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Review of Progress in Quantitative Nondestructive Evaluation

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Full-Text Articles in Mechanical Engineering

Non Destructive Evaluation Of Containment Walls In Nuclear Power Plants, V. Garnier, C. Payan, Martin Lott, Nari Ranaivamonana, Jp Balayssac, E. Larose, Yuxiang Zhang, J. Saliba, A. Boniface, Z. M. Sbartai, Bogdan Piwakowski, Charles Ciccarone, Hamid Hafid, Jean Marie Henault, Florian Ouvrier Buffet Jan 2016

Non Destructive Evaluation Of Containment Walls In Nuclear Power Plants, V. Garnier, C. Payan, Martin Lott, Nari Ranaivamonana, Jp Balayssac, E. Larose, Yuxiang Zhang, J. Saliba, A. Boniface, Z. M. Sbartai, Bogdan Piwakowski, Charles Ciccarone, Hamid Hafid, Jean Marie Henault, Florian Ouvrier Buffet

Review of Progress in Quantitative Nondestructive Evaluation

Two functions are regularly tested on the containment walls in order to anticipate a possible accident. The first is mechanical to resist at a possible internal over-pressure and the second is to prevent leakage. The reference accident LLOCA (Large Loss of Coolant 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 ...


Low Frequency Ultrasonic Array Imaging Using Signal Post-Processing For Concrete Material, Akio Ozawa, Hideki Izumi, Kazuyuki Nakahata, Katsumi Ohira, Kenzo Ogawa Jan 2016

Low Frequency Ultrasonic Array Imaging Using Signal Post-Processing For Concrete Material, Akio Ozawa, Hideki Izumi, Kazuyuki Nakahata, Katsumi Ohira, Kenzo Ogawa

Review of Progress in Quantitative Nondestructive Evaluation

The use of ultrasonic arrays for conducting non-destructive evaluation has been drastically increased in recent years. As one of the array imaging, a post-processing beam-forming technique has been proposed that utilizes a complete set of signals of all combinations of transmission and reception elements. This approach is referred to as full matrix capture (FMC) [1]. In FMC, each array element is sequentially used as an emitter and all other array elements are used as receivers. By changing the emitting element, we obtained a set of flaw signals that was used to form the focal beam. The delay-and-sum beam reconstruction based ...


A New Khz Rate Laser-Ultrasound Scanner For Ply-By-Ply Imaging Of Defects, Pores And Inconsistencies In Composite Structures, Ivan Pelivanov, Łukasz Ambrozinski, Matthew O’Donnell Jan 2016

A New Khz Rate Laser-Ultrasound Scanner For Ply-By-Ply Imaging Of Defects, Pores And Inconsistencies In Composite Structures, Ivan Pelivanov, Łukasz Ambrozinski, Matthew O’Donnell

Review of Progress in Quantitative Nondestructive Evaluation

Among NDT methods, only US and X-ray tomography can precisely locate three- dimensional defects regardless of composite type. X-ray systems, however, are very expensive, time-consuming and cumbersome. In addition, the chamber limits the size of the sample to several centimeters and makes it completely unsuitable for field applications. Conventional US pulse-echo techniques usually require couplants or full sample immersion for optimal energy transfer, which can affect overall scan speed and limit the applications where they can be used. Laser-ultrasound (LU) has many advantages over conventional US. First, laser-generated US transients are ultra-wideband, providing at least 3 times better resolution compared ...


Novel Methods To Measure Surface Wave Velocity By Using Laser-Generated Tone-Burst Surface Wave, Ju-Ho Lee, Jongbeom Kim, Kyung-Young Jhang Jan 2016

Novel Methods To Measure Surface Wave Velocity By Using Laser-Generated Tone-Burst Surface Wave, Ju-Ho Lee, Jongbeom Kim, Kyung-Young Jhang

Review of Progress in Quantitative Nondestructive Evaluation

Ultrasonic wave velocity is a characteristic of material, which is considered as a significant factor of nondestructive testing (NDT) techniques. Generally, bulk wave velocity is measured by Time-of-Flight (TOF) of pulse echo from back wall reflection; however, pulse-echo method cannot be applied to surface acoustic wave in a case that an edge does not exist in a close range. Even when we use through-transmission method, it is quite cumbersome to measure the accurate distance between transmitter and receiver; this problem is more critical when using contact angle transducers.

This study proposes two new signal processing methods to measure laser-generated surface ...


Influence Of Grain Size Distribution On Ultrasonic Scattering, Andrea Arguelles, Joseph A. Turner Jan 2016

Influence Of Grain Size Distribution On Ultrasonic Scattering, Andrea Arguelles, Joseph A. Turner

Review of Progress in Quantitative Nondestructive Evaluation

Elastic wave scattering at grain boundaries in polycrystalline media can be quantified to determine microstructural properties. The amplitude drop observed for coherent wave propagation (attenuation) as well as diffuse-field scattering events (such as the single-scattering response) have been extensively studied. In all cases, the scattering shows a clear dependence on grain size, grain geometric morphology, and material texture (i.e., macroscale anisotropy). Scattering models used to quantify such scattering experiments are often developed under the assumption of a single effective grain diameter implying a very narrow distribution of grain size throughout the sample. However, several microscopy studies suggest that most ...


Blind Sparse Deconvolution Of Regularly Spaced Ultrasonic Echoes For Thickness Measurement, Sébastien Bourguignon, Ewen Carcreff, Chunze Lin, Jiafan Peng Jan 2016

Blind Sparse Deconvolution Of Regularly Spaced Ultrasonic Echoes For Thickness Measurement, Sébastien Bourguignon, Ewen Carcreff, Chunze Lin, Jiafan Peng

Review of Progress in Quantitative Nondestructive Evaluation

We present a method for estimating the thickness of thin materials from ultrasonic data, in the context of coating measurement or thickness estimation of tubes and pipes. When sending an ultrasonic pulse in normal incidence in a homogeneous material, a set of regularly spaced echoes is received. Thickness is then obtained from the estimation of the time delay between echoes. If thin structures are inspected (or if a low frequency transducer is used), then echoes may overlap. Then, visual interpretation is made difficult and standard automatic methods may fail. We propose a blind sparse deconvolution approach to this problem, where ...


Multi-Site Delamination Detection And Quantification In Composites Through Guided Wave Based Global-Local Sensing, Zhenhua Tian, Cara Leckey, Lingyu Yu Jan 2016

Multi-Site Delamination Detection And Quantification In Composites Through Guided Wave Based Global-Local Sensing, Zhenhua Tian, Cara Leckey, Lingyu Yu

Review of Progress in Quantitative Nondestructive Evaluation

Advanced composite materials are contributing to a revolution in aerospace applications. Rapid inspection techniques for detecting and quantifying damage in large composites are critical for ensuring operability and safety of composite structures. Moreover, in the development and manufacturing of next-generation composite materials, rapid inspection techniques are imperative for evaluating and certifying the materials.

This paper presents a guided wave based global-local sensing method for rapid detection and quantification of delamination damage in large composite panels. The global-local approach uses a hybrid system consisting of a piezoelectric transducer (PZT) for generating guided waves and a non-contact scanning laser Doppler vibrometer (SLDV ...


Gas Turbine Coatings Eddy-Current Quantitative And Qualitative Evaluation, Remo Ribichini, Carlo Giolli, Erica Scrinzi Jan 2016

Gas Turbine Coatings Eddy-Current Quantitative And Qualitative Evaluation, Remo Ribichini, Carlo Giolli, Erica Scrinzi

Review of Progress in Quantitative Nondestructive Evaluation

Gas turbine blades (buckets) are among the most critical and expensive components of the engine. Buckets rely on protective coatings in order to withstand the harsh environment in which they operate. The thickness and the microstructure of coatings during the lifespan of a unit are fundamental to evaluate their fitness for service. A frequency scanning Eddy Current instrument can allow the measurement of the thickness and of physical properties of coatings in a Non-Destructive manner. The method employed relies on the acquisition of impedance spectra and on the inversion of the experimental data to derive the coating properties and structure ...


Wave Speed Propagation Measurements On Highly Attenuative Wax At Elevated Temperatures, David G. Moore, Sarah L. Stair, David A. Jack Jan 2016

Wave Speed Propagation Measurements On Highly Attenuative Wax At Elevated Temperatures, David G. Moore, Sarah L. Stair, David A. Jack

Review of Progress in Quantitative Nondestructive Evaluation

Ultrasonic stress wave amplitude and time-of-flight values change drastically as a media is heated. The measurement of relatively small variations in velocity and material attenuation can detect and quantify significant variations within a material microstructure. This paper discusses experimental setups, ultrasonic wave speed tracking methods and signal analysis algorithms that document the changes within highly attenuative wax material as it is either being heated or cooled from 25˚C to 90˚C. The experimental set-up utilizes ultrasonic probes in a pulse-echo and through-transmission configuration. The ultrasonic waveforms are recorded and analyzed during long duration thermal experiments. To complement the ultrasonic ...


Improved Scattering Models For Guided Wave Tomography, P. Huthwaite Jan 2016

Improved Scattering Models For Guided Wave Tomography, P. Huthwaite

Review of Progress in Quantitative Nondestructive Evaluation

Water collecting at pipe supports will accelerate corrosion, reducing the pipe life at a very difficult-to-inspect location. A traditional approach would require the pipe to be emptied, lifted and an ultrasonic thickness gauge be scanned across the surface. Guided wave tomography could potentially address these problems: by sending waves from an array on one side of the support through to a set of receivers on the other side, an image of the thickness can be produced, which is typically achieved by exploiting the dispersive nature of guided waves causing their speed to change depending on the thickness. However, this assumption ...


Effect Of Skew Angle On Second Harmonic Guided Wave Measurement In Composite Plates, Hwanjeong Cho, Sungho Choi, Cliff J. Lissenden Jan 2016

Effect Of Skew Angle On Second Harmonic Guided Wave Measurement In Composite Plates, Hwanjeong Cho, Sungho Choi, Cliff J. Lissenden

Review of Progress in Quantitative Nondestructive Evaluation

Waves propagating in anisotropic media are subject to skewing effects due to the media having directional wave speed dependence, which are characterized by slowness curves. Likewise, the generation of second harmonics is sensitive to micro-scale damage that is generally not detectable from linear features of ultrasonic waves. Here, the effect of skew angle on second harmonic guided wave measurement in a transversely isotropic lamina and a quasi-isotropic laminate are studied numerically. The strain energy density function for a nonlinear transversely isotropic material is formulated in terms of the Green-Lagrange strain invariants. The guided wave mode pairs for cumulative second harmonic ...


Thermal Diffusivity Measurements On Certified Standards Using Flash Ir Thermography, Vijay Nalladega, Bryon Knight Jan 2016

Thermal Diffusivity Measurements On Certified Standards Using Flash Ir Thermography, Vijay Nalladega, Bryon Knight

Review of Progress in Quantitative Nondestructive Evaluation

Infrared thermography has been increasingly used as an NDE tool for detection of defects in different types of components. At GE Global Research, the flash IR system is routinely used for inspecting for delaminations, porosity, and coating thickness and integrity. For defects such as delaminations and other larger defects, single-sided imaging, where the heat buildup due to the presence of defects can be visualized is used. However, in some cases, measurement of thermal diffusivity can also be used as an indicator of presence of damage. In this study, we report our findings on the accuracy of the diffusivity measurements using ...


Results Of The 2016 Ut Modeling Benchmark Obtained With Models Implemented In Civa, Gwénaël Toullelan, Raphaële Raillon, Steve Mahaut, Sylvain Chatillon, Sébastien Lonne Jan 2016

Results Of The 2016 Ut Modeling Benchmark Obtained With Models Implemented In Civa, Gwénaël Toullelan, Raphaële Raillon, Steve Mahaut, Sylvain Chatillon, Sébastien Lonne

Review of Progress in Quantitative Nondestructive Evaluation

For several years, the World Federation of NDE Centers, WFNDEC, proposes benchmark studies in which simulated results (in either ultrasonic, X-rays or eddy current NDT configurations) obtained with various models are compared to experiments. This year the proposed UT benchmark concerns inspection configurations with multi-skips echoes. This technique is commonly used to inspect thin specimen and/or in case of limited access inspection. This technique relies on the use of T45° mode in order to avoid mode conversion and to facilitate the interpretation of the echoes. To evaluate the influence of the beam divergence on the detectability after several skips ...


A Non-Collinear Mixing Technique To Measure The Acoustic Nonlinearity Parameter Of Adhesive Bond From Only One Side Of The Sample, Taeho Ju, Jan D. Achenbach, Laurence J. Jacobs, Jianmin Qu Jan 2016

A Non-Collinear Mixing Technique To Measure The Acoustic Nonlinearity Parameter Of Adhesive Bond From Only One Side Of The Sample, Taeho Ju, Jan D. Achenbach, Laurence J. Jacobs, Jianmin Qu

Review of Progress in Quantitative Nondestructive Evaluation

The acoustic nonlinearity parameter (ANLP) of a material is often positively correlated with the damage in the material. Therefore, the ability to nondestructively measure the ANLP may enable the nondestructive characterization of the material’s remaining strength. In this work, we developed a non-collinear mixing technique to measure the ANLP of adhesive bonds. One of the most significant features of the new method is that it requires only one-side access to the adhesive bond being measured, which significantly increases it utility in field measurements. Specifically, the test sample considered in this study consists of two aluminum plates adhesively joined together ...


A Fully Coupled Model For Actuation Of Higher Order Modes Of Lamb Waves, Baiyang Ren, Cliff J. Lissenden Jan 2016

A Fully Coupled Model For Actuation Of Higher Order Modes Of Lamb Waves, Baiyang Ren, Cliff J. Lissenden

Review of Progress in Quantitative Nondestructive Evaluation

Lamb waves have proven to be a valuable tool for structural health monitoring (SHM) of plate-like structures susceptible to degradation. It is well-known that the multi-modal propagation characteristics provide both challenges and opportunities. Piezoelectric transducers are widely used in SHM applications because of their low cost, small profile and strong electromechanical coupling. Properly designing a piezoelectric transducer to excite a particular mode is of great importance to successful SHM practice. The mode tuning capability of piezoelectric transducers has been studied both theoretically and experimentally in the literature for exciting A0 and S0 modes. However, the tuning characteristics of higher order ...


Influence Of Local Mechanical Properties Of High Strength Steel From Large Size Forged Ingot On Ultrasonic Wave Velocities, Frederic Dupont-Marillia, Mohammad Jahazi, Pierre Belanger, Serge Lafreniere Jan 2016

Influence Of Local Mechanical Properties Of High Strength Steel From Large Size Forged Ingot On Ultrasonic Wave Velocities, Frederic Dupont-Marillia, Mohammad Jahazi, Pierre Belanger, Serge Lafreniere

Review of Progress in Quantitative Nondestructive Evaluation

In the metallurgical industry, ultrasonic inspection is routinely used for the detection of defects. For the nondestructive inspection of small high strength steel parts, the material can be considered isotropic. However, when the size of the parts under inspection is large, the isotropic material hypothesis does not necessarily hold. The aim of this study is to investigate the effect of the variation in mechanical properties such as grain size, Young's modulus, Poisson’s ratio, chemical composition on longitudinal and transversal ultrasonic wave velocities. A 2 cm thick slice cut from a 40-ton bainitic steel ingot that was forged and ...


Evaluation Of The Depth Of Surface Deterioration For Concrete Structure Using Dispersion Characteristics Of Surface Wave, Chia-Chi Cheng, Ying-Tzu Ke, Keng-Tsang Hsu, Hung-Yu Tao, Chih-Hung Chiang Jan 2016

Evaluation Of The Depth Of Surface Deterioration For Concrete Structure Using Dispersion Characteristics Of Surface Wave, Chia-Chi Cheng, Ying-Tzu Ke, Keng-Tsang Hsu, Hung-Yu Tao, Chih-Hung Chiang

Review of Progress in Quantitative Nondestructive Evaluation

Surface waves generated by an impact are used to assess depth of deterioration for concrete plate. The proposed method uses one receiver positioned away from the impacting source. The spectrogram of the group velocity obtained from the signal recorded from the receiver is calculated by Short-Time Fourier Transform and the reassignment technique [1]. Experiments were conduct on the concrete plate with different thickness of mortar top layer to simulate concrete with serious aggregate segregation and bleeding. In the experiment, the source-receiver distance for concrete plate with different thickness of weak top layer are explored. Figure 1 shows the comparison between ...


Calibration Of Air-Coupled Transducers For Absolute Nonlinear Ultrasonic Measurements, Nicholas Selby, David Torello, Jin-Yeon Kim, Laurence J. Jacobs Jan 2016

Calibration Of Air-Coupled Transducers For Absolute Nonlinear Ultrasonic Measurements, Nicholas Selby, David Torello, Jin-Yeon Kim, Laurence J. Jacobs

Review of Progress in Quantitative Nondestructive Evaluation

We describe a novel calibration technique of air-coupled transducers for nonlinear ultrasonic measurements through homogenous, isotropic media. Our calibration technique combines laser interferometrywith a model-based approach to derive a relationship between received force at the transducer face and the measured output voltage. Conventional nonlinear ultrasonic measurement techniques have relied upon contact receiving transducers that are heavily influenced by contact conditions (e.g. inconsistent coupling) and laser interferometers that are prohibitively expensive and rely on a mirror-finished surface or complicated optics. Air-coupled transducers are significantly less expensive than laser interferometers and are robust relative to surface conditions, but current calibration techniques ...


Damage Detection Using High Order Longitudinal Guided Waves In The Anchorage Zone Of Stayed-Cable, Yongdong Pan, Feng Yang Jan 2016

Damage Detection Using High Order Longitudinal Guided Waves In The Anchorage Zone Of Stayed-Cable, Yongdong Pan, Feng Yang

Review of Progress in Quantitative Nondestructive Evaluation

High order longitudinal guided waves (HOLGW) are studied for the damage detection in the anchorage zone of stayed cable through the theoretical analysis, numerical simulation and experimental validation. First, based on the theory of elastic wave propagation in cylinder, the dispersion curves of longitudinal modes were obtained and calculated analytically and the high-frequency such as 5MHz corresponding to the higher order longitudinal guided wave modes are identified for the damage detection. Then, the ultrasonic guided waves propagating in a steel wire with or without defects were simulated by using the finite element method and the effects of defect depth and ...


Optimal Design Of A Piezoelectric Transducer For Exciting Guided Wave Ultrasound In Rails, Dineo A. Ramatlo, Daniel N. Wilke, Philip W. Loveday Jan 2016

Optimal Design Of A Piezoelectric Transducer For Exciting Guided Wave Ultrasound In Rails, Dineo A. Ramatlo, Daniel N. Wilke, Philip W. Loveday

Review of Progress in Quantitative Nondestructive Evaluation

An existing Ultrasonic Broken Rail Detection System [1] installed in South Africa on a heavy duty railway line is currently being upgraded to include defect detection and location. To accomplish this, an ultrasonic piezoelectric transducer to strongly excite a guided wave mode with energy concentrated in the web (web mode) of a rail is required. A previous study [2] demonstrated that the recently developed SAFE-3D (Semi-Analytical Finite Element – 3 Dimensional) method can effectively predict the guided waves excited by a resonant piezoelectric transducer. In this study, the SAFE-3D model is used in the design optimization of a rail web transducer ...


Acoustic Emission As A Screening Tool For Ceramic Matrix Composites, Greg Ojard, Dan Goberman, John Holowczak Jan 2016

Acoustic Emission As A Screening Tool For Ceramic Matrix Composites, Greg Ojard, Dan Goberman, John Holowczak

Review of Progress in Quantitative Nondestructive Evaluation

Ceramic matrix composites are composite materials with ceramic fibers in a high temperature matrix of ceramic or glass-ceramic. This emerging class of materials is viewed as enabling for efficiency improvements in many energy conversion systems. The key controlling property of ceramic matrix composites is a relatively weak interface between the matrix and the fiber that aids crack deflection and fiber pullout resulting in greatly increased toughness over monolithic ceramics. United Technologies Research Center has been investigating glass-ceramic composite systems as a tool to understand processing effects on material performance related to the performance of the weak interface. Changes in the ...


A Parameterized Delamination Model For Use In Complex Damage Characterization Of Composite Laminatesin Ultrasonic Inspections, Heather Reed, Gerald Harvey, Jeff Dobson, Cara Leckey Jan 2016

A Parameterized Delamination Model For Use In Complex Damage Characterization Of Composite Laminatesin Ultrasonic Inspections, Heather Reed, Gerald Harvey, Jeff Dobson, Cara Leckey

Review of Progress in Quantitative Nondestructive Evaluation

Ultrasonic damage detection and characterization is commonly used in nondestructive evaluation (NDE) of aerospace composite components. However, in real materials and structures, the dispersive waves can result in complicated behavior, particularly in the presence of complex damage scenarios and structural components. Accurate three dimensional finite element models (FEMs), using PZFlex, of guided wave interactions with realistic damage scenarios can be used to study quantitative NDE ultrasonic damage detection techniques numerically, to supplement or replace expensive experimental testing. Novel data analysis techniques such as filter reconstruction imaging methods can be used to create practical comparisons between experimental and simulated data. To ...


Full-Field Imaging Vibrometry For Rapid Non-Destructive Evaluation, James Kilpatrick, Adela Apostol, Vladimir Markov Jan 2016

Full-Field Imaging Vibrometry For Rapid Non-Destructive Evaluation, James Kilpatrick, Adela Apostol, Vladimir Markov

Review of Progress in Quantitative Nondestructive Evaluation

NDE methods calling for spatially extended measurement of surface structural dynamics may be of limited practical application because measurement times are prohibitively slow for use under environmentally variable conditions. However, scanning single beam ultrasound and scanned single beam laser Doppler vibrometry (SLDV), remain as the foremost viable NDE sensor technologies developed over the past several decades.

This paper discusses new developments in sensor technology for Full-field Imaging Vibrometry at AS&T Inc. These sensors are capable of extended field measurement of structural dynamics at bandwidths extending from near DC to ultrasonic [1]. As compared to manual deployment of spatially distributed ...


Interaction Of Feature Guided Waves With Defects In Composite Structural Bends, X. Yu, M. Ratassepp, Z. Fan Jan 2016

Interaction Of Feature Guided Waves With Defects In Composite Structural Bends, X. Yu, M. Ratassepp, Z. Fan

Review of Progress in Quantitative Nondestructive Evaluation

Complex-shaped composite structures such as bends, stiffeners, and ribs are increasingly incorporated in aerospace applications because of their attractive mechanical properties and good moldability. However, damages like matrix cracking and delamination can be caused in these structures by stress concentration and out-of-plane impacts during the in-service use, consequently degrading the system integrity and reliability. Ultrasonic feature guided waves (FGW) can serve as promising candidates for their inspection as they can propagate along the feature long distances and potentially detect the possible defects. In this study, potential FGW modes have been identified in 90° carbon fiber/epoxy (CF/EP) quasi-isotropic bent ...


Attenuation Of Ultrasonic Waves Generated From Laser Ultrasound During Annealing Of Steel; A Comparison Between Theory And Experiment And Potential Application To Additive Manufacturing, Christopher M. Kube, Ricardo Rodriguez, Ed Habtour, Larry Holmes Jan 2016

Attenuation Of Ultrasonic Waves Generated From Laser Ultrasound During Annealing Of Steel; A Comparison Between Theory And Experiment And Potential Application To Additive Manufacturing, Christopher M. Kube, Ricardo Rodriguez, Ed Habtour, Larry Holmes

Review of Progress in Quantitative Nondestructive Evaluation

The advancement of additive manufacturing methods for the production of metallic parts has initiated the potential development of materials with tailored microstructures to enhance their material properties. To help facilitate the development, methods based on ultrasonic grain scattering are proposed to provide in-situ monitoring of the microstructure’s evolution during the build process. In this work, the longitudinal attenuation coefficient is considered, theoretically and experimentally, as a function of temperature during an annealing process of steel. Theoretically, an iterative solution to the attenuation model of Stanke and Kino is given. The theory is compared against experimental measurements of the longitudinal ...


Defect Characterization From Limited View Pipeline Radiography, Misty I. Haith, Peter Huthwaite, Michael J.S. Lowe Jan 2016

Defect Characterization From Limited View Pipeline Radiography, Misty I. Haith, Peter Huthwaite, Michael J.S. Lowe

Review of Progress in Quantitative Nondestructive Evaluation

Accurate characterization of pipeline corrosion defects is required in order to identify the criticality of the defect, and calculate the remaining lifespan of the pipe. In radiography, accurate characterization of a defect generally requires an additional object – such as a step wedge – to be included in the exposure setup. This is used to calibrate the resulting radiograph, allowing for accurate measurements. In the case of the step wedge, calibration means calculating the relationship between intensity and wall thickness, allowing wall thickness loss to be found from the change in intensity caused by the defect. However, in situations where pipe access ...


Fatigue Crack Monitoring Under High-Cycle Fatigue Loading Using Large-Area Soft Elastomeric Capacitive Sensor, Jian Li, Xiangxiong Kong, William Collins, Caroline Bennett, Simon Laflamme Jan 2016

Fatigue Crack Monitoring Under High-Cycle Fatigue Loading Using Large-Area Soft Elastomeric Capacitive Sensor, Jian Li, Xiangxiong Kong, William Collins, Caroline Bennett, Simon Laflamme

Review of Progress in Quantitative Nondestructive Evaluation

Fatigue cracks under high-cycle fatigue loading due to normal traffic are one of the major damage modes of steel bridges. Monitoring these cracks is of great importance especially for fracture-critical bridges in order to ensure safe operation by preventing catastrophic failure due to excessive damage. A newly developed soft elastomeric capacitive (SEC) sensor [1] is able to monitor strain changes over a large area of structural surface and resist large deformation due to cracking without being damaged. To examine the feasibility of monitoring fatigue cracks under high-cycle fatigue loading using the SEC sensor, a compact tension specimen is tested under ...


Resolution Of Overlapping Ultrasonic Echoes Using Consistent Frequency Domain Amplitude-Phase Relationships, Chi-Hang Kwan, Anthony N. Sinclair Jan 2016

Resolution Of Overlapping Ultrasonic Echoes Using Consistent Frequency Domain Amplitude-Phase Relationships, Chi-Hang Kwan, Anthony N. Sinclair

Review of Progress in Quantitative Nondestructive Evaluation

The ability to identify overlapping echoes is crucial to the enhancement of temporal resolution in ultrasonic testing. The majority of the techniques currently being investigated for separation of overlapping ultrasonic echoes are based on deconvolution. However, single reference deconvolution techniques are sensitive to the choice of the reference waveform and dictionary based deconvolution techniques require the enforcement of sparsity conditions. We propose a new post-processing algorithm that exploits the consistent frequency domain amplitude and phase relationships of two overlapping echoes. The frequency amplitude profiles are used as inputs and the corresponding set of phase values are calculated as the outputs ...


Curvature-Dependence Of Cut-Off Frequencies Of Guided Waves Propagating Through Curved Structures Obtained By A Semi-Analytical Finite Element Method, Kosuke Kanda, Toshihiko Sugiura Jan 2016

Curvature-Dependence Of Cut-Off Frequencies Of Guided Waves Propagating Through Curved Structures Obtained By A Semi-Analytical Finite Element Method, Kosuke Kanda, Toshihiko Sugiura

Review of Progress in Quantitative Nondestructive Evaluation

Non-destructive testing (NDT) and structural health monitoring (SHM) are engineering techniques for investigating defects without breaking structures. Guided wave ultrasonic modes propagating over long distances can be applied to NDT for long structures such as plates, rods and pipes. Guided waves have a dispersion property, which represents dependence of propagation velocities on frequencies. Therefore, for effective use of guided waves, we need to know this property, which is usually expressed as dispersion curves [1]~[3].

The goal of this paper is to numerically investigate effects of curvatures on the dispersion property of guided waves propagating in a helical structure and ...


Ultrasonic Techniques For The Detection Of Discontinuities In Aluminum Foams, Pablo Katchadjian, Alejandro García, Jose Brizuela, Jorge Camacho, Bruno Chiné, Valerio Mussi Jan 2016

Ultrasonic Techniques For The Detection Of Discontinuities In Aluminum Foams, Pablo Katchadjian, Alejandro García, Jose Brizuela, Jorge Camacho, Bruno Chiné, Valerio Mussi

Review of Progress in Quantitative Nondestructive Evaluation

Metal foams are interesting materials with many potential applications [1, 2, 3]. They are characterized by a cellular structure, that is the metals or metal alloys foamed include gas voids in the material. Their particular lightweight structure and physical, chemical and mechanical properties make them suitable for a wide range of industrial applications in different sectors. For industrial applications, metal foams offer attractive combinations of low density, high stiffness to weight ratio, good energy absorption and vibration damping capacity that cannot be obtained with other materials.

The control of the foaming process and the characterization of the metal foam are ...