Open Access. Powered by Scholars. Published by Universities.®

Applied Mechanics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 46

Full-Text Articles in Applied Mechanics

Magnetostrictive Transducers (Mst) Utilizing Reversed Wiedemann Effect, S. Vinogradov, A. Cobb, G. Light Jan 2016

Magnetostrictive Transducers (Mst) Utilizing Reversed Wiedemann Effect, S. Vinogradov, A. Cobb, G. Light

Review of Progress in Quantitative Nondestructive Evaluation

Magnetostrictive transduction has been widely utilized in NDE applications and, specifically, for generation and reception of guided waves for long-range inspection of components such as pipes, vessels, and small tubes. Transverse-motion guided wave modes (e.g., torsional vibrations in pipes) are the most typical choice for long-range inspection applications because the wave motion is in the plane of the structure. Magnetostrictive-based sensors have been available for the last several years for these wave modes based on the Wiedemann effect. For these sensors, a permanent magnetic bias is applied that is perpendicular to the direction of the propagated guided wave. This ...


Generation Of Axial Pipe Homc Using Comb Transduction, Sri Harsha Reddy K, Prabhu Rajagopal, Krishnan Balasubramaniam, Samuel Hill, Steve Dixon Jan 2016

Generation Of Axial Pipe Homc Using Comb Transduction, Sri Harsha Reddy K, Prabhu Rajagopal, Krishnan Balasubramaniam, Samuel Hill, Steve Dixon

Review of Progress in Quantitative Nondestructive Evaluation

Guided wave non-destructive evaluation (NDE) is the most widely used technique to perform long range inspection. Higher Order Modes Cluster (HOMC), discovered at the author’s research group [1] consist of multiple higher order guided wave modes that travel together as a cluster and without any appreciable dispersion for distances in the range of meters. These waves not only propagate along the length of the structure but also cover the entire thickness and circumference, and in view of the higher frequencies, they can offer improved resolution over conventional low-frequency guided waves. This paper introduces a novel approach for generation of ...


Materials Classification Using Multichannel Radiographs, Noelle Collins, Edward Jimenez, Kyle Thompson Jan 2016

Materials Classification Using Multichannel Radiographs, Noelle Collins, Edward Jimenez, Kyle Thompson

Review of Progress in Quantitative Nondestructive Evaluation

This work aims to validate previous exploratory work done to characterize materials by matching their attenuation profiles using a multichannel radiograph given an initial energy spectrum. The experiment was performed in order to evaluate the effects of noise on the resulting attenuation profiles, which was ignored in simulation. Spectrum measurements have also been collected from various materials of interest. Additionally, a MATLAB optimization algorithm has been applied to these candidate spectrum measurements in order to extract an estimate of the attenuation profile. Being able to characterize materials through this nondestructive method has an extensive range of applications for national security.


The Early Stage Wheel Fatigue Crack Detection Using Eddy Current Pulsed Thermography, Jianping Peng, Kang Zhang, Kai Yang, Zhu He, Yu Zhang, Chaoyong Peng, Xiaorong Gao Jan 2016

The Early Stage Wheel Fatigue Crack Detection Using Eddy Current Pulsed Thermography, Jianping Peng, Kang Zhang, Kai Yang, Zhu He, Yu Zhang, Chaoyong Peng, Xiaorong Gao

Review of Progress in Quantitative Nondestructive Evaluation

The in-service wheel-set quality is one of critical challenges for railway safety, especially for the high-speed train. The defect in wheel tread, initiated by rolling contact fatigue (RCF) damage, is one of the most significant phenomena and has serious influence on rail industry. Eddy current pulsed thermography (ECPT) is studied to compensate the Ultrasonic Testing (UT) method for detection these early stage of fatigue cracks in wheel tread. This paper proposes several induction coils, such as linear coil, Yoke coil and Helmholtz coils, based ECPT method to meet the imaging of multiple cracks and irregular surface in wheel tread through ...


Development Of An Electromagnetic Imaging System For Well Bore Integrity Inspection, Y. A. Plotnikov, F. W. Wheeler, S. Mandal, W. R. Ross, J. S. Price, E. J. Nieters, A. Ivan, S. Dolinsky, H. C. Climent, A. M. Kasten Jan 2016

Development Of An Electromagnetic Imaging System For Well Bore Integrity Inspection, Y. A. Plotnikov, F. W. Wheeler, S. Mandal, W. R. Ross, J. S. Price, E. J. Nieters, A. Ivan, S. Dolinsky, H. C. Climent, A. M. Kasten

Review of Progress in Quantitative Nondestructive Evaluation

State-of-the-art imaging technologies for monitoring the integrity of oil and gas well bores are typically limited to inspection of metal casings and cement bond interfaces close to the first casing region. The objective of this study is to develop a novel well-integrity inspection system that is capable of providing enhanced information about the flaw structure and topology of hydrocarbon producing well bores. In order to achieve this, we propose the development of a multi-element electromagnetic (EM) inspection tool that can provide information about material loss in the first and second casing structure as well as information about eccentricity between multiple ...


Crack Detection And Localization Inweld Structure Using The Topological Energy Method, Emma Lubeigt, Serge Mensah, Jean-François Chaix, Sandrine Rakotonarivo, Gilles Gobillot, François Baqué Jan 2016

Crack Detection And Localization Inweld Structure Using The Topological Energy Method, Emma Lubeigt, Serge Mensah, Jean-François Chaix, Sandrine Rakotonarivo, Gilles Gobillot, François Baqué

Review of Progress in Quantitative Nondestructive Evaluation

Due to both significant primary loads (weight, pressure) and thermal transients, important supporting structures (bedspring, deck…) subjected to thermo-mechanical fatigues require that periodical inspections are carried out in nuclear power plant.


The bedspring and the deck are complex welded structures of very restricted access; the ability to reliably detect and locate defects like cracks is therefore a difficult challenge. Ultrasonic testing is a well-recognized non-invasive technic which exhibits high characterization performances in homogeneous media (steel). However, its capabilities are hampered when operating in heterogeneous and anisotropic austenitic welds because of deviation and splitting of the ultrasonic beam.


In order to ...


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 ...


Novel Wavelet Threshold Denoising Method In Axle Press-Fit Zone Ultrasonic Detection, Chaoyong Peng, Xiaorong Gao, Jianping Peng, Ai Wang Jan 2016

Novel Wavelet Threshold Denoising Method In Axle Press-Fit Zone Ultrasonic Detection, Chaoyong Peng, Xiaorong Gao, Jianping Peng, Ai Wang

Review of Progress in Quantitative Nondestructive Evaluation

Axles are important part of railway locomotives and vehicles. Periodic ultrasonic inspection of axles can effectively detect and monitor axle fatigue cracks. However, in the axle press-fit zone, the complex interface contact condition reduces the signal-noise ratio (SNR). Therefore, the probability of false positives and false negatives increases. In this work, a novel wavelet threshold function is created to remove noise and suppress press-fit interface echoes in axle ultrasonic defect detection. The exponential threshold function proposed by Andria [1] can't get a gradual curve for later optimum searching process; and the novel wavelet threshold function with two variables is ...


Evaluation Of Stiffness Loss With Guided Wave Tomography, Madis Ratassepp, Jing Rao, Zheng Fan Jan 2016

Evaluation Of Stiffness Loss With Guided Wave Tomography, Madis Ratassepp, Jing Rao, Zheng Fan

Review of Progress in Quantitative Nondestructive Evaluation

Identification of local stiffness reduction is a challenging problem for many engineering materials and structures. The aim of this study is to investigate the potential of guided wave tomography to quantify the stiffness of an isotropic plate. Full-waveform inversion based on acoustic model is applied to estimate the Young’s modulus from the velocity field data of an elastic model. Finite element simulations were carried out to obtain the signals of a guided mode propagating through various stiffness defects in a plate. The inversion results have demonstrated accurate determination of an averaged through-thickness stiffness loss of the waveguide. These results ...


The Evaluation Of Fatigue Caused By Plane-Bending Stress On Stainless Steel Using The Stacked-Coil Type Magnetic Sensor, Mohachiro Oka, Terutoshi Yakushiji, Masato Enokizono Jan 2016

The Evaluation Of Fatigue Caused By Plane-Bending Stress On Stainless Steel Using The Stacked-Coil Type Magnetic Sensor, Mohachiro Oka, Terutoshi Yakushiji, Masato Enokizono

Review of Progress in Quantitative Nondestructive Evaluation

To prevent an accident due to the metal degradation of stainless steels, we have previously proposed fatigue evaluation methods (such as the remnant magnetization method using a thin-film flux-gate magnetic sensor [1] and the inductance method using a pan-cake type coil [2]). These two fatigue evaluation methods demonstrated a good correlation between the magnetic sensor output signal and the amount of plane-bending fatigue damage in stainless steels. We developed a stacked-coil type magnetic sensor shown in Fig. 1(a) in order to achieve a magnetic sensor for an accurate fatigue evaluation. This magnetic sensor was composed of two detection coils ...


Phased Array Ultrasonic Inspection Method For Homogeneous Tube Inspection Over Wide Oblique Angle Range, Benoit Lepage, Guillaume Painchaud-April Jan 2016

Phased Array Ultrasonic Inspection Method For Homogeneous Tube Inspection Over Wide Oblique Angle Range, Benoit Lepage, Guillaume Painchaud-April

Review of Progress in Quantitative Nondestructive Evaluation

As seamless tube manufacturers push quality requirements for their products, automated phased array Rotating Tube Inspection Systems (RTIS) are now required to provide continuous NDE detection performances over a wide angular range of oblique flaws. One major impact of this new reality is a paradigm shift for the calibration method driven by the requirement to meet homogeneous detection over broad oblique flaw angle intervals, whereas standard practice only requires calibration at specific discrete angles. An innovative method specifically designed to obtain high productivity and homogeneous inspection measurements over an oblique flaw range extending from -45 to 45 degrees is presented ...


Lamb Wave (A0 Mode) Scattering Directionality At Defects, Paul Fromme Jan 2016

Lamb Wave (A0 Mode) Scattering Directionality At Defects, Paul Fromme

Review of Progress in Quantitative Nondestructive Evaluation

Localized and distributed guided ultrasonic waves array systems offer an efficient way for the structural health monitoring for large structures. The detection sensitivity for fatigue cracks depends on the orientation of the crack relative to the location of the sensor elements. Crack-like defects have a directionality pattern of the scattered field depending on the angle of the incident wave relative to the defect orientation and on the ratio of the defect depth and length to the wavelength. From FE simulations it has been shown that for cracks and notches almost no energy is scattered in certain directions from the defect ...


Torsional Vibration Transduction In A Solid Shaft By Mpts, Jun Kyu Lee, Hong Min Seung, Chung Il Park, Joo Kyung Lee, Do Hyeong Lim, Yoon Young Kim Jan 2016

Torsional Vibration Transduction In A Solid Shaft By Mpts, Jun Kyu Lee, Hong Min Seung, Chung Il Park, Joo Kyung Lee, Do Hyeong Lim, Yoon Young Kim

Review of Progress in Quantitative Nondestructive Evaluation

In this study, we aim to investigate the feasibility to use MPTs (Magnetostrictive Patch Transducers) for torsional vibration measurement in solid ferromagnetic cylinders. MPTs consisting of thin magnetostrictive patches, permanent magnets and a solenoid coil have been widely used for elastic wave transduction in the ultrasound frequency range [1] but they have been seldom used for sonic-frequency range vibration measurement, in spite of their unique wireless transduction characteristics. While a MPT was used in Ref. [2] to perform torsional modal testing in a hollow cylinder or a pipe having relatively small torsional rigidity, no investigation has been reported yet on ...


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 ...


Subwavelength Resolution Of Cracks In The Metallic Materials, Amireddy Kiran Kumar, Prabhu Rajagopal, Krishnan Balasubramaniam Jan 2016

Subwavelength Resolution Of Cracks In The Metallic Materials, Amireddy Kiran Kumar, Prabhu Rajagopal, Krishnan Balasubramaniam

Review of Progress in Quantitative Nondestructive Evaluation

In recent years, various types of acoustic metamaterials have been proposed with capabilities for overcoming the diffraction limit. However, typically such developments only consider the acoustic regime [1] or imaging in liquid media [2]. In this paper we demonstrate the application of a holey structured metamaterial lens for sub-wavelength imaging of defects in a metallic sample, in the ultrasonic regime. Finite Element (FE) simulations are used to study longitudinal wave interaction with ideal cracks in isotropic elastic materials. Holey-structured meta-lenses are then used to transmit the scattered waves. We experimentally demonstrate a subwavelength resolution of λ/7 with a sub-wavelength ...


Far-Field Microwave Time Reversal Experiments For Imaging Disbonds In Metal-Composite Structures, Saptarshi Mukherjee, Antonello Tamburrino, Lalita Udpa, Satish Udpa Jan 2016

Far-Field Microwave Time Reversal Experiments For Imaging Disbonds In Metal-Composite Structures, Saptarshi Mukherjee, Antonello Tamburrino, Lalita Udpa, Satish Udpa

Review of Progress in Quantitative Nondestructive Evaluation

Composites are being increasingly used to replace metals, in several industries because of their light weight, corrosion resistance, and mechanical strength. In these structures involving metals and composites, adhesively bonded joints are preferred in contrast to conventional fasteners as they provide light weight designs, reduce stress concentrations. However, disbonds and delamination can compromise the integrity of the structure affecting their performance. Hence a robust and effective Non Destructive Evaluation (NDE) technique is required to accurately detect defects in composite materials. Microwave NDE is increasingly being used as an alternate method since it is well suited for lossless and low loss ...


Characterization Of Defects And Designed Flaws In Metal Additive Manufacturing (Am) Parts With X-Ray Computed Tomography (Xct), Felix H. Kim, Shawn P. Moylan, Adam Pintar, Herminso Villarraga-Gómez, John Slotwinski Jan 2016

Characterization Of Defects And Designed Flaws In Metal Additive Manufacturing (Am) Parts With X-Ray Computed Tomography (Xct), Felix H. Kim, Shawn P. Moylan, Adam Pintar, Herminso Villarraga-Gómez, John Slotwinski

Review of Progress in Quantitative Nondestructive Evaluation

Metal Additive Manufacturing (AM) has great potential to revolutionize manufacturing industries, but a reliable method to detect defects in AM-produced parts with complex internal structures must be developed prior to its widespread adoption. In this research, defects occurring in additively manufactured metal parts are characterized with X-ray Computed Tomography (XCT). In addition, the concept of metrological XCT is introduced, with the goal of providing more accurate dimensional measurements of the internal features.

Preliminary experiments have been conducted toward the larger goal of evaluating XCT as a viable option for nondestructive evaluation of AM-produced components. Critical to this evaluation is the ...


Crack Detection Using Low-Frequency Ultrasonic Waves Caused By Low Directivity And Scattering, Shingo Onodera, Yuji Kato, Toshihiko Sugiura Jan 2016

Crack Detection Using Low-Frequency Ultrasonic Waves Caused By Low Directivity And Scattering, Shingo Onodera, Yuji Kato, Toshihiko Sugiura

Review of Progress in Quantitative Nondestructive Evaluation

In recent years, nondestructive testing techniques for maintenance and checking of materials and structures have been more required with social infrastructure’s aging. Although ultrasonic waves are valid in internal inspection, conventional ultrasonic detection techniques are inadequate for detecting fatigues or closed cracks, because ultrasound waves hardly reflect at them[1]. However, it has been reported that the transmitted wave through a closed crack contains nonlinear ultrasonic waves[2] such as super- and sub- harmonics, and they have been expected to be used for an alternative detecting method.

In our previous research, we experimentally examined transmission of ultrasonic waves through ...


Experimental Study Of Thin Film Sensor Networks For Wind Turbine Blade Damage Detection, A. Downey, S. Laflamme, F. Ubertini, H Sauder, P. Sarkar Jan 2016

Experimental Study Of Thin Film Sensor Networks For Wind Turbine Blade Damage Detection, A. Downey, S. Laflamme, F. Ubertini, H Sauder, P. Sarkar

Review of Progress in Quantitative Nondestructive Evaluation

Damage detection of wind turbine blades is difficult due to their complex geometry and large size, for which large deployment of sensing systems is typically not economical. A solution is to develop and deploy dedicated sensor networks fabricated from inexpensive materials and electronics. The authors have recently developed a novel skin-type strain gauge for measuring strain over very large surfaces. The skin, a type of large-area electronics, is constituted from a network of soft elastomeric capacitors. The sensing system is analogous to a biological skin, where local strain can be monitored over a global area. In this paper, we propose ...


Through-Wall Phased Array Imaging Of Small Surface-Breaking Cracks, Chao Zhang, Peter Huthwaite, Michael J. S. Lowe Jan 2016

Through-Wall Phased Array Imaging Of Small Surface-Breaking Cracks, Chao Zhang, Peter Huthwaite, Michael J. S. Lowe

Review of Progress in Quantitative Nondestructive Evaluation

Accurate and reliable measurements of small surface-breaking cracks are becoming increasingly important in safety-critical components such as in nuclear power plants, because of the desire for increased operational lifetimes. With great coverage and low cost, the use of imaging to find and size surface-breaking cracks with data from ultrasonic phased arrays is becoming more attractive. For the phased array imaging, both the array configuration and the technique used to generate the images from the measurements are key factors in the image quality and sizing accuracy. Thus, the selection of a proper imaging technique is essential to ensure accurate results for ...


Study Of Flexural Stress-Induced Surface Wave Velocity Variations In Concrete, Agustin Spalvier, James Bittner, John S. Popovics Jan 2016

Study Of Flexural Stress-Induced Surface Wave Velocity Variations In Concrete, Agustin Spalvier, James Bittner, John S. Popovics

Review of Progress in Quantitative Nondestructive Evaluation

This investigation studies the behavior of surface wave velocity in concrete specimens subjected to low levels of compressive and tensile stress in beams from applied flexural loads. Beam specimens are loaded in a 4-point-load bending configuration, generating uniaxial compression and tension stress fields at the beams’ top and bottom surfaces, respectively. Surface waves are generated through contactless air-coupled transducers and received through contact accelerometers. Results show a clear distinction in responses from compression and tension zones, where velocity increases in the former and decreases in the latter, with increasing load levels. These trends agree with existing acoustoelastic literature. Surface wave ...


Inspection Of Coatings Using Terahertz Time Domain Spectroscopy System, Tomasz Chady, Krzysztof Gorący Jan 2016

Inspection Of Coatings Using Terahertz Time Domain Spectroscopy System, Tomasz Chady, Krzysztof Gorący

Review of Progress in Quantitative Nondestructive Evaluation

Coatings and paints are use in almost all branches of modern industry. Mostly as a material for corrosion protection. It is understandable that failure of coating is critical for ability and time of protection.

Failure can occur for many reasons

– improper selection of coating material for given substrate

– lack of compatibility or chemical reactions,

– bad adhesion (blistering, flaking, peeling),

– strong exterior action as chemical exposure, abrasion, weathering,

– poor or inadequate surface preparation or improper application as surface,

– contamination, too low surface profile, pinholes, overspray, improper drying, lack of cure,

– incompetent design of structure

– sharp edges, skip welds.

Modern paints, especially ...


Time Reversal Method For Arch Bridge Cables Inspection Using Longitudinal Guided Waves, Zhang Pengfei, Tang Zhifeng, Lv Fuzai, Yang Keji Jan 2016

Time Reversal Method For Arch Bridge Cables Inspection Using Longitudinal Guided Waves, Zhang Pengfei, Tang Zhifeng, Lv Fuzai, Yang Keji

Review of Progress in Quantitative Nondestructive Evaluation

Arch bridge cables consist of anchor heads, steel wires parallel arranged in an equilateral hexagon and hot-extruding PE sheathing layers outside the wires. The complex structure and contact force between wires aggravates the dispersion and attenuation of guided waves in steel wires. In order to reduce the attenuation of acoustical energy, below 80kHz low-frequency longitudinal guided waves is usually adopted. Low-frequency guided waves attenuate more slowly than high-frequency waves, but the received signal packets are wider and less recognizable. In this paper, the process of the time reversal method[1] is presented and the related parameters are calculated. Over a ...


Angle-Beam Shear Wave Scattering From Buried Crack-Like Defects In Bonded Specimens, Carson T. Maki, Jennifer E. Michaels, Yu Weng, Thomas E. Michaels Jan 2016

Angle-Beam Shear Wave Scattering From Buried Crack-Like Defects In Bonded Specimens, Carson T. Maki, Jennifer E. Michaels, Yu Weng, Thomas E. Michaels

Review of Progress in Quantitative Nondestructive Evaluation

Ultrasonic wavefield imaging, which refers to the measurement of wave motion on a 2-D rectilinear grid resulting from a fixed source, has been previously applied to angle-beam shear wave propagation in simple plates with through-holes and far-surface notches [1]. In this prior work scattered waves were analyzed using baseline subtraction of wavefields acquired before and after a notch was introduced [2]. In practice, however, defects of interest often occur between bonded layers and it is generally not possible to record data from the same specimen in both the undamaged and damaged states, making direct baseline subtraction infeasible. This present work ...


Correlating Interlaminar Fatigue Fracture Behavior To Nde Parameters In Carbon/Epoxy Composites Containing Voids And Delamination, Issa Hakim, Norbert Meyendorf, Steven Donaldson, René Laquai, David Walter, Bernd Müller, Paul Graja Jan 2016

Correlating Interlaminar Fatigue Fracture Behavior To Nde Parameters In Carbon/Epoxy Composites Containing Voids And Delamination, Issa Hakim, Norbert Meyendorf, Steven Donaldson, René Laquai, David Walter, Bernd Müller, Paul Graja

Review of Progress in Quantitative Nondestructive Evaluation

Carbon fiber composites have been increasingly used in aerospace, military, sports, automotive and other fields due to their excellent properties, including high specific strength, high specific modulus, corrosion resistance, fatigue resistance, and low thermal expansion coefficient. Delamination, or interlaminar fracture, is a serious failure mode leading to a loss in composite stiffness and strength. Manufacturing process defects such as voids degrade the fatigue life and delamination resistance of the composite. This study investigates the effect of voids on fatigue interlaminar fracture behavior of carbon fiber composites. Samples with different vacuum levels: 0%, 50% and 100% were fabricated by varying the ...


Damage Depth Estimation On A Fatigue Loaded Composite Structure Using Thermography And Acoustic Emission, Joseph N. Zalameda, William P. Winfree, Michael R. Horne Jan 2016

Damage Depth Estimation On A Fatigue Loaded Composite Structure Using Thermography And Acoustic Emission, Joseph N. Zalameda, William P. Winfree, Michael R. Horne

Review of Progress in Quantitative Nondestructive Evaluation

Passive thermography and acoustic emission data were obtained on a three stringer panel during periodic fatigue loading. The acoustic emission data were mapped onto thermal data, revealing the cluster of acoustic emission event locations around the thermal signatures of interest. By combining both techniques, progression of damage growth is confirmed and areas of failure are identified. Furthermore, sudden changes in thermally measured damage growth related to a previously measured higher energy acoustic emission event are studied to determine damage depth. A multi-layered thermal model with a periodic flux heat source is presented using the quadrupole method to determine the relationship ...


Structural Health Monitoring Of Pipelines Using Permanently Installed Guided Wave Sensors, Sebastian Heinlein, Chang Liu, Peter Cawley Jan 2016

Structural Health Monitoring Of Pipelines Using Permanently Installed Guided Wave Sensors, Sebastian Heinlein, Chang Liu, Peter Cawley

Review of Progress in Quantitative Nondestructive Evaluation

Guided wave measurements are an established inspection method for pipelines in a variety of industries. Permanently installed guided wave sensors (gPIMS) have been used in the past to reduce the access cost for pipes in hard to reach locations which require repeated inspections. Making use of the existing gPIMS technology a method was devised to move from the current single inspection approach to a structural health monitoring system. With changes due to the environmental conditions of the pipe, such as temperature variations or content changes, the usefulness of simple baseline subtraction methods is very limited as temperature compensation methods do ...


1-D Profiling Guided Wave Profiling Using Travel Time And Amplitude Loss, Arno Volker, Martijn Brandenburg Jan 2016

1-D Profiling Guided Wave Profiling Using Travel Time And Amplitude Loss, Arno Volker, Martijn Brandenburg

Review of Progress in Quantitative Nondestructive Evaluation

Corrosion is one of the industries major issues regarding the integrity of assets. Currently inspections are conducted at regular intervals to ensure a sufficient integrity level of these assets. There are many situations where the actual defect location is not accessible, e.g., a pipe support or a partially buried pipe. Last year an approach was presented using a phase inversion of guided waves that propagated around the circumference of a pipe. This approach works well for larger corrosion spots, but shows significant under-sizing of small spots due to lack of sufficient phase rotation. In this paper the use of ...


Windowing Of Full Wavefield Data In Multiple Domains To Characterize Angle-Beam Shear Wave Scattering, Yu Weng, Jennifer E. Michaels Jan 2016

Windowing Of Full Wavefield Data In Multiple Domains To Characterize Angle-Beam Shear Wave Scattering, Yu Weng, Jennifer E. Michaels

Review of Progress in Quantitative Nondestructive Evaluation

Angle-beam ultrasonic inspection methods are frequently based on shear waves since they are readily generated using conventional longitudinal transducers and a wedge. Full wavefield imaging can be employed to measure such waves on the surface of a plate-like specimen after they have scattered from a feature or defect of interest, and multiple shear wave arrivals, or “skips,” are readily visible due to beam spread [1]. Because of the complexity of the total wavefield, which also includes Rayleigh and longitudinal waves, it is challenging to experimentally quantify scattering from the primary skip of interest. Considered here is a methodology to isolate ...


Nonlinear Ultrasounic Resonance Spectroscopy Of Intact Carbon Fiber/Epoxy Composites, Sunil Kishore Chakrapani, Daniel J. Barnard, Vinay Dayal Jan 2016

Nonlinear Ultrasounic Resonance Spectroscopy Of Intact Carbon Fiber/Epoxy Composites, Sunil Kishore Chakrapani, Daniel J. Barnard, Vinay Dayal

Review of Progress in Quantitative Nondestructive Evaluation

The present study reports the influence of fiber orientation, laminate sequence and fabric type on the inherent nonlinearity of intact carbon fiber/epoxy composites using nonlinear resonant ultrasonic spectroscopy (NRUS) [1-2]. Fiber orientation of the CFRP samples were changed relative to the length of the sample. Since the fundamental flexural mode is excited, the properties of the composite along the length of the sample would influence the nonlinear response [3]. Two hypothesis were developed using the orientation results and theory of interlaminar stress. Additionally four different laminate sequences were also tested to study the influence of laminate sequence on the ...