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Full-Text Articles in Computational Engineering

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 ...


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 ...


Inspection And Model Based Inversion Of Highly Curved Composite Surfaces With Flash Thermography, Bryan E. Schiefelbein, Stephen D. Holland Jan 2016

Inspection And Model Based Inversion Of Highly Curved Composite Surfaces With Flash Thermography, Bryan E. Schiefelbein, Stephen D. Holland

Review of Progress in Quantitative Nondestructive Evaluation

With the development of advanced aircraft structures and stringent mechanical requirements, robust and reliable inspection methods are needed to ensure safe operation and maximum utilization of the equipment [1]. Aircraft composite parts can exhibit complex geometries and tight curvature, such as leading edges and chines. These curved structures are difficult to inspect for defects, especially where the local curvature is high [2–4]. Pulsed thermography has the potential for rapid inspection of large areas, making it attractive for depot or field inspection of large aircraft parts. When imaging areas of high curvature, there are a number of confounding factors, including ...


Scanning Acoustic Microscopy Technologies Applied To 3d Semiconductor Integration Applications, Peter Czurratis, Bernd Köhler, Martin Barth, Tatjana Djuric, Peter Hoffrogge Jan 2016

Scanning Acoustic Microscopy Technologies Applied To 3d Semiconductor Integration Applications, Peter Czurratis, Bernd Köhler, Martin Barth, Tatjana Djuric, Peter Hoffrogge

Review of Progress in Quantitative Nondestructive Evaluation

In semiconductor industry new approaches are employed for increasing functionality and complexity while reducing a systems footprint by integrating components in the third spatial dimension. However, this new design concept requires new and adapted methods for failure analysis and quality assessment. Acoustic microscopy is a powerful method providing detailed information of a samples interior while operating non-destructively. By employing the methods capability of acquiring the information in 3D by performing a rapid acquisition scan full access is given to the samples interior structure and parameters including the elastic properties. However, the new concept of 3D integration required the development of ...


Damage Detection In Composite Structures Using Time-Reversal Migration Technique, Dan Xiang, Fuh-Gwo Yuan, Jason He Jan 2016

Damage Detection In Composite Structures Using Time-Reversal Migration Technique, Dan Xiang, Fuh-Gwo Yuan, Jason He

Review of Progress in Quantitative Nondestructive Evaluation

The use of composites in aircraft manufacturing is growing dramatically. Ultrasonic guided waves (UGW) can propagate a long distance, and thus have been used in structural health monitoring (SHM) for large area composite structures like wings and fuselages. UGW can detect not only the damages on the surface of the structures, but also the flaws inside the structures. In this paper, a time-reversal migration (TRM) technique, which originates from the geophysical migration technique, is used to reconstruct the image of damage in composites. The TRM technique uses a linear-array transducer. Each time, one element is used as actuator and the ...


An Hdf5 Based Framework For The Distribution And Analysis Of Ultrasonic Concrete Data, Luke Prince, Dwight Clayton, Hector Santos-Villalobos Jan 2016

An Hdf5 Based Framework For The Distribution And Analysis Of Ultrasonic Concrete Data, Luke Prince, Dwight Clayton, Hector Santos-Villalobos

Review of Progress in Quantitative Nondestructive Evaluation

There are many commercial ultrasonic tomography devices available for use in nondestructive evaluation (NDE) of reinforced concrete structures. These devices operate by using an array of transducers to transmit and receive ultrasonic data. Time-staggered ultrasonic impulses are released at each transmitting transducer through a concrete medium, after which the shear wave reflections are recorded at all receiving transducers. This ultrasonic data representing the received impulse responses between all unique transducer pairings are collected by the devices and often stored in a proprietary format. Because of this, both academic and industrial researchers are prevented from using the collected data for NDE ...


Rapid Multichannel Impact-Echo Scanning Of Concrete Bridge Decks From A Continuously Moving Platform, Brian A. Mazzeo, Jacob Larsen, Joseph Mcelderry, W. Spencer Guthrie Jan 2016

Rapid Multichannel Impact-Echo Scanning Of Concrete Bridge Decks From A Continuously Moving Platform, Brian A. Mazzeo, Jacob Larsen, Joseph Mcelderry, W. Spencer Guthrie

Review of Progress in Quantitative Nondestructive Evaluation

Impact-echo testing is a non-destructive evaluation technique for determining the presence of defects in reinforced concrete bridge decks based on the acoustic response of the bridge deck when struck by an impactor. Impact events excite Lamb-wave as well as flexural vibrations which, when properly measured and interpreted, can reveal the presence of defects, specifically delaminations, in the bridge deck. Because of the utility of the impact-echo technique, a number of attempts have been made at improving the speed of data acquisition to especially reduce the required traffic control, which may exceed the cost of the testing itself or prohibit the ...


Model-Based Probe State Estimation And Crack Inverse Methods Addressing Eddy Current Probe Variability, John C. Aldrin, Eric B. Shell, Erin K. Oneida, Harold A. Sabbagh, Elias Sabbagh, R. Kim Murphy, Siamack Mazdiyasni, Eric A. Lindgren, Ryan D. Mooers Jan 2016

Model-Based Probe State Estimation And Crack Inverse Methods Addressing Eddy Current Probe Variability, John C. Aldrin, Eric B. Shell, Erin K. Oneida, Harold A. Sabbagh, Elias Sabbagh, R. Kim Murphy, Siamack Mazdiyasni, Eric A. Lindgren, Ryan D. Mooers

Review of Progress in Quantitative Nondestructive Evaluation

Recent work on model-based inverse methods with eddy current inspections of surface breaking discontinuities has shown some sizing error due to variability in probes with the same design specifications [1]. This is an important challenge for model-based inversion crack sizing techniques, to be robust to the varying characteristics of eddy current probes found in the field [1-2]. In this paper, a model-based calibration process is introduced that estimates the state of the probe. First, a carefully designed surrogate model was built using VIC-3D® simulations covering the critical range of probe rotation angles, tilt in two directions, and probe offset (liftoff ...


Quantitative Diagnosis And Prognosis Framework For Concrete Degradation Due To Alkali- Silica Reaction, Sankaran Mahadevan, Kyle Neal, Paromita Nath, Yanqing Bao, Guowei Cai, Peter Orme, Douglas Adams Jan 2016

Quantitative Diagnosis And Prognosis Framework For Concrete Degradation Due To Alkali- Silica Reaction, Sankaran Mahadevan, Kyle Neal, Paromita Nath, Yanqing Bao, Guowei Cai, Peter Orme, Douglas Adams

Review of Progress in Quantitative Nondestructive Evaluation

This research is seeking to develop a probabilistic framework for health diagnosis and prognosis of aging concrete structures in nuclear power plants that are subjected to physical, chemical, environment, and mechanical degradation. The proposed framework consists of four elements: monitoring, data analytics, uncertainty quantification, and prognosis. The current work focuses on degradation caused by ASR (alkali-silica reaction). Controlled concrete specimens with reactive aggregate are prepared to develop accelerated ASR degradation. Different monitoring techniques—infrared thermography [1], digital image correlation (DIC), mechanical deformation measurements, nonlinear impact resonance acoustic spectroscopy [2] (NIRAS), and vibro-acoustic modulation [3] (VAM)—are studied for ASR diagnosis ...


Stationary-Phase Method Vs. Pencil Method For The Modal Radiation Of Guided Waves By Finite-Sized Sources In A Semi-Infinite Isotropic Plate, Mathilde Stévenin, Alain Lhémery Jan 2016

Stationary-Phase Method Vs. Pencil Method For The Modal Radiation Of Guided Waves By Finite-Sized Sources In A Semi-Infinite Isotropic Plate, Mathilde Stévenin, Alain Lhémery

Review of Progress in Quantitative Nondestructive Evaluation

Modal decomposition of guided waves (GW) in isotropic plates over Lamb and shear horizontal modes is helpful to interpret signals measured in GW NDE methods. Simulation tools of GW NDE examinations are developed notably to provide help interpretation. Thus, models on which they rely can provide an even greater help if they predict the various phenomena involved in terms of modal amplitudes. Most GW sources being of finite size, diffraction effects occur. Plate-like structures to be tested being of finite size, edge reflection with mode-conversion occurs too. Two models are proposed for the fast prediction of how the two phenomena ...


Model Benchmarking And Reference Signals For Angled-Beam Shear Wave Ultrasonic Nde Inspections, John C. Aldrin, Deborah Hopkins, Mark Warchol, Lyudmila V. Warchol, David S. Forsyth, Charlie Buynak, Eric A. Lindgren Jan 2016

Model Benchmarking And Reference Signals For Angled-Beam Shear Wave Ultrasonic Nde Inspections, John C. Aldrin, Deborah Hopkins, Mark Warchol, Lyudmila V. Warchol, David S. Forsyth, Charlie Buynak, Eric A. Lindgren

Review of Progress in Quantitative Nondestructive Evaluation

NDE modeling and simulation are important tools to support the development and validation of enhanced localization and characterization techniques. Previously, important achievements were made by the USAF to address crack detection in aircraft structures using angled-beam shear wave inspection techniques. However, new work on model benchmarking is needed to move beyond detection and achieve reliable crack characterization. To achieve this goal, simulated studies are needed to verify that models can accurately represent all of the key variables with the inspection of multilayer structures with fastener sites and varying crack conditions. Often with model benchmark studies, the accuracy of the model ...


A Novel Thermosonic Imaging System For Non-Destructive Testing, Dan Xiang, Micheal Long, Carson Willey Jan 2016

A Novel Thermosonic Imaging System For Non-Destructive Testing, Dan Xiang, Micheal Long, Carson Willey

Review of Progress in Quantitative Nondestructive Evaluation

Thermosonic (Sonic IR) Imaging is a new nondestructive testing (NDT) technique that uses high-frequency sonic excitation together with infrared (IR) detection to image surface and subsurface defects. This Sonic IR imaging technique uses a short (usually fraction of a second) pulse of high frequency (typically 20-40 kHz) sound which is applied at some convenient point on the surface of the object under inspection to produce localized frictional heating at the defect. An IR camera images the heating of the surface resulting from the effects of friction or other irreversible internal surface interactions in the vicinity of defects. These effects result ...


Numerical Simulation In Alternating Current Field Measurement (Acfm) Inducer Design, Zhixiong Zhou, Wenpei Zheng Jan 2016

Numerical Simulation In Alternating Current Field Measurement (Acfm) Inducer Design, Zhixiong Zhou, Wenpei Zheng

Review of Progress in Quantitative Nondestructive Evaluation

Inducer design plays an important part in Alternating Current Field Measurement (ACFM). It involves influence analysis of some key parameters on the perturbation of the magnetic field above the crack. Experimental analysis methods are time-consuming, high cost and have experimental errors. Finite element method (FEM) can overcome these shortcomings, and is adopted in this paper to aid design of ACFM inducer. Two kinds of ACFM Inducer, twin coil and U-shaped inducer are proposed, and corresponding numerical simulation models are built. In the model for the U-shaped inducer, the inducer comprises a U-shaped core and a current-carrying coil. The specimen is ...


Investigation On The Damage Localization In A Pipe Using Torsional Guided Waves And Sensor Array Reconstruction Techniques, Erick Rojas, Karla Fernandez, Arturo Baltazar, Jorge Aranda Jan 2016

Investigation On The Damage Localization In A Pipe Using Torsional Guided Waves And Sensor Array Reconstruction Techniques, Erick Rojas, Karla Fernandez, Arturo Baltazar, Jorge Aranda

Review of Progress in Quantitative Nondestructive Evaluation

Continuous monitoring for damage detection and localization on large fluid filled pipe-like structures is needed. To address this problem we propose the use of a Macro Fiber Composite (MFC) sensor to generate the first order torsional mode and to detect scatter signals from the discontinuities by an EMAT sensor positioned in various locations on the surface of the structure to simulate an array of sensors. Signals are post-processed with a developed algorithm based on entropy and arrival time. Numerical results were obtained for simulated signals and experimentally tested on a stainless steel pipe A-36 (43.6 and 48.2 mm ...


Subsurface Inclusion Quantification Using Multi-Frequency Ultrasonic Surface Waves, Musa Norouzian, Joseph A. Turner, Allen J. Fuller, Brent M. Wilson Jan 2016

Subsurface Inclusion Quantification Using Multi-Frequency Ultrasonic Surface Waves, Musa Norouzian, Joseph A. Turner, Allen J. Fuller, Brent M. Wilson

Review of Progress in Quantitative Nondestructive Evaluation

Rolling contact fatigue (RCF) is one of the major sources of subsurface-initiated spalling in bearing components. These types of spalls initiate in regions where microcracks are formed due to a localized increase in stress from inclusions near the surface. Ultrasonic bulk inspection is a powerful method to detect defects in a large volume of steel. However, inclusions near the surface of a sample can elude detection because reflections from the inclusion can be masked by reflections from the sample surface. This limitation can be eliminated if ultrasonic surface wave methods are used for inspection. Surface waves have material displacements localized ...


Localization And Characterization Of Fatigue Cracks Around Fastener Holes Using Spherically Focused Ultrasonic Probes, Deborah Hopkins, Marvin Datuin, John Aldrin, Mark Warchol, Lyudmila Warchol, David Forsyth, Charlie Buynak, Eric Lindgren Jan 2016

Localization And Characterization Of Fatigue Cracks Around Fastener Holes Using Spherically Focused Ultrasonic Probes, Deborah Hopkins, Marvin Datuin, John Aldrin, Mark Warchol, Lyudmila Warchol, David Forsyth, Charlie Buynak, Eric Lindgren

Review of Progress in Quantitative Nondestructive Evaluation

Results are presented from laboratory experiments and simulations designed to determine the ability to localize and characterize fatigue cracks around fastener holes using spherically fo-cused ultrasonic (UT) probes for shear-wave inspections. In designing and evaluating inspection protocols, the number of cases that can be studied through laboratory experiments is severely limited by cost and time constraints. Simulations therefore stand to play a significant role in the design and optimization of inspection strategies for those conditions that can be accurately mod-eled. Moving from benchmark studies for relatively simple geometries toward more realistic conditions creates significant challenges. For shear-wave inspections of fastener ...


Full Wave Modeling Of Ultrasonic Scattering Using Nystrom Method For Nde Applications, Praveen Gurrala, Kun Chen, Jiming Song, Ron Roberts Jan 2016

Full Wave Modeling Of Ultrasonic Scattering Using Nystrom Method For Nde Applications, Praveen Gurrala, Kun Chen, Jiming Song, Ron Roberts

Review of Progress in Quantitative Nondestructive Evaluation

Approximate methods for ultrasonic scattering like the Kirchhoff approximation and the geometrical theory of diffraction (GTD) can deliver fast solutions with relatively small computational resources compared to accurate numerical methods. However, these models are prone to inaccuracies in predicting scattered fields from defects that are not very large compared to wavelength. Furthermore, they do not take into account physical phenomena like multiple scattering and surface wave generation on defects. Numerical methods like the finite element method (FEM) and the boundary element method (BEM) can overcome these limitations of approximate models. Commercial softwares such as Abaqus FEA and PZFlex use FEM ...


Validation Of Utsim2, A New Ultrasonic Simulation Package, Robert Grandin, Timothy Gray Jan 2016

Validation Of Utsim2, A New Ultrasonic Simulation Package, Robert Grandin, Timothy Gray

Review of Progress in Quantitative Nondestructive Evaluation

The Center for NDE (CNDE) at Iowa State University has a long history of developing physics models for NDE and packaging these models into simulation tools which make the modeling capabilities accessible to CNDE’s industrial sponsors. Recent work at CNDE has led to the development of a new ultrasonic simulation package, UTSim2, which aims to continue this tradition of supporting industrial application of CNDE models. In order to meet this goal, UTSim2 has been designed as an extensible software package which can support previously-developed physics models as well as future models yet to be developed. Initial work has focused ...


Compton Imaging Tomography For Nondestructive Evaluation Of Spacecraft Thermal Protection Systems, Volodymyr Romanov, Eric Burke, Victor Grubsky Jan 2016

Compton Imaging Tomography For Nondestructive Evaluation Of Spacecraft Thermal Protection Systems, Volodymyr Romanov, Eric Burke, Victor Grubsky

Review of Progress in Quantitative Nondestructive Evaluation

Novel nondestructive evaluation (NDE) systems based on a recently pioneered Compton Imaging Tomography (CIT) technique [1-4] are currently being developed by Physical Optics Corporation (POC). CIT provides high-resolution, three-dimensional, Compton scattered X-ray imaging of the internal structure of evaluated objects, using a set of acquired two-dimensional, Compton scattered X-ray images of consecutive cross sections of these objects. Unlike conventional computerized tomography, CIT requires only one-sided access to objects, has no limitation on the dimensions and geometry of such objects, and can be applied to large, multilayer, nonuniform objects. Also, CIT does not require any contact with objects during its application ...


Comparison Of Numerical Simulations And Analytical Theories For Elastic Wave Scattering Within Polycrystalline Materials, A. Van Pamel, G. Sha, S. I. Rokhlin, M. J. S. Lowe Jan 2016

Comparison Of Numerical Simulations And Analytical Theories For Elastic Wave Scattering Within Polycrystalline Materials, A. Van Pamel, G. Sha, S. I. Rokhlin, M. J. S. Lowe

Review of Progress in Quantitative Nondestructive Evaluation

Understanding the propagation and scattering of ultrasonic waves within polycrystalline materials is relevant to both material characterisation and flaw detection NDE. Validating analytical theories of scattering however has historically been hampered by the difficulty of obtaining sufficiently reliable experimental data where the statistical properties of the grains within the volume of the material are known well enough. Instead, this presentation exploits important recent progress in numerical modelling, which for the first time enables accurate three-dimensional simulations of wave propagation and scattering in polycrystals. The presentation reports work using such a model to compare and validate 3D numerical simulations of wave ...


Hybrid Ray-Fdtd Model For The Simulation Of The Ultrasonic Inspection Of Cfrp Parts, Pierre Calmon, Karim Jezzine, Damien Segur, Romain Ecault, Nicolas Dominguez Jan 2016

Hybrid Ray-Fdtd Model For The Simulation Of The Ultrasonic Inspection Of Cfrp Parts, Pierre Calmon, Karim Jezzine, Damien Segur, Romain Ecault, Nicolas Dominguez

Review of Progress in Quantitative Nondestructive Evaluation

Carbon Fiber Reinforced Polymers (CFRP) are commonly used in structural parts in the aeronautic industry, to reduce the weight of aircraft while maintaining high mechanical performances. Simulation of the ultrasonic inspections of these parts has to face the highly heterogeneous and anisotropic characteristics of these materials. To model the propagation of ultrasound in these composite structures, we propose two complementary approaches. The first one is based on a ray model predicting the propagation of the ultrasound in an anisotropic effective medium obtained from a homogenization of the material. The ray model is designed to deal with possibly curved parts and ...


Ultrasound Scatter In Heterogeneous 3d Microstructures, Brady Engle, Ronald A. Roberts, Robert Grandin Jan 2016

Ultrasound Scatter In Heterogeneous 3d Microstructures, Brady Engle, Ronald A. Roberts, Robert Grandin

Review of Progress in Quantitative Nondestructive Evaluation

This paper reports on a computational study of ultrasound propagation in heterogeneous metal microstructures. Random spatial fluctuations in elastic properties over a range of length scales relative to ultrasound wavelength can give rise to scatter-induced attenuation, backscatter noise, and phase front aberration. It is of interest to quantify the dependence of these phenomena on the microstructure parameters, for the purpose of quantifying deleterious consequences on flaw detectability, and for the purpose of material characterization. Valuable tools for estimation of microstructure parameters (e.g. grain size) through analysis of ultrasound backscatter have been developed based on approximate weak-scattering models. While useful ...


Simulative Evaluation Of Intragrain Precipitate Influence On The Material Nonlinearity Using Nonlinear Ultrasound, Daniel Grün, Laurent Capolungo, Jin-Yeon Kim, Laurence J. Jacobs Jan 2016

Simulative Evaluation Of Intragrain Precipitate Influence On The Material Nonlinearity Using Nonlinear Ultrasound, Daniel Grün, Laurent Capolungo, Jin-Yeon Kim, Laurence J. Jacobs

Review of Progress in Quantitative Nondestructive Evaluation

Nondestructive evaluation using ultrasonic waves is commonly used to experimentally probe for the presence of defects (i.e. dislocations, precipitates, cracks) in complex metallic microstructures. Such defects and abnormalities are evidenced by monitoring the acoustic nonlinearity parameter β. However, from the mathematical standpoint, the correlation between the microstructural behavior and the measured acoustic nonlinearity parameter is not explicit yet. The present work aims to assess the existence of statistical correlations between microstructural defects and material nonlinearity. The effects of defect geometry, density, and geometrical arrangements (i.e. relative position) on material nonlinearity are studied. To do so, the acoustic response ...


Volumetric Characterization Of A Simulated Delamination Field Within An Isotropic Medium Via Ultrasonic Inspection, John Wertz, Sarah Wallentine, Josiah Dierken Jan 2016

Volumetric Characterization Of A Simulated Delamination Field Within An Isotropic Medium Via Ultrasonic Inspection, John Wertz, Sarah Wallentine, Josiah Dierken

Review of Progress in Quantitative Nondestructive Evaluation

Volumetric characterization of composite delaminations was prioritized for rigorous composite damage progression modeling. In this study, angle longitudinal wave ultrasound was used to characterize simulated delaminations with distinct shadow regions in an isotropic medium. Simple representations of the specimen were modeled in CIVA to determine the optimal inspection parameters, including the transducer frequency and inspection angle. Experiments conducted with those optimal parameters provided visual evidence of the three-dimensional delamination field with indications from shadowed regions. The methods developed within this study serve as the foundation for more rigorous volumetric characterization of a delamination field within actual composite materials.


Model Development And Validation Of Geometrically Complex Eddy Current Coils Using Finite Element Methods, Alexander Brown, Connor Eviston, Ryan Mooers, Matt Cherry Jan 2016

Model Development And Validation Of Geometrically Complex Eddy Current Coils Using Finite Element Methods, Alexander Brown, Connor Eviston, Ryan Mooers, Matt Cherry

Review of Progress in Quantitative Nondestructive Evaluation

Multiple FEM models of complex eddy current coil geometries were created and validated to calculate the change of impedance due to the presence of a notch. Capable realistic simulations of eddy current inspections are required for model assisted probability of detection (MAPOD) studies, inversion algorithms, experimental verification, and tailored probe design for NDE applications. An FEM solver was chosen to model complex real world situations including varying probe dimensions and orientations along with complex probe geometries. This will also enable creation of a probe model library database with variable parameters. Verification and validation was performed using other commercially available eddy ...


Characterization Of Complex Defects Using Eddy Currents With Uniform Field Probes And Giant Magneto-Resistor (Gmr) Detectors, Dario Pasadas, A. Lopes Ribeiro, H. G. Ramos, T. Rocha Jan 2016

Characterization Of Complex Defects Using Eddy Currents With Uniform Field Probes And Giant Magneto-Resistor (Gmr) Detectors, Dario Pasadas, A. Lopes Ribeiro, H. G. Ramos, T. Rocha

Review of Progress in Quantitative Nondestructive Evaluation

Some defects in metallic plates present complex forms that difficult their geometric characterization. This is the case of defects with ramifications where the eddy currents cannot penetrate some concavity areas. The illumination of the material under test with a coherent excitation field presents some advantages, such as the possibility of applying the excitation into different directions, thus obtaining different patterns that may be correlated to increase the definition of the acquired signals. The generation of the coherent excitation is obtained by using a planar coil that produces a uniform excitation field inside a given area.

It is not easy to ...


Surrogate Modeling Of Ultrasonic Testing Simulations Using Variable-Fidelity Models And Data-Driven Methods, Robert Grandin, Leifur Leifsson Jan 2016

Surrogate Modeling Of Ultrasonic Testing Simulations Using Variable-Fidelity Models And Data-Driven Methods, Robert Grandin, Leifur Leifsson

Review of Progress in Quantitative Nondestructive Evaluation

Ultrasonic testing (UT) is used to detect internal flaws in materials or to characterize material properties [1]. Computational simulations are an important part of the UT process. Having fast surrogate models for ultrasonic testing (UT) simulations is key for inverse analysis and model-assisted probability of detection (MAPOD) in the field of nondestructive evaluation. In fact, it is impractical to perform the aforementioned tasks in a timely manner using current simulation models directly. Fast surrogate models can make these processes computationally tractable. This paper presents investigations of using surrogate modeling techniques to create fast approximate models of UT simulator responses. In ...


Model-Based Software For Simulating Ultrasonic Pulse/Echo Inspections Of Metal Components, C.P. Thomas Chiou, Frank J. Margetan, Daniel J. Barnard, Ronald A. Roberts, Matthew R. Mckillip, Jared L. Taylor Jan 2016

Model-Based Software For Simulating Ultrasonic Pulse/Echo Inspections Of Metal Components, C.P. Thomas Chiou, Frank J. Margetan, Daniel J. Barnard, Ronald A. Roberts, Matthew R. Mckillip, Jared L. Taylor

Review of Progress in Quantitative Nondestructive Evaluation

The use of models to simulate inspections has played a key role in UT NDE R&D efforts. Over the years, a series of wave propagation models, flaw response models, and microstructural backscatter models have been developed at CNDE to address inspection problems of interest. One use of the combined models is the estimation of signal-to-noise ratios (S/N) in circumstances where backscattered echoes from the microstructure (grain noise) act to mask sonic echoes from internal defects. Such S/N models have been used to address questions of inspection reliability, such as how to optimize the choices of transducer properties ...


Multimode Model Based Defect Characterization In Composites, R. Roberts, S. Holland Jan 2016

Multimode Model Based Defect Characterization In Composites, R. Roberts, S. Holland

Review of Progress in Quantitative Nondestructive Evaluation

This paper reports on work to explore model based defect characterization methods for NDE of CFRP composites. The work is examining defect responses obtained with ultrasound and thermography, for the purpose of classifying and characterizing the defect through combined analysis of the multiple-mode data. Analysis is premised on the availability of forward scattering models to predict NDE response to specified defects. The approach to defect characterization identifies a set of parameters describing the defect, then optimizes agreement between NDE measurements and measurement predictions through manipulation of defect descriptors, subject to ancillary measures of defect properties imposed to regularize an otherwise ...


Interaction Of Guided Waves With Cracks In An Embedded Multilayered Anisotropic Plate By Using A Boundary Element Approach, Pierric Mora, Eric Ducasse, Marc Deschamps Jan 2016

Interaction Of Guided Waves With Cracks In An Embedded Multilayered Anisotropic Plate By Using A Boundary Element Approach, Pierric Mora, Eric Ducasse, Marc Deschamps

Review of Progress in Quantitative Nondestructive Evaluation

In this work, the interaction of a transient guided elastic wave with a planar crack is studied by using a Boundary Finite Element approach on the crack. The originality of this work is to use the numerical Green functions of the multilayered plate. So, the key point of the method is to calculate rapidly and accurately these Green functions for such complex plane structures. For the space variables related to the plate surface, the fields are transformed in the 2D Fourier associated to the wave-vectors on this surface, and they are expressed in the partial-wave basis [1]. To ensure causality ...