energy power balance equation and an ambient thermal-energy transport equation containing the anomalous transport fluxes produced by the fluctuations. The wave energy equation relates the wave energy density and wave energy flux to the anomalous transport flux and the dissipation of the fluctuations. The thermal balance equation determines the evolution of the temperature profiles from the divergence of the anomalous heat flux, the collisional heating and cooling mechanisms and the toroidal pumping effect. (author)

COMPUTER SIMULATION OF THE THERMAL TESTING PROCESS FOR STUDENTS OF «NONDESTRUCTIVE TESTING AND TECHNICAL DIAGNOSTICS» SPECIALITY

Directory of Open Access Journals (Sweden)

Anatolii H. Protasov

2010-08-01

Full Text Available This paper is devoted to the computer simulation method of thermal nondestructive testing procedure. FEMLAB is interactive software package and used for simulation. It allows forming a model of physical objects with given parameters and properties. A proposed method helps students to understand better the processes happen in solid under the action of temperature.

QUANTITATIVE NON-DESTRUCTIVE EVALUATION (QNDE) OF THE ELASTIC MODULI OF POROUS TIAL ALLOYS

International Nuclear Information System (INIS)

Yeheskel, O.

2008-01-01

The elastic moduli of γ-TiA1 were studied in porous samples consolidated by various techniques e.g. cold isostatic pressing (CIP), pressure-less sintering, or hot isostatic pressing (HIP). Porosity linearly affects the dynamic elastic moduli of samples. The results indicate that the sound wave velocities and the elastic moduli affected by the processing route and depend not only on the attained density but also on the consolidation temperature. In this paper we show that there is linear correlation between the shear and the longitudinal sound velocities in porous TiA1. This opens the way to use a single sound velocity as a tool for quantitative non-destructive evaluation (QNDE) of porous TiA1 alloys. Here we demonstrate the applicability of an equation derived from the elastic theory and used previously for porous cubic metals

Nondestructive methods for quality evaluation of livestock products.

Science.gov (United States)

Narsaiah, K; Jha, Shyam N

2012-06-01

The muscles derived from livestock are highly perishable. Rapid and nondestructive methods are essential for quality assurance of such products. Potential nondestructive methods, which can supplement or replace many of traditional time consuming destructive methods, include colour and computer image analysis, NIR spectroscopy, NMRI, electronic nose, ultrasound, X-ray imaging and biosensors. These methods are briefly described and the research work involving them for products derived from livestock is reviewed. These methods will be helpful in rapid screening of large number of samples, monitoring distribution networks, quick product recall and enhance traceability in the value chain of livestock products. With new developments in the areas of basic science related to these methods, colour, image processing, NIR spectroscopy, biosensors and ultrasonic analysis are expected to be widespread and cost effective for large scale meat quality evaluation in near future.

Advanced uses of radiation in non-destructive evaluation

International Nuclear Information System (INIS)

Baldev Raj; Viswanathan, B.; Venkataraman, B.

1998-01-01

The increasing demand for newer materials and stringency of specifications, have expanded the scope of advanced uses of radiation in non-destructive evaluation of materials and industrial components. This paper highlights the application of some of the advanced techniques of radiography and residual stress measurements, using x-ray diffraction, for materials characterisation and testing, based on the results obtained at the author's laboratory. The application of positron annihilation techniques based on the use of radioisotopes and high resolution gamma ray spectroscopy, is introduced as non-destructive tools for materials characterisation. Selective examples of significant results obtained using this technique, on the radiation damage and early stages of fatigue damage in technologically important steels are reviewed from recent works at the author's laboratory and elsewhere. The scope of application of charge particle based thin layer activation method is briefly outlined. (author)

Use of nondestructive evaluation to detect moisture in flexible pavements.

Science.gov (United States)

2006-01-01

The purpose of this study was to identify the currently available nondestructive evaluation technology that holds the greatest potential to detect moisture in flexible pavements and then apply the technology in multiple locations throughout Virginia....

Non-destructive evaluation of containment walls in nuclear power plants

Science.gov (United States)

Garnier, V.; Payan, C.; Lott, M.; Ranaivomanana, N.; Balayssac, J. P.; Verdier, J.; Larose, E.; Zhang, Y.; Saliba, J.; Boniface, A.; Sbartai, Z. M.; Piwakowski, B.; Ciccarone, C.; Hafid, H.; Henault, J. M.; Buffet, F. Ouvrier

2017-02-01

Two functions are regularly tested on containment walls in order to anticipate a possible accident. The first is mechanical to resist a possible internal over-pressure and the second is to prevent leakage. The AAPR reference accident is the rupture of a pipe in the primary circuit of a nuclear plant. In this case, the pressure and temperature can reach 5 bar and 180°C in 20 seconds. The national project `Non-destructive testing of the containment structures of nuclear plants' aims at studying the non-destructive techniques capable to evaluate the concrete properties and its damaging and cracks. This 4-year-project is segmented into two parts. The first consists in developing and selecting the most relevant NDEs in the laboratory to reach these goals. These evaluations are developed in conditions representing the real conditions of the stresses generated during ten-yearly visits of the plants or those related to an accident. The second part consists in applying the selected techniques to two containment structures under pressure. The first structure is proposed by ONERA and the second is a mockup of a containment wall on a 1/3 scale made by EDF within the VeRCoRs project. Communication is focused on the part of the project that concerns the damage and crack process characterization by means of NDT. The tests are done in 3 or 4 points bending in order to study the cracks' generation, their propagation, as well as their opening and closing. The main ultrasonic techniques developed concern linear or non-linear acoustic: acoustic emission [1], Locadiff [2], energy diffusion, surface wave's velocity and attenuation, DAET [3]. The recorded data contribute to providing the mapping of the investigated parameters, either in volume, in surface or globally. Digital image correlation is an important additional asset to validate the coherence of the data. The spatial normalization of the data in the specimen space allows proposing algorithms on the combination of the

Numerical modeling for the electromagnetic non-destructive evaluation: application to the non-destructive evaluation of concrete; Modelisation numerique pour l'evaluation non destructive electromagnetique: application au controle non destructif des structures en beton

Energy Technology Data Exchange (ETDEWEB)

Travassos, L

2007-06-15

Concrete is the most common building material and accounts for a large part of the systems that are necessary for a country to operate smoothly including buildings, roads, and bridges. Nondestructive testing is one of the techniques that can be used to assess the structural condition. It provides non perceptible information that conventional techniques of evaluation unable to do. The main objective of this work is the numerical simulation of a particular technique of nondestructive testing: the radar. The numerical modeling of the radar assessment of concrete structures make it possible to envisage the behavior of the system and its capacity to detect defects in various configurations. To achieve this objective, it was implemented electromagnetic wave propagation models in concrete structures, by using various numerical techniques to examine different aspects of the radar inspection. First of all, we implemented the finite-difference time-domain method in 3D which allows to take into account concrete characteristics such as porosity, salt content and the degree of saturation of the mixture by using Debye models. In addition, a procedure to improve the radiation pattern of bow-tie antennas is presented. This approach involves the Moment Method in conjunction with the Multi objective Genetic Algorithm. Finally, we implemented imaging algorithms which can perform fast and precise characterization of buried targets in inhomogeneous medium by using three different methods. The performance of the proposed algorithms is confirmed by numerical simulations. (author)

Review of Micro/Nano Nondestructive Evaluation Technique (II): Measurement of Acoustic Properties

International Nuclear Information System (INIS)

Kim, Chung Seok; Park, Ik Keun

2012-01-01

The present paper reviews the micro and nano nondestructive evaluation(NDE) technique that is possible to investigate the surface and measure the acoustic properties. The technical theory, features and applications of the ultrasonic atomic force microscopy(UAFM) and scanning acoustic microscopy(SAM) are illustrated. Especially, these technologies are possible to evaluate the mechanical properties in micro/nano structure and surface through the measurement of acoustic properties in addition to the observation of surface and subsurface. Consequently, it is thought that technique developments and applications of these micro/nano NDE in advanced industrial parts together with present nondestructive industry are widely possible hereafter.

Non-destructive evaluation of timber structures in a historical building of Tiradentes , MG

Directory of Open Access Journals (Sweden)

Luciana Barbosa de Abreu

2013-09-01

Full Text Available Problems related to the durability of wood are commonly found in historical buildings structures. Preservation and conservation resolutions must be adopted, in order to avoid losses and substitutions, which mischaracterize buildings. Non-destructive methods for detecting deterioration should be used in order to substantiate decisions and increase the longevity of historical heritage. This work was carried out in order to perform non-destructive essays to infer about the integrity of a beam and a pillar of the original construction of the Sobrado Ramalho, a historical building of the city of Tiradentes, MG. The equipments utilized were the Stress Wave Timer and resistograph. Samples of the elements were taken for analysis of density. The results showed that, in both structures, to calculate the dynamic modulus of elasticity, there was no significant difference for the application of stress wave timer on the alignments studied. There was no significant difference between the directions of application of the resistograph on the pillar, due to its apparent entirety and regular sessions, practically square, and to not being loaded eccentrically. In the case of the beam, there was significant difference, presumably because it has cracks in its traction line. The equipments, unknown by professionals of heritage conservation allow promising methodologies for inspection of timber structures in service.

Attenuation Analysis of Lamb Waves Using the Chirplet Transform

NARCIS (Netherlands)

Kerber, Florian; Sprenger, Helge; Niethammer, Marc; Luangvilai, Kritsakorn; Jacobs, Laurence J.

2010-01-01

Guided Lamb waves are commonly used in nondestructive evaluation to monitor plate-like structures or to characterize properties of composite or layered materials. However, the dispersive propagation and multimode excitability of Lamb waves complicate their analysis. Advanced signal processing

Local defect resonance for sensitive non-destructive testing

Science.gov (United States)

Adebahr, W.; Solodov, I.; Rahammer, M.; Gulnizkij, N.; Kreutzbruck, M.

2016-02-01

Ultrasonic wave-defect interaction is a background of ultrasound activated techniques for imaging and non-destructive testing (NDT) of materials and industrial components. The interaction, primarily, results in acoustic response of a defect which provides attenuation and scattering of ultrasound used as an indicator of defects in conventional ultrasonic NDT. The derivative ultrasonic-induced effects include e.g. nonlinear, thermal, acousto-optic, etc. responses also applied for NDT and defect imaging. These secondary effects are normally relatively inefficient so that the corresponding NDT techniques require an elevated acoustic power and stand out from conventional ultrasonic NDT counterparts for their specific instrumentation particularly adapted to high-power ultrasonic. In this paper, a consistent way to enhance ultrasonic, optical and thermal defect responses and thus to reduce an ultrasonic power required is suggested by using selective ultrasonic activation of defects based on the concept of local defect resonance (LDR). A strong increase in vibration amplitude at LDR enables to reliably detect and visualize the defect as soon as the driving ultrasonic frequency is matched to the LDR frequency. This also provides a high frequency selectivity of the LDR-based imaging, i.e. an opportunity of detecting a certain defect among a multitude of other defects in material. Some examples are shown how to use LDR in non-destructive testing techniques, like vibrometry, ultrasonic thermography and shearography in order to enhance the sensitivity of defect visualization.

Advanced nondestructive evaluation for creep damage

International Nuclear Information System (INIS)

Anon.

1987-01-01

As a result of operation at elevated temperatures, power plant components experience creep. Changes in metallurgical structure and microscopic cracking occur after periods of operation and lead to component failure. In order to detect the presence of creep and avoid creep-related failures, EPRI has just initiated a five year program entitled Advanced NDE for Creep Damage (RP 1856-7). The objective of this program is to develop NDE methods for detection and characterization of microscopic creep damage. Several NDE methods will be initially evaluated to determine their potential for detecting and characterizing such damage. These NDE methods include ultrasonics, eddy current, Barkhausen, positron annihilation, and thermal-wave imaging. A prototype system will be developed and tested for commercial applications in a follow-on project, utilizing characteristics of the best NDE method for creep detection. A brief description of the project and results of a theoretical investigation, to determine feasibility of ultrasonic NDE method, for detection of creep damage are presented

Solitary wave and periodic wave solutions for the thermally forced gravity waves in atmosphere

International Nuclear Information System (INIS)

Li Ziliang

2008-01-01

By introducing a new transformation, a new direct and unified algebraic method for constructing multiple travelling wave solutions of general nonlinear evolution equations is presented and implemented in a computer algebraic system, which extends Fan's direct algebraic method to the case when r > 4. The solutions of a first-order nonlinear ordinary differential equation with a higher degree nonlinear term and Fan's direct algebraic method of obtaining exact solutions to nonlinear partial differential equations are applied to the combined KdV-mKdV-GKdV equation, which is derived from a simple incompressible non-hydrostatic Boussinesq equation with the influence of thermal forcing and is applied to investigate internal gravity waves in the atmosphere. As a result, by taking advantage of the new first-order nonlinear ordinary differential equation with a fifth-degree nonlinear term and an eighth-degree nonlinear term, periodic wave solutions associated with the Jacobin elliptic function and the bell and kink profile solitary wave solutions are obtained under the effect of thermal forcing. Most importantly, the mechanism of propagation and generation of the periodic waves and the solitary waves is analysed in detail according to the values of the heating parameter, which show that the effect of heating in atmosphere helps to excite westerly or easterly propagating periodic internal gravity waves and internal solitary waves in atmosphere, which are affected by the local excitation structures in atmosphere. In addition, as an illustrative sample, the properties of the solitary wave solution and Jacobin periodic solution are shown by some figures under the consideration of heating interaction

Welding induced residual stress evaluation using laser-generated Rayleigh waves

Science.gov (United States)

Ye, Chong; Zhou, Yuanlai; Reddy, Vishnu V. B.; Mebane, Aaron; Ume, I. Charles

2018-04-01

Welding induced residual stress could affect the dimensional stability, fatigue life, and chemical resistance of the weld joints. Ultrasonic method serves as an important non-destructive tool for the residual stress evaluation due to its easy implementation, low cost and wide application to different materials. Residual stress would result in the ultrasonic wave velocity variation, which is the so called acoustoelastic effect. In this paper, Laser/EMAT ultrasonic technique was proposed to experimentally study the relative velocity variation ΔV/V of Rayleigh wave, which has the potential to evaluate surface/subsurface longitudinal residual stress developed during the Gas Metal Arc Welding process. Broad band ultrasonic waves were excited by pulsed Q-Switched Nd: YAG laser. An electromagnetic acoustic transducer (EMAT) attached to the welded plates was used to capture the Rayleigh wave signals propagating along the weld seam direction. Different time of flight measurements were conducted by varying the distance between the weld seam and Rayleigh wave propagating path in the range of 0 to 45 mm. The maximum relative velocity difference was found on the weld seam. With the increasing distance away from the weld seam, the relative velocity difference sharply decreased to negative value. With further increase in distance, the relative velocity difference slowly increased and approached zero. The distribution of relative velocity variations indicates that tensile stress appears in the melted zone as it becomes compressive near the heat-affected zone.

Addition of magnetic markers for non-destructive evaluation of polymer composites

Directory of Open Access Journals (Sweden)

Ana Paula Pereira Fulco

2011-12-01

Full Text Available Polymer composite pipes are an appealing option as a substitute for conventional steel pipes, particularly due to their inherent corrosion resistance. However, the composite pipes currently used do not allow non-destructive evaluation (NDE using instrumented devices which operate with magnetic sensors. The present work aims at the development of polymer composites with the addition magnetic markers to allow the application non-destructive evaluation techniques which use magnetic sensors. Glass-polyester composite flat, circular plates were fabricated with the addition of ferrite particles (barium ferrite and strontium ferrite and four types of notches were introduced on the plates' surfaces. The influence of these notches on the measured magnetic properties of each material was measured. X-ray diffraction (XRD, X-ray fluorescence (XRF and Brunauer, Emmett, and Teller (BET nitrogen adsorption were used for the characterization of the ferrite particles. Particle dispersion in the polymer matrix was analyzed by scanning electron microscopy (SEM. According to the results, a particular variation in magnetic field was detected over the region surrounding each type of notch. The results suggest that the proposed technique has great potential for damage detection in polymer composites using magnetic sensors and thus constitute a valuable contribution which may ultimately lead to the development of non-destructive evaluation techniques for assessing the structural integrity polymer composite pipes.

Improving the Repair Planning System for Mining Equipment on the Basis of Non-destructive Evaluation Data

Science.gov (United States)

Drygin, Michael; Kuryshkin, Nicholas

2017-11-01

The article tells about forming a new concept of scheduled preventive repair system of the equipment at coal mining enterprises, based on the use of modem non-destructive evaluation methods. The approach to the solution for this task is based on the system-oriented analysis of the regulatory documentation, non-destructive evaluation methods and means, experimental studies with compilation of statistics and subsequent grapho-analytical analysis. The main result of the work is a feasible explanation of using non-destructive evaluation methods within the current scheduled preventive repair system, their high efficiency and the potential of gradual transition to condition-based maintenance. In practice wide use of nondestructive evaluation means w;ill allow to reduce significantly the number of equipment failures and to repair only the nodes in pre-accident condition. Considering the import phase-out policy, the solution for this task will allow to adapt the SPR system to Russian market economy conditions and give the opportunity of commercial move by reducing the expenses for maintenance of Russian-made and imported equipment.

Thermal history sensors for non-destructive temperature measurements in harsh environments

Energy Technology Data Exchange (ETDEWEB)

Pilgrim, C. C. [Mechanical Engineering, Imperial College London, London, SW7 2AZ, UK and Sensor Coating Systems, Imperial Incubator, Bessemer Building, Level 1 and 2, Imperial College London, London SW7 2AZ (United Kingdom); Heyes, A. L. [Energy Technology and Innovation Initiative, University of Leeds, Leeds, LS2 9JT (United Kingdom); Feist, J. P. [Sensor Coating Systems, Imperial Incubator, Bessemer Building, Level 1 and 2, Imperial College London, London SW7 2AZ (United Kingdom)

2014-02-18

The operating temperature is a critical physical parameter in many engineering applications, however, can be very challenging to measure in certain environments, particularly when access is limited or on rotating components. A new quantitative non-destructive temperature measurement technique has been proposed which relies on thermally induced permanent changes in ceramic phosphors. This technique has several distinct advantages over current methods for many different applications. The robust ceramic material stores the temperature information allowing long term thermal exposures in harsh environment to be measured at a convenient time. Additionally, rare earth dopants make the ceramic phosphorescent so that the temperature information can be interpreted by automated interrogation of the phosphorescent light. This technique has been demonstrated by application of YAG doped with dysprosium and europium as coatings through the air-plasma spray process. Either material can be used to measure temperature over a wide range, namely between 300°C and 900°C. Furthermore, results show that the material records the peak exposure temperature and prolonged exposure at lower temperatures would have no effect on the temperature measurement. This indicates that these materials could be used to measure peak operating temperatures in long-term testing.

Stress wave propagation on standing trees. Part 2, Formation of 3D stress wave contour maps.

Science.gov (United States)

Juan Su; Houjiang Zhang; Xiping Wang

2009-01-01

Nondestructive evaluation (NDE) of wood quality in standing trees is an important procedure in the forest operational value chain worldwide. The goal of this paper is to investigate how a stress wave travel in a tree stem as it is introduced into the tree through a mechanical impact. Experimental stress wave data was obtained on freshly cut red pine logs in the...

Non-destructive evaluation studies for cultural heritage

International Nuclear Information System (INIS)

Jayakumar, T.; Babu Rao, C.; Kumar, Anish; Rajkumar, K.V.; Sharma, G.K.; Raj, Baldev

2009-01-01

The results of the nondestructive evaluation studies carried out on the Delhi iron pillar and the musical pillars of the Vithala temple at Hampi, Karnataka are discussed. While studies on Delhi iron pillar were carried out with a primary aim to understand the methodology of fabrication of this pillar, the studies on the musical pillars were carried out to finger print/petroligically characterize the stones used in the construction of the musical pillars and to understand the origin of various sounds generated on tapping of the musical pillars by carrying out various acoustic studies. (author)

Review of progress in quantitative nondestructive evaluation

International Nuclear Information System (INIS)

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

1983-01-01

A comprehensive review of the current state of quantitative nondestructive evaluation (NDE), this volume brings together papers by researchers working in government, private industry, and university laboratories. Their papers cover a wide range of interests and concerns for researchers involved in theoretical and applied aspects of quantitative NDE. Specific topics examined include reliability probability of detection--ultrasonics and eddy currents weldments closure effects in fatigue cracks technology transfer ultrasonic scattering theory acoustic emission ultrasonic scattering, reliability and penetrating radiation metal matrix composites ultrasonic scattering from near-surface flaws ultrasonic multiple scattering

Space Qualified Non-Destructive Evaluation and Structural Health Monitoring Technology, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — NextGen Aeronautics is proposing an innovative space qualified non-destructive evaluation and health monitoring technology. The technology is built on concepts...

NDE for Ablative Thermal Protection Systems, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — This program addresses the need for non-destructive evaluation (NDE) methods for quality assessment and defect evaluation of thermal protection systems (TPS),...

Development of nondestructive evaluation methods for ceramic coatings

International Nuclear Information System (INIS)

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

2002-01-01

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

Nondestructive Evaluation of Railway Bridge by System Identification Using Field Vibration Measurement

International Nuclear Information System (INIS)

Ho, Duc Duy; Hong, Dong Soo; Kim, Jeong Tae

2010-01-01

This paper presents a nondestructive evaluation approach for system identification (SID) of real railway bridges using field vibration test results. First, a multi-phase SID scheme designed on the basis of eigenvalue sensitivity concept is presented. Next, the proposed multi-phase approach is evaluated from field vibration tests on a real railway bridge (Wondongcheon bridge) located in Yangsan, Korea. On the steel girder bridge, a few natural frequencies and mode shapes are experimentally measured under the ambient vibration condition. The corresponding modal parameters are numerically calculated from a three-dimensional finite element (FE) model established for the target bridge. Eigenvalue sensitivities are analyzed for potential model-updating parameters of the FE model. Then, structural subsystems are identified phase-by-phase using the proposed model-updating procedure. Based on model-updating results, a baseline model and a nondestructive evaluation of test bridge are identified

NDE for Ablative Thermal Protection Systems, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — This program addresses the need for non-destructive evaluation (NDE) methods for quality assessment and defect evaluation of thermal protection systems (TPS). Novel...

Thermal noise from optical coatings in gravitational wave detectors.

Science.gov (United States)

Harry, Gregory M; Armandula, Helena; Black, Eric; Crooks, D R M; Cagnoli, Gianpietro; Hough, Jim; Murray, Peter; Reid, Stuart; Rowan, Sheila; Sneddon, Peter; Fejer, Martin M; Route, Roger; Penn, Steven D

2006-03-01

Gravitational waves are a prediction of Einstein's general theory of relativity. These waves are created by massive objects, like neutron stars or black holes, oscillating at speeds appreciable to the speed of light. The detectable effect on the Earth of these waves is extremely small, however, creating strains of the order of 10(-21). There are a number of basic physics experiments around the world designed to detect these waves by using interferometers with very long arms, up to 4 km in length. The next-generation interferometers are currently being designed, and the thermal noise in the mirrors will set the sensitivity over much of the usable bandwidth. Thermal noise arising from mechanical loss in the optical coatings put on the mirrors will be a significant source of noise. Achieving higher sensitivity through lower mechanical loss coatings, while preserving the crucial optical and thermal properties, is an area of active research right now.

Nonconventional concrete hollow blocks evaluation by destructive and non-destructive testing

Directory of Open Access Journals (Sweden)

M.S. Rodrigues

Full Text Available The aim of this study was to evaluate cementitious matrices properties by partial replacement of Portland cement by silica fume (SF or by rice husk ash (RHA, and their application in nonbearing hollow blocks, tested by destructive and non-destructive methods. The following mixtures were produced: reference (100% of Portland cement and Portland cement replacement (10% by mass with SF or RHA. The non-destructive testing showed that the highest values of UPV were obtained for SF-based blocks and RHA-based blocks. The destructive test showed better results for SF-based blocks, but there was no statistical difference between the RHA-based and control ones.

Magnetic sensor for nondestructive evaluation of deteriorated prestressing strand : phase II.

Science.gov (United States)

2011-08-01

This report gives an account of the execution and achievements in Phase II of the project completed through August 2011. The main objective of this project is to advance the practical development of a nondestructive testing and evaluation method usin...

Modal approach for the full simulation of nondestructive tests by elastic guided waves

International Nuclear Information System (INIS)

Jezzine, K.

2006-11-01

Tools for simulating nondestructive tests by elastic guided waves are developed. Two overall formulations based on modal formalism and reciprocity are derived depending on whether transmission and reception are separated or not. They relate phenomena of guided wave radiation by a transducer, their propagation, their scattering by a non-uniformity of the guide or a defect and their reception. Receiver electrical output is expressed as a product of terms relating to each phenomenon that can be computed separately. Their computation uses developments based on the semi-analytical finite elements method, dealing with guides of arbitrary cross-section and cracks normal to the guide axis. Simulation tools are used to study means for selecting a single mode using a transducer positioned on the guide section, such a selection making easier the interpretation of the results of testing by guided waves. Two methods of mode selection are proposed, based on the use of two specific frequencies (which existence depends on guide geometry and mode symmetry). Mimicking the normal stress distribution of the mode at one of these two frequencies or the other makes it possible to radiate solely or predominantly the mode chosen. Examinations are simulated in configurations using a single or two separated transducers positioned on the section of various guide geometries and cracks of various shapes. The interest and performances of the two methods of mode selection are studied in these configurations. (author)

Nondestructive testing at the CEA

International Nuclear Information System (INIS)

Colomer, J.; Lucas, G.

1976-01-01

The different nondestructive testing methods used at the CEA are presented: X-ray or gamma radiography, X-ray stress analysis, neutron radiography, ultrasonic testing, eddy currents, electrical testing, microwaves, thermal testing, acoustic emission, optical holography, tracer techniques. (102 references are cited) [fr

In Situ Guided Wave Structural Health Monitoring System

Science.gov (United States)

Zhao, George; Tittmann, Bernhard R.

2011-01-01

Aircraft engine rotating equipment operates at high temperatures and stresses. Noninvasive inspection of microcracks in those components poses a challenge for nondestructive evaluation. A low-cost, low-profile, high-temperature ultrasonic guided wave sensor was developed that detects cracks in situ. The transducer design provides nondestructive evaluation of structures and materials. A key feature of the sensor is that it withstands high temperatures and excites strong surface wave energy to inspect surface and subsurface cracks. The sol-gel bismuth titanate-based surface acoustic wave (SAW) sensor can generate efficient SAWs for crack inspection. The sensor is very thin (submillimeter) and can generate surface waves up to 540 C. Finite element analysis of the SAW transducer design was performed to predict the sensor behavior, and experimental studies confirmed the results. The sensor can be implemented on structures of various shapes. With a spray-coating process, the sensor can be applied to the surface of large curvatures. It has minimal effect on airflow or rotating equipment imbalance, and provides good sensitivity.

Quantitative Method to Measure Thermal Conductivity of One-Dimensional Nanostructures Based on Scanning Thermal Wave Microscopy

Energy Technology Data Exchange (ETDEWEB)

Park, Kyung Bae; Chung, Jae Hun; Hwang, Gwang Seok; Jung, Eui Han; Kwon, Oh Myoung [Korea University, Seoul (Korea, Republic of)

2014-12-15

We present a method to quantitatively measure the thermal conductivity of one-dimensional nanostructures by utilizing scanning thermal wave microscopy (STWM) at a nanoscale spatial resolution. In this paper, we explain the principle for measuring the thermal diffusivity of one-dimensional nanostructures using STWM and the theoretical analysis procedure for quantifying the thermal diffusivity. The SWTM measurement method obtains the thermal conductivity by measuring the thermal diffusivity, which has only a phase lag relative to the distance corresponding to the transferred thermal wave. It is not affected by the thermal contact resistances between the heat source and nanostructure and between the nanostructure and probe. Thus, the heat flux applied to the nanostructure is accurately obtained. The proposed method provides a very simple and quantitative measurement relative to conventional measurement techniques.

Non-destructive system to evaluate critical properties of asphalt compaction : [research brief].

Science.gov (United States)

2013-12-01

The Wisconsin Highway Research Program sponsored a two-stage investigation to develop a non-destructive system to evaluate critical compaction properties and characteristics of asphalt pavements during the densification process. Stage One activities ...

Internal inspection of reinforced concrete for nuclear structures using shear wave tomography

International Nuclear Information System (INIS)

Scott, David B.

2013-01-01

Highlights: • Aging of reinforced concrete used for worldwide nuclear structures is increasing and necessitating evaluation. • Nondestructive evaluation is a tool for assessing the condition of reinforced concrete of nuclear structures. • Ultrasonic shear wave tomography as a stress wave technique has begun to be utilized for investigation of concrete material. • A study using ultrasonic shear wave tomography indicates anomalies vital to the long-term operation of the structure. • The use of this technique has shown to successfully evaluate the internal state of reinforced concrete members. - Abstract: Reinforced concrete is important for nuclear related structures. Therefore, the integrity of structural members consisting of reinforced concrete is germane to the safe operation and longevity of these facilities. Many issues that reduce the likelihood of safe operation and longevity are not visible on the surface of reinforced concrete material. Therefore, an investigation of reinforced concrete material should include techniques which will allow peering into the concrete member and determining its internal state. The performance of nondestructive evaluations is pursuant to this goal. Some of the categories of nondestructive evaluations are electrochemical, magnetism, ground penetrating radar, and ultrasonic testing. A specific ultrasonic testing technique, namely ultrasonic shear wave tomography, is used to determine presence and extent of voids, honeycombs, cracks perpendicular to the surface, and/or delamination. This technique, and others similar to it, has been utilized in the nuclear industry to determine structural conditions

Simulation of non-destructive inspections and acoustic emission measurements involving guided waves

International Nuclear Information System (INIS)

Baronian, V; Lhemery, A; Bonnet-BenDhia, A-S

2009-01-01

In a structure that guides elastic waves, a discontinuity (defect, shape variation) causes scattering (reflection, partial extinction or mode conversion). Two modal formulations have been developed to link separate models dealing with the calculation of the modal decomposition, with the generation and reception of guided waves (GW), with their scattering. The first concerns pulse-echo configurations (involving a single transducer), the other concerns pitch-catch configurations (two transducers involved). A new finite element (FE) method has been developed to compute the scattering by an arbitrary discontinuity, based on the modal decomposition of the field. Perfectly transparent boundary conditions (Dirichlet-to-Neuman boundaries) are developed, allowing the FE computation zone to be reduced to a minimum. A specific variational problem including these boundary conditions was obtained and solved using FE tools. By combining the modal formulations, the new FE scheme and tools for GW radiation, propagation and reception based on the Semi-Analytical Finite Element (SAFE) method, a new simulation tool has been developed. It can address almost arbitrary configurations of GW nondestructive testing. Moreover, a source inside the FE computation zone can be defined so that configurations of testing by acoustic emission can also be simulated. Examples of use of this tool are shown, some dealing with junctions of complex geometry between two guides, other with surface or bulk sources of acoustic emission.

Measurement of through-thickness thermal diffusivity of thermoplastics using thermal wave method

Science.gov (United States)

Singh, R.; Mellinger, A.

2015-04-01

Thermo-physical properties, such as thermal conductivity, thermal diffusivity and specific heat are important quantities that are needed to interpret and characterize thermoplastic materials. Such characterization is necessary for many applications, ranging from aerospace engineering to food packaging, electrical and electronic industry and medical science. In this work, the thermal diffusivity of commercially available polymeric films is measured in the thickness direction at room temperature using thermal wave method. The results obtained with this method are in good agreement with theoretical and experimental values.

Wavelet Analysis of Ultrasonic Echo Waveform and Application to Nondestructive Evaluation

International Nuclear Information System (INIS)

Park, Ik Keun; Park, Un Su; Ahn, Hyung Keun; Kwun, Sook In; Byeon, Jai Won

2000-01-01

Recently, advanced signal analysis which is called 'time-frequency analysis' has been used widely in nondestructive evaluation applications. Wavelet transform(WT) and Wigner Distribution are the most advanced techniques for processing signals with time-varying spectra. Wavelet analysis method is an attractive technique for evaluation of material characterization nondestructively. Wavelet transform is applied to the time-frequency analysis of ultrasonic echo waveform obtained by an ultrasonic pulse-echo technique. In this study, the feasibility of noise suppression of ultrasonic flaw signal and frequency-dependent ultrasonic group velocity and attenuation coefficient using wavelet analysis of ultrasonic echo waveform have been verified experimentally. The Gabor function is adopted the analyzing wavelet. The wavelet analysis shows that the variations of ultrasonic group velocity and attenuation coefficient due to the change of material characterization can be evaluated at each frequency. Furthermore, to assure the enhancement of detectability and new sizing performance, both computer simulated results and experimental measurements using wavelet signal processing are used to demonstrate the effectiveness of the noise suppression of ultrasonic flaw signal obtained from austenitic stainless steel weld including EDM notch

Performance and non-destructive evaluation methods of airborne radome and stealth structures

Science.gov (United States)

Panwar, Ravi; Ryul Lee, Jung

2018-06-01

In the past few years, great effort has been devoted to the fabrication of highly efficient, broadband radome and stealth (R&S) structures for distinct control, guidance, surveillance and communication applications for airborne platforms. The evaluation of non-planar aircraft R&S structures in terms of their electromagnetic performance and structural damage is still a very challenging task. In this article, distinct measurement techniques are discussed for the electromagnetic performance and non-destructive evaluation (NDE) of R&S structures. This paper deals with an overview of the transmission line method and free space measurement based microwave measurement techniques for the electromagnetic performance evaluation of R&S structures. In addition, various conventional as well as advanced methods, such as millimetre and terahertz wave based imaging techniques with great potential for NDE of load bearing R&S structures, are also discussed in detail. A glimpse of in situ NDE techniques with corresponding experimental setup for R&S structures is also presented. The basic concepts, measurement ranges and their instrumentation, measurement method of different R&S structures and some miscellaneous topics are discussed in detail. Some of the challenges and issues pertaining to the measurement of curved R&S structures are also presented. This study also lists various mathematical models and analytical techniques for the electromagnetic performance evaluation and NDE of R&S structures. The research directions described in this study may be of interest to the scientific community in the aerospace sectors.

Nondestructive Testing Technique to Quantify Deterioration from Marine Borer Attack in Sitka Spruce and Western Hemlock Logs: Observations from a Pilot Test

Science.gov (United States)

Robert Ross; John W. Forsman; John R. Erickson; Allen M. Brackley

2014-01-01

Stress-wave nondestructive evaluation (NDE) techniques are used widely in the forest products industry—from the grading of wood veneer to inspection of timber structures. Inspection professionals frequently use stress-wave NDE techniques to locate internal voids and decayed or deteriorated areas in large timbers. Although these techniques have proven useful, little...

Optical generation,detection and non-destructive testing applications of terahertz waves

Institute of Scientific and Technical Information of China (English)

ZHANG; Weili; LIANG; Dachuan; TIAN; Zhen; HAN; Jiaguang; GU; Jianqiang; HE; Mingxia; OUYANG; Chunmei

2016-01-01

Optoelectronic terahertz generation and detection play a key role in the applications of non-destructive testing,which involves different areas such as physics,biological,material science,imaging,explosions detection,astronomy applications,semiconductor technology and superconductiong electronics. In this article,we present a reviewof the principle and performance of typical terahertz sources,detectors and non-destructive testing applications. On this basis,the newdevelopment and trends of terahertz radiation detectors are also discussed.

Nondestructive Evaluation of Ceramic Candle Filters Using Vibration Response

International Nuclear Information System (INIS)

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

1997-01-01

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

Nondestructive testing 89

International Nuclear Information System (INIS)

1989-01-01

The proceedings contain 24 contributions, out of which 14 have been inputted in INIS. These deal with materials for nondestructive testing and various nondestructive testing systems, with the evaluation of radiograms and with the application of radiographic, ultrasonic and eddy current methods to the detection of defects in materials, to the inspection of nuclear reactor components and in other fields of technology. (B.S.)

Quantitative subsurface analysis using frequency modulated thermal wave imaging

Science.gov (United States)

Subhani, S. K.; Suresh, B.; Ghali, V. S.

2018-01-01

Quantitative depth analysis of the anomaly with an enhanced depth resolution is a challenging task towards the estimation of depth of the subsurface anomaly using thermography. Frequency modulated thermal wave imaging introduced earlier provides a complete depth scanning of the object by stimulating it with a suitable band of frequencies and further analyzing the subsequent thermal response using a suitable post processing approach to resolve subsurface details. But conventional Fourier transform based methods used for post processing unscramble the frequencies with a limited frequency resolution and contribute for a finite depth resolution. Spectral zooming provided by chirp z transform facilitates enhanced frequency resolution which can further improves the depth resolution to axially explore finest subsurface features. Quantitative depth analysis with this augmented depth resolution is proposed to provide a closest estimate to the actual depth of subsurface anomaly. This manuscript experimentally validates this enhanced depth resolution using non stationary thermal wave imaging and offers an ever first and unique solution for quantitative depth estimation in frequency modulated thermal wave imaging.

Quantitative Nondestructive Evaluation

Science.gov (United States)

1979-10-01

about 0.9 times the shear wave velocity. Waves which propagate in materials having thicknesses comparable to the wave length are called Lamb waves... Lamb wave particle motion is very complex and many modes are possible, some symmetric and some unsymmetric with respect to the midplane of the plate...DRXMR-PL 1 -MT, Mr. Farrow 1 Watertown, Massachusetts 02172 Commander White Sands Missile Range ATTN: STEWS -AD-L 1 White Sands Missile

Aging Mechanisms and Nondestructive Aging Indicator of Filled Cross-linked Polyethylene (XLPE) Exposed to Simultaneous Thermal and Gamma Radiation

Energy Technology Data Exchange (ETDEWEB)

Liu, Shuaishuai; Fifield, Leonard S.; Bowler, Nicola

2018-04-11

Aging mechanisms and a nondestructive aging indicator of filled cross-linked polyethylene (XLPE) cable insulation material used in nuclear power plants (NPPs) are studied. Using various material characterization techniques, likely candidates and functions for the main additives in a commercial filled-XLPE insulation material have been identified. These include decabromodiphenyl ether and Sb2O3 as flame retardants, ZnS as white pigment and polymerized 1,2-dihydro-2,2,4-trimethylquinoline as antioxidant. Gas chromatography-mass spectrometry, differential scanning calorimetry, oxidation induction time and measurements of dielectric loss tangent are utilized to monitor property changes as a function of thermal and radiation exposure of the cable material. Small-molecular-weight hydrocarbons are evolve with gamma radiation aging at 90 °C. The level of antioxidant decreases with aging by volatilization and chemical reaction with free radicals. Thermal aging at 90 °C for 25 days or less causes no observable change to the cross-linked polymer structure. Gamma radiation causes damage to crystalline polymer regions and introduces defects. Dielectric loss tangent is shown to be an effective and reliable nondestructive indicator of the aging severity of the filled-XLPE insulation material.

Implementation of nondestructive testing and mechanical performance approaches to assess low temperature fracture properties of asphalt binders

Directory of Open Access Journals (Sweden)

Salman Hakimzadeh

2017-05-01

Full Text Available In the present work, three different asphalt binders were studied to assess their fracture behavior at low temperatures. Fracture properties of asphalt materials were obtained through conducting the compact tension [C(T] and indirect tensile [ID(T] strength tests. Mechanical fracture tests were followed by performing acoustic emissions test to determine the “embrittlement temperature” of binders which was used in evaluation of thermally induced microdamages in binders. Results showed that both nondestructive and mechanical testing approaches could successfully capture low-temperature cracking behavior of asphalt materials. It was also observed that using GTR as the binder modifier significantly improved thermal cracking resistance of PG64-22 binder. The overall trends of AE test results were consistent with those of mechanical tests. Keywords: Thermal cracking, Indirect tensile strength test, Compact tension test, Nondestructive approach, Acoustic emission test, Embrittlement temperature

Millimeter-wave nondestructive evaluation of pavement conditions

Science.gov (United States)

Vines-Cavanau, David; Busuioc, Dan; Birken, Ralf; Wang, Ming

2012-04-01

The United States is suffering from an aging civil infrastructure crisis. Key to recovery are rapid inspection technologies like that being investigated by the VOTERS project (Versatile Onboard Traffic Embedded Roaming Sensors), which aims to outfit ordinary road vehicles with compact low-cost hardware that enables them to rapidly assess and report the condition of roadways and bridge decks free of driver interaction. A key piece of hardware, and the focus of this paper, is a 24 GHz millimeter-wave radar system that measures the reflectivity of pavement surfaces. To account for the variability of real-world driving, such as changes in height, angle, speed, and temperature, a sensor fusion approach is used that corrects MWR measurements based on data from four additional sensors. The corrected MWR measurements are expected to be useful for various characterization applications, including: material type; deterioration such as cracks and potholes; and surface coverage conditions such as dry, wet, oil, water, and ice. Success at each of these applications is an important step towards achieving the VOTERS objective, however, this paper focuses on surface coverage, as whatever covers the driving surface will be most apparent to the MWR sensor and if not accounted for could significantly limit the accuracy of other applications. Contributions of the paper include findings from static lab tests, which validate the approach and show the effects of height and angle. Further contributions come from lab and in-field dynamic tests, which show the effects of speed and demonstrate that the MWR approach is accurate under city driving conditions.

Nondestructive Damage Evaluation in Ceramic Matrix Composites for Aerospace Applications

Directory of Open Access Journals (Sweden)

Konstantinos G. Dassios

2013-01-01

Full Text Available 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.

Thermal wave interference with high-power VCSEL arrays for locating vertically oriented subsurface defects

Science.gov (United States)

Thiel, Erik; Kreutzbruck, Marc; Studemund, Taarna; Ziegler, Mathias

2018-04-01

Among the photothermal methods, full-field thermal imaging is used to characterize materials, to determine thicknesses of layers, or to find inhomogeneities such as voids or cracks. The use of classical light sources such as flash lamps (impulse heating) or halogen lamps (modulated heating) led to a variety of nondestructive testing methods, in particular, lock-in and flash-thermography. In vertical-cavity surface-emitting lasers (VCSELs), laser light is emitted perpendicularly to the surface with a symmetrical beam profile. Due to the vertical structure, they can be arranged in large arrays of many thousands of individual lasers, which allows power scaling into the kilowatt range. Recently, a high-power yet very compact version of such a VCSEL-array became available that offers both the fast timing behavior of a laser as well as the large illumination area of a lamp. Moreover, it allows a spatial and temporal control of the heating because individual parts of the array can be controlled arbitrarily in frequency, amplitude, and phase. In conjunction with a fast infrared camera, such structured heating opens up a field of novel thermal imaging and testing methods. As a first demonstration of this approach, we chose a testing problem very challenging to conventional thermal infrared testing: The detection of very thin subsurface defects perpendicularly oriented to the surface of metallic samples. First, we generate destructively interfering thermal wave fields, which are then affected by the presence of defects within their reach. It turned out that this technique allows highly sensitive detection of subsurface defects down to depths in excess of the usual thermographic rule of thumb, with no need for a reference or surface preparation.

The Nuclear Renaissance - Implications on Quantitative Nondestructive Evaluations

International Nuclear Information System (INIS)

Matzie, Regis A.

2007-01-01

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

Stress evaluation of metallic material under steady state based on nonlinear critically refracted longitudinal wave

Science.gov (United States)

Mao, Hanling; Zhang, Yuhua; Mao, Hanying; Li, Xinxin; Huang, Zhenfeng

2018-06-01

This paper presents the study of applying the nonlinear ultrasonic wave to evaluate the stress state of metallic materials under steady state. The pre-stress loading method is applied to guarantee components with steady stress. Three kinds of nonlinear ultrasonic experiments based on critically refracted longitudinal wave are conducted on components which the critically refracted longitudinal wave propagates along x, x1 and x2 direction. Experimental results indicate the second and third order relative nonlinear coefficients monotonically increase with stress, and the normalized relationship is consistent with simplified dislocation models, which indicates the experimental result is logical. The combined ultrasonic nonlinear parameter is proposed, and three stress evaluation models at x direction are established based on three ultrasonic nonlinear parameters, which the estimation error is below 5%. Then two stress detection models at x1 and x2 direction are built based on combined ultrasonic nonlinear parameter, the stress synthesis method is applied to calculate the magnitude and direction of principal stress. The results show the prediction error is within 5% and the angle deviation is within 1.5°. Therefore the nonlinear ultrasonic technique based on LCR wave could be applied to nondestructively evaluate the stress of metallic materials under steady state which the magnitude and direction are included.

Nondestructive evaluation of metallic structures using a SQUID magnetometer

International Nuclear Information System (INIS)

Weinstock, H.; Nisenoff, M.

1985-01-01

We present one of the first reports of the use of SQUID instrumentation for nondestructive evaluation of electrically conducting and ferromagnetic specimens. We report preliminary experiments on the use of SQUIDs for the detection of defects (such as cracks, holes, weld seams, variations in wall thickness, effects of corrosion, etc.) in the walls of a hollow pipe, and for monitoring the magnetic state of a ferromagnetic sample under stress-strain loading conditions. (orig./BUD)

Thermal imaging method to visualize a hidden painting thermally excited by far infrared radiations

Science.gov (United States)

Davin, T.; Wang, X.; Chabane, A.; Pawelko, R.; Guida, G.; Serio, B.; Hervé, P.

2015-06-01

The diagnosis of hidden painting is a major issue for cultural heritage. In this paper, a non-destructive active infrared thermographic technique was considered to reveal paintings covered by a lime layer. An extended infrared spectral range radiation was used as the excitation source. The external long wave infrared energy source delivered to the surface is then propagated through the material until it encounters a painting zone. Due to several thermal effects, the sample surface then presents non-uniformity patterns. Using a high sensitive infrared camera, the presence of covered pigments can thus be highlighted by the analysis of the non-stationary phenomena. Reconstituted thermal contrast images of mural samples covered by a lime layer are shown.

Electromagnetic ultrasonic guided waves

CERN Document Server

Huang, Songling; Li, Weibin; Wang, Qing

2016-01-01

This book introduces the fundamental theory of electromagnetic ultrasonic guided waves, together with its applications. It includes the dispersion characteristics and matching theory of guided waves; the mechanism of production and theoretical model of electromagnetic ultrasonic guided waves; the effect mechanism between guided waves and defects; the simulation method for the entire process of electromagnetic ultrasonic guided wave propagation; electromagnetic ultrasonic thickness measurement; pipeline axial guided wave defect detection; and electromagnetic ultrasonic guided wave detection of gas pipeline cracks. This theory and findings on applications draw on the author’s intensive research over the past eight years. The book can be used for nondestructive testing technology and as an engineering reference work. The specific implementation of the electromagnetic ultrasonic guided wave system presented here will also be of value for other nondestructive test developers.

Updated thermal model using simplified short-wave radiosity calculations

International Nuclear Information System (INIS)

Smith, J.A.; Goltz, S.M.

1994-01-01

An extension to a forest canopy thermal radiance model is described that computes the short-wave energy flux absorbed within the canopy by solving simplified radiosity equations describing flux transfers between canopy ensemble classes partitioned by vegetation layer and leaf slope. Integrated short-wave reflectance and transmittance-factors obtained from measured leaf optical properties were found to be nearly equal for the canopy studied. Short-wave view factor matrices were approximated by combining the average leaf scattering coefficient with the long-wave view factor matrices already incorporated in the model. Both the updated and original models were evaluated for a dense spruce fir forest study site in Central Maine. Canopy short-wave absorption coefficients estimated from detailed Monte Carlo ray tracing calculations were 0.60, 0.04, and 0.03 for the top, middle, and lower canopy layers corresponding to leaf area indices of 4.0, 1.05, and 0.25. The simplified radiosity technique yielded analogous absorption values of 0.55, 0.03, and 0.01. The resulting root mean square error in modeled versus measured canopy temperatures for all layers was less than 1°C with either technique. Maximum error in predicted temperature using the simplified radiosity technique was approximately 2°C during peak solar heating. (author)

Updated thermal model using simplified short-wave radiosity calculations

Energy Technology Data Exchange (ETDEWEB)

Smith, J. A.; Goltz, S. M.

1994-02-15

An extension to a forest canopy thermal radiance model is described that computes the short-wave energy flux absorbed within the canopy by solving simplified radiosity equations describing flux transfers between canopy ensemble classes partitioned by vegetation layer and leaf slope. Integrated short-wave reflectance and transmittance-factors obtained from measured leaf optical properties were found to be nearly equal for the canopy studied. Short-wave view factor matrices were approximated by combining the average leaf scattering coefficient with the long-wave view factor matrices already incorporated in the model. Both the updated and original models were evaluated for a dense spruce fir forest study site in Central Maine. Canopy short-wave absorption coefficients estimated from detailed Monte Carlo ray tracing calculations were 0.60, 0.04, and 0.03 for the top, middle, and lower canopy layers corresponding to leaf area indices of 4.0, 1.05, and 0.25. The simplified radiosity technique yielded analogous absorption values of 0.55, 0.03, and 0.01. The resulting root mean square error in modeled versus measured canopy temperatures for all layers was less than 1°C with either technique. Maximum error in predicted temperature using the simplified radiosity technique was approximately 2°C during peak solar heating. (author)

Multi-resolution analysis for region of interest extraction in thermographic nondestructive evaluation

Science.gov (United States)

Ortiz-Jaramillo, B.; Fandiño Toro, H. A.; Benitez-Restrepo, H. D.; Orjuela-Vargas, S. A.; Castellanos-Domínguez, G.; Philips, W.

2012-03-01

Infrared Non-Destructive Testing (INDT) is known as an effective and rapid method for nondestructive inspection. It can detect a broad range of near-surface structuring flaws in metallic and composite components. Those flaws are modeled as a smooth contour centered at peaks of stored thermal energy, termed Regions of Interest (ROI). Dedicated methodologies must detect the presence of those ROIs. In this paper, we present a methodology for ROI extraction in INDT tasks. The methodology deals with the difficulties due to the non-uniform heating. The non-uniform heating affects low spatial/frequencies and hinders the detection of relevant points in the image. In this paper, a methodology for ROI extraction in INDT using multi-resolution analysis is proposed, which is robust to ROI low contrast and non-uniform heating. The former methodology includes local correlation, Gaussian scale analysis and local edge detection. In this methodology local correlation between image and Gaussian window provides interest points related to ROIs. We use a Gaussian window because thermal behavior is well modeled by Gaussian smooth contours. Also, the Gaussian scale is used to analyze details in the image using multi-resolution analysis avoiding low contrast, non-uniform heating and selection of the Gaussian window size. Finally, local edge detection is used to provide a good estimation of the boundaries in the ROI. Thus, we provide a methodology for ROI extraction based on multi-resolution analysis that is better or equal compared with the other dedicate algorithms proposed in the state of art.

Thermal Cracking in Westerly Granite Monitored Using Direct Wave Velocity, Coda Wave Interferometry, and Acoustic Emissions

Science.gov (United States)

Griffiths, L.; Lengliné, O.; Heap, M. J.; Baud, P.; Schmittbuhl, J.

2018-03-01

To monitor both the permanent (thermal microcracking) and the nonpermanent (thermo-elastic) effects of temperature on Westerly Granite, we combine acoustic emission monitoring and ultrasonic velocity measurements at ambient pressure during three heating and cooling cycles to a maximum temperature of 450°C. For the velocity measurements we use both P wave direct traveltime and coda wave interferometry techniques, the latter being more sensitive to changes in S wave velocity. During the first cycle, we observe a high acoustic emission rate and large—and mostly permanent—apparent reductions in velocity with temperature (P wave velocity is reduced by 50% of the initial value at 450°C, and 40% upon cooling). Our measurements are indicative of extensive thermal microcracking during the first cycle, predominantly during the heating phase. During the second cycle we observe further—but reduced—microcracking, and less still during the third cycle, where the apparent decrease in velocity with temperature is near reversible (at 450°C, the P wave velocity is decreased by roughly 10% of the initial velocity). Our results, relevant for thermally dynamic environments such as geothermal reservoirs, highlight the value of performing measurements of rock properties under in situ temperature conditions.

Three new nondestructive evaluation tools based on high flux neutron sources

International Nuclear Information System (INIS)

Hubbard, C.R.; Raine, D.; Peascoe, R.; Wright, M.

1997-01-01

Nondestructive evaluation methods and systems based on specific attributes of neutron interactions with materials are being developed. The special attributes of neutrons are low attenuation in most engineering materials, strong interaction with low Z elements, and epithermal neutron absorption resonances. The three methods under development at ORNL include neutron based tomography and radiography; through thickness, nondestructive texture mapping; and internal, noninvasive temperature measurement. All three techniques require high flux sources such as the High Flux Isotope Reactor, a steady state source, or the Oak Ridge Electron Linear Accelerator, a pulsed neutron source. Neutrons are quite penetrating in most engineering materials and thus can be useful to detect internal flaws and features. Hydrogen atoms, such as in a hydrocarbon fuel, lubricant, or a metal hydride, are relatively opaque to neutron transmission and thus neutron based tomography/radiography is ideal to image their presence. Texture, the nonrandom orientation of crystalline grains within materials, can be mapped nondestructively using neutron diffraction methods. Epithermal neutron resonance absorption is being studied as a noncontacting temperature sensor. This paper highlights the underlying physics of the methods, progress in development, and the potential benefits for science and industry of the three facilities

Nondestructive Techniques to Evaluate the Characteristics and Development of Engineered Cartilage

Science.gov (United States)

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

2016-01-01

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

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

International Nuclear Information System (INIS)

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

1998-01-01

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

Timber bridge evaluation : a global nondestructive approach using impact generated FRFs

Science.gov (United States)

Angus Morison; C.D. Van Karsen; H.A. Evensen; J.B. Ligon; J.R. Erickson; R.J. Ross; J.W. Forsman

2002-01-01

Bridges require periodic inspections to ensure the safety of those using the structure. A visual inspection has historically been the most common form of investigation for timber bridges. This poses many problems when inspecting bridge timbers since often the damage is internal, leaving no visible signs of decay on the surface. Localized nondestructive evaluation (NDE...

Nondestructive detection of surface flaws in materials by infrared thermography

International Nuclear Information System (INIS)

Ishii, Toshimitsu; Ooka, Norikazu; Eto, Motokuni; Hoshiya, Taiji; Okamoto, Yoshizo

1999-01-01

Infrared thermography is one of the useful remote sensing techniques applied to the nondestructive detection of surface flaws in materials. Radiation temperatures of the specimen surface and surrounding walls as well as the difference in them are crucial factors to detect surface flaws from thermal images, and it is essential that these factors be properly evaluated beforehand in order to detect the flaws by infrared thermography. In this study, the radiation temperature of nuclear graphite specimens heated uniformly was measured by infrared thermography to evaluate the radiation characteristics such as emissivity, radiosity coefficient and variation of radiation temperature. The influence of the temperature difference between the test specimen and its surroundings on the limit of detection of pinhole flaws was discussed on the basis of the thermal images of graphite specimen with surface flaws. It was found that the thermal image of a small flaw was clearly visible with increase in the temperature difference. (author)

An accurately controllable imitative stress corrosion cracking for electromagnetic nondestructive testing and evaluations

International Nuclear Information System (INIS)

Yusa, Noritaka; Uchimoto, Tetsuya; Takagi, Toshiyuki; Hashizume, Hidetoshi

2012-01-01

Highlights: ► We propose a method to simulate stress corrosion cracking. ► The method offers nondestructive signals similar to those of actual cracking. ► Visual and eddy current examinations validate the method. - Abstract: This study proposes a simple and cost-effective approach to fabricate an artificial flaw that is identical to stress corrosion cracking especially from the viewpoint of electromagnetic nondestructive evaluations. The key idea of the approach is to embed a partially-bonded region inside a material by bonding together surfaces that have grooves. The region is regarded as an area of uniform non-zero conductivity from an electromagnetic nondestructive point of view, and thus simulates the characteristics of stress corrosion cracking. Since the grooves are introduced using electro-discharge machining, one can control the profile of the imitative stress corrosion cracking accurately. After numerical simulation to evaluate the spatial resolution of conventional eddy current testing, six specimens made of type 316L austenitic stainless steel were fabricated on the basis of the results of the simulations. Visual and eddy current examinations were carried out to demonstrate that the artificial flaws well simulated the characteristics of actual stress corrosion cracking. Subsequent destructive test confirmed that the bonding did not change the depth profiles of the artificial flaw.

Role of research in non-destructive evaluation for nuclear technology

International Nuclear Information System (INIS)

Jayakumar, T.; Rao, B.P.C.; Raj, Baldev

2010-01-01

This paper presents the role of research in non-destructive evaluation (NDE) of microstructures and mechanical properties in materials, assessment of manufacturing quality and early detection of in-service damage in nuclear components and structures. A few applications and case studies are discussed based on the results of systematic research and developmental activities pursued in different NDE techniques at the authors' laboratory for three different types of Indian nuclear reactors. (author)

ALTERNATIVE METHOD FOR ON SITE EVALUATION OF THERMAL TRANSMITTANCE

Directory of Open Access Journals (Sweden)

Aleksandar Janković

2017-08-01

Full Text Available Thermal transmittance or U-value is an indicator of the building envelope thermal properties and a key parameter for evaluation of heat losses through the building elements due to heat transmission. It can be determined by calculation based on thermal characteristics of the building element layers. However, this value does not take into account the effects of irregularities and degradation of certain elements of the envelope caused by aging, which may lead to errors in calculation of the heat losses. An effective and simple method for determination of thermal transmittance is in situ measurement, which is governed by the ISO 9869-1:2014 that defines heat flow meter method. This relatively expensive method leaves marks and damages surface of the building element. Furthermore, the final result is not always reliable, in particular when the building element is light or when the weather conditions are not suitable. In order to avoid the above mentioned problems and to estimate the real thermal transmittance value an alternative experimental method, here referred as the natural convection and radiation method, is proposed in this paper. For determination of thermal transmittance, this method requires only temperatures of inside and outside air, as well as the inner wall surface temperature. A detailed statistical analysis, performed by the software package SPSS ver. 20, shows several more advantages of this method comparing to the standard heat flow meter one, besides economic and non-destructive benefits.

Computational electromagnetics and model-based inversion a modern paradigm for eddy-current nondestructive evaluation

CERN Document Server

Sabbagh, Harold A; Sabbagh, Elias H; Aldrin, John C; Knopp, Jeremy S

2013-01-01

Computational Electromagnetics and Model-Based Inversion: A Modern Paradigm for Eddy Current Nondestructive Evaluation describes the natural marriage of the computer to eddy-current NDE. Three distinct topics are emphasized in the book: (a) fundamental mathematical principles of volume-integral equations as a subset of computational electromagnetics, (b) mathematical algorithms applied to signal-processing and inverse scattering problems, and (c) applications of these two topics to problems in which real and model data are used. By showing how mathematics and the computer can solve problems more effectively than current analog practices, this book defines the modern technology of eddy-current NDE. This book will be useful to advanced students and practitioners in the fields of computational electromagnetics, electromagnetic inverse-scattering theory, nondestructive evaluation, materials evaluation and biomedical imaging. Users of eddy-current NDE technology in industries as varied as nuclear power, aerospace,...

Detection and quantification of defects in composite material by using thermal wave method

International Nuclear Information System (INIS)

Ranjit, Shrestha; Kim, Won Tae

2015-01-01

This paper explored the results of experimental investigation on carbon fiber reinforced polymer (CFRP) composite sample with thermal wave technique. The thermal wave technique combines the advantages of both conventional thermal wave measurement and thermography using a commercial Infrared camera. The sample comprises the artificial inclusions of foreign material to simulate defects of different shape and size at different depths. Lock-in thermography is employed for the detection of defects. The temperature field of the front surface of sample was observed and analysed at several excitation frequencies ranging from 0.562 Hz down to 0.032 Hz. Four-point methodology was applied to extract the amplitude and phase of thermal wave's harmonic component. The phase images are analyzed to find qualitative and quantitative information about the defects

Detection and quantification of defects in composite material by using thermal wave method

Energy Technology Data Exchange (ETDEWEB)

Ranjit, Shrestha; Kim, Won Tae [Dept. of Mechanical Engineering, Kongju National University, Cheonan (Korea, Republic of)

2015-12-15

This paper explored the results of experimental investigation on carbon fiber reinforced polymer (CFRP) composite sample with thermal wave technique. The thermal wave technique combines the advantages of both conventional thermal wave measurement and thermography using a commercial Infrared camera. The sample comprises the artificial inclusions of foreign material to simulate defects of different shape and size at different depths. Lock-in thermography is employed for the detection of defects. The temperature field of the front surface of sample was observed and analysed at several excitation frequencies ranging from 0.562 Hz down to 0.032 Hz. Four-point methodology was applied to extract the amplitude and phase of thermal wave's harmonic component. The phase images are analyzed to find qualitative and quantitative information about the defects.

Quality evaluation of soil-cement-plant residue bricks by the combination of destructive and non-destructive tests

Directory of Open Access Journals (Sweden)

Regis de C. Ferreira

Full Text Available ABSTRACT Residues from agricultural activity can be used to improve the quality of soil-based bricks, constituting an interesting alternative for their destination. The technical quality of soil-cement-plant residue bricks was evaluated by the combination of non-destructive and destructive methods. A predominant clayey soil, Portland cement and residues of husks of both rice and Brachiaria brizantha cv. Marandu (0, 10, 20, 30 and 40%, in mass, in substitution to the 10% cement content were used. The bricks were submitted to destructive (water absorption and compressive strength and nondestructive (ultrasound tests for their physical and mechanical characterization. Results from both destructive and non-destructive tests were combined to determine the quantitative parameter named “anisotropic resistance” in order to evaluate the quality of the bricks. The addition that promoted best technical quality was 10% residue content, regardless of the residue type. The anisotropic resistance proved to be adequate for the technical quality evaluation of the bricks.

Fast non-stationary thermal phenomena and associated metrology; Phenomenes thermiques instationnaires rapides et metrologie associee

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-31

This workshop has been organized by the thermo-kinetics section of the French Society of Thermal Engineers. Most studies presented during this workshop deal with heat transfers in materials in various situations like: surface treatment processes (spay coating), solidification of metal drops on cold surfaces, laser photo-ablation of materials, thermoelastic microscopy of materials, non-destructive testing using thermally generated ultrasonic waves, during the determination of interface properties of thin films, etc. Only one paper dealing with thermal diffusivity measurements on materials has been selected for ETDE. (J.S.)

Spontaneous generation of electromagnetic waves in plasmas with electron thermal flux

International Nuclear Information System (INIS)

Okada, Toshio

1977-01-01

Spontaneous generation of propagating electromagnetic fields due to a microinstability is investigated for plasmas which convey electron thermal fluxes. The following two cases are examined: 1) Electromagnetic fields spontaneously excited by electrons in a velocity distribution of skewed Maxwellian type. 2) Electromagnetic waves generated by electrons in a velocity distribution which consists of a main part and a high energy part. In this case, the electron thermal flux can be very high. In both cases, induced electromagnetic waves with relatively low frequencies propagate parallel to the direction of Thermal flux. (auth.)

Signal characteristics of guided wave for condenser tube of NPP

International Nuclear Information System (INIS)

Min, Lee Dong; Hoon, Choi Sang; Yeong, Yang Tae

2012-01-01

A Condenser is a large heat exchanger of the shell and tube type. Cooling water enters through the water box, through the tubesheet and into the tubes(about 80,000 tubes/unit). The shell side of the condenser receives steam from the low pressure turbines exhaust. The steam is cooled to a liquid by passing over the tubes where the cooling water is circulated. Because seawater is used as a coolant, condenser tubes are easily damaged. For such a reason, nondestructive testing conducted periodically. But nondestructive testing takes a lot of manpower and time. Guided wave technique can overcome these shortcomings. In this study, we made an effort evaluating a guided wave defect signal

Measurement of thermal conductivity of Bi2Te3 nanowire using high-vacuum scanning thermal wave microscopy

Science.gov (United States)

Park, Kyungbae; Hwang, Gwangseok; Kim, Hayeong; Kim, Jungwon; Kim, Woochul; Kim, Sungjin; Kwon, Ohmyoung

2016-02-01

With the increasing application of nanomaterials in the development of high-efficiency thermoelectric energy conversion materials and electronic devices, the measurement of the intrinsic thermal conductivity of nanomaterials in the form of nanowires and nanofilms has become very important. However, the current widely used methods for measuring thermal conductivity have difficulties in eliminating the influence of interfacial thermal resistance (ITR) during the measurement. In this study, by using high-vacuum scanning thermal wave microscopy (HV-STWM), we propose a quantitative method for measuring the thermal conductivity of nanomaterials. By measuring the local phase lag of high-frequency (>10 kHz) thermal waves passing through a nanomaterial in a high-vacuum environment, HV-STWM eliminates the measurement errors due to ITR and the distortion due to heat transfer through air. By using HV-STWM, we measure the thermal conductivity of a Bi2Te3 nanowire. Because HV-STWM is quantitatively accurate and its specimen preparation is easier than in the thermal bridge method, we believe that HV-STWM will be widely used for measuring the thermal properties of various types of nanomaterials.

The Nuclear Renaissance — Implications on Quantitative Nondestructive Evaluations

Science.gov (United States)

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.

Development of non-destructive testing system of shoes for infrared rays

Energy Technology Data Exchange (ETDEWEB)

Kim, Jae Yeol; Park, Chang Sun; Oh, Ki Jang; Ma, Sang Dong; Kim, Bong Jae [Chosun Univesity, Kwangju (Korea, Republic of); Yang, Dong Jo [Research Institute of Industrial Science and Technology, Pohang (Korea, Republic of)

2001-05-15

Diagnosis or measurements using Infrared thermo-image hasn't been available. A quick diagnosis and thermal analysis can be possible when that kind of system is introduced to the investigation of each part. In this study, Infrared Camera, Thermo-vision 900 of AGEMA Company was used in order to investigate. Infrared Camera usually detects only Infrared wave from the light in order to illustrate the temperature distribution. Infrared diagnosis system can be applied to various field. But the defect discrimination can be automatic or mechanization on the special shoes total inspection system. Also, it is more effective to development and composition on the shoes total inspection system. In this study, it is introduction method of special shoes nondestructive total inspection. Performance of the proposed method are shown by through thermo-Image.

Nondestructive testing method

International Nuclear Information System (INIS)

Porter, J.F.

1996-01-01

Nondestructive testing (NDT) is the use of physical and chemical methods for evaluating material integrity without impairing its intended usefulness or continuing service. Nondestructive tests are used by manufaturer's for the following reasons: 1) to ensure product reliability; 2) to prevent accidents and save human lives; 3) to aid in better product design; 4) to control manufacturing processes; and 5) to maintain a uniform quality level. Nondestructive testing is used extensively on power plants, oil and chemical refineries, offshore oil rigs and pipeline (NDT can even be conducted underwater), welds on tanks, boilers, pressure vessels and heat exchengers. NDT is now being used for testing concrete and composite materials. Because of the criticality of its application, NDT should be performed and the results evaluated by qualified personnel. There are five basic nondestructive examination methods: 1) liquid penetrant testing - method used for detecting surface flaws in materials. This method can be used for metallic and nonmetallic materials, portable and relatively inexpensive. 2) magnetic particle testing - method used to detect surface and subsurface flaws in ferromagnetic materials; 3) radiographic testing - method used to detect internal flaws and significant variation in material composition and thickness; 4) ultrasonic testing - method used to detect internal and external flaws in materials. This method uses ultrasonics to measure thickness of a material or to examine the internal structure for discontinuities. 5) eddy current testing - method used to detect surface and subsurface flaws in conductive materials. Not one nondestructive examination method can find all discontinuities in all of the materials capable of being tested. The most important consideration is for the specifier of the test to be familiar with the test method and its applicability to the type and geometry of the material and the flaws to be detected

Microstructure analysis for quantification of Barkhausen noise method and nondestructive evaluation of fracture characteristics

International Nuclear Information System (INIS)

Kim, Dong Won; Kwon, Dong Il

1999-01-01

Barkhausen noise method as a magnetic nondestructive test has the advantages for evaluating the properties of magnetic material more precisely and high-sensitively compared to other magnetic NDT methods. For a long time Barkhausen noise method was applied to measure the bulk magnetic properties of magnetic materials and recently to evaluate microstructure, stress analysis, fatigue, creep, and fracture characteristics as a NDT method. But so far Barkhausen noise method has been used as evaluating orientation of material properties rather qualitatively. For this reason, many NDT testing methods have seldom been applied to industrial plants and laboratories. In this study we make experiments on the variation of Barkhausen noise as microstructure, and quantify Barkhausen noise(rms voltage) via formula of velocity of magnetic domain walls using coercive force as retarding force of domain wall movement. As a result, we could evaluate the microstructure of magnetic materials and trends of fracture toughness quantitatively by measuring Barkhausen noise, therefore directly evaluate microstructure and fracture toughness by Barkhausen noise method as accurate in-situ nondestructive testing method.

Recent Advances in Active Infrared Thermography for Non-Destructive Testing of Aerospace Components

Directory of Open Access Journals (Sweden)

Francesco Ciampa

2018-02-01

Full Text Available Active infrared thermography is a fast and accurate non-destructive evaluation technique that is of particular relevance to the aerospace industry for the inspection of aircraft and helicopters’ primary and secondary structures, aero-engine parts, spacecraft components and its subsystems. This review provides an exhaustive summary of most recent active thermographic methods used for aerospace applications according to their physical principle and thermal excitation sources. Besides traditional optically stimulated thermography, which uses external optical radiation such as flashes, heaters and laser systems, novel hybrid thermographic techniques are also investigated. These include ultrasonic stimulated thermography, which uses ultrasonic waves and the local damage resonance effect to enhance the reliability and sensitivity to micro-cracks, eddy current stimulated thermography, which uses cost-effective eddy current excitation to generate induction heating, and microwave thermography, which uses electromagnetic radiation at the microwave frequency bands to provide rapid detection of cracks and delamination. All these techniques are here analysed and numerous examples are provided for different damage scenarios and aerospace components in order to identify the strength and limitations of each thermographic technique. Moreover, alternative strategies to current external thermal excitation sources, here named as material-based thermography methods, are examined in this paper. These novel thermographic techniques rely on thermoresistive internal heating and offer a fast, low power, accurate and reliable assessment of damage in aerospace composites.

Recent Advances in Active Infrared Thermography for Non-Destructive Testing of Aerospace Components.

Science.gov (United States)

Ciampa, Francesco; Mahmoodi, Pooya; Pinto, Fulvio; Meo, Michele

2018-02-16

Active infrared thermography is a fast and accurate non-destructive evaluation technique that is of particular relevance to the aerospace industry for the inspection of aircraft and helicopters' primary and secondary structures, aero-engine parts, spacecraft components and its subsystems. This review provides an exhaustive summary of most recent active thermographic methods used for aerospace applications according to their physical principle and thermal excitation sources. Besides traditional optically stimulated thermography, which uses external optical radiation such as flashes, heaters and laser systems, novel hybrid thermographic techniques are also investigated. These include ultrasonic stimulated thermography, which uses ultrasonic waves and the local damage resonance effect to enhance the reliability and sensitivity to micro-cracks, eddy current stimulated thermography, which uses cost-effective eddy current excitation to generate induction heating, and microwave thermography, which uses electromagnetic radiation at the microwave frequency bands to provide rapid detection of cracks and delamination. All these techniques are here analysed and numerous examples are provided for different damage scenarios and aerospace components in order to identify the strength and limitations of each thermographic technique. Moreover, alternative strategies to current external thermal excitation sources, here named as material-based thermography methods, are examined in this paper. These novel thermographic techniques rely on thermoresistive internal heating and offer a fast, low power, accurate and reliable assessment of damage in aerospace composites.

Life evaluation of FR-CV cable on thermal-radiation combined aging by micro-hardness

International Nuclear Information System (INIS)

Sugiyama, Masahiko; Ogata, Akimasa; Nitta, Makoto; Tani, Tsuneo; Yagi, Toshiaki; Seguchi, Tadao.

1996-01-01

For the evaluation of cable life for the application to nuclear facilities, the accelerated test was conducted by the combination of radiation and thermal oxidation. The degradation of FR-CV cable by the aging was monitored by tensile test, micro-hardness test, and gel-fraction measurement. The micro-hardness increased with the progress of degradation and related well with decrease of ultimate elongation of the sheath material, and was also reflected by the loss of plasticizer. The micro-hardness technique has a possibility to detect the degradation of cable as a non-destructive detector. (author)

Is there a Biological Basis for Therapeutic Applications of Millimetre Waves and THz Waves?

Science.gov (United States)

Mattsson, Mats-Olof; Zeni, Olga; Simkó, Myrtill

2018-03-01

Millimetre wave (MMW) and THz wave (THz) applications are already employed in certain industrial and medical environments for non-destructive quality control, and medical imaging, diagnosis, and therapy, respectively. The aim of the present study is to investigate if published experimental studies (in vivo and in vitro) provide evidence for "non-thermal" biological effects of MMW and THz. Such effects would occur in absence of tissue heating and associated damage and are the ones that can be exploited for therapeutic medical use. The investigated studies provide some evidence for both MMW and THz that can influence biological systems in a manner that is not obviously driven by tissue heating. However, the number of relevant studies is very limited which severely limits the drawing of any far-reaching conclusions. Furthermore, the studies have not addressed specific interaction mechanisms and do not provide hints for future mechanistic studies. Also, the studies do not indicate any specific importance regarding power density levels, frequencies, or exposure duration. It is also unclear if any specific biological endpoints are especially sensitive. Any therapeutic potential of MMW or THz has to be evaluated based on future high-quality studies dealing with physical, bio-physical, and biological aspects that have specific health-related perspectives in mind.

Fourier diffraction theorem for diffusion-based thermal tomography

International Nuclear Information System (INIS)

Baddour, Natalie

2006-01-01

There has been much recent interest in thermal imaging as a method of non-destructive testing and for non-invasive medical imaging. The basic idea of applying heat or cold to an area and observing the resulting temperature change with an infrared camera has led to the development of rapid and relatively inexpensive inspection systems. However, the main drawback to date has been that such an approach provides mainly qualitative results. In order to advance the quantitative results that are possible via thermal imaging, there is interest in applying techniques and algorithms from conventional tomography. Many tomography algorithms are based on the Fourier diffraction theorem, which is inapplicable to thermal imaging without suitable modification to account for the attenuative nature of thermal waves. In this paper, the Fourier diffraction theorem for thermal tomography is derived and discussed. The intent is for this thermal-diffusion based Fourier diffraction theorem to form the basis of tomographic reconstruction algorithms for quantitative thermal imaging

Rapid, non-destructive and non-contact inspection of solid foods by means of photothermal radiometry; thermal effusivity and initial heating coefficient

Science.gov (United States)

Gijsbertsen, A.; Bicanic, D.; Gielen, J. L. W.; Chirtoc, M.

2004-03-01

CO 2-laser photothermal radiometry (PTR) was demonstrated to be suitable for the non-destructive and non-contact characterization (both optical and thermal) of solid phase agricultural commodities (fresh vegetables, fruits) and confectionery products (candy). Proper interpretation of PTR signals enable one to calculate two parameters, i.e. the well known thermal effusivity e ( e= λρc p, where λ and ρcp are the thermal conductivity and the volume specific heat, respectively) and a newly introduced physical quantity termed 'initial heating coefficient' chi ( χ= β/( ρcp), β is the absorption coefficient). Obtained values for e are in a good agreement with data reported in the literature. PTR enables one to rapidly determine e via a single measurement. As opposed to this, the knowledge of two out of three thermophysical parameters (thermal diffusivity, thermal conductivity and volume specific heat) is a condition sine qua non for determining effusivity in the conventional manner.

Mechanical and Non-Destructive Study of CFRP Adhesive Bonds Subjected to Pre-Bond Thermal Treatment and De-Icing Fluid Contamination

Directory of Open Access Journals (Sweden)

Paweł H. Malinowski

2018-04-01

Full Text Available Composite materials are commonly used in many branches of industry. One of the effective methods to join the carbon fibre reinforced polymer (CFRP parts includes the use of adhesives. There is a search on effective methods for quality assurance of bonded parts. In the research here reported the influence of surface pre-bond modification on the adhesive bonds of CFRP plates has been analyzed. Adherends surface modifications, to include defects affecting the bonding quality, were obtained through surface thermal treatment, surface contamination with de-icing fluid and a combination of both the previously described treatments. Characterization of bonded joints was performed by means of mechanical testing, ultrasounds and electromechanical impedance (EMI measurements. The study here proposed has also the aim to evaluate the ability of different destructive and non-destructive techniques to assess the quality of the bonds. While mechanical tests were strongly affected by the surface modifications, results obtained ultrasound and EMI test have demonstrate only a limited ability of these techniques to differentiate between the different samples. In fact, ultrasounds did not show any changes in the bondline, due to pre-bond modifications. However, this technique was able to detect delamination in CFRP for one of the samples thermally treated at 280 °C. Electromechanical impedance (EMI measurements showed similar behavior as mechanical tests for samples thermally treated at 260 °C and 280 °C, and for the sample whose surface modification was made with a combination of thermally and de-icing fluid treatments.

Non-destructive controls in the mechanical industry

Energy Technology Data Exchange (ETDEWEB)

Jarlan, L

1978-12-01

The sequence of operations implicating the mechanical industries from the suppliers to their customers is briefly recalled; a description of the field of application of non-destructive control methods in these industries is given. Follows a description of some recent typical applications of the principal methods: radiography, ultrasonic waves, magnetism, acoustic emission, sonic control, tracer techniques.

Periodic heat wave determination of thermal diffusivity of clays ...

African Journals Online (AJOL)

The responses of Ankaful, Tetegu (# 1 & 2) and Mamfe clays to periodic heat waves were analyzed to deter-mine the thermal diffusivity values. The temperature amplitude attenuated with depth of penetration, while the phase shift increased. The thermal diffusivity values ranged from 3.0 - 9.5 x 10P-7P mP2P/s by amplitude ...

Analysis of Non-contact Acousto Thermal Signature Data (Postprint)

Science.gov (United States)

2016-02-01

AFRL-RX-WP-JA-2016-0321 ANALYSIS OF NON-CONTACT ACOUSTO-THERMAL SIGNATURE DATA (POSTPRINT) Amanda K. Criner AFRL/RX...October 2014 – 16 September 2015 4. TITLE AND SUBTITLE ANALYSIS OF NON-CONTACT ACOUSTO-THERMAL SIGNATURE DATA (POSTPRINT) 5a. CONTRACT NUMBER...words) The non-contact acousto-thermal signature (NCATS) is a nondestructive evaluation technique with potential to detect fatigue in materials such as

Laser photothermal non-destructive metrology of cracks in un-sintered powder metallurgy manufactured automotive transmission sprockets

International Nuclear Information System (INIS)

Tolev, J; Mandelis, A

2010-01-01

A non-contact and non-intrusive method of revealing crack presence in un-sintered (green) automotive transmission parts (sprockets), manufactured by means of a powder metallurgy technology based on analysis of photo-thermal radiometric (PTR) signals and their statistical analysis was developed. The inspection methodology relies on the interaction of a modulated laser generated thermal wave with the potential crack and the resulting change in amplitude and phase of the detected signal [1-5]. The crack existence at points in high stress regions of a group of green (unsintered) sprockets was evaluated through frequency scans. The results were validated by independent destructive cross-sectioning of the sprockets following sintering and polishing. Examination of the sectioned sprockets under a microscope at the locations where signal changes was used for correlation with the PTR signals. Statistical analysis confirmed the capabilities of the method to detect the presence of hairline cracks (∼5 - 10 μm size) with excellent sensitivity (91%) and good accuracy (78%) and specificity (61%). This measurement technique and the associated statistical analysis can be used as a simple and reliable on-line inspection methodology of industrial powder metallurgy manufactured steel products for non-destructive quality and feedback control of the parts forming process.

Development of nondestructive evaluation methods for structural ceramics

International Nuclear Information System (INIS)

Ellingson, W.A.; Roberts, R.A.; Vannier, M.W.; Ackerman, J.L.; Sawicka, B.D.; Gronemeyer, S.; Kriz, R.J.

1987-01-01

Advanced nondestructive evaluation methods are being developed to characterize ceramic materials and allow improvement of process technology. If one can spatially determine porosity, map organic binder/plasticizer distributions, measure average through-volume and in-plane density, as well as detect inclusions, process and machining operations may be modified to enhance the reliability of ceramics. Two modes of X-ray tomographic imaging -- advanced film (analog) tomography and computed tomography -- are being developed to provide flaw detection and density profile mapping capability. Nuclear magnetic resonance imaging is being developed to determine porosity and map the distribution of organic binder/plasticizer. Ultrasonic backscatter and through-transmission are being developed to measure average through-thickness densities and detect surface inclusions

High-Temperature Surface-Acoustic-Wave Transducer

Science.gov (United States)

Zhao, Xiaoliang; Tittmann, Bernhard R.

2010-01-01

Aircraft-engine rotating equipment usually operates at high temperature and stress. Non-invasive inspection of microcracks in those components poses a challenge for the non-destructive evaluation community. A low-profile ultrasonic guided wave sensor can detect cracks in situ. The key feature of the sensor is that it should withstand high temperatures and excite strong surface wave energy to inspect surface/subsurface cracks. As far as the innovators know at the time of this reporting, there is no existing sensor that is mounted to the rotor disks for crack inspection; the most often used technology includes fluorescent penetrant inspection or eddy-current probes for disassembled part inspection. An efficient, high-temperature, low-profile surface acoustic wave transducer design has been identified and tested for nondestructive evaluation of structures or materials. The development is a Sol-Gel bismuth titanate-based surface-acoustic-wave (SAW) sensor that can generate efficient surface acoustic waves for crack inspection. The produced sensor is very thin (submillimeter), and can generate surface waves up to 540 C. Finite element analysis of the SAW transducer design was performed to predict the sensor behavior, and experimental studies confirmed the results. One major uniqueness of the Sol-Gel bismuth titanate SAW sensor is that it is easy to implement to structures of various shapes. With a spray coating process, the sensor can be applied to surfaces of large curvatures. Second, the sensor is very thin (as a coating) and has very minimal effect on airflow or rotating equipment imbalance. Third, it can withstand temperatures up to 530 C, which is very useful for engine applications where high temperature is an issue.

A Monte Carlo approach applied to ultrasonic non-destructive testing

Science.gov (United States)

Mosca, I.; Bilgili, F.; Meier, T.; Sigloch, K.

2012-04-01

Non-destructive testing based on ultrasound allows us to detect, characterize and size discrete flaws in geotechnical and architectural structures and materials. This information is needed to determine whether such flaws can be tolerated in future service. In typical ultrasonic experiments, only the first-arriving P-wave is interpreted, and the remainder of the recorded waveform is neglected. Our work aims at understanding surface waves, which are strong signals in the later wave train, with the ultimate goal of full waveform tomography. At present, even the structural estimation of layered media is still challenging because material properties of the samples can vary widely, and good initial models for inversion do not often exist. The aim of the present study is to combine non-destructive testing with a theoretical data analysis and hence to contribute to conservation strategies of archaeological and architectural structures. We analyze ultrasonic waveforms measured at the surface of a variety of samples, and define the behaviour of surface waves in structures of increasing complexity. The tremendous potential of ultrasonic surface waves becomes an advantage only if numerical forward modelling tools are available to describe the waveforms accurately. We compute synthetic full seismograms as well as group and phase velocities for the data. We invert them for the elastic properties of the sample via a global search of the parameter space, using the Neighbourhood Algorithm. Such a Monte Carlo approach allows us to perform a complete uncertainty and resolution analysis, but the computational cost is high and increases quickly with the number of model parameters. Therefore it is practical only for defining the seismic properties of media with a limited number of degrees of freedom, such as layered structures. We have applied this approach to both synthetic layered structures and real samples. The former contributed to benchmark the propagation of ultrasonic surface

Thermal and Driven Stochastic Growth of Langmuir Waves in the Solar Wind and Earth's Foreshock

Science.gov (United States)

Cairns, Iver H.; Robinson, P. A.; Anderson, R. R.

2000-01-01

Statistical distributions of Langmuir wave fields in the solar wind and the edge of Earth's foreshock are analyzed and compared with predictions for stochastic growth theory (SGT). SGT quantitatively explains the solar wind, edge, and deep foreshock data as pure thermal waves, driven thermal waves subject to net linear growth and stochastic effects, and as waves in a pure SGT state, respectively, plus radiation near the plasma frequency f(sub p). These changes are interpreted in terms of spatial variations in the beam instability's growth rate and evolution toward a pure SGT state. SGT analyses of field distributions are shown to provide a viable alternative to thermal noise spectroscopy for wave instruments with coarse frequency resolution, and to separate f(sub p) radiation from Langmuir waves.

Non-destructive controls in the steel tube industry

International Nuclear Information System (INIS)

Mondot, J.

1978-01-01

The main non-destructive control methods in the tube industry are reviewed: eddy currents, particularly well adapted to small tubes; magnetoscopic testing for weldless tubes; ultrasonic waves widely used for thick weldless tubes and weldings; radiography, to examine tube ends and the known questionable zones; measure of diameters by laser [fr

Thermal chiral vortical and magnetic waves: New excitation modes in chiral fluids

Energy Technology Data Exchange (ETDEWEB)

Kalaydzhyan, Tigran, E-mail: tigran@caltech.edu [Department of Physics, University of Illinois, 845 W Taylor Street, Chicago, IL 60607 (United States); Jet Propulsion Laboratory, 4800 Oak Grove Dr, M/S 298, Pasadena, CA 91109 (United States); Murchikova, Elena [TAPIR, California Institute of Technology, MC 350-17, Pasadena, CA 91125 (United States)

2017-06-15

In certain circumstances, chiral (parity-violating) medium can be described hydrodynamically as a chiral fluid with microscopic quantum anomalies. Possible examples of such systems include strongly coupled quark–gluon plasma, liquid helium {sup 3}He-A, neutron stars and the Early Universe. We study first-order hydrodynamics of a chiral fluid on a vortex background and in an external magnetic field. We show that there are two previously undiscovered modes describing heat waves propagating along the vortex and magnetic field. We call them the Thermal Chiral Vortical Wave and Thermal Chiral Magnetic Wave. We also identify known gapless excitations of density (chiral vortical and chiral magnetic waves) and transverse velocity (chiral Alfvén wave). We demonstrate that the velocity of the chiral vortical wave is zero, when the full hydrodynamic framework is applied, and hence the wave is absent and the excitation reduces to the charge diffusion mode. We also comment on the frame-dependent contributions to the obtained propagation velocities.

Thermal chiral vortical and magnetic waves: New excitation modes in chiral fluids

International Nuclear Information System (INIS)

Kalaydzhyan, Tigran; Murchikova, Elena

2017-01-01

In certain circumstances, chiral (parity-violating) medium can be described hydrodynamically as a chiral fluid with microscopic quantum anomalies. Possible examples of such systems include strongly coupled quark–gluon plasma, liquid helium "3He-A, neutron stars and the Early Universe. We study first-order hydrodynamics of a chiral fluid on a vortex background and in an external magnetic field. We show that there are two previously undiscovered modes describing heat waves propagating along the vortex and magnetic field. We call them the Thermal Chiral Vortical Wave and Thermal Chiral Magnetic Wave. We also identify known gapless excitations of density (chiral vortical and chiral magnetic waves) and transverse velocity (chiral Alfvén wave). We demonstrate that the velocity of the chiral vortical wave is zero, when the full hydrodynamic framework is applied, and hence the wave is absent and the excitation reduces to the charge diffusion mode. We also comment on the frame-dependent contributions to the obtained propagation velocities.

Thermal chiral vortical and magnetic waves: New excitation modes in chiral fluids

Directory of Open Access Journals (Sweden)

Tigran Kalaydzhyan

2017-06-01

Full Text Available In certain circumstances, chiral (parity-violating medium can be described hydrodynamically as a chiral fluid with microscopic quantum anomalies. Possible examples of such systems include strongly coupled quark–gluon plasma, liquid helium 3He-A, neutron stars and the Early Universe. We study first-order hydrodynamics of a chiral fluid on a vortex background and in an external magnetic field. We show that there are two previously undiscovered modes describing heat waves propagating along the vortex and magnetic field. We call them the Thermal Chiral Vortical Wave and Thermal Chiral Magnetic Wave. We also identify known gapless excitations of density (chiral vortical and chiral magnetic waves and transverse velocity (chiral Alfvén wave. We demonstrate that the velocity of the chiral vortical wave is zero, when the full hydrodynamic framework is applied, and hence the wave is absent and the excitation reduces to the charge diffusion mode. We also comment on the frame-dependent contributions to the obtained propagation velocities.

Overcoming thermal noise in non-volatile spin wave logic

Science.gov (United States)

Dutta, Sourav; Nikonov, Dmitri; Manipatruni, Sasikanth; Young, Ian; Naeemi, Azad

Spin waves are propagating disturbances in magnetically ordered materials. To compete as a promising candidate for beyond-CMOS application, the all-magnon based computing system must undergo the essential steps of careful selection of materials and demonstrate robustness with respect to thermal noise/variability. Here, we identify suitable materials and investigate two viable options for translating the theoretical idea of phase-dependent switching of the spin wave detector to a practical realization of a thermally reliable magnonic device by - (a) using the built-in strain in the ME cell, arising from the lattice mismatch and/or thermal expansion coefficient mismatch between the film and the substrate, for compensation of the demagnetization, and (b) using an exchange-spring structure that exhibits a strong exchange-coupling between the ME cell and PMA SWB and provides a modification of the energy landscape of the ME cell magnet. A high switching success and error-free logic functionality can be ensured if the amplitude of the detected spin wave () remains higher than a threshold value of around 6°C and the detected phase falls within the window from 280°C through 0 to 20°C or from 100°C to 200°C with a maximum allowable ϕ range of around 100°C.

Electromagnetic nondestructive evaluation of tempering process in AISI D2 tool steel

Science.gov (United States)

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.

Propagation of thermal and hydromagnetic waves in an ionizing-recombining hydrogen plasma

International Nuclear Information System (INIS)

Di Sigalotti, Leonardo G.; Sira, Eloy; Rendon, Otto; Tremola, Ciro; Mendoza-Briceno, Cesar A.

2004-01-01

The propagation of thermal and magnetohydrodynamic (MHD) waves in a heat-conducting, hydrogen plasma, threaded by an external uniform magnetic field (B) and in which photoionization and photorecombination [H + +e - H+hν(χ)] processes are progressing, is investigated here using linear analysis. The resulting dispersion equation is solved analytically for varied strength (β<<1 and ∼1) and orientation of the magnetic field, where β denotes the ratio of plasma to magnetic pressures. Application of this model to the interstellar medium shows that heat conduction governs the propagation of thermal waves only at relatively high frequencies regardless of the plasma temperature, strength, and orientation of the magnetic field. When the direction of wave propagation is held perpendicular to B (i.e., k perpendicular B), the magnetosonic phase velocity is closely Alfvenic for β<<1, while for β∼1 both the hydrostatic and magnetic pressures determine the wave velocity. As long as k parallel B, the fast (transverse) magnetosonic wave becomes an Alfven wave for all frequencies independent of the plasma temperature and field strength, while the slow (longitudinal) magnetosonic wave becomes a pure sound wave. Amplification of thermal and MHD waves always occur at low frequencies and preferentially at temperatures for which the plasma is either weakly or partially ionized. Compared to previous analysis for the same hydrogen plasma model with B=0, the presence of the magnetic field makes the functional dependence of the physical quantities span a longer range of frequencies, which becomes progressively longer as the field strength is increased

Development of a Tomography Technique for Assessment of the Material Condition of Concrete Using Optimized Elastic Wave Parameters

Directory of Open Access Journals (Sweden)

Hwa Kian Chai

2016-04-01

Full Text Available Concrete is the most ubiquitous construction material. Apart from the fresh and early age properties of concrete material, its condition during the structure life span affects the overall structural performance. Therefore, development of techniques such as non-destructive testing which enable the investigation of the material condition, are in great demand. Tomography technique has become an increasingly popular non-destructive evaluation technique for civil engineers to assess the condition of concrete structures. In the present study, this technique is investigated by developing reconstruction procedures utilizing different parameters of elastic waves, namely the travel time, wave amplitude, wave frequency, and Q-value. In the development of algorithms, a ray tracing feature was adopted to take into account the actual non-linear propagation of elastic waves in concrete containing defects. Numerical simulation accompanied by experimental verifications of wave motion were conducted to obtain wave propagation profiles in concrete containing honeycomb as a defect and in assessing the tendon duct filling of pre-stressed concrete (PC elements. The detection of defects by the developed tomography reconstruction procedures was evaluated and discussed.

A Solitary Wave-Based Sensor to Monitor the Setting of Fresh Concrete

Directory of Open Access Journals (Sweden)

Piervincenzo Rizzo

2014-07-01

Full Text Available We present a proof-of-principle study about the use of a sensor for the nondestructive monitoring of strength development in hydrating concrete. The nondestructive evaluation technique is based on the propagation of highly nonlinear solitary waves (HNSWs, which are non-dispersive mechanical waves that can form and travel in highly nonlinear systems, such as one-dimensional particle chains. A built-in transducer is adopted to excite and detect the HNSWs. The waves are partially reflected at the transducer/concrete interface and partially transmitted into the concrete. The time-of-flight and the amplitude of the waves reflected at the interface are measured and analyzed with respect to the hydration time, and correlated to the initial and final set times established by the penetration test (ASTM C 403. The results show that certain features of the HNSWs change as the concrete curing progresses indicating that it has the potential of being an efficient, cost-effective tool for monitoring strengths/stiffness development.

Influence of thermal effects induced by nonlinear absorption on four-wave mixing in silicon waveguides

DEFF Research Database (Denmark)

Pu, Minhao; Chen, Yaohui; Yvind, Kresten

2014-01-01

Influence of thermal effects induced by nonlinear absorption on four-wave mixing in silicon waveguides is investigated. A conversion bandwidth reduction up to 63% is observed in simulation due to the thermal effects.......Influence of thermal effects induced by nonlinear absorption on four-wave mixing in silicon waveguides is investigated. A conversion bandwidth reduction up to 63% is observed in simulation due to the thermal effects....

Non-destructive evaluation of material degradation in RPV steel by magnetic methods

International Nuclear Information System (INIS)

Takahashi, S.; Kikuchi, H.; Kamada, Y.; Ara, K.; Zhang, L.; Liu, T.

2004-01-01

The minor hysteresis loops are measured with increasing magnetic field amplitude, H a , step by step and analyzed in connection with the lattice defects such as dislocations in deformed and neutron irradiated A533B steels. We have defined several new magnetic parameters in the minor loops: they are a pseudo coercive force H c *, a pseudo remanence B R *, a magnetic susceptibility at pseudo coercive force χ H *, pseudo hysteresis loss W f *, pseudo remanence work W r *. H c * is the magnetic field where the magnetization becomes zero in the minor loop. Six coefficients sensitive to lattice defects are obtained by the pseudo magnetic properties and they are independent of H a as well as the magnetic field. These coefficients are effective parameters for nondestructive evaluation of degradation before the initiation of cracking. The minor loops have several advantages for the nondestructive evaluation compared with the major loop. The coefficients have much information about lattice defects and the high accuracy. The measurement is available for low magnetic field of 20 Oe and the H a step is not necessarily fine for the detailed information because of the similarity. (orig.)

Non-destructive material investigation with thermal neutrons at the TRIGA Mark II reactor in Vienna

International Nuclear Information System (INIS)

Bastuerk, M.; Boeck, H.; Zamani, B.; Zawisky, M.; Rauch, H.

2004-01-01

Neutron tomography providing 3D information about interior of an object is a very efficient tool to visualize inner defects of the materials, non-destructively. In this study, some applications of neutron tomography in different fields such as geology, aerospace, civil engineering and archaeology were presented. Distribution of minerals in pumice and rock samples, visualization of inner defects within a new developed titan aluminum turbine blade, and distribution of silica gel as an important impregnating agent in construction and restoration of buildings were investigated. The measurements of tomography projections taken in the 0 to 180 o angle were performed with a thermal neutron flux of 10 5 at the TRIGA Mark II research reactor in Vienna, and the common filtered back projection method was used for the 3D image reconstruction. (author)

Suspension-thermal noise in spring–antispring systems for future gravitational-wave detectors

Science.gov (United States)

Harms, Jan; Mow-Lowry, Conor M.

2018-01-01

Spring–antispring systems have been investigated in the context of low-frequency seismic isolation in high-precision optical experiments. These systems provide the possibility to tune the fundamental resonance frequency to, in principle, arbitrarily low values, and at the same time maintain a compact design. It was argued though that thermal noise in spring–antispring systems would not be as small as one may naively expect from lowering the fundamental resonance frequency. In this paper, we present calculations of suspension-thermal noise for spring–antispring systems potentially relevant in future gravitational-wave detectors, i.e. the beam-balance tiltmeter, and the Roberts linkage. We find a concise expression of the suspension-thermal noise spectrum, which assumes a form very similar to the well-known expression for a simple pendulum. For systems such as the Roberts linkage foreseen as passive seismic isolation, we find that while they can provide strong seismic isolation due to a very low fundamental resonance frequency, their thermal noise is determined by the dimension of the system and is insensitive to fine-tunings of the geometry that can strongly influence the resonance frequency. By analogy, i.e. formal similarity of the equations of motion, this is true for all horizontal mechanical isolation systems with spring–antispring dynamics. This imposes strict requirements on mechanical spring–antispring systems for seismic isolation in potential future low-frequency gravitational-wave detectors as we discuss for the four main concepts, atom-interferometric, superconducting, torsion-bars, and conventional laser interferometer, and generally suggests that thermal noise needs to be evaluated carefully for high-precision experiments implementing spring–antispring dynamics.

Evaluation of the basic mechanical and thermal properties of deep crystalline rocks

International Nuclear Information System (INIS)

Park, Byoung Yoon; Bae, Dae Seok; Kim, Chun Soo; Kim, Kyung Su; Koh, Young Kwon; Jeon, Seok Won

2001-04-01

This report provides the mechanical and thermal properties of granitic intact rocks obtained from Deep Core Drilling Program which is carried out as part of the assessment of deep geological environmental condition. These data are the basic material properties of the core samples from the boreholes drilled up to 500 m depth at the Yusung and Kosung sites. These sites were selected based on the result of preliminary site evaluation study. In this study, the mechanical properties include density, porosity, P-wave velocity, S-wave velocity, uniaxial compressive strength, Young's modulus, Poisson's ratio, tensile strength, and shear strength of fractures, and the thermal properties are heat conductivity, thermal expansion coefficient, specific heat and so on. Those properties were measured through laboratory tests and these data are compared with the existing test results of several domestic rocks

Evaluation of the basic mechanical and thermal properties of deep crystalline rocks

Energy Technology Data Exchange (ETDEWEB)

Park, Byoung Yoon; Bae, Dae Seok; Kim, Chun Soo; Kim, Kyung Su; Koh, Young Kwon; Jeon, Seok Won

2001-04-01

This report provides the mechanical and thermal properties of granitic intact rocks obtained from Deep Core Drilling Program which is carried out as part of the assessment of deep geological environmental condition. These data are the basic material properties of the core samples from the boreholes drilled up to 500 m depth at the Yusung and Kosung sites. These sites were selected based on the result of preliminary site evaluation study. In this study, the mechanical properties include density, porosity, P-wave velocity, S-wave velocity, uniaxial compressive strength, Young's modulus, Poisson's ratio, tensile strength, and shear strength of fractures, and the thermal properties are heat conductivity, thermal expansion coefficient, specific heat and so on. Those properties were measured through laboratory tests and these data are compared with the existing test results of several domestic rocks.

Non-destructive control: technologies, applications and markets

International Nuclear Information System (INIS)

Anon.

1995-01-01

A description of NDC - nondestructive controls - (acoustic emission, Eddy currents, infrared and thermal, liquid penetrants, magnetic particles, radiographic, ultrasonic, visual and optical techniques) is given with various industrial applications and market trends. Some research projects, contacts and a list of NDC systems main manufacturers are given. (A.B.). 37 figs. and tabs

Ultrasonic guided wave for monitoring corrosion of steel bar

Science.gov (United States)

Liu, Xi; Qin, Lei; Huang, Bosheng

2018-01-01

Steel corrosion of reinforced concrete structures has become a serious problem all over the word. In this paper, the work aims at monitoring steel corrosion using ultrasonic guided wave (UGW). Ultrasonic guided wave monitoring is a dynamic and non-destructive testing technology. The advantages of ultrasonic guided wave monitoring for reinforcement corrosion are real-time, online and continuous. In addition, it can judge the different stages of steel bar corrosion, which achieved non-destructive detection.

Nondestructive evaluation of reinforced plastics by a radiometric measurement technique

International Nuclear Information System (INIS)

Entine, Gerald; Afshari, Sia; Verlinden, Matt

1990-01-01

The demand for new high-performance plastics has greatly increased with advances in the performance characteristics of sophisticated reinforced engineering resins. However, conventional methods for the evaluation of the glass and filler contents of reinforced plastics are destructive, labor intensive, and time consuming. We have developed a new instrument, to address this problem, which provides for the rapid, accurate, and nondestructive measurement of glass or filler content in reinforced plastics. This instrument utilizes radiation transmission and scattering techniques for analytical measurement of glass, graphite and other fillers used in reinforced plastics. (author)

Evaluation of corrosion of prestressing steel in concrete using non-destructive techniques

International Nuclear Information System (INIS)

Ali, M.G.; Maddocks, A.R.

2003-01-01

Use of high strength steel in pre-stressed concrete structures has been in use in Australia for many decades. Highway bridges, among other structures, have extensively used pre-stress-ing and post-tensioning techniques. Although prestressing offers many competitive edges to it's traditional rival reinforced concrete, the consequence of damage to prestressing tendons could be catastrophic. Periodic visual inspections of prestressed concrete bridges throughout the world have demonstrated the growing problem of deterioration of prestressing steel as a result of corrosion. Early detection of damage to prestressing steel therefore is of paramount importance. Unfortunately no reliable and practical non-destructive evaluation technique has been available for assessing the condition of prestressing steel within concrete although a number of techniques appear promising. The following inspection methods have been highlighted in recent literature for their use as non-destructive inspection methods for prestressed concrete structures. In addition to the techniques discussed, a number of destructive, or invasive techniques also exist for determination of the corrosion status of prestressing tendons in prestressed structures. The following non-destructive techniques are discussed in some detail: Radiography; Computed Tomography; Surface Penetrating Radar; Impact Echo; Acoustic Emission Monitoring; Magnetic Field Disturbance Technique; Remnant Magnetism Method; Linear Polarisation Method; Electrical Resistance and Surface Potential Survey. The portability, limitations and use in Australia of these techniques are summarised in a table

Conjunction of standing wave and resonance in asymmetric nanowires: a mechanism for thermal rectification and remote energy accumulation.

Science.gov (United States)

Liu, Yue-Yang; Zhou, Wu-Xing; Chen, Ke-Qiu

2015-12-02

As an important way to control and manage heat transport, thermal rectification has become an elementary issue in the field of phononics and plays a key role in the designing of thermal devices. Here we investigate systematically the standing wave and the accompanying resonance process in asymmetric nanowires to understand the standing wave itself and its great effect on thermal rectification. Results show that the standing wave is sensitive to both the structural and thermal properties of the material, and its great effect on enhancing the thermal rectification is realized not only by the energy-localization nature of the standing wave, but also by the resonance-caused large amplitude and high energy of the standing wave.

Compressed Sensing mm-Wave SAR for Non-Destructive Testing Applications Using Multiple Weighted Side Information

Directory of Open Access Journals (Sweden)

Mathias Becquaert

2018-05-01

Full Text Available This work explores an innovative strategy for increasing the efficiency of compressed sensing applied on mm-wave SAR sensing using multiple weighted side information. The approach is tested on synthetic and on real non-destructive testing measurements performed on a 3D-printed object with defects while taking advantage of multiple previous SAR images of the object with different degrees of similarity. The tested algorithm attributes autonomously weights to the side information at two levels: (1 between the components inside the side information and (2 between the different side information. The reconstruction is thereby almost immune to poor quality side information while exploiting the relevant components hidden inside the added side information. The presented results prove that, in contrast to common compressed sensing, good SAR image reconstruction is achieved at subsampling rates far below the Nyquist rate. Moreover, the algorithm is shown to be much more robust for low quality side information compared to coherent background subtraction.

Non-destructive evaluation of welding part of stainless steels by phased array system

International Nuclear Information System (INIS)

Tatematsu, Nobuhiro; Matsumoto, Eiji

2009-01-01

Recently, more accurate and convenient Non-Destructive Evaluation techniques are required for flaw inspection of structural materials. Phased array ultrasonic transducers are expected as such as NDE technique but there are many subjects to be solved. Furthermore, commercial phased array systems with conventional scanning and imaging techniques have not fulfilled their maximum potential. The purpose of this paper is to improve the phased array system to be applicable to the inhomogeneity evaluation of welding part of stainless steels. (author)

Quantitative one-dimensional thermal-wave cavity measurements of fluid thermophysical properties through equivalence studies with three-dimensional geometries

International Nuclear Information System (INIS)

Matvienko, Anna; Mandelis, Andreas

2006-01-01

The thermal-wave field in a photopyroelectric thermal-wave cavity was calculated with two theoretical approaches: a computationally straightforward, conventional, one-dimensional approach and a three-dimensional experimentally more realistic approach. The calculations show that the dimensionality of the thermal-wave field in the cavity depends on the lateral heat transfer boundary conditions and the relation between the beam size of the laser impinging on the thermal-wave generating metallic film and the diameter of the film itself. The theoretical calculations and the experimental data on the photopyroelectric signal in the cavity were compared. The study resulted in identifying ranges of heat transfer rates, beam sizes, and cavity radii for which accurate quantitative measurements of the thermal diffusivity of intracavity fluids can be made within the far simpler, but only approximate, one-dimensional approach conventionally adopted by users of thermal-wave cavities. It was shown that the major parameters affecting the dimensionality of thermal-wave cavities are the laser beam spot size and the Biot number of the medium comprising the sidewalls of the (cylindrical) cavity

Nondestructive Evaluation of Thick Concrete Using Advanced Signal Processing Techniques

Energy Technology Data Exchange (ETDEWEB)

Clayton, Dwight A [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Barker, Alan M [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Santos-Villalobos, Hector J [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Albright, Austin P [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hoegh, Kyle [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Khazanovich, Lev [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

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.

Evaluation of Creep-Fatigue Damage in 304 Stainless Steel using Ultrasonic Non-Destructive Test

Energy Technology Data Exchange (ETDEWEB)

Lee, Sung Sik [Safetech Co. Ltd., Kimhae (Korea, Republic of); Oh, Yong Jun [Hanbat National Univ., Daejon (Korea, Republic of); Nam, Soo Woo [KISTI ReSEAT Program, Seoul (Korea, Republic of)

2011-12-15

It is well known that grain boundary cavitation is the main failure mechanism in austenitic stainless steel under tensile hold creep-fatigue interaction conditions. The cavities are nucleated at the grain boundary during cyclic loading and grow to become grain boundary cracks. The attenuation of ultrasound depends on scattering and absorption in polycrystalline materials. Scattering occurs when a propagation wave encounters microstructural discontinuities, such as internal voids or cavities. Since the density of the creepfatigue cavities increases with the fatigue cycles, the attenuation of ultrasound will also be increased with the fatigue cycles and this attenuation can be detected nondestructively. In this study, it is found that individual grain boundary cavities are formed and grow up to about 100 cycles and then, these cavities coalesce to become cracks. The measured ultrasonic attenuation increased with the cycles up to cycle 100, where it reached a maximum value and then decreased with further cycles. These experimental measurements strongly indicate that the open pores of cavities contribute to the attenuation of ultrasonic waves. However, when the cavities develop, at the grain boundary cracks whose crack surfaces are in contact with each other, there is no longer any open space and the ultrasonic wave may propagate across the cracks. Therefore, the attenuation of ultrasonic waves will be decreased. This phenomenon of maximum attenuation is very important to judge the stage of grain boundary crack development, which is the indication of the dangerous stage of the structures.

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

Science.gov (United States)

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

Lamb waves increase sensitivity in nondestructive testing

Science.gov (United States)

Di Novi, R.

1967-01-01

Lamb waves improve sensitivity and resolution in the detection of small defects in thin plates and small diameter, thin-walled tubing. This improvement over shear waves applies to both longitudinal and transverse flaws in the specimens.

Application of the thermal step method to space charge measurements in inhomogeneous solid insulating structures: A theoretical approach

International Nuclear Information System (INIS)

Cernomorcenco, Andrei; Notingher, Petru Jr.

2008-01-01

The thermal step method is a nondestructive technique for determining electric charge distribution across solid insulating structures. It consists in measuring and analyzing a transient capacitive current due to the redistribution of influence charges when the sample is crossed by a thermal wave. This work concerns the application of the technique to inhomogeneous insulating structures. A general equation of the thermal step current appearing in such a sample is established. It is shown that this expression is close to the one corresponding to a homogeneous sample and allows using similar techniques for calculating electric field and charge distribution

Non-destructive control at the Kozloduy NPP; Nerazrushayushchij kontrol` v AEhS `Kozloduy`

Energy Technology Data Exchange (ETDEWEB)

Mikhovsky, M [Institute of Mechanics, Bulgarian Academy of Sciences, Sofia (Bulgaria); Skordev, A [SIME-CONTROL, Sofia (Bulgaria); Nichev, V; Tsokov, P; Popova, N [Kombinat Atomna Energetika, Kozloduj (Bulgaria)

1996-12-31

A program for technical diagnostics using non-destructive methods is being carried out at the Kozloduy NPP. The main target is to test mechanical equipment integrity (metal control, mechanical stress control, etc.) as well as electrical equipment. Computer methods and simulation are widely used in program implementation. Non-destructive testing is based on methods involving optical, radiation, ultrasonic and magnetic processes. Control procedures are standardised in special technological documents and one of them is described as an example. It refers to ultrasonic control of the austenitic steel welds of the WWER-440 piping system (DU-500). Graphic representing the microstructure of the welds, the distribution of surface ultrasonic wave and the longitudinal and vertically polarised perpendicular waves are presented. 6 refs. 8 figs.

Non-destructive evaluation of water ingress in photovoltaic modules

Energy Technology Data Exchange (ETDEWEB)

Bora, Mihail; Kotovsky, Jack

2017-03-07

Systems and techniques for non-destructive evaluation of water ingress in photovoltaic modules include and/or are configured to illuminate a photovoltaic module comprising a photovoltaic cell and an encapsulant with at least one beam of light having a wavelength in a range from about 1400 nm to about 2700 nm; capture one or more images of the illuminated photovoltaic module, each image relating to a water content of the photovoltaic module; and determine a water content of the photovoltaic module based on the one or more images. Systems preferably include one or more of a light source, a moving mirror, a focusing lens, a beam splitter, a stationary mirror, an objective lens and an imaging module.

Electromagnetic nondestructive evaluation of tempering process in AISI D2 tool steel

International Nuclear Information System (INIS)

Kahrobaee, Saeed; Kashefi, Mehrdad

2015-01-01

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 ε 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. - Highlights: • D2 steel parts were tempered at 200-650 °C to produce various microstructures. • Precipitation of ε and Fe 3 C carbides and spheroidization of carbides were detected. • Retained austenite decomposition and secondary hardening effect were determined. • Variations of electrical resistivity (ρ) and magnetic saturation (Bs) were studied. • Combined effects of ρ and Bs on the EC outputs were evaluated

Electromagnetic nondestructive evaluation of tempering process in AISI D2 tool steel

Energy Technology Data Exchange (ETDEWEB)

Kahrobaee, Saeed, E-mail: saeed.kahrobaee@yahoo.com; Kashefi, Mehrdad, E-mail: m-kashefi@um.ac.ir

2015-05-15

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 ε 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. - Highlights: • D2 steel parts were tempered at 200-650 °C to produce various microstructures. • Precipitation of ε and Fe{sub 3}C carbides and spheroidization of carbides were detected. • Retained austenite decomposition and secondary hardening effect were determined. • Variations of electrical resistivity (ρ) and magnetic saturation (Bs) were studied. • Combined effects of ρ and Bs on the EC outputs were evaluated.

NonDestructive Evaluation for Industrial & Development Applications

Energy Technology Data Exchange (ETDEWEB)

Hunter, James F. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-10-12

Provide overview of weld inspection for Non-Destructive Testing at LANL. This includes radiography (RT/DR/CR/CT for x-ray & neutron sources), ultrasonic testing (UT/PAUT), dye penetrant inspection (PT), eddy current inspection (ET) and magnetic particle testing (MT). Facilities and capabilities for weld inspection will be summarized with examples.

Physical Principles Pertaining to Ultrasonic and Mechanical Properties of Anisotropic Media and Their Application to Nondestructive Evaluation of Fiber-Reinforced Composite Materials

Science.gov (United States)

Handley, Scott Michael

The central theme of this thesis is to contribute to the physics underlying the mechanical properties of highly anisotropic materials. Our hypothesis is that a fundamental understanding of the physics involved in the interaction of interrogating ultrasonic waves with anisotropic media will provide useful information applicable to quantitative ultrasonic measurement techniques employed for the determination of material properties. Fiber-reinforced plastics represent a class of advanced composite materials that exhibit substantial anisotropy. The desired characteristics of practical fiber -reinforced composites depend on average mechanical properties achieved by placing fibers at specific angles relative to the external surfaces of the finished part. We examine the physics underlying the use of ultrasound as an interrogation probe for determination of ultrasonic and mechanical properties of anisotropic materials such as fiber-reinforced composites. Fundamental constituent parameters, such as elastic stiffness coefficients (c_{rm IJ}), are experimentally determined from ultrasonic time-of-flight measurements. Mechanical moduli (Poisson's ratio, Young's and shear modulus) descriptive of the anisotropic mechanical properties of unidirectional graphite/epoxy composites are obtained from the ultrasonically determined stiffness coefficients. Three-dimensional visualizations of the anisotropic ultrasonic and mechanical properties of unidirectional graphite/epoxy composites are generated. A related goal of the research is to strengthen the connection-between practical ultrasonic nondestructive evaluation methods and the physics underlying quantitative ultrasonic measurements for the assessment of manufactured fiber-reinforced composites. Production defects such as porosity have proven to be of substantial concern in the manufacturing of composites. We investigate the applicability of ultrasonic interrogation techniques for the detection and characterization of porosity in

Nondestructive testing for bridge diagnosis

International Nuclear Information System (INIS)

Oshima, Toshiyuki; Mikami, Shuichi; Yamazaki, Tomoyuki

1997-01-01

There are many motivations for bridge diagnosis using Nondestructive testing (NDT) to monitor its integrity. The measured frequency and damping on real bridge are compared in one figure as a function of span length and general aspects are explained. These date were measured in every construction of bridges and applied to design new bridges. Ultrasonic testing is also well used for concrete and steel members mainly to detect internal damages or delaminations. Detail analysis on reflected waves gives us more accurate information about the defect. Experimental results are shown as examples in this paper.

Lamb Wave Stiffness Characterization of Composites Undergoing Thermal-Mechanical Aging

Science.gov (United States)

Seale, Michael D.; Madaras, Eric I.

2004-01-01

The introduction of new, advanced composite materials into aviation systems requires a thorough understanding of the long term effects of combined thermal and mechanical loading upon those materials. Analytical methods investigating the effects of intense thermal heating combined with mechanical loading have been investigated. The damage mechanisms and fatigue lives were dependent on test parameters as well as stress levels. Castelli, et al. identified matrix dominated failure modes for out-of-phase cycling and fiber dominated damage modes for in-phase cycling. In recent years, ultrasonic methods have been developed that can measure the mechanical stiffness of composites. To help evaluate the effect of aging, a suitably designed Lamb wave measurement system is being used to obtain bending and out-of-plane stiffness coefficients of composite laminates undergoing thermal-mechanical loading. The system works by exciting an antisymmetric Lamb wave and calculating the velocity at each frequency from the known transducer separation and the measured time-of-flight. The same peak in the waveforms received at various distances is used to measure the time difference between the signals. The velocity measurements are accurate and repeatable to within 1% resulting in reconstructed stiffness values repeatable to within 4%. Given the material density and plate thickness, the bending and out-of-plane shear stiffnesses are calculated from a reconstruction of the dispersion curve. A mechanical scanner is used to move the sensors over the surface to map the time-of-flight, velocity, or stiffnesses of the entire specimen. Access to only one side of the material is required and no immersion or couplants are required because the sensors are dry coupled to the surface of the plate. In this study, the elastic stiffnesses D(sub 11), D(sub 22), A(sub 44), and A(sub 55) as well as time-of-flight measurements for composite samples that have undergone combined thermal and mechanical aging for

Nondestructive Testing

Energy Technology Data Exchange (ETDEWEB)

Berger, Harold [Argonne National Laboratory

1969-01-01

A nondestructive test is an examination of an object in any manner which will not impair the future usefulness of the object. This booklet discusses a few basic methods of nondestructive testing, and some of their characteristics. In addition, it discusses possible future methods for nondestructive testing by taking a quick look at some of the methods now under study.

Thermal responses in a coronal loop maintained by wave heating mechanisms

Science.gov (United States)

Matsumoto, Takuma

2018-05-01

A full 3-dimensional compressible magnetohydrodynamic (MHD) simulation is conducted to investigate the thermal responses of a coronal loop to the dynamic dissipation processes of MHD waves. When the foot points of the loop are randomly and continuously forced, the MHD waves become excited and propagate upward. Then, 1-MK temperature corona is produced naturally as the wave energy dissipates. The excited wave packets become non-linear just above the magnetic canopy, and the wave energy cascades into smaller spatial scales. Moreover, collisions between counter-propagating Alfvén wave packets increase the heating rate, resulting in impulsive temperature increases. Our model demonstrates that the heating events in the wave-heated loops can be nanoflare-like in the sense that they are spatially localized and temporally intermittent.

Non-destructive Engineering

International Nuclear Information System (INIS)

Ko, Jin Hyeon; Ryu, Taek In; Ko, Jun Bin; Hwang, Yong Hwa

2006-08-01

This book gives descriptions of non-destructive engineering on outline of non-destructive test, weld defects, radiographic inspection radiography, ultrasonic inspection, magnetic particle testing, liquid penetrant testing, eddy current inspection method, strain measurement, acoustic emission inspection method, other non-destructive testing like leakage inspection method, and non-destructive mechanics for fault analysis such as Griffiths creaking theory, and stress analysis of creaking.

APNEA/WIT system nondestructive assay capability evaluation plan for select accessibly stored INEL RWMC waste forms

International Nuclear Information System (INIS)

Becker, G.K.

1997-01-01

Bio-Imaging Research Inc. (BIR) and Lockheed Martin Speciality Components (LMSC) are engaged in a Program Research and Development Agreement and a Rapid Commercialization Initiative with the Department of Energy, EM-50. The agreement required BIR and LMSC to develop a data interpretation method that merges nondestructive assay and nondestructive examination (NDA/NDE) data and information sufficient to establish compliance with applicable National TRU Program (Program) waste characterization requirements and associated quality assurance performance criteria. This effort required an objective demonstration of the BIR and LMSC waste characterization systems in their standalone and integrated configurations. The goal of the test plan is to provide a mechanism from which evidence can be derived to substantiate nondestructive assay capability and utility statement for the BIT and LMSC systems. The plan must provide for the acquisition, compilation, and reporting of performance data thereby allowing external independent agencies a basis for an objective evaluation of the standalone BIR and LMSC measurement systems, WIT and APNEA respectively, as well as an expected performance resulting from appropriate integration of the two systems. The evaluation is to be structured such that a statement regarding select INEL RWMC waste forms can be made in terms of compliance with applicable Program requirements and criteria

Effect of Local Thermal Equilibrium Misbalance on Long-wavelength Slow Magnetoacoustic Waves

Energy Technology Data Exchange (ETDEWEB)

Nakariakov, V. M. [Centre for Fusion, Space and Astrophysics, Physics Department, University of Warwick, Coventry CV4 7AL (United Kingdom); Afanasyev, A. N. [Institute of Solar-Terrestrial Physics SB RAS, P.O. Box 291, Lermontov St. 126A, Irkutsk 664033 (Russian Federation); Kumar, S.; Moon, Y.-J., E-mail: V.Nakariakov@warwick.ac.uk [School of Space Research, Kyung Hee University, Yongin, 446-701, Gyeonggi (Korea, Republic of)

2017-11-01

Evolution of slow magnetoacoustic waves guided by a cylindrical magnetic flux tube that represents a coronal loop or plume, is modeled accounting for the effects of finite gas pressure, weak nonlinearity, dissipation by thermal conduction and viscosity, and the misbalance between the cooling by optically thin radiation and unspecified heating of the plasma. An evolutionary equation of the Burgers–Malthus type is derived. It is shown that the cooling/heating misbalance, determined by the derivatives of the combined radiative cooling and heating function, with respect to the density, temperature, and magnetic field at the thermal equilibrium affect the wave rather strongly. This effect may either cause additional damping, or counteract it, or lead to the gradual amplification of the wave. In the latter case, the coronal plasma acts as an active medium for the slow magnetoacoustic waves. The effect of the cooling/heating misbalance could be important for coronal slow waves, and could be responsible for certain discrepancies between theoretical results and observations, in particular, the increased or decreased damping lengths and times, detection of the waves at certain heights only, and excitation of compressive oscillations. The results obtained open up a possibility for the diagnostics of the coronal heating function by slow magnetoacoustic waves.

Research on Debonding Defects in Thermal Barrier Coatings Structure by Thermal-Wave Radar Imaging (TWRI)

Science.gov (United States)

Wang, Fei; Liu, Junyan; Mohummad, Oliullah; Wang, Yang

2018-06-01

In this paper, thermal-wave radar imaging (TWRI) is introduced to detect debonding defects in SiC-coated Ni-based superalloy plates. Linear frequency modulation signal (chirp) is used as the excitation signal which has a large time-bandwidth product. Artificial debonding defects in SiC coating are excited by the laser beam with the light intensity modulated by a chirp signal. Cross-correlation algorithm and chirp lock-in algorithm are introduced to extract the thermal-wave signal characteristic. The comparative experiment between TWRI reflection mode and transmission mode was carried out. Experiments are conducted to investigate the influence of laser power density, chirp period, and excitation frequency. Experimental results illustrate that chirp lock-in phase has a better detection capability than other characteristic parameters. TWRI can effectively detect simulated debonding defects of SiC-coated Ni-based superalloy plates.

Voluntary Consensus Organization Standards for Nondestructive Evaluation of Thin-Walled Metallic Liners and Composite Overwraps in Composite Overwrapped Pressure Vessels

Science.gov (United States)

Waller, Jess; Saulsberry, Regor

2012-01-01

NASA fracture control requirements outlined in NASA-STD-5009 and NASA-STD-5014 are predicated on the availability and use of sensitive nondestructive evaluation (NDE) methods that can detect and monitor defects, thereby providing data that can be used to predict failure or reduce the risk of failure in fracture critical components. However, in the case of composite materials and components, including composite overwrapped pressure vessels (COPVs), the effect of defects is poorly understood, the NDE methods used to evaluate locate and size defects are typically at lower technical readiness level than analogous NDE methods used for metals, and demonstration studies to verify the probability of detection (POD) are generally lacking or unavailable. These factors together make failure prediction of fracture critical composite materials and components based on size, quantity, or orientation of defects nearly impossible. Also, when inspecting metal liners in as-manufactured COPVs, sensitivity is lost and only the inner surface of the liner is accessible. Also, NDE of COPVs as applied during manufacturing varies significantly from manufacturer to manufacturer and has not yet been standardized. Although requirements exist to perform NDE immediately after manufacturing to establish initial integrity of the parts, procedural detail for NDE of composites is still nonexistent or under development. For example, in practice, only a visual inspection of COPVs is performed during manufacturing and service, leaving in question whether defects of concern, for example, bridging, overwrap winding anomalies, impact damage below visible threshold, out-of-family strain growth, and liner buckling have been adequately detected and monitored. To address these shortcomings, in 2005 the NASA Nondestructive Evaluation Working Group (NNWG) began funding work to develop and adopt standards for nondestructive evaluation of aerospace composites in collaboration with the American Society for Testing

Non-destructive evaluation of the hidden voids in integrated circuit packages using terahertz time-domain spectroscopy

International Nuclear Information System (INIS)

Park, Sung-Hyeon; Kim, Hak-Sung; Jang, Jin-Wook

2015-01-01

In this work, a terahertz time-domain spectroscopy (THz-TDS) imaging technique was used as a non-destructive inspection method for detecting voids in integrated circuit (IC) packages. Transmission and reflection modes, with an angle of incidence of 30°, were used to detect voids in IC packages. The locations of the detected voids in the IC packages could be calculated by analyzing THz waveforms. Finally, voids that are positioned at the different interfaces in the IC package samples could be successfully detected and imaged. Therefore, this THz-TDS imaging technique is expected to be a promising technique for non-destructive evaluation of IC packages. (paper)

FIBWR2 evaluation of fuel thermal limits during density wave oscillaions in BWRs

Energy Technology Data Exchange (ETDEWEB)

Nik, N.; Rajan, S.R.; Karasulu, M. [New York Power Authority, White Plains, NY (United States)

1995-09-01

Analyses were performed to evaluate hydraulic and thermal margin responses of three different BWR fuel designs subjected to the same periodic power/flow oscillations, such as those that might be exhibited during an instability event. The power/flow versus time information from the oscillations was used as a forcing function to calculate the hydraulic response and the MCPR performance of the limiting fuel bundles during the regional oscillations using the analytical code FIBWR2. The results of the calculations were used to determine the thermal margin variation as a function of oscillation magnitude.

Experimental Design for Evaluating Selected Nondestructive Measurement Technologies - Advanced Reactor Technology Milestone: M3AT-16PN2301043

Energy Technology Data Exchange (ETDEWEB)

Ramuhalli, Pradeep [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hirt, Evelyn H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Pitman, Stan G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Dib, Gerges [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Roy, Surajit [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Good, Morris S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Walker, Cody M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2016-07-16

The harsh environments in advanced reactors (AdvRx) increase the possibility of degradation of safety-critical passive components, and therefore pose a particular challenge for deployment and extended operation of these concepts. Nondestructive evaluation technologies are an essential element for obtaining information on passive component condition in AdvRx, with the development of sensor technologies for nondestructively inspecting AdvRx passive components identified as a key need. Given the challenges posed by AdvRx environments and the potential needs for reducing the burden posed by periodic in-service inspection of hard-to-access and hard-to-replace components, a viable solution may be provided by online condition monitoring of components. This report identifies the key challenges that will need to be overcome for sensor development in this context, and documents an experimental plan for sensor development, test, and evaluation. The focus of initial research and development is on sodium fast reactors, with the eventual goal of the research being developing the necessary sensor technology, quantifying sensor survivability and long-term measurement reliability for nondestructively inspecting critical components. Materials for sensor development that are likely to withstand the harsh environments are described, along with a status on the fabrication of reference specimens, and the planned approach for design and evaluation of the sensor and measurement technology.

Lamb wave characterization of the effects of long-term thermal-mechanical aging on composite stiffness

Science.gov (United States)

Seale, M. D.; Madaras, E. I.

1999-01-01

Lamb waves offer a promising method of evaluating damage in composite materials. The Lamb wave velocity is directly related to the material parameters, so an effective tool exists to monitor damage in composites by measuring the velocity of these waves. The Lamb Wave Imager (LWI) uses a pulse/receive technique that excites an antisymmetric Lamb mode and measures the time-of-flight over a wide frequency range. Given the material density and plate thickness, the bending and out-of-plane shear stiffnesses are calculated from a reconstruction of the dispersion curve. In this study, the time-of-flight as well as the elastic stiffnesses D11, D22, A44, and A55 for composite samples which have undergone combined thermal and mechanical aging are obtained. The samples examined include a baseline specimen with 0 cycles, specimens which have been aged 2350 and 3530 cycles at high strain levels, and one specimen aged 3530 cycles at low strain levels.

Measurement of the Length of Installed Rock Bolt Based on Stress Wave Reflection by Using a Giant Magnetostrictive (GMS) Actuator and a PZT Sensor.

Science.gov (United States)

Luo, Mingzhang; Li, Weijie; Wang, Bo; Fu, Qingqing; Song, Gangbing

2017-02-23

Rock bolts, as a type of reinforcing element, are widely adopted in underground excavations and civil engineering structures. Given the importance of rock bolts, the research outlined in this paper attempts to develop a portable non-destructive evaluation method for assessing the length of installed rock bolts for inspection purposes. Traditionally, piezoelectric elements or hammer impacts were used to perform non-destructive evaluation of rock bolts. However, such methods suffered from many major issues, such as the weak energy generated and the requirement for permanent installation for piezoelectric elements, and the inconsistency of wave generation for hammer impact. In this paper, we proposed a portable device for the non-destructive evaluation of rock bolt conditions based on a giant magnetostrictive (GMS) actuator. The GMS actuator generates enough energy to ensure multiple reflections of the stress waves along the rock bolt and a lead zirconate titantate (PZT) sensor is used to detect the reflected waves. A new integrated procedure that involves correlation analysis, wavelet denoising, and Hilbert transform was proposed to process the multiple reflection signals to determine the length of an installed rock bolt. The experimental results from a lab test and field tests showed that, by analyzing the instant phase of the periodic reflections of the stress wave generated by the GMS transducer, the length of an embedded rock bolt can be accurately determined.

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

International Nuclear Information System (INIS)

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 ∼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

Introduction to non-destructive testing of materials: part II

International Nuclear Information System (INIS)

Ahmed, M.; Ahmed, B.

2001-01-01

Ultrasonic waves are mechanical vibrations that require a medium, which functions as carrier. Ultrasonics are widely used in non-destructive testing of materials in which high frequency sound waves are introduced into the material being inspected. If the frequency of sound waves in within the range 10 to 20,000 Hz, the sound is audible, i.e. the range of hearing, above 20,000 Hz, the sound waves are referred to as Ultrasound or Ultrasonics. Sound waves do not cause any permanent change in material although its transient presence is very noticeable. An energy transport through a sound wave is possible only when constituent particles are connected to each other by elastic forces. Liquids and Gases are also suitable media for the transmission of sound. In vacuum no matter exists and thus no sound transmission is possible. At the end of this article advantages and limitations of ultrasonic testing are also given. (A.B.)

On the propagation of hydromagnetic waves in a plasma of thermal and suprathermal components

Science.gov (United States)

Kumar, Nagendra; Sikka, Himanshu

2007-12-01

The propagation of MHD waves is studied when two ideal fluids, thermal and suprathermal gases, coupled by magnetic field are moving with the steady flow velocity. The fluids move independently in a direction perpendicular to the magnetic field but gets coupled along the field. Due to the presence of flow in suprathermal and thermal fluids there appears forward and backward waves. All the forward and backward modes propagate in such a way that their rate of change of phase speed with the thermal Mach number is same. It is also found that besides the usual hydromagnetic modes there appears a suprathermal mode which propagates with faster speed. Surface waves are also examined on an interface formed with composite plasma (suprathermal and thermal gases) on one side and the other is a non-magnetized plasma. In this case, the modes obtained are two or three depending on whether the sound velocity in thermal gas is equal to or greater than the sound velocity in suprathermal gas. The results lead to the conclusion that the interaction of thermal and suprathermal components may lead to the occurrence of an additional mode called suprathermal mode whose phase velocity is higher than all the other modes.

Thermal noise reduction for present and future gravitational wave detectors

Energy Technology Data Exchange (ETDEWEB)

Amico, P.; Bosi, L.; Gammaitoni, L.; Losurdo, G.; Marchesoni, F.; Mazzoni, M.; Punturo, M. E-mail: michele.punturo@pg.infn.it; Stanga, R.; Toncelli, A.; Tonelli, M.; Travasso, F.; Vetrano, F.; Vocca, H

2004-02-01

Thermal noise in mirror suspension is and will be the most severe fundamental limit to the low-frequency sensitivity of interferometric gravitational wave detectors currently under construction. The technical solutions, adopted in the Virgo detector, optimize the current suspension scheme, but new materials and new designs are needed to further reduce the suspension thermal noise. Silicon fibers are promising candidates both for room temperature advanced detectors and for future cryogenic interferometric detectors.

Problems of thermal IR-imaging in evaluation of burn wounds

International Nuclear Information System (INIS)

Nowakowski, A.

2009-01-01

Results of the research devoted to application of thermal IR-imaging in diagnostics of burn wounds are discussed. The main aim of the work was to develop an effective method for quantitative evaluation of the depth of a burn wound and for classification of regions for surgical treatment. The criterion of determination the area of the wound to be treated surgically is the time, which should not exceed three weeks for natural healing of a burn wound. Prediction that the healing process may last longer is concluded by immediate surgical intervention. We concentrate on using for this purpose QIRT - NDT TI methods (Quantitative Infra-Red Thermography - Non-Destructive Testing Thermal Imaging); especially - active dynamic thermography - ADT. In this work both, classical thermography using a high quality thermal camera as well as ADT are applied and the results of analysis are joined, allowing multimodality diagnostic approach and improved classification of burns requiring surgical treatment. Now our work in application of thermal imaging in determination of burns is continued for around 10 years, as the first publication showing our methodology was presented in 1999. In 2001, during the Thermosense conference, we have been awarded the Andronicos Kantsios Award for the work on Medical applications of model based dynamic thermography. Important reports of our experience in classical as well as ADT thermography are already published. Now we concentrate on practical aspects of the problem, trying to construct a measuring set to be operative even by not experienced staff and meeting all of necessary requirements for clinical applications. (author)

Detection of fatigue damage of high and medium pressure rotor by X-ray diffraction method. Survey and research of nondestructive examination of thermal power generation facilities

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, Tatsuo; Suesada, Yasuhiko; Nishioka, Noriaki; Goto, Toru; Ito, Hitomi; Kadoya, Yoshikuni

1987-03-25

In recent years, the existing thermal power generation facilities have been required to be operated in securing dependability from the standpoints of the operating conditions which have been getting severer and the demands to use them for longer periods, accordingly it is hoped to establish the diagnostic technology of aged deterioration by the non-destructive examination method for the facilities. In the beginning of 1959 the Kansai Electric Power Co. surveyed the current situation of this technology at various thermal power generation turbine facilities and discovered that concerning the diagnostic technology of aged deterioration by the non-destructive examination method, there remained many matters untouched in the basic research field. The company consequently started a survey and research jointly with Mitsubishi Heavy Industries in the first half of 1959. This report summarizes the research on the detection of aged deterioration due to thermal fatigue of Cr-Mo-V rotor material by the X-ray diffraction method which was conducted during the full fiscal year of 1984 and the first half of FY 1985 as a part of the above joint research. With respect to the conditions for the detection method of thermal fatigue damages of dummy grooves of the high and medium pressure rotor by the application of the X-ray diffraction method, it is preferred to measure a diffraction strength curve of the diffraction surface by using a Co tube as X-ray tube and it is also desirable to use a position sensitive proportional counter tube for X-ray detector. (5 figs, 6 refs)

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

Science.gov (United States)

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.

Guided wave crack detection and size estimation in stiffened structures

Science.gov (United States)

Bhuiyan, Md Yeasin; Faisal Haider, Mohammad; Poddar, Banibrata; Giurgiutiu, Victor

2018-03-01

Structural health monitoring (SHM) and nondestructive evaluation (NDE) deals with the nondestructive inspection of defects, corrosion, leaks in engineering structures by using ultrasonic guided waves. In the past, simplistic structures were often considered for analyzing the guided wave interaction with the defects. In this study, we focused on more realistic and relatively complicated structure for detecting any defect by using a non-contact sensing approach. A plate with a stiffener was considered for analyzing the guided wave interactions. Piezoelectric wafer active transducers were used to produce excitation in the structures. The excitation generated the multimodal guided waves (aka Lamb waves) that propagate in the plate with stiffener. The presence of stiffener in the plate generated scattered waves. The direct wave and the additional scattered waves from the stiffener were experimentally recorded and studied. These waves were considered as a pristine case in this research. A fine horizontal semi-circular crack was manufactured by using electric discharge machining in the same stiffener. The presence of crack in the stiffener produces additional scattered waves as well as trapped waves. These scattered waves and trapped wave modes from the cracked stiffener were experimentally measured by using a scanning laser Doppler vibrometer (SLDV). These waves were analyzed and compared with that from the pristine case. The analyses suggested that both size and shape of the horizontal crack may be predicted from the pattern of the scattered waves. Different features (reflection, transmission, and mode-conversion) of the scattered wave signals are analyzed. We found direct transmission feature for incident A0 wave mode and modeconversion feature for incident S0 mode are most suitable for detecting the crack in the stiffener. The reflection feature may give a better idea of sizing the crack.

Thermal gravitational-wave background in the general pre-inflationary scenario

Energy Technology Data Exchange (ETDEWEB)

Wang, Kai; Santos, Larissa; Zhao, Wen [CAS Key Laboratory for Researches in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Chinese Academy of Sciences, Hefei, Anhui 230026 (China); Xia, Jun-Qing, E-mail: ljwk@mail.ustc.edu.cn, E-mail: larissa@ustc.edu.cn, E-mail: xiajq@bnu.edu.cn, E-mail: wzhao7@ustc.edu.cn [Department of Astronomy, Beijing Normal University, Beijing 100875 (China)

2017-01-01

We investigate the primordial gravitational waves (PGWs) in the general scenario where the inflation is preceded by a pre-inflationary stage with the effective equation of state w . Comparing with the results in the usual inflationary models, the power spectrum of PGWs is modified in two aspects: one is the mixture of the perturbation modes caused by he presence of the pre-inflationary period, and the other is the thermal initial state formed at the Planck era of the early Universe. By investigating the observational imprints of these modifications on the B-mode polarization of cosmic microwave background (CMB) radiation, we obtain the constraints on the conformal temperature of the thermal gravitational-wave background T <5.01× 10{sup −4} Mpc{sup −1} and a tensor-to-scalar ratio r <0.084 (95% confident level), which follows the bounds on total number of e-folds N >63.5 for the model with w =1/3, and N >65.7 for that with w =1. By taking into account various noises and the foreground radiations, we forecast the detection possibility of the thermal gravitational-wave background by the future CMBPol mission, and find that if r >0.01, the detection is possible as long as T >1.5× 10{sup −4} Mpc{sup −1}. However, the effect of different w is quite small, and it seems impossible to determine its value from the potential observations of CMBPol mission.

Efficiency evaluation test of waste non-destructive analysis device

International Nuclear Information System (INIS)

Maeda, Kouichi; Ogasawara, Kensuke; Nisizawa, Ichio

2000-03-01

A device for non-destructive analysis of plutonium in alpha solid waste has been installed in NUCEF; Nuclear Fuel Cycle Safety Engineering Research Facility. The device has been designed to determine the amount of radioisotopes in carton-boxes, 45 l steel cans and 200 l steel cans containing relatively low density waste. Considering the waste density and the heterogeneity of radio-sources, the proper distance between the detector and the waste, and the open degree of the collimator have been settled, because real waste may contain several kinds of material and the heterogeneity of radioactivity. It has been confirmed from the evaluation of the detect limit that plutonium of about 8 MBq can be determined with the accuracy of 10% and the device may be proper for the practical application. (author)

Nondestructive characterization of hydrogen concentration in zircaloy cladding tubes with laser ultrasound technique

International Nuclear Information System (INIS)

Yang, Che Hua; Lai, Yu An

2006-01-01

This paper describes a laser ultrasound technique (LUT) for nondestructive characterization of hydrogen concentration (HC) in Zircaloy cladding tubes. With the LUT, guided ultrasonic waves are generated remotely and then propagate in the axial direction of Zircaloy tubes, and finally detected remotely by an optical probe. By measuring the dispersion spectra with the LUT, relations between the dispersion spectra and the HC of the Zircaloy tubes can be established. The LUT is non-contact, capable of remote inspection, and therefore suitable for nondestructive inspection of HC in Zircaloy cladding tubes used in nuclear power plant.

Application of optical interferometric techniques for non-destructive evaluation of novel "green" composite materials

Science.gov (United States)

Pagliarulo, Vito; Russo, Pietro; Bianco, Vittorio; Ferraro, Pietro; Simeoli, Giorgio; Cimino, Francesca; Ruggiero, Berardo

2018-04-01

Nowadays the use of advanced composite materials in aeronautics, both civil and military, in automotive and in sport applications, citing some, is well established. The characteristics of composite materials in terms of weight, fatigue resistance and corrosion resistance make them competitive with respect to conventional ones. On the other side, the fabrication process of the most employed composites reinforced by carbon fibers or glass fibers, needs of complex steps that not always are environmental complaisant. Moreover, such fibers are not themselves "green". For these reasons, in the last decades, the use of natural reinforcing fibers has gained an increasing attention allowing the development of new materials with the same advantages of composite systems but respecting the environment. Furthermore, such materials for their structural complexity are not always compatible with the use of standard non-destructive evaluation as the ultrasounds methods. In this work the efficiency of the employment of optical interferometric techniques as nondestructive evaluation methods in full field modality is proved on novel "green" composite materials. In particular, Electronic Speckle Pattern Interferometry has been tested on different kinds of specimens after flexural tests.

Ultrasonic transverse velocity calibration of standard blocks for use in non-destructive testing

International Nuclear Information System (INIS)

Silva, C E R; Braz, D S; Maggi, L E; Felix, R P B Costa

2015-01-01

Standard blocks are employed in the verification of the equipment used in Ultrasound Non-Destructive Testing. To assure the metrology reliability of all the measurement process, it is necessary to calibrate or certify these Standard blocks. In this work, the transverse wave velocity and main dimensions were assessed according to the specifications ISO Standards. For transverse wave velocity measurement, a 5 MHz transverse wave transducer, a waveform generator, an oscilloscope and a computer with a program developed in LabVIEW TM were used. Concerning the transverse wave velocity calibration, only two Standard blocks of the 4 tested is in accordance with the standard

Ionizing radiations for non-destructive evaluation

International Nuclear Information System (INIS)

Raj, Baldev; Venkataraman, B.

1989-01-01

A state of the art of major non-destructive testing (NDT) techniques based on ionising radiations is presented. These techniques are broadly classified into three categories, namely, radiography, radiation gaging and analytical applications. The basic principles behind each method are explained and salient features of each technique which make it suitable for a particular task are described. Several illustrative applications drawn from the nuclear industry are given. The monograph is intended to serve as an introductory guide to scientist and engineers engaged in NDT activities. (M.G.B.). 32 refs., 13 figs., 5 tabs

Model-based dispersive wave processing: A recursive Bayesian solution

International Nuclear Information System (INIS)

Candy, J.V.; Chambers, D.H.

1999-01-01

Wave propagation through dispersive media represents a significant problem in many acoustic applications, especially in ocean acoustics, seismology, and nondestructive evaluation. In this paper we propose a propagation model that can easily represent many classes of dispersive waves and proceed to develop the model-based solution to the wave processing problem. It is shown that the underlying wave system is nonlinear and time-variable requiring a recursive processor. Thus the general solution to the model-based dispersive wave enhancement problem is developed using a Bayesian maximum a posteriori (MAP) approach and shown to lead to the recursive, nonlinear extended Kalman filter (EKF) processor. The problem of internal wave estimation is cast within this framework. The specific processor is developed and applied to data synthesized by a sophisticated simulator demonstrating the feasibility of this approach. copyright 1999 Acoustical Society of America.

Use of Guided Acoustic Waves to Assess the Effects of Thermal-Mechanical Cycling on Composite Stiffness

Science.gov (United States)

Seale, Michael D.; Madaras, Eric I.

2000-01-01

The introduction of new, advanced composite materials into aviation systems requires it thorough understanding of the long-term effects of combined thermal and mechanical loading. As part of a study to evaluate the effects of thermal-mechanical cycling, it guided acoustic (Lamb) wave measurement system was used to measure the bending and out-of-plane stiffness coefficients of composite laminates undergoing thermal-mechanical loading. The system uses a pulse/receive technique that excites an antisymmetric Lamb mode and measures the time-of-flight over a wide frequency range. Given the material density and plate thickness, the bending and out-of-plane shear stiffnesses are calculated from a reconstruction of the velocity dispersion curve. A series of 16 and 32-ply composite laminates were subjected to it thermal-mechanical loading profile in load frames equipped with special environmental chambers. The composite systems studied were it graphite fiber reinforced amorphous thermoplastic polyimide and it graphite fiber reinforced bismaleimide thermoset. The samples were exposed to both high and low temperature extremes its well as high and low strain profiles. The bending and out-of-plane stiffnesses for composite sample that have undergone over 6,000 cycles of thermal-mechanical loading are reported. The Lamb wave generated elastic stiffness results have shown decreases of up to 20% at 4,936 loading cycles for the graphite/thermoplastic samples and up to 64% at 4,706 loading cycles for the graphite/thermoset samples.

Response of thermal ions to electromagnetic ion cyclotron waves

Science.gov (United States)

Anderson, B. J.; Fuselier, S. A.

1994-01-01

Electromagnetic ion cyclotron waves generated by 10 - 50 keV protons in the Earth's equatorial magnetosphere will interact with the ambient low-energy ions also found in this region. We examine H(+) and He(+) distribution functions from approx. equals 1 to 160 eV using the Hot Plasma Composition Experiment instrument on AMPTE/CCE to investigate the thermal ion response to the waves. A total of 48 intervals were chosen on the basis of electromagnetic ion cyclotron (EMIC) wave activity: 24 with prevalent EMIC waves and 24 with no EMIC waves observed on the orbit. There is a close correlation between EMIC waves and perpendicular heated ion distributions. For protons the perpendicular temperature increase is modest, about 5 eV, and is always observed at 90 deg pitch angles. This is consistent with a nonresonant interaction near the equator. By contrast, He(+) temperatures during EMIC wave events averaged 35 eV and sometimes exceeded 100 eV, indicating stronger interaction with the waves. Furthermore, heated He(+) ions have X-type distributions with maximum fluxes occurring at pitch angles intermediate between field-aligned and perpendicular directions. The X-type He(+) distributions are consistent with a gyroresonant interaction off the equator. The concentration of He(+) relative to H(+) is found to correlate with EMIC wave activity, but it is suggested that the preferential heating of He(+) accounts for the apparent increase in relative He(+) concentration by increasing the proportion of He(+) detected by the ion instrument.

Prospects for determination of thermal history after inflation with future gravitational wave detectors

International Nuclear Information System (INIS)

Kuroyanagi, Sachiko; Nakayama, Kazunori; Saito, Shun

2011-01-01

Thermal history of the Universe between inflation and big-bang nucleosynthesis has not yet been revealed observationally. It will be probed by the detection of primordial gravitational waves generated during inflation, which contain information on the reheating temperature as well as the equation of state of the Universe after inflation. Based on the Fisher information formalism, we examine how accurately the tensor-to-scalar ratio and reheating temperature after inflation can be simultaneously determined with space-based gravitational wave detectors such as the DECI-hertz Interferometer Gravitational-wave Observatory and the Big-Bang Observer. We show that the reheating temperature is best determined if it is around 10 7 GeV for tensor-to-scalar ratio of around 0.1, and explore the detectable parameter space. We also find that equation of state of the early Universe can be also determined accurately enough to distinguish different equation-of-state parameters if the inflationary gravitational waves are successfully detected. Thus, future gravitational wave detectors provide a unique and promising opportunity to reveal the thermal history of the Universe around 10 7 GeV.

Pressure Wave Measurements from Thermal Cook-Off of an HMX Based High Explosive PBX 9501

International Nuclear Information System (INIS)

Garcia, F.; Forbes, J.W.; Tarver, C.M.; Urtiew, P.A.; Greenwood, D.W.; Vandersall, K.S.

2001-01-01

A better understanding of thermal cook-off is important for safe handling and storing explosive devices. A number of safety issues exist about what occurs when a cased explosive thermally cooks off. For example, violence of the events as a function of confinement are important for predictions of collateral damage. This paper demonstrates how adjacent materials can be gauged to measure the resulting pressure wave and how this wave propagates in this adjacent material. The output pulse from the thermal cook-off explosive containing fixture is of obvious interest for assessing many scenarios

Nondestructive Evaluation of Advanced Materials with X-ray Phase Mapping

Science.gov (United States)

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.

Nondestructive evaluation of wall thinning occurred under reinforced plate by MFL method

International Nuclear Information System (INIS)

Kikuchi, Hiroaki; Sato, Kaito; Shimizu, Isamu

2013-01-01

Basic study on applying magnetic flux leakage (MFL) method using ac excitation to a nondestructive evaluation of wall thinning occurred under reinforcing plates in nuclear power plants were performed. Frequently, MFL method by means of dc field for exciting specimens is adopted, and only intensity of magnetic flux density is evaluated. On the other hand, MFL with alternating current enable us to utilize not only amplitude of magnetic flux density but also phase difference, which contributes to evaluation with higher accuracy. Here, specimens with slit and pipe with imitated wall thinning are prepared and magnetized using magnetic yoke with ac field, and then the leakage magnetic flux density and the phase difference on the specimen surface are investigated. Additionally, specimens imitated wall thinning occurred under reinforcing plates were investigated by MFL with ac excitation. (author)

Laser active thermography for non-destructive testing

International Nuclear Information System (INIS)

Semerok, A.; Grisolia, C.; Fomichev, S.V.; Thro, P.Y.

2013-01-01

Thermography methods have found their applications in different fields of human activity. The non-destructive feature of these methods along with the additional advantage by automated remote control and tests of nuclear installations without personnel attendance in the contaminated zone are of particular interest. Laser active pyrometry and laser lock-in thermography for in situ non-destructive characterization of micrometric layers on graphite substrates from European tokamaks were under extensive experimental and theoretical studies in CEA (France). The studies were aimed to obtain layer characterization with cross-checking the layer thermal contact coefficients determined by active laser pyrometry and lock-in thermography. The experimental installation comprised a Nd-YAG pulsed repetition rate laser (1 Hz - 10 kHz repetition rate frequency, homogeneous spot) and a home-made pyrometer system based on two pyrometers for the temperature measurements in 500 - 2600 K range. For both methods, the layer characterization was provided by the best fit of the experimental results and simulations. The layer thermal contact coefficients determined by both methods were quite comparable. Though there was no gain in the measurements accuracy, lock-in measurements have proved their advantage as being much more rapid. The obtained experimental and theoretical results are presented. Some practical applications and possible improvements of the methods are discussed. (authors)

Laser active thermography for non-destructive testing

Science.gov (United States)

Semerok, A.; Grisolia, C.; Fomichev, S. V.; Thro, P.-Y.

2013-11-01

Thermography methods have found their applications in different fields of human activity. The non-destructive feature of these methods along with the additional advantage by automated remote control and tests of nuclear installations without personnel attendance in the contaminated zone are of particular interest. Laser active pyrometry and laser lock-in thermography for in situ non-destructive characterization of micrometric layers on graphite substrates from European tokamaks were under extensive experimental and theoretical studies in CEA (France). The studies were aimed to obtain layer characterization with cross-checking the layer thermal contact coefficients determined by active laser pyrometry and lock-in thermography. The experimental installation comprised a Nd-YAG pulsed repetition rate laser (1 Hz - 10 kHz repetition rate frequency, homogeneous spot) and a home-made pyrometer system based on two pyrometers for the temperature measurements in 500 - 2600 K range. For both methods, the layer characterization was provided by the best fit of the experimental results and simulations. The layer thermal contact coefficients determined by both methods were quite comparable. Though there was no gain in the measurements accuracy, lock-in measurements have proved their advantage as being much more rapid. The obtained experimental and theoretical results are presented. Some practical applications and possible improvements of the methods are discussed.

Prospects on the application of HTS SQUID magnetometry to nondestructive evaluation (NDE)

Science.gov (United States)

Weinstock, H.

1993-04-01

In light of recent advances in the fabrication of low-noise HTS SQUIDs, a review is presented on the use of LTS SQUID magnetometry for nondestructive evaluation (NDE). Examples are given on applications relating to defects in steel, subsurface cracks in aircraft frames, and voids in non-metallic structures. HTS SQUIDs may make a significant difference in the acceptance of these applications because sensing coils will be closer to a sample under test, there will be greater instrument portability and the problem of bringing liquid helium to remote locations will be eliminated.

Thermal and ghost reflection modeling for a 180-deg. field-of-view long-wave infrared lens

Science.gov (United States)

Shi, Weimin; Couture, Michael E.

2001-03-01

Optics 1, Inc. has successfully designed and developed a 180 degree(s) field of view long wave infrared lens for USAF/AFRL under SBIR phase I and II funded projects in support of the multi-national Programmable Integrated Ordinance Suite (PIOS) program. In this paper, a procedure is presented on how to evaluate image degradation caused by asymmetric aerodynamic dome heating. In addition, a thermal gradient model is proposed to evaluate degradation caused by axial temperature gradient throughout the entire PIOS lens. Finally, a ghost reflection analysis is demonstrated with non-sequential model.

Nondestructive inspection of concrete structures by nonlinear elastic wave spectroscopy methods

Czech Academy of Sciences Publication Activity Database

Převorovský, Zdeněk; Krofta, Josef; Kober, Jan; Chlada, Milan

2014-01-01

Roč. 19, č. 12 (2014) ISSN 1435-4934. [European Conference on Non-Destructive Testing (ECNDT 2014) /11./. Praha, 06.10.2014-10.10.2014] Institutional support: RVO:61388998 Keywords : civil engineering * nuclear * power plant * structural health monitoring (SHM) * signal processing * other medhods * ultrasonic testing (UT) Subject RIV: BI - Acoustics http://www.ndt.net/events/ECNDT2014/app/content/Slides/642_Prevorovsky_Rev1.pdf

Advanced quantitative magnetic nondestructive evaluation methods - Theory and experiment

Science.gov (United States)

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.

Non-destructive testing of electronic parts

International Nuclear Information System (INIS)

Widenhorn, G.

1980-01-01

The requirements on quality, safety, faultlessness and reliability of electric components increase because of the high complexity of the appliances in which they are used. By means of examples a survey is given on the common non-destructive testing methods, testing operation and evaluation of test results on electric components which must meet in their application high requirements on quality and reliability. Defective components, especially those with hidden failures are sorted out by non-destructive testing and the failure frequency of the appliances and plants in testing and operation is greatly reduced. (orig.) [de

Nondestructive characterization of austenitic stainless steels

International Nuclear Information System (INIS)

Jayakumar, T.; Kumar, Anish

2010-01-01

The paper presents an overview of the non-destructive methodologies developed at the authors' laboratory for characterization of various microstructural features, residual stresses and corrosion in austenitic stainless steels. Various non-destructive evaluation (NDE) parameters such as ultrasonic velocity, ultrasonic attenuation, spectral analysis of the ultrasonic signals, magnetic hysteresis parameters and eddy current amplitude have been used for characterization of grain size, precipitation behaviour, texture, recrystallization, thermomechanical processing, degree of sensitization, formation of martensite from metastable austenite, assessment of residual stresses, degree of sensitization and propensity for intergranular corrosion in different austenitic steels. (author)

Thermal-wave balancing flow sensor with low-drift power feedback

NARCIS (Netherlands)

Dijkstra, Marcel; Lammerink, Theodorus S.J.; Pjetri, O.; de Boer, Meint J.; Berenschot, Johan W.; Wiegerink, Remco J.; Elwenspoek, Michael Curt

2014-01-01

A control system using a low-drift power-feedback signal was implemented applying thermal waves, giving a sensor output independent of resistance drift and thermo-electric offset voltages on interface wires. Kelvin-contact sensing and power control is used on heater resistors, thereby inhibiting the

Operation of the EPRI Nondestructive Evaluation Center

International Nuclear Information System (INIS)

Stone, R.M.; Ammirato, F.V.; Becker, F.L.

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

Superconducting Quantum Interferometers for Nondestructive Evaluation

Directory of Open Access Journals (Sweden)

M. I. Faley

2017-12-01

Full Text Available We review stationary and mobile systems that are used for the nondestructive evaluation of room temperature objects and are based on superconducting quantum interference devices (SQUIDs. The systems are optimized for samples whose dimensions are between 10 micrometers and several meters. Stray magnetic fields from small samples (10 µm–10 cm are studied using a SQUID microscope equipped with a magnetic flux antenna, which is fed through the walls of liquid nitrogen cryostat and a hole in the SQUID’s pick-up loop and returned sidewards from the SQUID back to the sample. The SQUID microscope does not disturb the magnetization of the sample during image recording due to the decoupling of the magnetic flux antenna from the modulation and feedback coil. For larger samples, we use a hand-held mobile liquid nitrogen minicryostat with a first order planar gradiometric SQUID sensor. Low-Tc DC SQUID systems that are designed for NDE measurements of bio-objects are able to operate with sufficient resolution in a magnetically unshielded environment. High-Tc DC SQUID magnetometers that are operated in a magnetic shield demonstrate a magnetic field resolution of ~4 fT/√Hz at 77 K. This sensitivity is improved to ~2 fT/√Hz at 77 K by using a soft magnetic flux antenna.

Modelling of waves propagation on irregular surfaces using ray tracing and GTD approaches: Application to head waves simulation in TOFD inspections for NDT

Science.gov (United States)

Ferrand, Adrien; Darmon, Michel; Chatillon, Sylvain; Deschamps, Marc

2014-04-01

The Time of Flight Diffraction (TOFD) technique is a classical ultrasonic method used in ultrasonic non-destructive evaluation, which allows a precise positioning and a quantitative size evaluation of cracks in the inspected material. Among the typical phenomena arising in the current TOFD inspection, the so-called "head wave" is the first contribution reaching the receiver. The head wave propagation on a planar interface is well known and identified as a critical refraction taking place on the material surface. On irregular surfaces, it has been shown that the head wave results from the melting of surface and bulk waves mechanisms and that surface irregularities are responsible for numerous diffractions of the incident head wave. To simulate such behaviour, a model has been developed using a ray tracing technique based on time of flight minimization (generalized Fermat's principle). It enables the calculation of the ray path and the corresponding time of flight of all waves propagating in the material, including the head wave. To obtain a complete propagation model for these waves (both trajectory and amplitude), the integration of Geometrical Theory of Diffraction (GTD) models is currently performed by coupling them with the ray-based approach discussed above.

Additive Manufacturing (AM) Activities and Non-Destructive Evaluation (NDE) at GSFC

Science.gov (United States)

Jones, Justin S.

2017-01-01

NASA personnel will be meeting with a delegation from the Japan Aerospace Exploration Agency (JAXA) Office of Safety and Mission Assurance (OSMA) at Langley Research Center on 2217 through 3217. The purpose of the meeting is a technical interchange between NASA and JAXA to discuss Non-Destructive Evaluation (NDE) of Additive Manufacturing (AM) parts and the HALT process (relates to accelerated life testing). The visitors will be a small group of Japanese citizens. Goddard Space Flight Center (GSFC) has been asked to participate in the meeting, either in person or via teleconference. This presentation covers NDE efforts at GSFC and provides a cursory overview of AM and lab capabilities.

Stress wave timing nondestructive evaluation tools for inspecting historic structures : a guide for use and interpretation.

Science.gov (United States)

Robert Ross; Roy F. Pellerin; Norbert Volny; William W. Salsig; Robert H. Falk

2000-01-01

This guide was prepared to assist inspectors in the use of stress wave timing instruments and various methods of locating and defining areas of decay in timber members in historic structures. The first two sections provide (a) background information regarding conventional methods to locate and measure decay in historic structures and (b) the principles of stress wave...

Recent advances in seismic non-destructive testing of concrete plate like structures

International Nuclear Information System (INIS)

Ryden, N.; Kristensen, A.; Jovall, O.

2009-01-01

This paper describes recent advances in seismic/acoustic non-destructive testing of concrete containment walls. The presented technique is focused on the characterization of the mean stiffness (seismic velocities) and thickness of the containment wall. The Impact Echo (IE) method is a well-established technique to measure the thickness of concrete plates or to locate defects in concrete plate like structures. The method relies on a good estimate of the mean velocity through the thickness of the plate and a precisely measured thickness resonant frequency. Recently the underlying theory of the IE method has been redefined and improved based on Lamb waves in a free plate. Based on this theory we have developed a new data processing technique where both propagating and standing Lamb waves are analysed in a combined manner using multichannel data. With this approach the mean velocity through the plate thickness is evaluated by using the fundamental mode Lamb wave dispersion curves. The accuracy and detection ability of the measured resonant frequency is improved by utilizing both amplitude and phase information from the multichannel record. The method has been tested on several nuclear power plants in Sweden and Finland and proved to be more robust compared to conventional IE and surface wave measurements

Effects of vortex-like and non-thermal ion distributions on non-linear dust-acoustic waves

International Nuclear Information System (INIS)

Mamun, A.A.; Cairns, R.A.; Shukla, P.K.

1996-01-01

The effects of vortex-like and non-thermal ion distributions are incorporated in the study of nonlinear dust-acoustic waves in an unmagnetized dusty plasma. It is found that owing to the departure from the Boltzmann ion distribution to a vortex-like phase space distribution, the dynamics of small but finite amplitude dust-acoustic waves is governed by a modified Kortweg endash de Vries equation. The latter admits a stationary dust-acoustic solitary wave solution, which has larger amplitude, smaller width, and higher propagation velocity than that involving adiabatic ions. On the other hand, consideration of a non-thermal ion distribution provides the possibility of coexistence of large amplitude rarefactive as well as compressive dust-acoustic solitary waves, whereas these structures appear independently when the wave amplitudes become infinitely small. The present investigation should help us to understand the salient features of the non-linear dust-acoustic waves that have been observed in a recent numerical simulation study. copyright 1996 American Institute of Physics

Development of a guided wave simulator and its application to monitoring of pipe wall thinning

International Nuclear Information System (INIS)

Furukawa, Akinori; Kojima, Fumio

2009-01-01

Motivated by growing demand for quantitative nondestructive evaluation of pipe wall thinning, the aim of this paper is to develop a simulator for guided wave analysis. First, an inspection system can be represented by a linear elastic system in cylindrical coordinates. Secondly a dynamical numerical scheme for wave propagation on a pipe wall is proposed based on Fourier-Galerkin approach. Finally, the effectiveness and validity of the proposed method are shown in computational experiments. (author)

Technologies for Nondestructive Evaluation of Surfaces and Thin Coatings

Science.gov (United States)

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

ANL-1(A) - Development of nondestructive evaluation methods for structural ceramics

International Nuclear Information System (INIS)

Ellingson, W.A.; Roberts, R.A.; Gopalsami, N.; Dieckman, S.; Hentea, T.; Vaitekunas, J.J.

1989-01-01

This section includes the following papers: Development of Nondestructive Evaluation Methods for Structural Ceramics; Effects of Flaws on the Fracture Behavior of Structural Ceramics; Design, Fabrication, and Interface Characterization of Ceramic Fiber-Ceramic Matrix Composites; Development of Advanced Fiber-Reinforced Ceramics; Modeling of Fibrous Preforms for CVD Infiltration; NDT of Advanced Ceramic Composite Materials; Joining of Silicon Carbide Reinforced Ceramics; Superconducting Film Fabrication Research; Short Fiber Reinforced Structural Ceramics; Structural Reliability and Damage Tolerance of Ceramic Composites for High-Temperature Applications; Fabrication of Ceramic Fiber-Ceramic Matrix Composites by Chemical Vapor Infiltration; Characterization of Fiber-CVD Matrix interfacial Bonds; Microwave Sintering of Superconducting Ceramics; Improved Ceramic Composites Through Controlled Fiber-Matrix Interactions; Evaluation of Candidate Materials for Solid Oxide Fuel Cells; Ceramic Catalyst Materials: Hydrous Metal Oxide Ion-Exchange Supports for Coal Liquefaction; and Investigation of Properties and Performance of Ceramic Composite Components

Nondestructive methods for the structural evaluation of wood floor systems in historic buildings : preliminary results : [abstract

Science.gov (United States)

Zhiyong Cai; Michael O. Hunt; Robert J. Ross; Lawrence A. Soltis

1999-01-01

To date, there is no standard method for evaluating the structural integrity of wood floor systems using nondestructive techniques. Current methods of examination and assessment are often subjective and therefore tend to yield imprecise or variable results. For this reason, estimates of allowable wood floor loads are often conservative. The assignment of conservatively...

Effect of the Environmental Stimuli upon the Human Body in Winter Outdoor Thermal Environment

Directory of Open Access Journals (Sweden)

Yoshihito Kurazumi

2013-01-01

Full Text Available In order to manage the outdoor thermal environment with regard to human health and the environmental impact of waste heat, quantitative evaluations are indispensable. It is necessary to use a thermal environment evaluation index. The purpose of this paper is to clarify the relationship between the psychological thermal responses of the human body and winter outdoor thermal environment variables. Subjective experiments were conducted in the winter outdoor environment. Environmental factors and human psychological responses were measured. The relationship between the psychological thermal responses of the human body and the outdoor thermal environment index ETFe (enhanced conduction-corrected modified effective temperature in winter was shown. The variables which influence the thermal sensation vote of the human body are air temperature, long-wave thermal radiation and short-wave solar radiation. The variables that influence the thermal comfort vote of the human body are air temperature, humidity, short-wave solar radiation, long-wave thermal radiation, and heat conduction. Short-wave solar radiation, and heat conduction are among the winter outdoor thermal environment variables that affect psychological responses to heat. The use of thermal environment evaluation indices that comprise short-wave solar radiation and heat conduction in winter outdoor spaces is a valid approach.

Effect of the Environmental Stimuli upon the Human Body in Winter Outdoor Thermal Environment

Science.gov (United States)

Kurazumi, Yoshihito; Kondo, Emi; Ishii, Jin; Sakoi, Tomonori; Fukagawa, Kenta; Bolashikov, Zhecho Dimitrov; Tsuchikawa, Tadahiro; Matsubara, Naoki; Horikoshi, Tetsumi

2013-01-01

In order to manage the outdoor thermal environment with regard to human health and the environmental impact of waste heat, quantitative evaluations are indispensable. It is necessary to use a thermal environment evaluation index. The purpose of this paper is to clarify the relationship between the psychological thermal responses of the human body and winter outdoor thermal environment variables. Subjective experiments were conducted in the winter outdoor environment. Environmental factors and human psychological responses were measured. The relationship between the psychological thermal responses of the human body and the outdoor thermal environment index ETFe (enhanced conduction-corrected modified effective temperature) in winter was shown. The variables which influence the thermal sensation vote of the human body are air temperature, long-wave thermal radiation and short-wave solar radiation. The variables that influence the thermal comfort vote of the human body are air temperature, humidity, short-wave solar radiation, long-wave thermal radiation, and heat conduction. Short-wave solar radiation, and heat conduction are among the winter outdoor thermal environment variables that affect psychological responses to heat. The use of thermal environment evaluation indices that comprise short-wave solar radiation and heat conduction in winter outdoor spaces is a valid approach. PMID:23861691

Thermal Conditions in the City of Poznań (Poland during Selected Heat Waves

Directory of Open Access Journals (Sweden)

Marek Półrolniczak

2018-01-01

Full Text Available The aim of the study was to characterise the occurrence of hot days and heat waves in Poznań in the 1966–2015 period, as well as to describe the thermal conditions in the city during selected heat waves between 2008 and 2015. The basis of the study was the daily maximum and minimum air temperature values for Poznań–Ławica station from 1966–2015 and the daily values of air temperature from eight measuring points located in the city in various land types from 2008 to 2015. A hot day was defined as a day with Tmax above the 95th annual percentile (from 1966 to 2015, while a heat wave was assumed to be at least five consecutive hot days. The research study conducted shows the increase of Tmax, number of hot days and frequency of heat waves in Poznań over the last 50 years. Across the area of the city (differentiation of urban area types according to Urban Atlas 2012, there was a great diversity of thermal conditions during the heat waves analysed.

Nondestructive testing: welding industry

International Nuclear Information System (INIS)

Raj, Baldev; Subramanian, C.V.

1992-01-01

This chapter highlights various conventional and advanced nondestructive testing (NDT) techniques that have been used for weld evaluation. Welding Codes and Standards of International and National organisations that have been followed in India for various weld evaluation purposes are also included. The chapter also emphasises the importance of NDT by way of a few case studies that have been carried out on important critical welded components. (author). 12 refs., 17 figs., 1 appendix

Proceedings CORENDE: Regional congress on nondestructive and structural evaluation; Actas CORENDE: Congreso regional de ensayos no destructivos y estructurales

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-12-31

Works are presented at the CORENDE: Regional Congress on Nondestructive and Structural Evaluation organized by the National Atomic Energy Commission and the National Technological University (Mendoza). This congress wants to be the forum where people from research, industry and marketing might meet and discuss ideas towards the fostering of these new cultural habits. Papers covering all disciplines contributing to the evaluation of components, systems and structures are welcome: nondestructive evaluation methods and techniques (ultrasound, eddy currents and other electromagnetic methods, acoustic emission, radiography, thermography, leak testing, dye-penetrants, visual inspection, etc.), personnel certification, welding inspection, nondestructive metallography, optics and lasers, fluid-structure interaction, vibrations, extensometry, modelling of structures refs., ills. [Espanol] Se presentan trabajos de CORENDE: Congreso Regional de Ensayos no Destructivos y Estructurales organizado por la Comision Nacional de Energia Atomica y la Universidad Tecnologica Nacional (Mendoza). Este congreso se propone como un foro de discusion, donde, desde la investigacion hasta la produccion y comercializacion, se intercambien y discutan ideas que sirvan de guia para fomentar ese necesario cambio cultural. Los topicos de discusion incluyen a todas las disciplinas presentes en la evaluacion de componentes, sistemas y estructuras: tecnicas no destructivas (ultrasonido, corrientes inducidas, radiografia industrial, emision acustica, particulas magnetizables, termografia, liquidos penetrantes, ensayos de perdidas, inspeccion visual, etc.), certificacion de personal, inspeccion en soldaduras, replicas metalograficas, tecnicas opticas y laser, interaccion fluido-estructura, vibraciones, extensometria, modelado de estructuras

Revisiting the thermal effect on shock wave propagation in weakly ionized plasmas

International Nuclear Information System (INIS)

Zhou, Qianhong; Dong, Zhiwei; Yang, Wei

2016-01-01

Many researchers have investigated shock propagation in weakly ionized plasmas and observed the following anomalous effects: shock acceleration, shock recovery, shock weakening, shock spreading, and splitting. It was generally accepted that the thermal effect can explain most of the experimental results. However, little attention was paid to the shock recovery. In this paper, the shock wave propagation in weakly ionized plasmas is studied by fluid simulation. It is found that the shock acceleration, weakening, and splitting appear after it enters the plasma (thermal) region. The shock splits into two parts right after it leaves the thermal region. The distance between the splitted shocks keeps decreasing until they recover to one. This paper can explain a whole set of features of the shock wave propagation in weakly ionized plasmas. It is also found that both the shock curvature and the splitting present the same photoacoustic deflection (PAD) signals, so they cannot be distinguished by the PAD experiments.

The role played by thermal feedback in heated Farley-Buneman waves at high latitudes

Directory of Open Access Journals (Sweden)

J.-P. St.-Maurice

2000-05-01

Full Text Available It is becoming increasingly clear that electron thermal effects have to be taken into account when dealing with the theory of ionospheric instabilities in the high-latitude ionosphere. Unfortunately, the mathematical complexity often hides the physical processes at work. We follow the limiting cases of a complex but systematic generalized fluid approach to get to the heart of the thermal processes that affect the stability of E region waves during electron heating events. We try to show as simply as possible under what conditions thermal effects contribute to the destabilization of strongly field-aligned (zero aspect angle Farley-Buneman modes. We show that destabilization can arise from a combination of (1 a reduction in pressure gradients associated with temperature fluctuations that are out of phase with density fluctuations, and (2 thermal diffusion, which takes the electrons from regions of enhanced temperatures to regions of negative temperature fluctuations, and therefore enhanced densities. However, we also show that, contrary to what has been suggested in the past, for modes excited along the E0×B direction thermal feedback decreases the growth rate and raises the threshold speed of the Farley-Buneman instability. The increase in threshold speed appears to be important enough to explain the generation of `Type IV' waves in the high-latitude ionosphere.Key words: Ionosphere (auroral ionosphere; iono- spheric irregularities; plasma waves and instabilities

Lamb Wave Damage Quantification Using GA-Based LS-SVM

Directory of Open Access Journals (Sweden)

Fuqiang Sun

2017-06-01

Full Text Available Lamb waves have been reported to be an efficient tool for non-destructive evaluations (NDE for various application scenarios. However, accurate and reliable damage quantification using the Lamb wave method is still a practical challenge, due to the complex underlying mechanism of Lamb wave propagation and damage detection. This paper presents a Lamb wave damage quantification method using a least square support vector machine (LS-SVM and a genetic algorithm (GA. Three damage sensitive features, namely, normalized amplitude, phase change, and correlation coefficient, were proposed to describe changes of Lamb wave characteristics caused by damage. In view of commonly used data-driven methods, the GA-based LS-SVM model using the proposed three damage sensitive features was implemented to evaluate the crack size. The GA method was adopted to optimize the model parameters. The results of GA-based LS-SVM were validated using coupon test data and lap joint component test data with naturally developed fatigue cracks. Cases of different loading and manufacturer were also included to further verify the robustness of the proposed method for crack quantification.

Lamb Wave Damage Quantification Using GA-Based LS-SVM.

Science.gov (United States)

Sun, Fuqiang; Wang, Ning; He, Jingjing; Guan, Xuefei; Yang, Jinsong

2017-06-12

Lamb waves have been reported to be an efficient tool for non-destructive evaluations (NDE) for various application scenarios. However, accurate and reliable damage quantification using the Lamb wave method is still a practical challenge, due to the complex underlying mechanism of Lamb wave propagation and damage detection. This paper presents a Lamb wave damage quantification method using a least square support vector machine (LS-SVM) and a genetic algorithm (GA). Three damage sensitive features, namely, normalized amplitude, phase change, and correlation coefficient, were proposed to describe changes of Lamb wave characteristics caused by damage. In view of commonly used data-driven methods, the GA-based LS-SVM model using the proposed three damage sensitive features was implemented to evaluate the crack size. The GA method was adopted to optimize the model parameters. The results of GA-based LS-SVM were validated using coupon test data and lap joint component test data with naturally developed fatigue cracks. Cases of different loading and manufacturer were also included to further verify the robustness of the proposed method for crack quantification.

Photothermal depth profiling: Comparison between genetic algorithms and thermal wave backscattering (abstract)

Science.gov (United States)

Li Voti, R.; Sibilia, C.; Bertolotti, M.

2003-01-01

Photothermal depth profiling has been the subject of many papers in the last years. Inverse problems on different kinds of materials have been identified, classified, and solved. A first classification has been done according to the type of depth profile: the physical quantity to be reconstructed is the optical absorption in the problems of type I, the thermal effusivity for type II, and both of them for type III. Another classification may be done depending on the time scale of the pump beam heating (frequency scan, time scan), or on its geometrical symmetry (one- or three-dimensional). In this work we want to discuss two different approaches, the genetic algorithms (GA) [R. Li Voti, C. Melchiorri, C. Sibilia, and M. Bertolotti, Anal. Sci. 17, 410 (2001); R. Li Voti, Proceedings, IV Int. Workshop on Advances in Signal Processing for Non-Destructive Evaluation of Materials, Quebec, August 2001] and the thermal wave backscattering (TWBS) [R. Li Voti, G. L. Liakhou, S. Paoloni, C. Sibilia, and M. Bertolotti, Anal. Sci. 17, 414 (2001); J. C. Krapez and R. Li Voti, Anal. Sci. 17, 417 (2001)], showing their performances and limits of validity for several kinds of photothermal depth profiling problems: The two approaches are based on different mechanisms and exhibit obviously different features. GA may be implemented on the exact heat diffusion equation as follows: one chromosome is associated to each profile. The genetic evolution of the chromosome allows one to find better and better profiles, eventually converging towards the solution of the inverse problem. The main advantage is that GA may be applied to any arbitrary profile, but several disadvantages exist; for example, the complexity of the algorithm, the slow convergence, and consequently the computer time consumed. On the contrary, TWBS uses a simplified theoretical model of heat diffusion in inhomogeneous materials. According to such a model, the photothermal signal depends linearly on the thermal effusivity

Evaluation of thermal efficiency and energy conversion of thermoacoustic Stirling engines

International Nuclear Information System (INIS)

Zhong Junhu; Zheng Yuli; Qing Li; Qiang Li

2010-01-01

Thermodynamic cycle transferring heat and work was executed in thermoacoustic engines, when the acoustic resonators substituted the moving mechanical components of the traditional heat engines. Based on the traveling-wave phasing and reversible heat transfer, thermoacoustic Stirling engines could achieve 70% of the Carnot efficiency theoretically, if the inevitable viscous dissipation in resonators was also counted as exported power. It should be pointed out an error on this efficiency evaluation in the previous literatures. More than 70% of the acoustic power production was often consumed by the side-branch resonator that was the essential configuration to build up a thermoacoustic Stirling engine. According to the simulation results and some experimental data, the actual available acoustic power consumed by the acoustic loads was restricted by the operating peak-to-mean pressure ratio, i.e. |p 1 /p m |. When the peak-to-mean pressure ratio operated on 4-6.5%, the thermal efficiency and power density of the available acoustic power reached higher levels. But the available acoustic power would approach zero when |p 1 /p m | attained 10%. It was approved that the turbulence oscillation occurred on the higher |p 1 /p m | (usually >4%) was the main reason of the excess dissipation in the side-branch resonator. This character of the available power limited the wide application of thermoacoustic Stirling engines. The evaluation of thermal efficiency and energy conversion also indicated the improving direction of thermoacoustic Stirling engines. Generators driven by the thermoacoustic Stirling engines were an effective way, due to the elimination of the side-branch resonator. To achieve a high power density and a high pressure ratio on the higher available power efficiency level, the standing-wave thermoacoustic engines might outvie the traveling-wave thermoacoustic engines. To enjoy the best features of standing-wave engines and traveling-wave engines simultaneously

Virtual reality presentation for nondestructive evaluation of rebar corrosion in concrete based on IBEM

International Nuclear Information System (INIS)

Kyung, Je Woon; Leelarkiet, V.; Ohtsu, Masayasu; Yokata, Masaru

2004-01-01

In order to evaluate the corrosion of reinforcing steel-bars (rebar) in concrete, a nondestructive evaluation by the half-cell potential method is currently applied. In this study, potentials measured on a concrete surface are compensated into those on the concrete-rebar interface by the inverse boundary element method (IBEM). Because these potentials are obtained three-dimensionally (3-D), 3-D visualization is desirable. To this end, a visualization system has been developed by using VRML (Virtual Reality Modeling Language). As an application, results of a reinforced concrete (RC) slab with corroded rebars are visualized and discussed.

Guided wave radiation in a finite-sized metallic or composite plate-like structure for its nondestructive testing

International Nuclear Information System (INIS)

Stevenin, Mathilde

2016-01-01

Different models are developed to provide generic tools for simulating nondestructive methods relying on elastic guided waves applied to metallic or composite plates. Various inspection methods of these structures exist or are under study. Most of them make use of ultrasonic sources of finite size; all are sensitive to reflection phenomena resulting from the finite size of the monitored objects. The developed models deal with transducer diffraction effects and edge reflection. As the interpretation of signals measured in guided wave inspection often uses the concept of modes, the models themselves are explicitly modal. The case of isotropic plates (metal) and anisotropic (multilayer composites) are considered; a general approach under the stationary phase approximation allows us to consider all the cases of interest. For the first, the validity of a Fraunhofer-like approximation leads to a very efficient computation of the direct and reflected fields radiated by a source. For the second, special attention is paid to the treatment of caustics. The stationary phase approximation being difficult to generalize, a model (so-called 'pencil model') of more geometrical nature is proposed with a high degree of genericity. It chains terms of isotropic or anisotropic propagation and terms of interaction with a boundary. The equivalence of the stationary phase approximation and the pencil model is demonstrated in the case of the radiation and reflection in an isotropic plate, for which an experimental validation is proceeded. (author) [fr

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

Science.gov (United States)

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.

Propagation of flexural waves in inhomogeneous plates exhibiting hysteretic nonlinearity: Nonlinear acoustic black holes.

Science.gov (United States)

Gusev, Vitalyi E; Ni, Chenyin; Lomonosov, Alexey; Shen, Zhonghua

2015-08-01

Theory accounting for the influence of hysteretic nonlinearity of micro-inhomogeneous material on flexural wave in the plates of continuously varying thickness is developed. For the wedges with thickness increasing as a power law of distance from its edge strong modifications of the wave dynamics with propagation distance are predicted. It is found that nonlinear absorption progressively disappearing with diminishing wave amplitude leads to complete attenuation of acoustic waves in most of the wedges exhibiting black hole phenomenon. It is also demonstrated that black holes exist beyond the geometrical acoustic approximation. Applications include nondestructive evaluation of micro-inhomogeneous materials and vibrations damping. Copyright © 2015 Elsevier B.V. All rights reserved.

ICRF Wave Propagation and Absorption in Plasmas with Non-thermal Populations

International Nuclear Information System (INIS)

Dumont, R.J.; Phillips, C.K.; Smithe, D.N.

2002-01-01

Some results obtained with the one dimensional, all orders, full wave code METS, which has been successfully employed in the past to describe a number of experiments, are reported. By using massively parallel computers, this code has been extended to handle non-thermal populations. Various physical situations, in which non-Maxwellian species are expected to be encountered, are studied, such as simultaneous neutral beam injection and high harmonic fast wave electron heating or ion cyclotron resonance heating in the presence of fusion products

Shock wave collisions and thermalization in AdS5

International Nuclear Information System (INIS)

Kovchegov, Yuri V.

2011-01-01

We study heavy ion collisions at strong 't Hooft coupling using AdS/CFT correspondence. According to the AdS/CFT dictionary heavy ion collisions correspond to gravitational shock wave collisions in AdS 5 . We construct the metric in the forward light cone after the collision perturbatively through expansion of Einstein equations in graviton exchanges. We obtain an analytic expression for the metric including all-order graviton exchanges with one shock wave, while keeping the exchanges with another shock wave at the lowest order. We read off the corresponding energy-momentum tensor of the produced medium. Unfortunately this energy-momentum tensor does not correspond to ideal hydrodynamics, indicating that higher order graviton exchanges are needed to construct the full solution of the problem. We also show that shock waves must completely stop almost immediately after the collision in AdS 5 , which, on the field theory side, corresponds to complete nuclear stopping due to strong coupling effects, likely leading to Landau hydrodynamics. Finally, we perform trapped surface analysis of the shock wave collisions demonstrating that a bulk black hole, corresponding to ideal hydrodynamics on the boundary, has to be created in such collisions, thus constructing a proof of thermalization in heavy ion collisions at strong coupling. (author)

Fabrication of imitative stress corrosion cracking using diffusion bonding for the development of nondestructive testing and evaluations

International Nuclear Information System (INIS)

Yusa, Noritaka; Hashizume, Hidetoshi

2011-01-01

This study reports a method to fabricate imitative stress corrosion cracking suitable for the development of nondestructive testing and evaluation methods. The method is to embed a partially-bonded region, which simulates the characteristics of stress corrosion cracking, inside a material by bonding together surfaces having artificial grooves. Since the sizes of the grooves are smaller than the spatial resolution of nondestructive testing method applied, the material property realized can be regarded as uniform as the actual stress corrosion cracking. The grooves are introduced using mechanical machining, which enables one to control the characteristics of the simulated flaw. Four specimens made of type 316L austenitic stainless steel are fabricated. The method is demonstrated by visual and eddy current examinations. (author)

Monocrystalline fibres for low thermal noise suspension in advanced gravitational wave detectors

International Nuclear Information System (INIS)

Amico, P; Bosi, L; Gammaitoni, L; Losurdo, G; Marchesoni, F; Mazzoni, M; Parisi, D; Punturo, M; Stanga, R; Toncelli, A; Tonelli, M; Travasso, F; Vetrano, F; Vocca, H

2004-01-01

Thermal noise in mirror suspension will be the most severe fundamental limit to the low-frequency sensitivity of future interferometric gravitational wave detectors. We propose a new type of materials to realize low thermal noise suspension in such detectors. Monocrystalline suspension fibres are good candidates both for cryogenic and for ambient temperature interferometers. Material characteristics and a production facility are described in this paper

Monocrystalline fibres for low thermal noise suspension in advanced gravitational wave detectors

Energy Technology Data Exchange (ETDEWEB)

Amico, P [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, Virgo Project, I-06100 Perugia (Italy); Bosi, L [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, Virgo Project, I-06100 Perugia (Italy); Gammaitoni, L [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, Virgo Project, I-06100 Perugia (Italy); Losurdo, G [Istituto Nazionale di Fisica Nucleare, Sezione di Firenze/Urbino, Florence (Italy); Marchesoni, F [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, Virgo Project, I-06100 Perugia (Italy); Mazzoni, M [Istituto Nazionale di Fisica Nucleare, Sezione di Firenze/Urbino, Florence (Italy); Parisi, D [NEST-Dipartimento di Fisica, Universita di Pisa, Pisa (Italy); Punturo, M [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, Virgo Project, I-06100 Perugia (Italy); Stanga, R [Istituto Nazionale di Fisica Nucleare, Sezione di Firenze/Urbino, Florence (Italy); Toncelli, A [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, Pisa (Italy); Tonelli, M [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, Pisa (Italy); Travasso, F [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, Virgo Project, I-06100 Perugia (Italy); Vetrano, F [Istituto Nazionale di Fisica Nucleare, Sezione di Firenze/Urbino, Florence (Italy); Vocca, H [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, Virgo Project, I-06100 Perugia (Italy)

2004-03-07

Thermal noise in mirror suspension will be the most severe fundamental limit to the low-frequency sensitivity of future interferometric gravitational wave detectors. We propose a new type of materials to realize low thermal noise suspension in such detectors. Monocrystalline suspension fibres are good candidates both for cryogenic and for ambient temperature interferometers. Material characteristics and a production facility are described in this paper.

Nondestructive evaluation of differently doped InP wafers by time-resolved four-wave mixing technique

International Nuclear Information System (INIS)

Kadys, A.; Sudzius, M.; Jarasiunas, K.; Mao Luhong; Sun Niefeng

2006-01-01

Photoelectric properties of semi-insulating, differently doped, and undoped indium phosphide wafers, grown by the liquid encapsulation Czochralski method, have been investigated by time-resolved picosecond four-wave mixing technique. Deep defect related carrier generation, recombination, and transport properties were investigated experimentally by measuring four-wave mixing kinetics and exposure characteristics. The presence of deep donor states in undoped InP was confirmed by a pronounced effect of a space charge electric field to carrier transport. On the other hand, the recharging dynamics of electrically active residual impurities was observed in undoped and Fe-doped InP through the process of efficient trapping of excess carriers. The bipolar diffusion coefficients and mobilities were determined for the all wafers

Research Developments in Nondestructive Evaluation and Structural Health Monitoring for the Sustainment of Composite Aerospace Structures at NASA

Science.gov (United States)

Cramer, K. Elliott

2016-01-01

The use of composite materials continues to increase in the aerospace community due to the potential benefits of reduced weight, increased strength, and manufacturability. Ongoing work at NASA involves the use of the large-scale composite structures for spacecraft (payload shrouds, cryotanks, crew modules, etc). NASA is also working to enable both the use and sustainment of composites in commercial aircraft structures. One key to the sustainment of these large composite structures is the rapid, in-situ characterization of a wide range of potential defects that may occur during the vehicle's life. Additionally, in many applications it is necessary to monitor changes in these materials over their lifetime. Quantitative characterization through Nondestructive Evaluation (NDE) of defects such as reduced bond strength, microcracking, and delamination damage due to impact, are of particular interest. This paper will present an overview of NASA's applications of NDE technologies being developed for the characterization and sustainment of advanced aerospace composites. The approaches presented include investigation of conventional, guided wave, and phase sensitive ultrasonic methods and infrared thermography techniques for NDE. Finally, the use of simulation tools for optimizing and validating these techniques will also be discussed.

Initial permeability and vickers hardness of thermally aged FeCu alloy

International Nuclear Information System (INIS)

Kikuchi, H.; Onuki, T.; Kamada, Y.; Ara, K.; Kobayashi, S.; Takahashi, S.

2007-01-01

The initial permeability obtained from small AC field excitation is a more useful parameter for nondestructive evaluation (NDE) of ferromagnetic materials than one obtained from a major hysteresis loop from the viewpoints of electricity consumption and real-time measurements. In this paper, in order to study the possibility of applying magnetic methods to pressure vessel surveillance at nuclear power plants, permeability of the thermally aged Fe-Cu specimens were evaluated using impedance measurements and the hardness of those specimens was also evaluated. The Vickers hardness increases as aging time increases. The permeability of the cold-rolled specimen decreases with thermal aging. On the other hand, the permeability of as-received specimens increased at first then decreases as thermal aging goes

Microwave Metamaterial Absorber for Non-Destructive Sensing Applications of Grain

Directory of Open Access Journals (Sweden)

Yin Zhang

2018-06-01

Full Text Available In this work, we propose a metamaterial absorber at microwave frequencies with significant sensitivity and non-destructive sensing capability for grain samples. This absorber is composed of cross-resonators periodically arranged on an ultrathin substrate, a sensing layer filled with grain samples, and a metal ground. The cross-resonator array is fabricated using the printed circuit board process on an FR-4 board. The performance of the proposed metamaterial is demonstrated with both full-wave simulation and measurement results, and the working mechanism is revealed through multi-reflection interference theory. It can serve as a non-contact sensor for food quality control such as adulteration, variety, etc. by detecting shifts in the resonant frequencies. As a direct application, it is shown that the resonant frequency displays a significant blue shift from 7.11 GHz to 7.52 GHz when the mass fraction of stale rice in the mixture of fresh and stale rice is changed from 0% to 100%. In addition, the absorber shows a distinct difference in the resonant absorption frequency for different varieties of grain, which also makes it a candidate for a grain classification sensor. The presented scheme could open up opportunities for microwave metamaterial absorbers to be applied as efficient sensors in the non-destructive evaluation of agricultural and food product quality.

Optical coherence tomography for nondestructive evaluation of fuel rod degradation

International Nuclear Information System (INIS)

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

2015-01-01

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

Optical coherence tomography for nondestructive evaluation of fuel rod degradation

Energy Technology Data Exchange (ETDEWEB)

Renshaw, Jeremy B., E-mail: jrenshaw@epri.com [Electric Power Research Institute, 1300 West WT Harris Blvd., Charlotte, NC 28262 (United States); Jenkins, Thomas P., E-mail: tjenkins@metrolaserinc.com; Buckner, Benjamin D., E-mail: tjenkins@metrolaserinc.com [MetroLaser, Inc., 22941 Mill Creek Drive, Laguna Hills, CA 92653 (United States); Friend, Brian [AREVA, Inc., 3315 Old Forest Road, Lynchburg, VA 24501 (United States)

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.

Ultrasonic C-scan Technique for Nondestructive Evaluation of Spot Weld Quality

International Nuclear Information System (INIS)

Park, Ik Gun

1994-01-01

This paper discusses the feasibility of ultrasonic C-scan technique for nondestructive evaluation of spot weld quality. Ultrasonic evaluation for spot weld quality was performed by immersion method with the mechanical and the electronic scanning of point-focussed ultrasonic beam(25 MHz). For the sake of the approach to the quantitative measurement of nugget diameter and the discrimination of the corona bond from nugget, preliminary infinitesimal gap experiment by newton ring is tried in order to set up the optimum ultrasonic test condition. Ultrasonic image data obtained were confirmed and compared by optical microscope and SAM(Scanning Acoustic Microscope) observation of the spot-weld cross section. The results show that the nugget diameter can be measured with the accuracy of 1.0mm, and voids included in nugget can be detected to 10μm extent with simplicity and accuracy. Finally, it was found that it is necessary to make a profound study of definite discrimination of corona bond from nugget and the approach of quantitative evaluation of nugget diameter by utilizing the various image processing techniques

Investigation and development of a non-destructive system to evaluate critical properties of asphalt pavements during the compaction process.

Science.gov (United States)

2013-10-01

The purpose of this report is to present findings from a two-stage investigation to develop a non-destructive system to : evaluate critical properties and characteristics of asphalt pavements during the compaction process. The first stage aligned : c...

Uranium and thorium loadings determined by chemical and nondestructive methods in HTGR fuel rods for the Fort St. Vrain Early Validation Irradiation Experiment

International Nuclear Information System (INIS)

Angelini, P.; Rushton, J.E.

1979-01-01

The Fort St. Vrain Early Validation Irradiation Experiment is an irradiation test of reference and of improved High-Temperature Gas-Cooled Reactor fuels in the Fort St. Vrain Reactor. The irradiation test includes fuel rods fabricated at ORNL on an engineering scale fuel rod molding machine. Fuel rods were nondestructively assayed for 235 U content by a technique based on the detection of prompt-fission neutrons induced by thermal-neutron interrogation and were later chemically assayed by using the modified Davies Gray potentiometric titration method. The chemical analysis of the thorium content was determined by a volumetric titration method. The chemical assay method for uranium was evaluated and the results from the as-molded fuel rods agree with those from: (1) large samples of Triso-coated fissile particles, (2) physical mixtures of the three particle types, and (3) standard solutions to within 0.05%. Standard fuel rods were fabricated in order to evaluate and calibrate the nondestructive assay device. The agreement of the results from calibration methods was within 0.6%. The precision of the nondestructive assay device was established as approximately 0.6% by repeated measurements of standard rods. The precision was comparable to that estimated by Poisson statistics. A relative difference of 0.77 to 1.5% was found between the nondestructive and chemical determinations on the reactor grade fuel rods

Aging material evaluation and studies by non-destructive techniques (AMES-NDT) - a European network project

International Nuclear Information System (INIS)

Dobmann, Gerd; Debarberis, Luigi; Coste, Jean-Francois

2001-01-01

This paper presents results obtained in a round-robin action organized in a concerted action of ten partners in the EURATOM program of the European Community. The objective of the research was to document the state of the art of available non-destructive testing (NDT) techniques in order to characterize material aging phenomena based on a reduction of Charpy-V energy and a shift in the fracture appearance transition temperature. Therefore, samples from the Japanese nuclear reactor pressure vessel JRQ-steel (ASMT Standard A533-B Class 1) have been thermally treated at 700 deg. C for 18 h with a subsequent water quenching. Besides micromagnetic and electromagnetic NDT, the positron annihilation technique, ultrasonic reverberation by using Laser ultrasonics and the thermo-electrical power have been applied to characterize the aged material states

Modelling of waves propagation on irregular surfaces using ray tracing and GTD approaches: Application to head waves simulation in TOFD inspections for NDT

International Nuclear Information System (INIS)

Ferrand, Adrien; Darmon, Michel; Chatillon, Sylvain; Deschamps, Marc

2014-01-01

The Time of Flight Diffraction (TOFD) technique is a classical ultrasonic method used in ultrasonic non-destructive evaluation, which allows a precise positioning and a quantitative size evaluation of cracks in the inspected material. Among the typical phenomena arising in the current TOFD inspection, the so-called 'head wave' is the first contribution reaching the receiver. The head wave propagation on a planar interface is well known and identified as a critical refraction taking place on the material surface. On irregular surfaces, it has been shown that the head wave results from the melting of surface and bulk waves mechanisms and that surface irregularities are responsible for numerous diffractions of the incident head wave. To simulate such behaviour, a model has been developed using a ray tracing technique based on time of flight minimization (generalized Fermat's principle). It enables the calculation of the ray path and the corresponding time of flight of all waves propagating in the material, including the head wave. To obtain a complete propagation model for these waves (both trajectory and amplitude), the integration of Geometrical Theory of Diffraction (GTD) models is currently performed by coupling them with the ray-based approach discussed above.

The evaluation of integrity and elasticity of thermally sprayed ceramic coatings by ultrasonics

Energy Technology Data Exchange (ETDEWEB)

Kauppinen, P. [VTT Manufacturing Technology, Espoo (Finland). Materials and Structural Integrity

1997-12-31

Thermally sprayed ceramic coatings are widely used in industrial applications where the coated component is subject to, e.g. high thermal loads or mechanical wear. The mechanical properties of the coating are finally created in the coating process and the chemical composition of the powder used as raw material can only give some hints about the properties of the final coating. Several non-destructive testing techniques are available for the detection of defects in ceramic materials or for the evaluation of density and density variations. In addition to this, ultrasonic techniques can be used for quantitative evaluation of elastic properties of materials. This evaluation is based on the measurement of sound velocities of different wave modes in the material and is normally applied only to relatively simple-shaped specimens having parallel surfaces. Acoustic microscopy operating at very high (> 100 MHz) frequencies has been used to measure the sound velocities in homogeneous and thin coatings. With this type of equipment, reliable and accurate results have been achieved in laboratory measurements. A lot of development work has been carried out world-wide to develop the measurement techniques and acoustic lenses (transducers) used in acoustic microscopy. However, less attention has been paid on the development of techniques for industrial applications on-site. The present work was focused on the development of measurement techniques for industrial applications. A new type of large-aperture low-frequency transducer was designed and constructed for the measurement of sound velocities in thermally sprayed ceramic coatings. The major difference to the lenses used in acoustic microscopy is that in the new transducer no separate lens is needed for focusing the sound beam. The piezoelectric element in the new transducer is a plastic (PVDF)-film that can be shaped to create the required focus. The practical measurement of the sound velocity is based on a modification of the V

Nonlinear electron-acoustic rogue waves in electron-beam plasma system with non-thermal hot electrons

Science.gov (United States)

Elwakil, S. A.; El-hanbaly, A. M.; Elgarayh, A.; El-Shewy, E. K.; Kassem, A. I.

2014-11-01

The properties of nonlinear electron-acoustic rogue waves have been investigated in an unmagnetized collisionless four-component plasma system consisting of a cold electron fluid, non-thermal hot electrons obeying a non-thermal distribution, an electron beam and stationary ions. It is found that the basic set of fluid equations is reduced to a nonlinear Schrodinger equation. The dependence of rogue wave profiles on the electron beam and energetic population parameter are discussed. The results of the present investigation may be applicable in auroral zone plasma.

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

Directory of Open Access Journals (Sweden)

Jin Zhang

2016-06-01

Full Text Available 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.

Yucca mountain container fabrication, closure and non-destructive evaluation development activities

International Nuclear Information System (INIS)

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

1990-01-01

Container fabrication, closure, and non-destructive evaluation process development activities are described. The design parameters for a tuff environment are: no significant hydrostatic or lithostatic loading of the container; very small water flux; benign water, an oxidizing, dilute sodium bicarbonate solution of neutral pH; temperatures reaching 250 C over the first 50 to 100 years, then falling to about 97 C over the remainder of the 300-year container period. The materials under consideration are three austenitic alloys: AISI 304L, AISI 316L, and alloy 825; as well as three copper alloys: CDA 102, CDA 613, and CDA 715. Targets are controlled, uniform microstructures for the base metal, the weld and the heat affected zones of the weld; controlled microchemistry; low residual stresses; small welds and heat-affected zones; and reliable methods of flaw detection by surface and volumetric activities. The recommended procedures and processes for fabricating, closing and evaluating each of the candidate materials are reviewed

LMFBR thermal-striping evaluation

International Nuclear Information System (INIS)

Brunings, J.E.

1982-10-01

Thermal striping is defined as the fluctuating temperature field that is imposed on a structure when fluid streams at different temperatures mix in the vicinity of the structure surface. Because of the uncertainty in structural damage in LMFBR structures subject to thermal striping, EPRI has funded an effort for the Rockwell International Energy Systems Group to evaluate this problem. This interim report presents the following information: (1) a Thermal Striping Program Plan which identifies areas of analytic and experimental needs and presents a program of specific tasks to define damage experienced by ordinary materials of construction and to evaluate conservatism in the existing approach; (2) a description of the Thermal Striping Test Facility and its operation; and (3) results from the preliminary phase of testing to characterize the fluid environment to be applied in subsequent thermal striping damage experiments

Spin wave differential circuit for realization of thermally stable magnonic sensors

Energy Technology Data Exchange (ETDEWEB)

Goto, Taichi, E-mail: goto@ee.tut.ac.jp; Kanazawa, Naoki; Buyandalai, Altansargai; Takagi, Hiroyuki; Nakamura, Yuichi; Inoue, Mitsuteru [Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, 1-1 Hibari-Ga-Oka, Tempaku, Toyohashi, Aichi 441-8580 (Japan); Okajima, Shingo; Hasegawa, Takashi [Murata Manufacturing Co., Ltd., Kyoto 617-8555 (Japan); Granovsky, Alexander B. [Faculty of Physics, Moscow State University, Leninskie Gory, Moscow 119992 (Russian Federation); Sekiguchi, Koji [Department of Physics, Keio University, Yokohama 223-8522 (Japan); JST-PRESTO, Kawaguchi, Saitama 332-0012 (Japan); Ross, Caroline A. [Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States)

2015-03-30

A magnetic-field sensor with a high sensitivity of 38 pT/Hz was demonstrated. By utilizing a spin-wave differential circuit (SWDC) using two yttrium iron garnet (YIG) films, the temperature sensitivity was suppressed, and the thermal stability of the phase of the spin waves was −0.0095° K{sup −1}, which is three orders of magnitude better than a simple YIG-based sensor, ∼20° K{sup −1}. The SWDC architecture opens the way to design YIG-based magnonic devices.

Spin wave differential circuit for realization of thermally stable magnonic sensors

International Nuclear Information System (INIS)

Goto, Taichi; Kanazawa, Naoki; Buyandalai, Altansargai; Takagi, Hiroyuki; Nakamura, Yuichi; Inoue, Mitsuteru; Okajima, Shingo; Hasegawa, Takashi; Granovsky, Alexander B.; Sekiguchi, Koji; Ross, Caroline A.

2015-01-01

A magnetic-field sensor with a high sensitivity of 38 pT/Hz was demonstrated. By utilizing a spin-wave differential circuit (SWDC) using two yttrium iron garnet (YIG) films, the temperature sensitivity was suppressed, and the thermal stability of the phase of the spin waves was −0.0095° K −1 , which is three orders of magnitude better than a simple YIG-based sensor, ∼20° K −1 . The SWDC architecture opens the way to design YIG-based magnonic devices

Operation of the EPRI nondestructive evaluation center: 1985 annual report

International Nuclear Information System (INIS)

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

Extraction of thermal Green's function using diffuse fields: a passive approach applied to thermography

Science.gov (United States)

Capriotti, Margherita; Sternini, Simone; Lanza di Scalea, Francesco; Mariani, Stefano

2016-04-01

In the field of non-destructive evaluation, defect detection and visualization can be performed exploiting different techniques relying either on an active or a passive approach. In the following paper the passive technique is investigated due to its numerous advantages and its application to thermography is explored. In previous works, it has been shown that it is possible to reconstruct the Green's function between any pair of points of a sensing grid by using noise originated from diffuse fields in acoustic environments. The extraction of the Green's function can be achieved by cross-correlating these random recorded waves. Averaging, filtering and length of the measured signals play an important role in this process. This concept is here applied in an NDE perspective utilizing thermal fluctuations present on structural materials. Temperature variations interacting with thermal properties of the specimen allow for the characterization of the material and its health condition. The exploitation of the thermographic image resolution as a dense grid of sensors constitutes the basic idea underlying passive thermography. Particular attention will be placed on the creation of a proper diffuse thermal field, studying the number, placement and excitation signal of heat sources. Results from numerical simulations will be presented to assess the capabilities and performances of the passive thermal technique devoted to defect detection and imaging of structural components.

Thermal properties and continuous-wave laser performance of Yb:LuVO4 crystal

Science.gov (United States)

Cheng, Y.; Zhang, H. J.; Yu, Y. G.; Wang, J. Y.; Tao, X. T.; Liu, J. H.; Petrov, V.; Ling, Z. C.; Xia, H. R.; Jiang, M. H.

2007-03-01

A laser crystal of Yb:LuVO4 with high optical quality was grown by the Czochralski technique. Its thermal properties including specific heat, thermal expansion coefficients, and thermal conductivities along the a- and c-axis have been measured for the first time. Continuous-wave laser output up to 3.5 W at 1031 nm was obtained at room temperature through end-pumping by a high-power diode laser. The corresponding optical conversion efficiency was 43% and the slope efficiency was 72%.

Interactive ultrasonic field simulations for complex non-destructive testing configurations

International Nuclear Information System (INIS)

Chouh, Hamza

2016-01-01

In order to fulfill increasing reliability and safety requirements, non-destructive testing techniques are constantly evolving and so does their complexity. Consequently, simulation is an essential part of their design. We developed a tool for the simulation of the ultrasonic field radiated by any planar probes into non-destructive testing configurations involving meshed geometries without prominent edges, isotropic and anisotropic, homogeneous and heterogeneous materials, and wave trajectories that can include reflections and transmissions. We approximate the ultrasonic wave fronts by using polynomial interpolators that are local to ultrasonic ray pencils. They are obtained using a surface research algorithm based on pencil tracing and successive subdivisions. Their interpolators enable the computation of the necessary quantities for the impulse responses on each point of a sampling of the transducer surface that fulfills the Shannon criterion. By doing so, we can compute a global impulse response which, when convolved with the excitation signal of the transducer, results in the ultrasonic field. The usage of task parallelism and of SIMD instructions on the most computationally expensive steps yields an important performance boost. Finally, we developed a tool for progressive visualization of field images. It benefits from an image reconstruction technique and schedules field computations in order to accelerate convergence towards the final image. (author) [fr

Enhanced polarization of the cosmic microwave background radiation from thermal gravitational waves.

Science.gov (United States)

Bhattacharya, Kaushik; Mohanty, Subhendra; Nautiyal, Akhilesh

2006-12-22

If inflation was preceded by a radiation era, then at the time of inflation there will exist a decoupled thermal distribution of gravitons. Gravitational waves generated during inflation will be amplified by the process of stimulated emission into the existing thermal distribution of gravitons. Consequently, the usual zero temperature scale invariant tensor spectrum is modified by a temperature dependent factor. This thermal correction factor amplifies the B-mode polarization of the cosmic microwave background radiation by an order of magnitude at large angles, which may now be in the range of observability of the Wilkinson Microwave Anisotropy Probe.

Application of advanced non-destructive testing to evaluate the foundation depth of the existing structures

International Nuclear Information System (INIS)

Nguyen Le Son; Nguyen Phuoc Lan; Pham The Hung; Vu Huy Thuc; Phan Chanh Vu; Bui Xuan Huy; Tran Thanh Luan; Nguyen Kien Chinh; Le Danh Chuan

2004-01-01

The applications of Parallel Seismic Test to evaluate deep foundations of the existing structures are still new in Vietnam. Under the framework of the basic VAEC project (2003) and project VIE/8/013, the parallel seismic test method (PSM) was evaluated at Center for Nuclear Techniques, Hochiminh City. Background information on principle and general description of the method as it is typically applied in the evaluation of deep foundations are also summarized. A suitable test site was selected, where the foundation depths can be controlled for the parallel seismic tests were conducted by impacting the driven piles, and the travel times down the pile, through the soil, to a receiver located in an adjacent water-filled borehole were measured. The primary objective of the test program is to evaluated the accuracy of method in determining the pile length, to evaluate the capabilities of the method and the equipped system SPL-97, to define the type of material which comprises a deep foundation, the distance of the compression wave can travel through the adjacent soil before the signal attenuates beyond recognition and the ware velocities in the various soil strata encountered. The parallel seismic testing program is described and results are presented. Parallel seismic tests, as conventionally practiced, i.e. with short distance between a structure and an access hole, can be used to define the bottom of the piles, as well as to identify the material type from the computed velocity in the structural material. The conventional approach of using changes of slop of the plot versus first arrival to identify the bottom of a deep foundation works best when the piles are in a soil with uniform stiffness and the accuracy of the evaluated depths can be obtained about ± 0.5 m. Supplementing this approach of interpretation by the examining the amplitudes of the first arrival on a plot with the same scale for all records allows one to better interpret signals in more common

Nondestructive evaluation of warm mix asphalt through resonant column testing.

Science.gov (United States)

2014-02-01

Non-destructive testing has been used for decades to characterize engineering properties of hot-mix asphalt. Among such tests is the resonant column (RC) test, which is commonly used to characterize soil materials. The resonant column device at Penn ...

Quantitative ultrasonic coda wave (diffuse field) NDE of carbon-fiber reinforced polymer plates

Science.gov (United States)

Livings, Richard A.

The increasing presence and applications of composite materials in aerospace structures precipitates the need for improved Nondestructive Evaluation (NDE) techniques to move from simple damage detection to damage diagnosis and structural prognosis. Structural Health Monitoring (SHM) with advanced ultrasonic (UT) inspection methods can potentially address these issues. Ultrasonic coda wave NDE is one of the advanced methods currently under investigation. Coda wave NDE has been applied to concrete and metallic specimens to assess damage with some success, but currently the method is not fully mature or ready to be applied for SHM. Additionally, the damage diagnosis capabilities and limitations of coda wave NDE applied to fibrous composite materials have not been widely addressed in literature. The central objective of this work, therefore, is to develop a quantitative foundation for the use of coda wave NDE for the inspection and evaluation of fibrous composite materials. Coda waves are defined as the superposition of late arriving wave modes that have been scattered or reflected multiple times. This results in long, complex signals where individual wave modes cannot be discriminated. One method of interpreting the changes in such signals caused by the introduction or growth of damage is to isolate and quantify the difference between baseline and damage signals. Several differential signal features are used in this work to quantify changes in the coda waves which can then be correlated to damage size and growth. Experimental results show that coda wave differential features are effective in detecting drilled through-holes as small as 0.4 mm in a 50x100x6 mm plate and discriminating between increasing hole diameter and increasing number of holes. The differential features are also shown to have an underlying basis function that is dependent on the hole volume and can be scaled by a material dependent coefficient to estimate the feature amplitude and size holes. The

Switching of the Spin-Density-Wave in CeCoIn5 probed by Thermal Conductivity

Science.gov (United States)

Kim, Duk Y.; Lin, Shi-Zeng; Weickert, Franziska; Bauer, Eric D.; Ronning, Filip; Thompson, Joe D.; Movshovich, Roman

Unconventional superconductor CeCoIn5 orders magnetically in a spin-density-wave (SDW) in the low-temperature and high-field corner of the superconducting phase. Recent neutron scattering experiment revealed that the single-domain SDW's ordering vector Q depends strongly on the direction of the magnetic field, switching sharply as the field is rotated through the anti-nodal direction. This switching may be manifestation of a pair-density-wave (PDW) p-wave order parameter, which develops in addition to the well-established d-wave order parameter due to the SDW formation. We have investigated the hypersensitivity of the magnetic domain with a thermal conductivity measurement. The heat current (J) was applied along the [110] direction such that the Q vector is either perpendicular or parallel to J, depending on the magnetic field direction. A discontinuous change of the thermal conductivity was observed when the magnetic field is rotated around the [100] direction within 0 . 2° . The thermal conductivity with the Q parallel to the heat current (J ∥Q) is approximately 15% lager than that with the Q perpendicular to the heat current (J ⊥Q). This result is consistent with additional gapping of the nodal quasiparticle by the p-wave PDW coupled to SDW. Work at Los Alamos was performed under the auspices of the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering.

A Study on Nondestructive Technique Using Laser Technique for Evaluation of Carbon fiber Reinforced Plastic

International Nuclear Information System (INIS)

Choi, Sang Woo; Lee, Joon Hyun; Seo, Kyeong Cheol; Byun, Joon Hyung

2005-01-01

Fiber reinforced plastic material should be inspected in fabrication process in order to enhance quality by prevent defects such as delamination and void. Generally, ultrasonic technique is widely used to evaluate FRP. In conventional ultrasonic techniques, transducer should be contacted on FRP. However, conventional contacting method could not be applied in fabrication process and novel non-contact evaluating technique was required. Laser-based ultrasonic technique was tried to evaluate CFRP plate. Laser-based ultrasonic waves propagated on CFRP were received with various transducers such as accelerometer and AE sensor in order to evaluate the properties of waves due to the variation of frequency. Velocities of laser-based ultrasonic waves were evaluated for various fiber orientation. In addition, laser interferometry was used to receive ultrasonic wave in CFRP and frequency was analysed

Radiation control in the nondestructive inspection

International Nuclear Information System (INIS)

Kariya, Yukihiro

1982-01-01

In the early days of radiation nondestructive inspection about ten years ago, the loss of radiation sources and careless radiation exposure gave the impression of radiography inspection being immediately slipshod management. In this problem, the peculiar nature of the business in this field is involved. In Nondestructive Inspection Co., Ltd., besides the safety management of radioisotopes, the radiation exposure control of personnel in the regular inspection of nuclear power plants has become increasingly important. The following matters are described: radiation utilization in nondestructive inspection (X- and #betta#-ray radiography, #betta#-ray leak test on shield), radiation control problems in nondestructive inspection business (the peculiar aspects of the business, the analysis of the incidents related with nondestructive inspection), and the practice of radiation control in nondestructive inspection in Nondestructive Inspection Co., Ltd. (Mori, K.)

Non-destructive evaluation methods to improve quality control in low enrichment MTR fuel plate production

International Nuclear Information System (INIS)

Milne, J.M.; Lidington, B.; Hawker, B.M.

1991-01-01

This paper summarises some preliminary non-destructive measurements made recently at the Harwell Laboratory on a prototype low enrichment MTR fuel plate. The measurements were intended to indicate the potential of two different techniques for improving quality control in plate production. Pulse Video Thermography (PVT) is being considered as an alternative to ultrasound transmission measurements for the detection and sizing of lack of thermal bonding between the fuel and the clad layers, either to verify the indications from the established ultrasonic methods before destroying the plate or as a replacement method of inspection. High frequency pulse-echo ultrasonics is being considered for providing maps of clad layer thickness on each side of the plate. The measurements have indicated the potential for both methods, but more work is required, using a test plate containing controlled defects, to establish their capability. (orig.)

Propagation of sound and thermal waves in an ionizing-recombining hydrogen plasma: Revision of results

International Nuclear Information System (INIS)

Di Sigalotti, Leonardo G.; Sira, Eloy; Tremola, Ciro

2002-01-01

The propagation of acoustic and thermal waves in a heat conducting, hydrogen plasma, in which photoionization and photorecombination [H + +e - H+hν(χ)] processes are progressing, is re-examined here using linear analysis. The resulting dispersion equation is solved analytically and the results are compared with previous solutions for the same plasma model. In particular, it is found that wave propagation in a slightly and highly ionized hydrogen plasma is affected by crossing between acoustic and thermal modes. At temperatures where the plasma is partially ionized, waves of all frequencies propagate without the occurrence of mode crossing. These results disagree with those reported in previous work, thereby leading to a different physical interpretation of the propagation of small linear disturbances in a conducting, ionizing-recombining, hydrogen plasma

Non-Destructive Testing for Building Diagnostics and Monitoring: Experience Achieved with Case Studies

Directory of Open Access Journals (Sweden)

Tavukçuoğlu Ayşe

2018-01-01

Full Text Available Building inspection on site, in other words in-situ examinations of buildings is a troublesome work that necessitates the use of non-destructive investigation (NDT techniques. One of the main concerns of non-destructive testing studies is to improve in-situ use of NDT techniques for diagnostic and monitoring studies. The quantitative infrared thermography (QIRT and ultrasonic pulse velocity (UPV measurements have distinct importance in that regard. The joint use of QIRT and ultrasonic testing allows in-situ evaluation and monitoring of historical structures and contemporary ones in relation to moisture, thermal, materials and structural failures while the buildings themselves remain intact. For instances, those methods are useful for detection of visible and invisible cracks, thermal bridges and damp zones in building materials, components and functional systems as well as for soundness assessment of materials and thermal performance assessment of building components. In addition, those methods are promising for moisture content analyses in materials and monitoring the success of conservation treatments or interventions in structures. The in-situ NDT studies for diagnostic purposes should start with the mapping of decay forms and scanning of building surfaces with infrared images. Quantitative analyses are shaped for data acquisition on site and at laboratory from representative sound and problem areas in structures or laboratory samples. Laboratory analyses are needed to support in-situ examinations and to establish the reference data for better interpretation of in situ data. Advances in laboratory tests using IRT and ultrasonic testing are guiding for in-situ materials investigations based on measurable parameters. The knowledge and experience on QIRT and ultrasonic testing are promising for the innovative studies on today’s materials technologies, building science and conservation/maintenance practices. Such studies demand a multi

Nondestructive examination development and demonstration plan

International Nuclear Information System (INIS)

Weber, J.R.

1991-01-01

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

Determination of crack size around rivet hole through neural network using ultrasonic Lamb wave

International Nuclear Information System (INIS)

Choi, Sang Woo; Lee, Joon Hyun

1998-01-01

Rivets are typical structural features that are potential initiation sites for fatigue crack due to combination of local stress concentration around rivet hole and moisture trapping. For the viewpoint of structural assurance, it is crucial to evaluate the size of crack around rivets by appropriate nondestructive techniques. Guided waves, which direct wave energy along the plate, carry information about the material in their path and offer a potentially more efficient tool for nondestructive inspection of structural material. Neural network that is considered to be the most suitable for pattern recognition and has been used by researchers in NDE field to classify different types of flaws and flaw size. In this study, crack size determination around rivet through a neural network based on the back-propagation algorithm has been done by extracting some feature from time-domain waveforms of ultrasonic Lamb wave for Al 2024-T3 skin panel of aircraft. Special attention was paid to reduce the coupling effect between transducer and specimen by extracting some features related to only time component data in ultrasonic waveform. It was demonstrated clearly that features extraction based on time component data of the time-domain waveform of Lamb wave was very useful to determine crack size initiated from rivet hole through neural network.

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

Science.gov (United States)

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.

Propagation of bulk longitudinal waves in thin films using laser ultrasonics

Energy Technology Data Exchange (ETDEWEB)

Kim, Yun Young [Dept. of Mechanical Engineering, Dong-eui University, Busan (Korea, Republic of)

2016-08-15

This paper presents the investigation of the propagation behavior of bulk longitudinal waves generated by an ultrafast laser system in thin films. A train of femtosecond laser pulses was focused onto the surface of a 150-nm thick metallic (chromium or aluminum) film on a silicon substrate to excite elastic waves, and the change in thermoreflectance at the spot was monitored to detect the arrival of echoes from the film/substrate interface. The experimental results show that the film material characteristics such as the wave velocity and Young's modulus can be evaluated through curve-fitting in numerical solutions. The material properties of nanoscale thin films are difficult to measure using conventional techniques. Therefore, this research provides an effective method for the nondestructive characterization of nanomaterials.

Use of nondestructive evaluation methods to improve power plant availability

International Nuclear Information System (INIS)

Weber, R.M.

1985-01-01

On an ever-increasing basis, utilities are relying on nondestructive evaluation (NDE) as a management and planning tool. In addition to the conventional ASME Code and Technical Specification-required examinations, progressive utilities are utilizing NDE sampling programs to monitor existing conditions and search for potential situations affecting plant safety and reliability. Improved NDE detection and sizing procedures give management personnel the accurate information needed to make the ''go/no go'' decisions on repair programs which can significantly affect plant availability. As the burden of regulatory-imposed inspection requirements increases, plant personnel are increasingly cognizant that NDE is a significant factor in their plant's outage schedule. Whether an outage is scheduled or forced, NDE becomes part of each plant's program to assure the safety and reliability of its critical components. Knowledge and planning of NDE application is important because of the time expended in examination performance and subsequent data evaluation. Managers who are knowledgeable in NDE application can effectively improve plant availability by scheduling NDE as an integral part of their maintenance programs. Examination results can then be used in making decisions directly affecting availability

Research on nondestructive examination methods for CANDU fuel channel inspection

International Nuclear Information System (INIS)

Soare, M.; Petriu, F.; Toma, V.; Revenco, V.; Calinescu, A.; Ciocan, R.; Iordache, C.; Popescu, L.; Mihalache, M.; Murgescu, C.

1995-01-01

The requirements of the 1994 edition of CAN/CSA-N285.4 Periodic Inspection Standard, which address all known and postulated degradation mechanisms and introduce material surveillance demands, involve a growing need for improved nondestructive examination (NDE) methods and technologies. In order to have a proper technical support in its decisions concerning fuel channel inspections at Cernavoda NPP, the Romanian Power Authority (RENEL) initiated a Research Program regarding the nondestructive characterization of the fuel channels structural integrity. The paper presents the most significant results obtained on this Research Program: the ENDUS experimental system for Laboratory simulation of the fuel channel inspection, ultrasonic Rayleigh-Lamb waves technique for pressure tubes examination, phase analysis technique for near-surface flaws, influence of the metallurgical state of the pressure tube material on the eddy current defectoscopic signals, characterization of plastic deformation and fracture of zirconium alloys by acoustic emission. (author)

Infrared electro-thermal NDE of stainless steel

International Nuclear Information System (INIS)

Green, D.R.; Hassberger, J.A.

1975-01-01

Electro-thermal examination, a branch of thermal testing, is a promising method being developed for nondestructive examination of stainless steel welds. This paper describes the first phase of development; i.e., preliminary demonstration and laboratory evaluation of the method's sensitivity to notches in Type 304 stainless steel plate specimens. It also includes a description of the basic principles, together with a description of the hardware and experimental results showing that electrical discharge machined notches down to 0.16 cm long x 0.08 cm deep were detected. A qualitative technique for interpreting the test results to determine whether defects are at the surface or deeper within the material is demonstrated

Non-destructive inspection protocol for reinforced concrete barriers and bridge railings

Energy Technology Data Exchange (ETDEWEB)

Chintakunta, Satish R. [Engineering and Software Consultants, Inc., 14123 Robert Paris Ct., Chantilly, VA 20151 (United States); Boone, Shane D. [Federal Highway Administration, Turner Fairbank Highway Research Center, 6300 Georgetown Pike, McLean, VA 22101 (United States)

2014-02-18

Reinforced concrete highway barriers and bridge railings serve to prevent errant vehicles from departing the travel way at grade separations. Despite the important role that they play in maintaining safety and their ubiquitous nature, barrier inspection rarely moves beyond visual inspection. In August 2008, a tractor-trailer fatally departed William Preston Lane, Jr. Memorial Bridge after it dislodged a section of the bridge barrier. Investigations following the accident identified significant corrosion of the anchor bolts attaching the bridge railing to the bridge deck. As a result of the information gathered during its investigation of the accident, the National Transportation Safety Board (NTSB) made recommendations to the Federal Highway Administration concerning Non-Destructive Evaluation (NDE) of concrete bridge railings. The Center for nondestructive evaluation (NDE) at Turner Fairbank Highway Research Center in McLean, VA is currently evaluating feasibility of using four technologies - ground penetrating radar (GPR), ultrasonic pulse-echo, digital radiography and infrared thermal imaging methods to develop bridge inspection methods that augment visual inspections, offer reliable measurement techniques, and are practical, both in terms of time and cost, for field inspection work. Controlled samples containing predefined corrosion levels in reinforcing steel were embedded at barrier connection points for laboratory testing. All four NDE techniques were used in the initial phase I testing. An inspection protocol for detecting and measuring the corrosion of reinforced steel embedded in the anchorage system will be developed as part of phase II research. The identified technologies shall be further developed for field testing utilizing a structure with a barrier in good condition and a structure with a barrier in poor condition.

Non-destructive inspection protocol for reinforced concrete barriers and bridge railings

Science.gov (United States)

Chintakunta, Satish R.; Boone, Shane D.

2014-02-01

Reinforced concrete highway barriers and bridge railings serve to prevent errant vehicles from departing the travel way at grade separations. Despite the important role that they play in maintaining safety and their ubiquitous nature, barrier inspection rarely moves beyond visual inspection. In August 2008, a tractor-trailer fatally departed William Preston Lane, Jr. Memorial Bridge after it dislodged a section of the bridge barrier. Investigations following the accident identified significant corrosion of the anchor bolts attaching the bridge railing to the bridge deck. As a result of the information gathered during its investigation of the accident, the National Transportation Safety Board (NTSB) made recommendations to the Federal Highway Administration concerning Non-Destructive Evaluation (NDE) of concrete bridge railings. The Center for nondestructive evaluation (NDE) at Turner Fairbank Highway Research Center in McLean, VA is currently evaluating feasibility of using four technologies - ground penetrating radar (GPR), ultrasonic pulse-echo, digital radiography and infrared thermal imaging methods to develop bridge inspection methods that augment visual inspections, offer reliable measurement techniques, and are practical, both in terms of time and cost, for field inspection work. Controlled samples containing predefined corrosion levels in reinforcing steel were embedded at barrier connection points for laboratory testing. All four NDE techniques were used in the initial phase I testing. An inspection protocol for detecting and measuring the corrosion of reinforced steel embedded in the anchorage system will be developed as part of phase II research. The identified technologies shall be further developed for field testing utilizing a structure with a barrier in good condition and a structure with a barrier in poor condition.

Non-destructive NIR-FT-Raman analyses in practice. Part I. Analyses of plants and historic textiles.

Science.gov (United States)

Andreev, G N; Schrader, B; Schulz, H; Fuchs, R; Popov, S; Handjieva, N

2001-12-01

Non-destructive analysis of natural substances in plants as well as of old dyed textiles by Raman spectroscopy has not been possible using conventional techniques. Exciting lines from the visible part of the spectrum produced photochemical and thermal decomposition of the objects as well as strong fluorescence. Using Nd:YAG laser excitation at 1,064 nm together with a special sample arrangement and interferometric recording, various polyacetylenes in Aethusa cynapium and in chamomile (Chamomilla recutita) and the main valuable substances in gentian species (Gentiana lutea and G. punctata), curcuma roots (Curcuma longa), cinnamon (Cinnamomum zeylanicum), fennel (Foeniculum vulgare), clove (Caryophyllus aromaticus), and ginger (Zingiber officinale) were analyzed non-destructively and discussed in comparison with the corresponding pure standard compounds. We further analyzed non-destructively the FT Raman spectra of collections of historical textiles and lakes used for dyeing. It is possible to distinguish the main dye component non-destructively by using Raman bands.

Thermal Depth Profiling Reconstruction by Multilayer Thermal Quadrupole Modeling and Particle Swarm Optimization

International Nuclear Information System (INIS)

Zhao-Jiang, Chen; Shu-Yi, Zhang

2010-01-01

A new hybrid inversion method for depth profiling reconstruction of thermal conductivities of inhomogeneous solids is proposed based on multilayer quadrupole formalism of thermal waves, particle swarm optimization and sequential quadratic programming. The reconstruction simulations for several thermal conductivity profiles are performed to evaluate the applicability of the method. The numerical simulations demonstrate that the precision and insensitivity to noise of the inversion method are very satisfactory. (condensed matter: structure, mechanical and thermal properties)

Thermal environment evaluation. Evaluation de l'ambiance thermique

Energy Technology Data Exchange (ETDEWEB)

Tilley, B

1988-01-01

This document describes interior thermal environment analysis and the techniques involved at three applicable stages of evaluation. They range from the study of plans and archives to physical measurement with sophisticated instrumentation. Environmental factors that influence the thermal state of the building occupant are measured. The occupant's perception of the thermal environment may also be investigated. One of the most important building functions is to isolate the occupants from adverse exterior thermal conditions and provide a productive and healthy interior environment. The thermal environment is determined by clothing level, activity level, air velocity, ambient air temperature, mean radiant temperature and moisture level. Since an optimal thermal environment may not be optimal in terms of the building's energy efficiency, the evaluation process will have to draw upon expertise in energy use and other disciplines at the stage where solutions are recommended. 16 refs., 4 figs., 2 tabs.

Pulsed TV holography measurement and digital reconstruction of compression acoustic wave fields: application to nondestructive testing of thick metallic samples

International Nuclear Information System (INIS)

Trillo, C; Doval, A F; Deán-Ben, X L; López-Vázquez, J C; Fernández, J L; Hernández-Montes, S

2011-01-01

This paper describes a technique that numerically reconstructs the complex acoustic amplitude (i.e. the acoustic amplitude and phase) of a compression acoustic wave in the interior volume of a specimen from a set of full-field optical measurements of the instantaneous displacement of the surface. The volume of a thick specimen is probed in transmission mode by short bursts of narrowband compression acoustic waves generated at one of its faces. The temporal evolution of the displacement field induced by the bursts emerging at the opposite surface is measured by pulsed digital holographic interferometry (pulsed TV holography). A spatio-temporal 3D Fourier transform processing of the measured data yields the complex acoustic amplitude at the plane of the surface as a sequence of 2D complex-valued maps. Finally, a numerical implementation of the Rayleigh–Sommerfeld diffraction formula is employed to reconstruct the complex acoustic amplitude at other planes in the interior volume of the specimen. The whole procedure can be regarded as a combination of optical digital holography and acoustical holography methods. The technique was successfully tested on aluminium specimens with and without an internal artificial defect and sample results are presented. In particular, information about the shape and position of the defect was retrieved in the experiment performed on the flawed specimen, which indicates the potential applicability of the technique for the nondestructive testing of materials

Laser-based linear and nonlinear guided elastic waves at surfaces (2D) and wedges (1D).

Science.gov (United States)

Hess, Peter; Lomonosov, Alexey M; Mayer, Andreas P

2014-01-01

The characteristic features and applications of linear and nonlinear guided elastic waves propagating along surfaces (2D) and wedges (1D) are discussed. Laser-based excitation, detection, or contact-free analysis of these guided waves with pump-probe methods are reviewed. Determination of material parameters by broadband surface acoustic waves (SAWs) and other applications in nondestructive evaluation (NDE) are considered. The realization of nonlinear SAWs in the form of solitary waves and as shock waves, used for the determination of the fracture strength, is described. The unique properties of dispersion-free wedge waves (WWs) propagating along homogeneous wedges and of dispersive wedge waves observed in the presence of wedge modifications such as tip truncation or coatings are outlined. Theoretical and experimental results on nonlinear wedge waves in isotropic and anisotropic solids are presented. Copyright © 2013 Elsevier B.V. All rights reserved.

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

Science.gov (United States)

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.

Simulasi Thermal Stress Pada Tube Superheater Package Boiler

OpenAIRE

Hamdani

2013-01-01

This project investigates the thermal stress behavior and the mechanisms of superheater tube failure with experimental method and numerical analysis. First of all the procedures for failure analysis were applied to determine the root cause of them. A visual assessment of boiler critical pressure parts was carried out, and then the failed tube is examined by nondestructive evaluation. For the numerical domain, initially the elastic solution for a superheater tube subjected to an internal press...

Basic Principles and Utilization Possibilities’ of Ultrasonic Phased Array in Material Nondestructive Evaluation

Directory of Open Access Journals (Sweden)

Dagmar Faktorova

2004-01-01

Full Text Available The paper deals with the basic principles of operation and with the utilization possibilities of phased array (PA in materials nondestructive testing (NDT. The first part deals with description of PA arrangement modes, which enable to generate, focus and steer the ultrasonic beem. The second part deals with the description of electromagnetic acoustic transducer PA operation. The last part deals with the description of the utilization of PA in nondestructive testing of conductive materials and the advantages of PA utilization in inhomogeneous materials NDT.

Eddy Current Nondestructive Residual Stress Assessment in Shot-Peened Nickel-Base Superalloys

International Nuclear Information System (INIS)

Blodgett, M.P.; Yu, F.; Nagy, P.B.

2005-01-01

Shot peening and other mechanical surface enhancement methods improve the fatigue resistance and foreign-object damage tolerance of metallic components by introducing beneficial near-surface compressive residual stresses and hardening the surface. However, the fatigue life improvement gained via surface enhancement is not explicitly accounted for in current engine component life prediction models because of the lack of accurate and reliable nondestructive methods that could verify the presence of compressive near-surface residual stresses in shot-peened hardware. In light of its frequency-dependent penetration depth, the measurement of eddy current conductivity has been suggested as a possible means to allow the nondestructive evaluation of subsurface residual stresses in surface-treated components. This technique is based on the so-called piezoresistivity effect, i.e., the stress-dependence of electrical resistivity. We found that, in contrast with most other materials, surface-treated nickel-base superalloys exhibit an apparent increase in electrical conductivity at increasing inspection frequencies, i.e., at decreasing penetration depths. Experimental results are presented to illustrate that the excess frequency-dependent apparent eddy current conductivity of shot-peened nickel-base superalloys can be used to estimate the absolute level and penetration depth of the compressive residual stress layer both before and after partial thermal relaxation

3D Guided Wave Motion Analysis on Laminated Composites

Science.gov (United States)

Tian, Zhenhua; Leckey, Cara; Yu, Lingyu

2013-01-01

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

Wave propagation in embedded inhomogeneous nanoscale plates incorporating thermal effects

Science.gov (United States)

Ebrahimi, Farzad; Barati, Mohammad Reza; Dabbagh, Ali

2018-04-01

In this article, an analytical approach is developed to study the effects of thermal loading on the wave propagation characteristics of an embedded functionally graded (FG) nanoplate based on refined four-variable plate theory. The heat conduction equation is solved to derive the nonlinear temperature distribution across the thickness. Temperature-dependent material properties of nanoplate are graded using Mori-Tanaka model. The nonlocal elasticity theory of Eringen is introduced to consider small-scale effects. The governing equations are derived by the means of Hamilton's principle. Obtained frequencies are validated with those of previously published works. Effects of different parameters such as temperature distribution, foundation parameters, nonlocal parameter, and gradient index on the wave propagation response of size-dependent FG nanoplates have been investigated.

The Effect of Localized Damage on the Electrical Conductivity of Bare Carbon Fiber Tow and its Use as a Non-Destructive Evaluation Tool for Composite Overwrapped Pressure Vessels

Science.gov (United States)

Wentzel, Daniel

2015-01-01

Composite materials are beneficial because of their high specific strength and low weight. Safety, Destructive testing and destructive testing, Non-Destructive Testing (NDT) and Non-Destructive Evaluation (NDE). Problem: Neither NDT nor NDE can provide sufficient data to determine life expectancy or quantify the damage state of a composite material.

Fabrication of imitative stress corrosion cracking specimens suitable for electromagnetic nondestructive evaluations using solid state bonding

International Nuclear Information System (INIS)

Yusa, Noritaka; Hashizume, Hidetoshi; Uchimoto, Tetsuya; Takagi, Toshiyuki

2011-01-01

This study proposes a method to fabricate an artificial defect that is almost identical to stress corrosion cracking from the viewpoint of electromagnetic nondestructive evaluations. The key idea is to realize a region having electrical resistance embedded inside a conductive materials using solid state bonding. A rough region is introduced into the surface of the materials to be bonded so that the region is partially bonded to realize electrical resistance. Experimental demonstrations are carried out using type 316L austenitic stainless steels. Eddy current tests and subsequent numerical evaluations are conducted to discuss the validity of the proposed method. (author)

Hydrogen attack evaluation of boiler tube using ultrasonic wave

International Nuclear Information System (INIS)

Won, Soon Ho; Hyun, Yang Ki; Lee, Jong O; Cho, Kyung Shik; Lee, Jae Do

2001-01-01

The presence of hydrogen in industrial plants is a source of damage. Hydrogen attack is one such form of degradation and often causing large tube ruptures that necessitate an immediate shutdown. Hydrogen attack may reduce the fracture toughness as well as the strength of steels. This reduction is caused partially by the presence of cavities and microcracks at the grain boundaries. In the past several techniques have been used with limited results. This paper describes the application of an ultrasonic velocity, attenuation and backscatter techniques for detecting the presence of hydrogen damage in utility boiler tubes. Ultrasonic tests showed a decrease in wave velocity and an increase in attenuation. Such results demonstrate the potential for ultrasonic nondestructive testing to quantify damage. Based on this study, recommendations are that both velocity and attenuation be used to detect hydrogen attack in steels.

Improvement of visualization efficiency for the nondestructive inspection image of internal defects in plate type nuclear fuel

International Nuclear Information System (INIS)

Park, Seung Kyu; Park, Nak Kyu; Baik, Sung Hoon; Lee, Yoon Sang; Cheong, Yong Moo; Kang, Young June

2012-01-01

Plate type nuclear fuel has been adopted in most research reactors. The production quality of the fuel is a key part for an efficient and stable generation of thermal energy in research reactors. Thus, a nondestructive quality inspection for the internal defects of plate type nuclear fuel is a key process during the production of nuclear fuel for safety insurance. Nondestructive quality inspections based on X rays and ultrasounds have been widely used for the defect detection of plate type nuclear fuel. X ray testing is a simple and fast inspection method, and provides an image in real time as the inspection results. Thus, the testing can be carried out by a non expert field worker. However, it is hard to detect closed type defects that should be detected during the production of plate type nuclear fuel. Ultrasonic testing is a powerful tool to detect internal defects including open type and closed type defects in plate type nuclear fuel. However, the inspection process is complicated because an immersion test should be carried out in a water tank. It is also a time consuming inspection method because area testing to acquire image is based on the scanning of the point by point inspections. Among nondestructive inspection techniques, the techniques based on laser interferometry and infrared thermography have been widely used in the detection of internal defects of plate type composite materials, such as aircraft, automotive etc. While infrared thermography technique (IRT) analyses the thermal behavior of the specimen surface, laser interferometry technique (LIT) analyses the deformation field. Both techniques are useful tools for detection and evaluation of internal defects in composite materials. Especially, the laser interferometry technique can provide the depth information of internal defects. Laser interferometry technique (LIT) is a non contact inspection method faster than thermography. Also, this technique requires less energy than thermography and the

Nondestructive testing of a weld repair on the I-65 Bridge over the Ohio River at Louisville.

Science.gov (United States)

2009-06-01

Nondestructive evaluation methods were applied to verify the structural integrity of a fracture critical structural member on the I-65 John F. Kennedy Memorial Bridge over the Ohio River at Louisville. Several nondestructive evaluation methods includ...

Qualifying program on Non-Destructive Testing, Visual Inspection of the welding (level 2)

International Nuclear Information System (INIS)

Shafee, M. A.

2011-01-01

Nondestructive testing is a wide group of analysis technique used in science and industry to evaluate the properties of a material, component or system without causing damage. Common Non-Destructive Testing methods include ultrasonic, magnetic-particle, liquid penetrate, radiographic, visual inspection and eddy-current testing. AAEA put the new book of the Non-Destructive Testing publication series that focused on Q ualifying program on Non-Destructive Testing, visual inspection of welding-level 2 . This book was done in accordance with the Arab standard certification of Non-Destructive Testing (ARAB-NDT-CERT-002) which is agreeing with the ISO-9712 (2005) and IAEA- TEC-DOC-487. It includes twenty one chapters dealing with engineering materials used in industry, the mechanical behavior of metals, metal forming equipments, welding, metallurgy, testing of welds, introduction to Non-Destructive Testing, defects in metals, welding defects and discontinuities, introduction to visual inspection theory, properties and tools of visual testing, visual testing, quality control regulations, standards, codes and specifications, procedures of welding inspections, responsibility of welding test inspector, qualification of Non-Destructive Testing inspector and health safety during working.

Guided ultrasonic wave beam skew in silicon wafers

Science.gov (United States)

Pizzolato, Marco; Masserey, Bernard; Robyr, Jean-Luc; Fromme, Paul

2018-04-01

In the photovoltaic industry, monocrystalline silicon wafers are employed for solar cells with high conversion efficiency. Micro-cracks induced by the cutting process in the thin wafers can lead to brittle wafer fracture. Guided ultrasonic waves would offer an efficient methodology for the in-process non-destructive testing of wafers to assess micro-crack density. The material anisotropy of the monocrystalline silicon leads to variations of the guided wave characteristics, depending on the propagation direction relative to the crystal orientation. Selective guided ultrasonic wave excitation was achieved using a contact piezoelectric transducer with custom-made wedges for the A0 and S0 Lamb wave modes and a transducer holder to achieve controlled contact pressure and orientation. The out-of-plane component of the guided wave propagation was measured using a non-contact laser interferometer. The phase slowness (velocity) of the two fundamental Lamb wave modes was measured experimentally for varying propagation directions relative to the crystal orientation and found to match theoretical predictions. Significant wave beam skew was observed experimentally, especially for the S0 mode, and investigated from 3D finite element simulations. Good agreement was found with the theoretical predictions based on nominal material properties of the silicon wafer. The important contribution of guided wave beam skewing effects for the non-destructive testing of silicon wafers was demonstrated.

Current nondestructive evaluation research and development trends in the United States

International Nuclear Information System (INIS)

Jackson, Jerry

1992-01-01

An underlying theme present in much of the nondestructive evaluation (NDE) research and development occurring in the United States as well as worldwide is the application of physics and engineering principles toward understanding and optimizing NDE processes. Expanding this trend of using mathematical models for NDE processes is critical to the entire spectrum of NDE technology. In NDE research, modeling anchors the investigation in scientific, proven principles and establishes a firm technical basis to guide the design and development of inspection equipment and approaches. It also provides for understanding the capabilities and the limitations of whatever designs are selected and ultimately applied in the field. This paper reviews the status of these efforts, presents several examples where mathematical modeling is being profitably used for practical inspection work, and shows the path being taken in ongoing research.

Robotic 3D SQUID imaging system for practical nondestructive evaluation applications

International Nuclear Information System (INIS)

Isawa, K.; Nakayama, S.; Ikeda, M.; Takagi, S.; Tosaka, S.; Kasai, N.

2005-01-01

A robotic three-dimensional (3D) scanning superconducting quantum interference device (SQUID) imaging system was developed for practical nondestructive evaluation (NDE) applications. The major feature of this SQUID-NDE system is that the SQUID sensor itself scans in 3D by traveling over the surface of an object during testing without the need for magnetic shielding. This imaging system consists of (i) DC-SQUID gradiometer for effective movement of the sensor, (ii) SQUID sensor manipulator utilizing an articulated-type robot used in industry, (iii) laser charge-coupled-device (CCD) displacement sensor to measure the 3D coordinates of points on the surface of the object, and (iv) computer-aided numerical interpolation scheme for 3D surface reconstruction of the object. The applicability of this system for NDE was demonstrated by successfully detecting artificial damage of cylindrical-shaped steel tubes

Nondestructive testing of the low-level radioactive waste drums for uni-axial compressive strength and free liquid content

International Nuclear Information System (INIS)

Yu Geping; Chang Mingyu; Wang Yeajeng; Chu, David S.L.; Ju Yihzen

1992-01-01

This paper summarizes the nondestructive test to determine the uni-axial compressive strength and free water content of solidified low level radioactive waste. The uni-axial compressive strength is determined by ultrasonic wave propagation speed, and the results are compared with those of compressive tests. Three methods of detecting the surface free water by ultrasonic testing are established, the ultrasonic wave speed, wave form and pulse height are used to determine the existence and amount of the surface free liquid. Possible difficulties are discussed. (author)

Feasibility study of the IE-SASW method for nondestructive evaluation of containment building structures in nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Kim, D.S. E-mail: dskim@kaist.ac.kr; Kim, H.W. E-mail: hwk@kaist.ac.kr; Seo, W.S.; Choi, K.C.; Woo, S.K

2003-02-01

The IE-SASW method, a combination of impact-echo (IE) acoustics with spectral analysis of surface waves (SASW), is proposed as a newly developed nondestructive testing method in concrete structures. This feasibility study examines the IE technique and uses elastic P-wave velocity data as measured from the SASW method on concrete members in nuclear power plant containment structures. It was shown that both the thickness of the concrete specimens used in this study and the depth of the introduced defects (i.e. voids) could be identified by the IE-SASW method. In contrast, the reinforced steel bar itself could not be identified by the IE-SASW method. Additionally, GPR (ground penetrating radar) techniques were used to examine the same specimens in order to establish some level of performance and reliability to compare with the performance of the IE-SASW method. The GPR method provides an objective and reliable image corresponding to the reinforced steel bars. The experimental studies show that it is more feasible to use the IE-SASW method rather than GPR to detect voids that were positioned beneath the steel reinforcing bars in the concrete specimens.

Control of propagation characteristics of spin wave pulses via elastic and thermal effects

Energy Technology Data Exchange (ETDEWEB)

Gómez-Arista, Ivan [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, CU, 04510 D.F., México (Mexico); Kolokoltsev, O., E-mail: oleg.kolokoltsev@ccadet.unam.mx [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, CU, 04510 D.F., México (Mexico); Acevedo, A.; Qureshi, N. [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, CU, 04510 D.F., México (Mexico); Ordóñez-Romero, César L. [Instituto de Física, Universidad Nacional Autónoma de México, CU, 04510 D.F., México (Mexico)

2017-05-01

A study of the magnetoelastic (ME) and thermal effects governing the phase (φ) and amplitude of magnetostatic surface spin wave (MSSW) pulses propagating in Ga:YIG/GGG and permalloy magnonic waveguides is presented. The ME effects were studied in a flexural configuration, under punctual mechanical force (F). Thermally induced ME and demagnetization phenomena were controlled by optically injected thermal power P{sub th}. It was determined that in an unclamped Ga:YIG waveguide, the force F that induces the phase shift Δφ=π, decreases by a quadratic law in the range from 1 mN to nN, and the P{sub th} at which Δφ=π decreases linearly from mW to μW as the waveguide volume decreases from mm{sup 3} to nm{sup 3}. For nano-volume waveguides the ME control energy (E{sub me}) can be of order of aJ, and the thermal control energy (ΔE{sub th}) can be as small as 50 fJ. The response time of these effects lies in the ns time scale. Both the mechanical and the thermo-magnetic forces provide an effective control of MSSW pulse amplitude, in addition to its phase shift. The thermo-magnetic effect allows one to realize variable delays of a MSSW pulse. - Highlights: • The Magneto-elastic (ME) and optically induced thermal effects governing the phase and amplitude of magnetostatic surface spin wave (MSSW) pulses propagating in Ga:YIG/GGG and permalloy magnonic waveguides are presented. • A mechanical force that causes phase shift Δφ=π for spin waves in the waveguides decreases by a quadratic law in the range from 1 mN to nN, and the optical power that induces the phase shift Δφ=π, decreases linearly from mW to μW as the waveguide volume decreases from mm{sup 3} to nm{sup 3}. • The response time of these effects can lie in the ns time scale.

Marble Ageing Characterization by Acoustic Waves

Science.gov (United States)

Boudani, Mohamed El; Wilkie-Chancellier, Nicolas; Martinez, Loïc; Hébert, Ronan; Rolland, Olivier; Forst, Sébastien; Vergès-Belmin, Véronique; Serfaty, Stéphane

In cultural heritage, statue marble characterization by acoustic waves is a well-known non-destructive method. Such investigations through the statues by time of flight method (TOF) point out sound speeds decrease with ageing. However for outdoor stored statues as the ones in the gardens of Chateau de Versailles, ageing affects mainly the surface of the Carrara marble. The present paper proposes an experimental study of the marble acoustic properties variations during accelerated laboratory ageing. The surface degradation of the marble is reproduced in laboratory for 29 mm thick marble samples by using heating/cooling thermal cycles on one face of a marble plate. Acoustic waves are generated by 1 MHz central frequency contact transducers excited by a voltage pulse placed on both sides of the plate. During the ageing and by using ad hoc transducers, the marble samples are characterized in transmission, along their volume by shear, compressional TOF measurements and along their surface by Rayleigh waves measurements. For Rayleigh waves, both TOF by transducers and laser vibrometry methods are used to detect the Rayleigh wave. The transmission measurements point out a deep decrease of the waves speeds in conjunction with a dramatic decrease of the maximum frequency transmitted. The marble acts as a low pass filter whose characteristic frequency cut decreases with ageing. This pattern occurs also for the Rayleigh wave surface measurements. The speed change in conjunction with the bandwidth translation is shown to be correlated to the material de-structuration during ageing. With a similar behavior but reversed in time, the same king of phenomena have been observed trough sol-gel materials during their structuration from liquid to solid state (Martinez, L. et all (2004). "Chirp-Z analysis for sol-gel transition monitoring". Ultrasonics, 42(1), 507-510.). A model is proposed to interpret the acoustical measurements

Computer simulation of ultrasonic waves in solids

International Nuclear Information System (INIS)

Thibault, G.A.; Chaplin, K.

1992-01-01

A computer model that simulates the propagation of ultrasonic waves has been developed at AECL Research, Chalk River Laboratories. This program is called EWE, short for Elastic Wave Equations, the mathematics governing the propagation of ultrasonic waves. This report contains a brief summary of the use of ultrasonic waves in non-destructive testing techniques, a discussion of the EWE simulation code explaining the implementation of the equations and the types of output received from the model, and an example simulation showing the abilities of the model. (author). 2 refs., 2 figs

Development and characterization of enhanced green fluorescent protein and luciferase expressing cell line for non-destructive evaluation of tissue engineering constructs.

NARCIS (Netherlands)

Blum, J.S.; Temenoff, J.S.; Park, H.; Jansen, J.A.; Mikos, A.G.; Barry, M.A.

2004-01-01

This study investigates the utility of genetically modified cells developed for the qualitative and quantitative non-destructive evaluation of cells on biomaterials. The Fisher rat fibroblastic cell line has been genetically modified to stably express the reporter genes enhanced green fluorescence

Detection and sizing of large-scale cracks in centrifugally cast stainless steel pipes using Lamb waves

International Nuclear Information System (INIS)

Ngoc, T.D.K.; Avioli, M.J. Jr.

1988-01-01

Application of conventional ultrasonic nondestructive evaluation (NDE) techniques to centrifugally cast stainless steel (CCSS) pipes in pressurized water reactors (PWRs) has been limited, mainly due to the anisotropy of the CCSS materials. Phenomena such as beam skewing and distortion are directly attributable to this anisotropy and cause severe difficulties in crack detection and sizing. To improve CCSS inspectability, the feasibility of using Lamb waves as the probing mechanism for detecting and characterizing a surface-breaking crack originating from the pipe interior surface is discussed. A similar research effort has been reported by Rokhlin who investigated the interaction of Lamb waves with delaminations in thin sheets. Rokhlin and Adler also reported recently on the use of Lamb waves for evaluating spot welds. The motivation for using this probing mechanism derives from the recognition that the difficulties introduced by beam skewing, beam distortion, and high attenuation are circumvented, since Lamb waves are not bulk waves, but are resonant vibrational modes of a solid plate

The Role of Higher-Order Modes on the Electromagnetic Whistler-Cyclotron Wave Fluctuations of Thermal and Non-Thermal Plasmas

Science.gov (United States)

Vinas, Adolfo F.; Moya, Pablo S.; Navarro, Roberto; Araneda, Jamie A.

2014-01-01

Two fundamental challenging problems of laboratory and astrophysical plasmas are the understanding of the relaxation of a collisionless plasmas with nearly isotropic velocity distribution functions and the resultant state of nearly equipartition energy density with electromagnetic plasma turbulence. Here, we present the results of a study which shows the role that higher-order-modes play in limiting the electromagnetic whistler-like fluctuations in a thermal and non-thermal plasma. Our main results show that for a thermal plasma the magnetic fluctuations are confined by regions that are bounded by the least-damped higher order modes. We further show that the zone where the whistler-cyclotron normal modes merges the electromagnetic fluctuations shifts to longer wavelengths as the beta(sub e) increases. This merging zone has been interpreted as the beginning of the region where the whistler-cyclotron waves losses their identity and become heavily damped while merging with the fluctuations. Our results further indicate that in the case of nonthermal plasmas, the higher-order modes do not confine the fluctuations due to the effective higher-temperature effects and the excess of suprathermal plasma particles. The analysis presented here considers the second-order theory of fluctuations and the dispersion relation of weakly transverse fluctuations, with wave vectors parallel to the uniform background magnetic field, in a finite temperature isotropic bi-Maxwellian and Tsallis-kappa-like magnetized electron-proton plasma. Our results indicate that the spontaneously emitted electromagnetic fluctuations are in fact enhanced over these quasi modes suggesting that such modes play an important role in the emission and absorption of electromagnetic fluctuations in thermal or quasi-thermal plasmas.

Non-destructive inservice inspections

International Nuclear Information System (INIS)

Kauppinen, P.; Sarkimo, M.; Lahdenperae, K.

1998-01-01

In order to assess the possible damages occurring in the components and structures of operating nuclear power plants during service the main components and structures are periodically inspected by non-destructive testing techniques. The reliability of non-destructive testing techniques applied in these inservice inspections is of major importance because the decisions concerning the needs for repair of components are mainly based on the results of inspections. One of the targets of this research program has been to improve the reliability of non-destructive testing. This has been addressed in the sub-projects which are briefly summarised here. (author)

A Study on Elastic Guided Wave Modal Characteristics in Multi-Layered Structures

International Nuclear Information System (INIS)

Cho, Youn Ho; Lee, Chong Myoung

2008-01-01

In this study, we have developed a program which can calculate phase and group velocities, attenuation and wave structures of each mode in multi-layered plates. The wave structures of each mode are obtained, varying material properties and number of layers. The key in the success of guided wave NDE is how to optimize the mode selection scheme by minimizing energy loss when a structure is in contact with liquid. In this study, the normalized out-of-plane displacements at the surface of a free plate are used to predict the variation of modal attenuation and verily the correlation between attenuation and wave structure. It turns out that the guided wave attenuation can be efficiently obtain from the out-of-plane displacement variation of a free wave guide alleviating such mathematical difficulties in extracting complex roots for the eigenvalue problem of a liquid loaded wave guide. Through this study, the concert to optimize guided wave mode selection is accomplished to enhance sensitivity and efficiency in nondestructive evaluation for multi-layered structures.

Nondestructive/in-situ evaluation of the tensile properties in industrial facilities using indentation system

International Nuclear Information System (INIS)

Jang, Jae Il; Choi, Yeol; Son, Dong Il; Kwon, Dong Il

2001-01-01

Exact reliability evaluation and lifetime prediction through the in-field diagnosis of materials properties is needed for safe usage of degraded industrial structures. But, conventional standard testing methods having destructive procedures are not applicable to in-field assessment of mechanical property. Therefore, an advanced indentation technique was proposed for simple and non-destructive testing of in-field structures and for selected testing of local range such as heat affected zone and weldment. This test measures indentation load-depth curve during indentation and analyzes the mechanical properties related to deformation and fracture. First of all, flow properties such as yield strength, tensile strength and work hardening index can be evaluated through the analysis of the deformation behavior beneath the spherical indenter. Additionally, case studies of advanced indentation techniques are introduced.

Non-destructive characterization of the materials for future nuclear reactors

International Nuclear Information System (INIS)

Snopek, J.; Slugen, V.

2016-01-01

For our experiments, we have used Barkhausen noise technique, which is powerful non-destructive method for monitoring stresses in lattices of magnetic materials. We have also used PAS, which is powerful non-destructive method for diagnosing vacancy defects in variable materials. We researched some ODS steels, which are primarily going to be used as fuel cladding or reactor pressure vessel internal components. This thesis describes the behavior of the microstructure of the oxide dispersion strengthened steels at intermediate temperature. Two, in principle, different techniques were used for the characterization of the microstructure of the oxide dispersion strengthened steels thermally aged at 475 grad C and 650 grad C. Both techniques, namely Positron annihilation lifetime spectroscopy (PAS) and Barkhausen noise (BN) measurements are very sensitive to metallurgical modifications and presence of nano-sized imperfections in the crystal lattice. Precipitation of the nano-sized α' phases shift the Barkhausen noise signal. (authors)

Transmission mode acoustic time-reversal imaging for nondestructive evaluation

Science.gov (United States)

Lehman, Sean K.; Devaney, Anthony J.

2002-11-01

In previous ASA meetings and JASA papers, the extended and formalized theory of transmission mode time reversal in which the transceivers are noncoincident was presented. When combined with the subspace concepts of a generalized MUltiple SIgnal Classification (MUSIC) algorithm, this theory is used to form super-resolution images of scatterers buried in a medium. These techniques are now applied to ultrasonic nondestructive evaluation (NDE) of parts, and shallow subsurface seismic imaging. Results are presented of NDE experiments on metal and epoxy blocks using data collected from an adaptive ultrasonic array, that is, a ''time-reversal machine,'' at Lawrence Livermore National Laboratory. Also presented are the results of seismo-acoustic subsurface probing of buried hazardous waste pits at the Idaho National Engineering and Environmental Laboratory. [Work performed under the auspices of the U.S. Department of Energy by University of California Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48.] [Work supported in part by CenSSIS, the Center for Subsurface Sensing and Imaging Systems, under the Engineering Research Centers Program of the NSF (award number EEC-9986821) as well as from Air Force Contracts No. F41624-99-D6002 and No. F49620-99-C0013.

Space Qualified Non-Destructive Evaluation and Structural Health Monitoring Technology, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Encouraged by Phase I accomplishments, the proposed Phase II program will significantly mature and align the development of a Space Qualified Non-Destructive...

Study on evaluation methods for Rayleigh wave dispersion characteristic

Science.gov (United States)

Shi, L.; Tao, X.; Kayen, R.; Shi, H.; Yan, S.

2005-01-01

The evaluation of Rayleigh wave dispersion characteristic is the key step for detecting S-wave velocity structure. By comparing the dispersion curves directly with the spectra analysis of surface waves (SASW) method, rather than comparing the S-wave velocity structure, the validity and precision of microtremor-array method (MAM) can be evaluated more objectively. The results from the China - US joint surface wave investigation in 26 sites in Tangshan, China, show that the MAM has the same precision with SASW method in 83% of the 26 sites. The MAM is valid for Rayleigh wave dispersion characteristic testing and has great application potentiality for site S-wave velocity structure detection.

Nondestructive controls and testings: the new developments and their applications; Controles et examens non destructifs: les developpements recents et leurs applications

Energy Technology Data Exchange (ETDEWEB)

Recolin, P [Centre d' Etude des Structures et Materiaux Navals (CESMAN), DCN Propulsion, 44 - La Montagne (France); Bremnes, O; Chassignole, B; Schumm, A; Chassignole, B; Doudet, L; Dupond, O; Fouquet, T; Richard, B; Delnondedieu, M [Electricite de France (EDF/RD), 92 - Clamart (France); Calmon, P; Mahaut, S; Sollier, T; Haiat, G; Leberre, S; Benoist, Ph; Casula, O [CEA Saclay Dir. de la Recherche Technologique, 91 - Gif sur Yvette (France); Lasserre, F; Pasquier, T; Legrandjacques, L [FRAMATOME ANP/Intercontrole, 94 - Rungis (France); Lutsen, M [Electricite de France (EDF CEIDRE), 93 - Saint-Denis (France); Levy, R [AREVA/Intercontrole, 75 - Paris (France); Piriou, M; Glass, B; Chanussot, J M [FRAMATOME ANP, 92 - Paris-La-Defence (France); Cattiaux, G [Institut de Radioprotection et de Surete Nucleaire (IRSN), 92 - Clamart (France); Fleury, G [IMASONIC, 25 - Besancon (France); Thiery, Ch [CEA Bruyeres-le-Chatel, 91 (France); COFREND, 75 - Paris [France; Breysse, D [Bordeaux-1 Univ., 33 (France); Abraham, O [Ecole Nationale des Ponts et Chaussees (ENPC), Laboratoire Central des Ponts et Chaussees (LCPC), 75 - Paris (France)

2005-07-01

This document provides the proceedings of the conference on nondestructive controls and testings, held at Paris the 18 November 2004. Ten presentations were discussed on the following topics: the nondestructive testing of shipbuilding, the nondestructive evaluation simulation, the ultrasonic testing of austenitic stainless steels joints, qualification of the PWR vessels control, evaluation of the nuclear power plants materials aging, automation of the PWR primary coolant circuit testing, the photothermal imaging facing the liquid penetrant testing, geometry control with adaptative transducers, industrial tomography developments, nondestructive evaluation of the reinforced concretes structures. (A.L.B.)

Development of non-destructive Young's modulus measurement techniques in non-oriented CeF$_{3}$ crystals

CERN Document Server

Pietroni, P; Lebeau, M; Majni, G; Rinaldi, D

2005-01-01

For a reliable mechanical assembly of scintillating crystals for the application to radiographic systems such as Positron Emission Tomographer (PET) and high-energy physics calorimeters (e.g. in CMS at CERN LHC), the evaluation of the monocrystal elastic constant (Young's modulus) is needed. Its knowledge is also essential in the photoelastic analysis for the determination of residual stresses. In this work non-destructive techniques based on elastic wave propagation are tested. They differ in the mechanical excitation device: instrumented hammer, traditional ultrasonic probes and laser- generated ultrasound. We have analysed three non-oriented cerium fluoride crystal samples produced for scintillation applications. Finally, we have validated the experimental results comparing them with the elastic constant calculated by using the stiffness matrix.

Development of non-destructive Young's modulus measurement techniques in non-oriented CeF3 crystals

International Nuclear Information System (INIS)

Pietroni, P.; Paone, N.; Lebeau, M.; Majni, G.; Rinaldi, D.

2005-01-01

For a reliable mechanical assembly of scintillating crystals for the application to radiographic systems such as Positron Emission Tomographer (PET) and high-energy physics calorimeters (e.g. in CMS at CERN LHC), the evaluation of the monocrystal elastic constant (Young's modulus) is needed. Its knowledge is also essential in the photoelastic analysis for the determination of residual stresses. In this work non-destructive techniques based on elastic wave propagation are tested. They differ in the mechanical excitation device: instrumented hammer, traditional ultrasonic probes and laser-generated ultrasound. We have analysed three non-oriented cerium fluoride crystal samples produced for scintillation applications. Finally, we have validated the experimental results comparing them with the elastic constant calculated by using the stiffness matrix

49 CFR 192.243 - Nondestructive testing.

Science.gov (United States)

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Nondestructive testing. 192.243 Section 192.243... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Welding of Steel in Pipelines § 192.243 Nondestructive testing. (a) Nondestructive testing of welds must be performed by any process, other than trepanning, that...

Effect of humid-thermal environment on wave dispersion characteristics of single-layered graphene sheets

Science.gov (United States)

Ebrahimi, Farzad; Dabbagh, Ali

2018-04-01

In the present article, the hygro-thermal wave propagation properties of single-layered graphene sheets (SLGSs) are investigated for the first time employing a nonlocal strain gradient theory. A refined higher-order two-variable plate theory is utilized to derive the kinematic relations of graphene sheets. Here, nonlocal strain gradient theory is used to achieve a more precise analysis of small-scale plates. In the framework of the Hamilton's principle, the final governing equations are developed. Moreover, these obtained equations are deemed to be solved analytically and the wave frequency values are achieved. Some parametric studies are organized to investigate the influence of different variants such as nonlocal parameter, length scale parameter, wave number, temperature gradient and moisture concentration on the wave frequency of graphene sheets.

Thermal Transmission through Existing Building Enclosures: Destructive Monitoring in Intermediate Layers versus Non-Destructive Monitoring with Sensors on Surfaces.

Science.gov (United States)

Echarri, Víctor; Espinosa, Almudena; Rizo, Carlos

2017-12-08

Opaque enclosures of buildings play an essential role in the level of comfort experienced indoors and annual energy demand. The impact of solar radiation and thermal inertia of the materials that make up the multi-layer enclosures substantially modify thermal transmittance behaviour of the enclosures. This dynamic form of heat transfer, additionally affected by indoor HVAC systems, has a substantial effect on the parameters that define comfort. It also has an impact on energy demand within a daily cycle as well as throughout a one-year use cycle. This study describes the destructive monitoring of an existing block of flats located in Alicante. Once the enclosure was opened, sensors of temperature (PT100), air velocity, and relative humidity were located in the different layers of the enclosure, as well as in the interior and exterior surfaces. A pyranometer was also installed to measure solar radiation levels. A temperature data correction algorithm was drawn up to address irregularities produced in the enclosure. The algorithm was applied using a Raspberry Pi processor in the data collection system. The comparative results of temperature gradients versus non-destructive monitoring systems are presented, providing measures of the transmittance value, surface temperatures and indoor and outdoor air temperatures. This remote sensing system can be used in future studies to quantify and compare the energy savings of different enclosure construction solutions.

Thermal Transmission through Existing Building Enclosures: Destructive Monitoring in Intermediate Layers versus Non-Destructive Monitoring with Sensors on Surfaces

Directory of Open Access Journals (Sweden)

Víctor Echarri

2017-12-01

Full Text Available Opaque enclosures of buildings play an essential role in the level of comfort experienced indoors and annual energy demand. The impact of solar radiation and thermal inertia of the materials that make up the multi-layer enclosures substantially modify thermal transmittance behaviour of the enclosures. This dynamic form of heat transfer, additionally affected by indoor HVAC systems, has a substantial effect on the parameters that define comfort. It also has an impact on energy demand within a daily cycle as well as throughout a one-year use cycle. This study describes the destructive monitoring of an existing block of flats located in Alicante. Once the enclosure was opened, sensors of temperature (PT100, air velocity, and relative humidity were located in the different layers of the enclosure, as well as in the interior and exterior surfaces. A pyranometer was also installed to measure solar radiation levels. A temperature data correction algorithm was drawn up to address irregularities produced in the enclosure. The algorithm was applied using a Raspberry Pi processor in the data collection system. The comparative results of temperature gradients versus non-destructive monitoring systems are presented, providing measures of the transmittance value, surface temperatures and indoor and outdoor air temperatures. This remote sensing system can be used in future studies to quantify and compare the energy savings of different enclosure construction solutions.

Thermal Transmission through Existing Building Enclosures: Destructive Monitoring in Intermediate Layers versus Non-Destructive Monitoring with Sensors on Surfaces

Science.gov (United States)

Echarri, Víctor; Espinosa, Almudena; Rizo, Carlos

2017-01-01

Opaque enclosures of buildings play an essential role in the level of comfort experienced indoors and annual energy demand. The impact of solar radiation and thermal inertia of the materials that make up the multi-layer enclosures substantially modify thermal transmittance behaviour of the enclosures. This dynamic form of heat transfer, additionally affected by indoor HVAC systems, has a substantial effect on the parameters that define comfort. It also has an impact on energy demand within a daily cycle as well as throughout a one-year use cycle. This study describes the destructive monitoring of an existing block of flats located in Alicante. Once the enclosure was opened, sensors of temperature (PT100), air velocity, and relative humidity were located in the different layers of the enclosure, as well as in the interior and exterior surfaces. A pyranometer was also installed to measure solar radiation levels. A temperature data correction algorithm was drawn up to address irregularities produced in the enclosure. The algorithm was applied using a Raspberry Pi processor in the data collection system. The comparative results of temperature gradients versus non-destructive monitoring systems are presented, providing measures of the transmittance value, surface temperatures and indoor and outdoor air temperatures. This remote sensing system can be used in future studies to quantify and compare the energy savings of different enclosure construction solutions. PMID:29292781

The evaluation of phasemeter prototype performance for the space gravitational waves detection.

Science.gov (United States)

Liu, He-Shan; Dong, Yu-Hui; Li, Yu-Qiong; Luo, Zi-Ren; Jin, Gang

2014-02-01

Heterodyne laser interferometry is considered as the most promising readout scheme for future space gravitational wave detection missions, in which the gravitational wave signals disguise as small phase variances within the heterodyne beat note. This makes the phasemeter, which extracts the phase information from the beat note, the key device to this system. In this paper, a prototype of phasemeter based on digital phase-locked loop technology is developed, and the major noise sources which may contribute to the noise spectra density are analyzed in detail. Two experiments are also carried out to evaluate the performance of the phasemeter prototype. The results show that the sensitivity is achieved 2π μrad/√Hz in the frequency range of 0.04 Hz-10 Hz. Due to the effect of thermal drift, the noise obviously increases with the frequencies down to 0.1 mHz.

Proceedings for the nondestructive assay and nondestructive examination waste characterization conference. No. 5

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-05-01

This report contains paper presented at the 5th Nondestructive Assay and nondestructive Examination Waste Characterization conference. Topics included compliance, neutron NDA techniques, gamma NDA techniques, tomographic methods, and NDA modality and information combination techniques. Individual reports have been processed separately for the United States Department of Energy databases.

Proceedings for the nondestructive assay and nondestructive examination waste characterization conference. No. 5

International Nuclear Information System (INIS)

1997-01-01

This report contains paper presented at the 5th Nondestructive Assay and nondestructive Examination Waste Characterization conference. Topics included compliance, neutron NDA techniques, gamma NDA techniques, tomographic methods, and NDA modality and information combination techniques. Individual reports have been processed separately for the United States Department of Energy databases

Electron thermal conductivity from heat wave propagation in Wendelstein 7-AS

Energy Technology Data Exchange (ETDEWEB)

Giannone, L.; Erckmann, V; Gasparino, U; Hartfuss, H J; Kuehner, G; Maassberg, H; Stroth, U; Tutter, M [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); W7-AS Team; ECRH Group IPF Stuttgart; Gyrotron Group KFK Karlsruhe

1992-11-01

Heat wave propagation experiments have been carried out on the Wendelstein 7-AS stellarator. The deposition of electron cyclotron resonance heating power is highly localized in the plasma centre, so that power modulation produces heat waves which propagate away from the deposition volume. Radiometry of the electron cyclotron emission is used to measure the generated temperature perturbation. The propagation time delay of the temperature perturbation as a function of distance to the power deposition region is used to determine the electron thermal conductivity [chi][sub e]. This value is then compared with the value determined by global power balance. In contrast to sawtooth propagation experiments in tokamaks, it is found that the value of [chi][sub e] from heat wave propagation is comparable to that calculated by power balance. In addition, inward propagating waves were produced by choosing a power deposition region away from the plasma centre. Experiments were carried out at 70 GHz in the ordinary mode and at 140 GHz in the extraordinary mode. Variations of the modulation power amplitude have demonstrated that the inferred value of [chi][sub e] is independent of the amplitude of the induced temperature perturbations. (author). 29 refs, 11 figs, 5 tabs.

Photoacoustic thermal characterization of Al{sub 2}O{sub 3}-Ag ceramic nanocomposites

Energy Technology Data Exchange (ETDEWEB)

George, Sajan D. [Institut fuer Nano- und Mikroprozesstechnik, Leibniz Universitaet Hannover, Callinstrasse 36, D 30167, Hannover (Germany)]|[International School of Photonics, Cochin University of Science and Technology, Cochin 682022 (India)], E-mail: george@nmp.uni-hannover.de; Anappara, Aji A. [NEST-INFM and Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa (Italy)]|[University College, Thiruvanathapuram 695001 (India)]|[Ceramic Technology Division, Regional Research Laboratory, CSIR, Thiruvanathapuram 695019 (India); Warrier, P.R.S. [University College, Thiruvanathapuram 695001 (India); Warrier, K.G.K. [Ceramic Technology Division, Regional Research Laboratory, CSIR, Thiruvanathapuram 695019 (India); Radhakrishnan, P.; Nampoori, V.P.N.; Vallabhan, C.P.G. [International School of Photonics, Cochin University of Science and Technology, Cochin 682022 (India)

2008-09-15

Laser-induced nondestructive photoacoustic (PA) technique has been employed to determine the thermal diffusivity of nanometal (Ag) dispersed ceramic alumina matrix sintered at different temperatures. The thermal diffusivity values are evaluated by knowing the transition frequency from the amplitude spectrum of PA signal using the one-dimensional heat flow model of Rosencwaig and Gersho. Analysis of the data shows that heat transport and hence the thermal diffusivity value is greatly affected by the influence of incorporation of foreign atom. It is also seen that sintering temperature affects the thermal diffusivity value in a substantial manner. The results are interpreted in terms of variation in porosity and carrier-assisted heat transport mechanism in nanometal dispersed ceramics.

Non-destructive investigations at the Dionisiac Frieze in the Villa of Mysteries, Pompeii

Science.gov (United States)

Cristiano, Luigia; Erkul, Ercan; Jepsen, Kalle; Meier, Thomas; Vanacore, Stefano; Stefani, Grete

2014-05-01

The Villa of Mysteries with its Dionisiac Frieze is one of the well-known buildings of ancient Pompeii. It has been excavated in the early 20th century. Since then many initiatives have been taken for its preservation. Currently, the Frieze is investigated in detail and tests have been made to clean the wall paintings. Non-destructive investigations as infrared thermography (IR), Ground penetrating radar (GPR), and ultrasonic measurements have been performed in order to test if these methods are well suited to reveal the walls' and paintings' structure and to identify the detachments or cracks. IR, GPR and ultrasonic measurements have different penetration capabilities and resolution in depths. So, using these three methods simultaneously can improve the knowledge of the investigated structures at several depths from millimetres and centimetres to metres. It has been tested if detachments of the paintings, cracks, or alterations of the paintings can be detected by passive and active IR measurements. 6 passive and 3 active measurements have been conducted on the Dionisiac Frieze. Lateral temperature differences present at the Frieze are mapped by passive measurements. Here, we show that temperature differences up to about 0.3°C are present and detectable. These small changes in temperature may be related to detachments, cracks, or wet areas. By active IR measurements the paintings are artificially heated by about 1°C and the cooling to normal temperature is observed and analyzed. Lateral differences in the heating and cooling behavior are related to variability in the heat absorption properties and in thermal conductivity. It is shown that detachments as well as restorative treatments are associated with changes in the thermal behavior. In order to image the construction and the condition of the investigated walls, Ground Penetrating Radar (GPR) was measured with a 2 GHz antenna. Each profile was 1.2 m long, the spacing cross-line was 3 cm and in-line 1 mm. The

Coupling photon Monte Carlo simulation and CAD software. Application to X-ray nondestructive evaluation

International Nuclear Information System (INIS)

Tabary, J.; Gliere, A.

2001-01-01

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. (orig.)

Simultaneous measurement of thermal conductivity and heat capacity by flash thermal imaging methods

Science.gov (United States)

Tao, N.; Li, X. L.; Sun, J. G.

2017-06-01

Thermal properties are important for material applications involved with temperature. Although many measurement methods are available, they may not be convenient to use or have not been demonstrated suitable for testing of a wide range of materials. To address this issue, we developed a new method for the nondestructive measurement of the thermal effusivity of bulk materials with uniform property. This method is based on the pulsed thermal imaging-multilayer analysis (PTI-MLA) method that has been commonly used for testing of coating materials. Because the test sample for PTI-MLA has to be in a two-layer configuration, we have found a commonly used commercial tape to construct such test samples with the tape as the first-layer material and the bulk material as the substrate. This method was evaluated for testing of six selected solid materials with a wide range of thermal properties covering most engineering materials. To determine both thermal conductivity and heat capacity, we also measured the thermal diffusivity of these six materials by the well-established flash method using the same experimental instruments with a different system setup. This paper provides a description of these methods, presents detailed experimental tests and data analyses, and discusses measurement results and their comparison with literature values.

Non-destructive analysis of spent nuclear fuel

International Nuclear Information System (INIS)

Popovic, D.

1961-12-01

Nondestructive analysis of fuel elements dealt with determining the isotope contents which provide information about the burnup level, quantities of fission products and neutron-multiplication properties of the irradiated fuel. Methods for determination of the isotope ratio of the spent fuel are both numerical and experimental. This report deals with the experimental method. This means development of the experimental methods for direct measurement of the isotope content. A number of procedures are described: measurements of α, β and γ activities of the isotopes; measurement of secondary effects of nuclear reactions with thermal neutrons and fast neutrons; measurement of cross sections; detection of prompt and delayed neutrons

Evaluating local and overall thermal comfort in buildings using thermal manikins

Energy Technology Data Exchange (ETDEWEB)

Foda, E.

2012-07-01

Evaluation methods of human thermal comfort that are based on whole-body heat balance with its surroundings may not be adequate for evaluations in non-uniform thermal conditions. Under these conditions, the human body's segments may experience a wide range of room physical parameters and the evaluation of the local (segmental) thermal comfort becomes necessary. In this work, subjective measurements of skin temperature were carried out to investigate the human body's local responses due to a step change in the room temperature; and the variability in the body's local temperatures under different indoor conditions and exposures as well as the physiological steady state local temperatures. Then, a multi-segmental model of human thermoregulation was developed based on these findings to predict the local skin temperatures of individuals' body segments with a good accuracy. The model predictability of skin temperature was verified for steady state and dynamic conditions using measured data at uniform neutral, cold and warm as well as different asymmetric thermal conditions. The model showed very good predictability with average absolute deviation ranged from 0.3-0.8 K. The model was then implemented onto the control system of the thermal manikin 'THERMINATOR' to adjust the segmental skin temperature set-points based on the indoor conditions. This new control for the manikin was experimentally validated for the prediction of local and overall thermal comfort using the equivalent temperature measure. THERMINATOR with the new control mode was then employed in the evaluation of localized floor-heating system variants towards maximum energy efficiency. This aimed at illustrating a design strategy using the thermal manikin to find the optimum geometry and surface area of a floor-heater for a single seated person. Furthermore, a psychological comfort model that is based on local skin temperature was adapted for the use with the model of human

Thermal effects on parallel-propagating electron cyclotron waves

International Nuclear Information System (INIS)

Robinson, P.A.

1987-01-01

Thermal effects on the dispersion of right-handed electron cyclotron waves propagating parallel to a uniform, ambient magnetic field are investigated in the strictly non-relativistic ('classical') and weakly relativistic approximations for real frequency and complex wave vector. In each approximation, the two branches of the RH mode reconnect near the cyclotron frequency as the plasma temperature is increased or the density is lowered. This reconnection occurs in a manner different from that previously assumed at parallel propagation and from that at perpendicular propagation, giving rise to a new mode near the cold plasma cut-off frequency ωsub(xC). For both parallel and perpendicular propagation, it is noted that reconnection occurs approximately when the cyclotron linewidth equals the width of the stop-band in the cold plasma dispersion relation. Inclusion of weakly relativistic effects is found to be necessary for quantitative calculations and for an accurate treatment of the new mode near ωsub(xC). Weakly relativistic effects also modify the analytic properties of the dispersion relation so as to introduce a new family of weakly damped and undamped solutions. (author)

Lock-in thermographic inspection of squats on rail steel head

Science.gov (United States)

Peng, D.; Jones, R.

2013-03-01

The development of squat defects has become a major concern in numerous railway systems throughout the world. Infrared thermography is a relatively new non-destructive inspection technique used for a wide range of applications. However, it has not been used for rail squat detection. Lock-in thermography is a non-destructive inspection technique that utilizes an infrared camera to detect the thermal waves. A thermal image is produced, which displays the local thermal wave variation in phase or amplitude. In inhomogeneous materials, the amplitude and phase of the thermal wave carries information related to both the local thermal properties and the nature of the structure being inspected. By examining the infrared thermal signature of squat damage on the head of steel rails, it was possible to generate a relationship matching squat depth to thermal image phase angle, using appropriate experimental/numerical calibration. The results showed that with the additional data sets obtained from further experimental tests, the clarity of this relationship will be greatly improved to a level whereby infrared thermal contours can be directly translated into the precise subsurface behaviour of a squat.

Thermal conductivity profile determination in proton-irradiated ZrC by spatial and frequency scanning thermal wave methods

International Nuclear Information System (INIS)

Jensen, C.; Chirtoc, M.; Horny, N.; Antoniow, J. S.; Pron, H.; Ban, H.

2013-01-01

Using complementary thermal wave methods, the irradiation damaged region of zirconium carbide (ZrC) is characterized by quantifiably profiling the thermophysical property degradation. The ZrC sample was irradiated by a 2.6 MeV proton beam at 600 °C to a dose of 1.75 displacements per atom. Spatial scanning techniques including scanning thermal microscopy (SThM), lock-in infrared thermography (lock-in IRT), and photothermal radiometry (PTR) were used to directly map the in-depth profile of thermal conductivity on a cross section of the ZrC sample. The advantages and limitations of each system are discussed and compared, finding consistent results from all techniques. SThM provides the best resolution finding a very uniform thermal conductivity envelope in the damaged region measuring ∼52 ± 2 μm deep. Frequency-based scanning PTR provides quantification of the thermal parameters of the sample using the SThM measured profile to provide validation of a heating model. Measured irradiated and virgin thermal conductivities are found to be 11.9 ± 0.5 W m −1 K −1 and 26.7 ±1 W m −1 K −1 , respectively. A thermal resistance evidenced in the frequency spectra of the PTR results was calculated to be (1.58 ± 0.1) × 10 −6 m 2 K W −1 . The measured thermal conductivity values compare well with the thermal conductivity extracted from the SThM calibrated signal and the spatially scanned PTR. Combined spatial and frequency scanning techniques are shown to provide a valuable, complementary combination for thermal property characterization of proton-irradiated ZrC. Such methodology could be useful for other studies of ion-irradiated materials

Nondestructive evaluation of free acid content in apples using near-infrared spectroscopy

International Nuclear Information System (INIS)

Sohn, M.R.; Cho, R.K.

1998-01-01

In non-destructive evaluation of free acid content in apples by near- infrared spectroscopy(NIRS), browning and heat treatment of squeezed apple juice affected to the accuracy but titratable alkali concentration did not. The free acid content in apples after harvest was able to determine using different apples in harvest time for calibration making. The result of MLR, multiple correlation coefficient(R) was 0.77 and standard error of prediction(SEP) was 0.03%. The free acid content in apples during storage was able to determine using calibration equation established with stored apples, R was 0.90 and SEP was ca. 0.04%. The prediction accuracy by NIR was not sufficient for use of quantitative analysis of free acid content in apple, but classification of low and high level in acid content was supposed to be applicable

Magnetic Non-destructive Testing of Plastically Deformed Mild Steel

Directory of Open Access Journals (Sweden)

Jozef Pala

2004-01-01

Full Text Available The Barkhausen noise analysis and coercive field measurement have been used as magnetic non-destructive testing methods for plastically deformed high quality carbon steel specimens. The strain dependence of root mean square value and power spectrum of the Barkhausen noise and the coercive field are explained in terms of the dislocation density. The specimens have been subjected to different magnetizing frequencies to show the overlapping nature of the Barkhausen noise. The results are discussed in the context of usage of magnetic non-destructive testing to evaluate the plastic deformation of high quality carbon steel products.

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

Science.gov (United States)

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.

The effective reflection of a pulse sequence from a four-wave mirror with thermal nonlinearity under parametric feedback

Science.gov (United States)

Barashkov, M. S.; Bel'Diugin, I. M.; Zolotarev, M. V.; Kruzhilin, Iu. I.; Krymskii, M. I.

1989-04-01

A four-wave mirror with thermal nonlinearity has been experimentally realized with the interaction of corunning waves under parametric feedback with a nonreciprocal element. The effective reflection of a sequence of pulses with duration of about 300 ns from a neodymium-glass laser with maximal reflection coefficients greater than 30 has been demonstrated. The quality of the radiation reflected from the mirror is studied. A significant reduction in the steady-state lasing threshold has been shown with thermal nonlinearity at small angles of the interacting beam convergence, compared to the case of counterrunning convergence.

Dispersive Wave Analysis Using the Chirplet Transform

International Nuclear Information System (INIS)

Kerber, Florian; Luangvilai, Kritsakorn; Kuttig, Helge; Niethammer, Marc; Jacobs, Laurence J.

2007-01-01

Time-frequency representations (TFR) are a widely used tool to analyze signals of guided waves such as Lamb waves. As a consequence of the uncertainty principle, however, the resolution in time and frequency is limited for all existing TFR methods. Due to the multi-modal and dispersive character of Lamb waves, displacement or energy related quantities can only be allocated to individual modes when they are well-separated in the time-frequency plane.The chirplet transform (CT) has been introduced as a generalization of both the wavelet and Short-time Fourier transform (STFT). It offers additional degrees of freedom to adjust time-frequency atoms which can be exploited in a model-based approach to match the group delay of individual modes. Thus, more exact allocation of quantities of interest is possible.The objective of this research is to use a previously developed adaptive algorithm based on the CT for nondestructive evaluation. Both numerically and experimentally generated data for a single aluminum plate is analyzed to determine the accuracy and robustness of the new method in comparison the classical STFT

Optical Production and Detection of Ultrasonic Waves in Metals for Nondestructive Testing

Science.gov (United States)

Morrison, R. A.

1972-01-01

Ultrasonic waves were produced by striking the surface of a metal with the focused one-joule pulse of a Q-switched ruby laser. Rayleigh (surface) waves and longitudinal waves were detected with conventional transducers. Optical methods of detection were tested and developed. Rayleigh waves were produced with an oscillator and transducer. They were optically detected on curved polished surfaces, and on unpolished surfaces. The technique uses a knife edge to detect small angle changes of the surface as the wave pulse passes the illuminated spot. Optical flaw detection using pulse echo and attenuation is demonstrated.

Non-destructive testing of CFC/Cu joints

International Nuclear Information System (INIS)

Casalegno, V.; Ferraris, M.; Salvo, M.; Vesprini, R.; Merola, M.

2006-01-01

Reliable non-destructive tests (NDT) are fundamental for the manufacturing of ITER components, especially for high heat flux plasma facing components. NDT include various techniques, which allow inspection of a component without impairing serviceability; it's important to detect and characterize defects (type, size and position) as well as the set-up of acceptance standards in order to predict their influence on the component performance in service conditions. The present study shows a description of NDT used to assess the manufacturing quality of CFC (carbon fibre reinforced carbon matrix composites)/Cu/CuCrZr joints. In the ITER divertor, armor tiles made of CFC are joined to the cooling structure made of precipitation hardened copper alloy CuCrZr; a soft pure Cu interlayer is required between the heat sink and the armour in order to mitigate the stresses at the joint interface. NDT on CFC/Cu joint are difficult because of the different behavior of CFC and copper with regard to physical excitations (e.g. ultrasonic wave) used to test the component; furthermore the response to this input must be accurately studied to identify the detachment of CFC tiles from Cu alloy. The inspected CFC/Cu/CuCrZr joints were obtained through direct casting of pure Cu on modified CFC surface and subsequently through brazing of CFC/Cu joints to CuCrZr by a Cu-based alloy. Different non-destructive methods were used for inspecting these joints: lock-in thermography, ultrasonic inspections, microtomography and microradiography. The NDT tests were followed by metallographic investigation on the samples, since the reliability of a certain non destructive test can be only validated by morphological evidence of the detected defects. This study will undertake a direct comparison of NDT used on CFC/Cu joints in terms of real flaws presence. The purpose of this work is to detect defects at the joining interface as well as in the cast copper ( for instance voids). The experimental work was

Development and Short-Range Testing of a 100 kW Side-Illuminated Millimeter-Wave Thermal Rocket

Science.gov (United States)

Bruccoleri, Alexander; Eilers, James A.; Lambot, Thomas; Parkin, Kevin

2015-01-01

The objective of the phase described here of the Millimeter-Wave Thermal Launch System (MTLS) Project was to launch a small thermal rocket into the air using millimeter waves. The preliminary results of the first MTLS flight vehicle launches are presented in this work. The design and construction of a small thermal rocket with a planar ceramic heat exchanger mounted along the axis of the rocket is described. The heat exchanger was illuminated from the side by a millimeter-wave beam and fed propellant from above via a small tank containing high pressure argon or nitrogen. Short-range tests where the rocket was launched, tracked, and heated with the beam are described. The rockets were approximately 1.5 meters in length and 65 millimeters in diameter, with a liftoff mass of 1.8 kilograms. The rocket airframes were coated in aluminum and had a parachute recovery system activated via a timer and Pyrodex. At the rocket heat exchanger, the beam distance was 40 meters with a peak power intensity of 77 watts per square centimeter. and a total power of 32 kilowatts in a 30 centimeter diameter circle. An altitude of approximately 10 meters was achieved. Recommendations for improvements are discussed.

Digital image analysis applied to industrial nondestructive evaluation and automated parts assembly

International Nuclear Information System (INIS)

Janney, D.H.; Kruger, R.P.

1979-01-01

Many ideas of image enhancement and analysis are relevant to the needs of the nondestructive testing engineer. These ideas not only aid the engineer in the performance of his current responsibilities, they also open to him new areas of industrial development and automation which are logical extensions of classical testing problems. The paper begins with a tutorial on the fundamentals of computerized image enhancement as applied to nondestructive testing, then progresses through pattern recognition and automated inspection to automated, or robotic, assembly procedures. It is believed that such procedures are cost-effective in many instances, and are but the logical extension of those techniques now commonly used, but often limited to analysis of data from quality-assurance images. Many references are given in order to help the reader who wishes to pursue a given idea further

Elastic wave scattering methods: assessments and suggestions

International Nuclear Information System (INIS)

Gubernatis, J.E.

1985-01-01

The author was asked by the meeting organizers to review and assess the developments over the past ten or so years in elastic wave scattering methods and to suggest areas of future research opportunities. He highlights the developments, focusing on what he feels were distinct steps forward in our theoretical understanding of how elastic waves interact with flaws. For references and illustrative figures, he decided to use as his principal source the proceedings of the various annual Reviews of Progress in Quantitative Nondestructive Evaluation (NDE). These meetings have been the main forum not only for presenting results of theoretical research but also for demonstrating the relevance of the theoretical research for the design and interpretation of experiment. In his opinion a quantitative NDE is possible only if this relevance exists, and his major objective is to discuss and illustrate the degree to which relevance has developed

Polarization characterization of PZT disks and of embedded PZT plates by thermal wave methods

International Nuclear Information System (INIS)

Eydam, Agnes; Suchaneck, Gunnar; Gerlach, Gerald; Esslinger, Sophia; Schönecker, Andreas; Neumeister, Peter

2014-01-01

In this work, the thermal wave method was applied to characterize PZT disks and embedded PZT plates with regard to the polarization magnitude and spatial homogeneity. The samples were exposed to periodic heating by means of a laser beam and the pyroelectric response was determined. Thermal relaxation times (single time constants or distributions of time constants) describe the heat losses of the PZT samples to the environment. The resulting pyroelectric current spectrum was fitted to the superposition of thermal relaxation processes. The pyroelectric coefficient gives insight in the polarization distribution. For PZT disks, the polarization distribution in the surface region showed a characteristic decrease towards the electrodes

46 CFR 151.03-38 - Nondestructive testing.

Science.gov (United States)

2010-10-01

... CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Definitions § 151.03-38 Nondestructive testing. Nondestructive testing includes ultrasonic examination, liquid penetrant examination, magnetic particle... 46 Shipping 5 2010-10-01 2010-10-01 false Nondestructive testing. 151.03-38 Section 151.03-38...

New soliton solution to the longitudinal wave equation in a magneto-electro-elastic circular rod

Science.gov (United States)

Seadawy, Aly R.; Manafian, Jalil

2018-03-01

This paper examines the effectiveness of an integration scheme which called the extended trial equation method (ETEM) in exactly solving a well-known nonlinear equation of partial differential equations (PDEs). In this respect, the longitudinal wave equation (LWE) that arises in mathematical physics with dispersion caused by the transverse Poisson's effect in a magneto-electro-elastic (MEE) circular rod, which a series of exact traveling wave solutions for the aforementioned equation is formally extracted. Explicit new exact solutions are derived in different form such as dark solitons, bright solitons, solitary wave, periodic solitary wave, rational function, and elliptic function solutions of the longitudinal wave equation. The movements of obtained solutions are shown graphically, which helps to understand the physical phenomena of this longitudinal wave equation. Many other such types of nonlinear equations arising in non-destructive evaluation of structures made of the advanced MEE material can also be solved by this method.

Crack-depth effects in the cylindrically guided wave technique for bolt and pump-shaft inspections

International Nuclear Information System (INIS)

Tsai, Y.M.; Liu, S.N.; Light, G.M.

1991-01-01

Nuclear power plants have experienced the failures of bolts and pump shafts. The industry is concerned about nondestructive evaluation (NDE) techniques that can be applied to these components. The cylindrically guided wave technique (CGWT) has been developed to detect the simulated circumferential defects in long bolts and studs. The ultrasonic CGWT employs the zero-degree longitudinal waves constrained to travel within the boundary of the components with cylindrical shape during inspection. When longitudinal waves are guided to travel along a cylinder, and impinge onto a circumferential defect, the waves are scattered at the crack on the cylinder surface. In this work, the wave scattering at the circumferential crack on a long cylinder is investigated. The transfer factor of the scattered waves is calculated for a wide range of frequency spectra. The scattered waveform at a distance away from a crack is calculated. The effect that crack depth exerts to the waveform in CGWT is shown. CGWT signals, waveform calculation and so on are reported. (K.I.)

New soliton solution to the longitudinal wave equation in a magneto-electro-elastic circular rod

Directory of Open Access Journals (Sweden)

Aly R. Seadawy

2018-03-01

Full Text Available This paper examines the effectiveness of an integration scheme which called the extended trial equation method (ETEM in exactly solving a well-known nonlinear equation of partial differential equations (PDEs. In this respect, the longitudinal wave equation (LWE that arises in mathematical physics with dispersion caused by the transverse Poisson’s effect in a magneto-electro-elastic (MEE circular rod, which a series of exact traveling wave solutions for the aforementioned equation is formally extracted. Explicit new exact solutions are derived in different form such as dark solitons, bright solitons, solitary wave, periodic solitary wave, rational function, and elliptic function solutions of the longitudinal wave equation. The movements of obtained solutions are shown graphically, which helps to understand the physical phenomena of this longitudinal wave equation. Many other such types of nonlinear equations arising in non-destructive evaluation of structures made of the advanced MEE material can also be solved by this method. Keywords: Extended trial equation method, Longitudinal wave equation in a MEE circular rod, Dark solitons, Bright solitons, Solitary wave, Periodic solitary wave

Effectiveness Analysis of a Non-Destructive Single Event Burnout Test Methodology

CERN Document Server

Oser, P; Spiezia, G; Fadakis, E; Foucard, G; Peronnard, P; Masi, A; Gaillard, R

2014-01-01

It is essential to characterize power MosFETs regarding their tolerance to destructive Single Event Burnouts (SEB). Therefore, several non-destructive test methods have been developed to evaluate the SEB cross-section of power devices. A power MosFET has been evaluated using a test circuit, designed according to standard non-destructive test methods discussed in the literature. Guidelines suggest a prior adaptation of auxiliary components to the device sensitivity before the radiation test. With the first value chosen for the de-coupling capacitor, the external component initiated destructive events and affected the evaluation of the cross-section. As a result, the influence of auxiliary components on the device cross-section was studied. This paper presents the obtained experimental results, supported by SPICE simulations, to evaluate and discuss how the circuit effectiveness depends on the external components.

Fast Lamb wave energy shift approach using fully contactless ultrasonic system to characterize concrete structures

Science.gov (United States)

Ham, Suyun; Popovics, John S.

2015-03-01

Ultrasonic techniques provide an effective non-destructive evaluation (NDE) method to monitor concrete structures, but the need to perform rapid and accurate structural assessment requires evaluation of hundreds, or even thousands, of measurement datasets. Use of a fully contactless ultrasonic system can save time and labor through rapid implementation, and can enable automated and controlled data acquisition, for example through robotic scanning. Here we present results using a fully contactless ultrasonic system. This paper describes our efforts to develop a contactless ultrasonic guided wave NDE approach to detect and characterize delamination defects in concrete structures. The developed contactless sensors, controlled scanning system, and employed Multi-channel Analysis of Surface Waves (MASW) signal processing scheme are reviewed. Then a guided wave interpretation approach for MASW data is described. The presence of delamination is interpreted by guided plate wave (Lamb wave) behavior, where a shift in excited Lamb mode phase velocity, is monitored. Numerically simulated and experimental ultrasonic data collected from a concrete sample with simulated delamination defects are presented, where the occurrence of delamination is shown to be associated with a mode shift in Lamb wave energy.

Nondestructive examination requirements for PWR vessel internals

International Nuclear Information System (INIS)

Spanner, J.

2015-01-01

This paper describes the requirements for the nondestructive examination of pressurized water reactor (PWR) vessel internals in accordance with the requirements of the EPRI Material Reliability Program (MRP) inspection standard for PWR internals (MRP-228) and the American Society of Mechanical Engineers Section XI In-service Inspection. The MRP vessel internals examinations have been performed at nuclear plants in the USA since 2009. The objective of the inspection standard is to provide the requirements for the nondestructive examination (NDE) methods implemented to support the inspection and evaluation of the internals. The inspection standard contains requirements specific to the inspection methodologies involved as well as requirements for qualification of the NDE procedures, equipment and personnel used to perform the vessel internals inspections. The qualification requirements for the NDE systems will be summarized. Six PWR plants in the USA have completed inspections of their internals using the Inspection and Evaluation Guideline (MRP-227) and the Inspection Standard (MRP-228). Examination results show few instances of service-induced degradation flaws, as expected. The few instances of degradation have mostly occurred in bolting

Grain size measurements by ultrasonic Rayleigh surface waves

International Nuclear Information System (INIS)

Palanichamy, P.; Jayakumar, T.

1996-01-01

The use of Rayleigh surface waves to determine average grain size nondestructively in an austenitic stainless steel AISI type 316 stainless is discussed. Two commercial type 4MHz frequency surface wave transducers, one as transmitter and the other as receiver were employed for the measurement of surface wave amplitudes. Relative amplitudes of the Rayleigh surface waves were correlated with the metallographically obtained grain sizes. Results indicate that surface/sub-surface average grain sizes of AISI type 316 austenitic stainless steel can be estimated with a confidence level of more than 80% in the grain size range 30-170 μm. (author)

Technical regulation of nondestructive inspection

International Nuclear Information System (INIS)

1995-01-01

It starts with the explanation of definition of nondestructive inspection and qualifications for a inspection. It lists the technical regulations of nondestructive inspections which are radiographic testing, ultrasonic flaw detecting test, liquid penetrant test, magnetic particle inspection, eddy current test visual inspection and leakage test.

Thermal analysis of gyrotron traveling-wave tube collector

International Nuclear Information System (INIS)

Zheng Zhiqing; Luo Yong; Jiang Wei; Tang Yong

2013-01-01

In order to solve cooling problem of the gyrotron traveling-wave tube(TWT) collector and guarantee the gyrotron TWT's reliability and stability, the electron trajectories in the gyrotron TWT are simulated using CST electron simulation software. Thermal analysis of the collector with finite element software ANSYS is performed. The ways of applying boundary that affects the distribution of collector temperature are compared. The influence of the water temperature and flow rate on collector temperature distribution under actual heat fluxes (boundary condition) is researched. The size and number of collector fins are optimized, and a relatively perfect structure is obtained finally. The result estimated by simulation is consistent with the experiment and proves that the model and method employed in this work are suitable. (authors)

Numerical analysis for thermal waves in gas generated by impulsive heating of a boundary surface

International Nuclear Information System (INIS)

Utsumi, Takayuki; Kunugi, Tomoaki

1996-01-01

Thermal wave in gas generated by an impulsive heating of a solid boundary was analyzed numerically by the Differential Algebraic CIP (Cubic Interpolated Propagation) scheme. Numerical results for the ordinary heat conduction equation were obtained with a high accuracy. As for the hyperbolic thermal fluid dynamics equation, the fundamental feature of the experimental results by Brown and Churchill with regard to thermoacoustic convection was qualitatively reproduced by the DA-CIP scheme. (author)

Nondestructive sensing and stress transferring evaluation of carbon nanotube, nanofiber, and Ni nanowire strands/polymer composites using an electro-micromechanical technique

Science.gov (United States)

Park, Joung-Man; Kim, Sung-Ju; Jung, Jin-Gyu; Hansen, George; Yoon, Dong-Jin

2006-03-01

Nondestructive damage sensing and load transfer mechanisms of carbon nanotube (CNT), nanofiber (CNF), and Ni nanowire strands/epoxy composites were investigated using electro-micromechanical technique. Electrospun PVDF nanofiber was also prepared as a piezoelectric sensor. High volume% CNT/epoxy composites showed significantly higher tensile properties than neat and low volume% CNT/epoxy composites. CNF /epoxy composites with smaller aspect ratio showed higher apparent modulus due to high volume content in case of shorter aspect ratio. Using Ni nanowire strands/silicone composites with different content, load sensing response of electrical contact resistivity was investigated under tensile and compression condition. The mechanical properties of Ni nanowire strands with different type and content/epoxy composites were indirectly measured apparent modulus using uniformed cyclic loading and electro-pullout test. CNT or Ni nanowire strands/epoxy composites showed humidity and temperature sensing within limited ranges, 20 vol% reinforcement. Thermal treated electrospun PVDF nanofiber showed higher mechanical properties than the untreated case due to increased crystallization, whereas load sensing decreased in heat treated case. Electrospun PVDF nanofiber web also responded the sensing effect on humidity and temperature. Nanocomposites using CNT, CNF, Ni nanowire strands, and electrospun PVDF nanofiber web can be applicable practically for multifunctional applications nondestructively.

Directional radiative cooling thermal compensation for gravitational wave interferometer mirrors

Energy Technology Data Exchange (ETDEWEB)

Justin Kamp, Carl [Department of Chemical Reaction Engineering, Chalmers University of Technology, SE-412 96 Goteborg (Sweden)], E-mail: carl.kamp@chalmers.se; Kawamura, Hinata [Yokoyama Junior High School, Sanda, Hachioji, Tokyo 193-0832 (Japan); Passaquieti, Roberto [Dipartimento di Fisica ' Enrico Fermi' and INFN Sezione di Pisa, Universita' di Pisa, Largo Bruno Pontecorvo, I-56127 Pisa (Italy); DeSalvo, Riccardo [LIGO Observatories, California Institute of Technology, Pasadena, CA 91125 (United States)

2009-08-21

The concept of utilizing directional radiative cooling to correct the problem of thermal lensing in the mirrors of the LIGO/VIRGO gravitational wave detectors has been shown and has prospects for future use. Two different designs utilizing this concept, referred to as the baffled and parabolic mirror solutions, have been proposed with different means of controlling the cooling power. The technique takes advantage of the power naturally radiated by the mirror surfaces at room temperature to prevent their heating by the powerful stored laser beams. The baffled solution has been simulated via COMSOL Multiphysics as a design tool. Finally, the parabolic mirror concept was experimentally validated with the results falling in close agreement with theoretical cooling calculations. The technique of directional radiative thermal correction can be reversed to image heat rings on the mirrors periphery to remotely and dynamically correct their radius of curvature without subjecting the mirror to relevant perturbations.

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

Science.gov (United States)

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.

Evaluation of High-Speed Railway Bridges Based on a Nondestructive Monitoring System

Directory of Open Access Journals (Sweden)

Mosbeh R. Kaloop

2016-01-01

Full Text Available Recently, trains’ velocities in Korea increased more than the speed used in the design of some bridges. Accordingly, this paper demonstrates the evaluation of a railway bridge due to high-speed trains’ movement. A nondestructive monitoring system is used to assess the bridge performance under train speeds of 290, 360, 400 and 406 km/h. This system is comprised of a wireless short-term acceleration system and strain monitoring sensors attached to the bridge girder. The results of the analytical methods in time and frequency domains are presented. The following conclusions are obtained: the cross-correlation models for accelerations and strain measurements are effective to predict the performance of the bridge; the static behavior is increased with train speed developments; and the vibration, torsion, fatigue and frequency contents analyses of the bridge show that the bridge is safe under applied trains’ speeds.

Magnetic fluctuations due to thermally excited Alfven waves

International Nuclear Information System (INIS)

Agim, Y.Z.; Prager, S.C.

1990-01-01

Magnetic fluctuations due to the thermally excited MHD waves are investigated using fluid and kinetic models to describe a stable, uniform, compressible plasma in the range above the drift wave frequency and below the ion cyclotron frequency. It is shown that the fluid model with resistivity yields spectral densities which are roughly Lorentzian, exhibit equipartition with no apparent cutoff in wavenumber space and a Bohm-type diffusion coefficient. Under certain conditions, the ensuing transport may be comparable to classical values. For a phenomenological cutoff imposed on the spectrum, the typical fluctuating-to-equilibrium magnetic field ratio is found to be of the order of 10 -10 . Physical mechanisms to obtain decay profiles of the spectra with increasing wavenumber due to dispersion and/or different forms of damping are investigated analytically in a cold fluid approximation and numerically, with a kinetic model. The mode dispersion due to the finite ion-gyrofrequency is identified as the leading effect determining the spectral profile shapes. It is found that the amplitude of fluctuations may be within a factor of the value suggested by the cold plasma model. The results from both models are presented and compared in low- and high-β regimes. 21 refs., 6 figs

Nondestructive evaluation of adhesive joints by C-scan ultrasonic testing

International Nuclear Information System (INIS)

Zeighami, Mehdi; Honarvar, Farhang

2009-01-01

Evaluation of the quality of adhesive bonding is an important issue in many industries who incorporate adhesive joints in their products. Over the past few decades, numerous acoustical techniques have been developed for nondestructive testing (NDT) of adhesively bonded joints. Among these techniques, the ultrasonic pulse-echo method is the most promising means for inspection of adhesive bonds. In practice, due to low impedance matching between adhesive and metal, the discrimination of a good bond from a bad bond is difficult. The low impedance matching also results in low contrast between perfect and disbanded zone in a C-scan image. In this paper, the quality of the interface between aluminum and epoxy is investigated by using an in-house built ultrasonic C-scan system. Two adhesion indices are proposed for producing C-scan images. To verify the capability of these indices, an adhesively bonded sample was fabricated using aluminum plates and epoxy. An artificial defect was implanted in the first interface of the specimens. The C-scan measurement prepared based on the proposed indices was able to reveal the defect much better than the C-scan image prepared by conventional approach. (author)

Non-destructive methods of control of thermo-physical properties of fuel rods

International Nuclear Information System (INIS)

Kruglov, A B; Kruglov, V B; Kharitonov, V S; Struchalin, P G; Galkin, A G

2017-01-01

Information about the change of thermal properties of the fuel elements needed for a successful and safe operation of the nuclear power plant. At present, the existing amount of information on the fuel thermal conductivity change and “fuel-shell” thermal resistance is insufficient. Also, there is no technique that would allow for the measurement of these properties on the non-destructive way of irradiated fuel elements. We propose a method of measuring the thermal conductivity of the fuel in the fuel element and the contact thermal resistance between the fuel and the shell without damaging the integrity of the fuel element, which is based on laser flash method. The description of the experimental setup, implementing methodology, experiments scheme. The results of test experiments on mock-ups of the fuel elements and their comparison with reference data, as well as the results of numerical modeling of thermal processes that occur during the measurement. Displaying harmonization of numerical calculation with the experimental thermograms layout shell portions of the fuel cell, confirming the correctness of the calculation model. (paper)

Dynamic laser speckle for non-destructive quality evaluation of bread

Science.gov (United States)

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.

Conical Refraction of Elastic Waves by Anisotropic Metamaterials and Application for Parallel Translation of Elastic Waves.