289 results found
Choi W, Shi F, Lowe MJS, et al., 2018, Rough surface reconstruction of real surfaces for numerical simulations of ultrasonic wave scattering, NDT & E INTERNATIONAL, Vol: 98, Pages: 27-36, ISSN: 0963-8695
Eckel S, Huthwaite P, Lowe M, et al., 2018, Establishment and validation of the Channelized Hotelling Model Observer for image assessment in industrial radiography, NDT & E INTERNATIONAL, Vol: 98, Pages: 1-7, ISSN: 0963-8695
Lan B, Ben Britton T, Jun TS, et al., 2018, Direct volumetric measurement of crystallographic texture using acoustic waves, Acta Materialia, Vol: 159, Pages: 384-394, ISSN: 1359-6454
© 2018 Acta Materialia Inc. Crystallographic texture in polycrystalline materials is often developed as preferred orientation distribution of grains during thermo-mechanical processes. Texture dominates many macroscopic physical properties and reflects the histories of structural evolution, hence its measurement and control are vital for performance optimisation and deformation history interogation in engineering and geological materials. However, exploitations of texture are hampered by state-of-the-art characterisation techniques, none of which can routinely deliver the desirable non-destructive, volumetric measurements, especially at larger lengthscales. Here we report a direct and general methodology retrieving important lower-truncation-order texture and phase information from acoustic (compressional elastic) wave speed measurements in different directions through the material volume (avoiding the need for forward modelling). We demonstrate its deployment with ultrasound in the laboratory, where the results from seven representative samples are successfully validated against measurements performed using neutron diffraction. The acoustic method we have developed includes both fundamental wave propagation and texture inversion theories which are free from diffraction limits, they are arbitrarily scalable in dimension, and can be rapidly deployed to measure the texture of large objects. This opens up volumetric texture characterisation capabilities in the areas of material science and beyond, for both scientific and industrial applications.
Lan B, Carpenter MA, Gan W, et al., 2018, Rapid measurement of volumetric texture using resonant ultrasound spectroscopy, Scripta Materialia, Vol: 157, Pages: 44-48, ISSN: 1359-6462
© 2018 Elsevier Ltd This paper presents a non-destructive evaluation method of volumetric texture using resonant ultrasound spectroscopy (RUS). It is based on a general theoretical platform that links the directional wave speeds of a polycrystalline aggregate to its texture through a simple convolution relationship, and RUS is employed to obtain the speeds by measuring the elastic constants, where well-established experimental and post-processing procedures are followed. Important lower-truncation-order textures of representative hexagonal and cubic metal samples with orthorhombic sample symmetries are extracted, and are validated against independent immersion ultrasound and neutron tests. The successful deployment of RUS indicates broader applications of the general methodology.
Phillips R, Duxbury D, Huthwaite P, et al., 2018, Simulating the ultrasonic scattering from complex surface-breaking defects with a three-dimensional hybrid model, NDT and E International, Vol: 97, Pages: 32-41, ISSN: 0963-8695
© 2018 Elsevier Ltd Modelling is increasingly relied on for the design and qualification of ultrasonic inspections applied to safety-critical components. Numerical methods enable the simulation of the ultrasonic interaction with realistic defect morphologies; however, the computational requirements often limit their deployment. The hybrid simulation technique, which combines semi-analytical and numerical methods, realises the potential of high fidelity numerical modelling without the limiting computational factors. The inspection of thick section components for near-backwall surface-breaking defects results in large propagation distances, making them a key application of hybrid modelling. This work presents a methodology for efficiently simulating the ultrasonic inspection of complex surface-breaking defects using a hybrid model. The model is initially verified against full numerical simulation; further validation is presented by comparison to an experimental scan over an artificially machined surface-breaking notch. The potential of the new hybrid method is then demonstrated by carrying out a Monte Carlo analysis on the scattered field from surface-breaking defects with randomly rough surfaces and the results are compared to the Kirchhoff approximation.
Phillips R, Duxbury D, Huthwaite P, et al., 2018, Simulating the ultrasonic scattering from complex surface-breaking defects with a three-dimensional hybrid model, NDT & E INTERNATIONAL, Vol: 97, Pages: 32-41, ISSN: 0963-8695
Shi F, Lowe MJS, Skelton EA, et al., 2018, A time-domain finite element boundary integral approach for elastic wave scattering, COMPUTATIONAL MECHANICS, Vol: 61, Pages: 471-483, ISSN: 0178-7675
Van Pamel A, Sha G, Lowe MJS, et al., 2018, Numerical and analytic modelling of elastodynamic scattering within polycrystalline materials, JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA, Vol: 143, Pages: 2394-2408, ISSN: 0001-4966
Zhang C, Huthwaite P, Lowe M, 2018, The Application of the Factorization Method to the Subsurface Imaging of Surface-Breaking Cracks, IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL, Vol: 65, Pages: 497-512, ISSN: 0885-3010
Zhang C, Huthwaite P, Lowe M, 2018, Eliminating backwall effects in the phased array imaging of near backwall defects., J Acoust Soc Am, Vol: 144
Ultrasonic array imaging is widely used to provide high quality defect detection and characterization. However, the current imaging techniques are poor at detecting and characterizing defects near a surface facing the array, as the signal scattered from the defect and the strong reflection from the planar backwall will overlap in both time and frequency domains, masking the presence of the defect. To address this problem, this paper explores imaging algorithms and relevant methods to eliminate the strong artefacts caused by the backwall reflection. The half-skip total focusing method (HSTFM), the factorization method (FM) and the time domain sampling method (TDSM) are chosen as the imaging algorithms used in this paper. Then, three methods, referred to as full matrix capture (FMC) subtraction, weighting function filtering, and the truncation method, are developed to eliminate or filter the effects caused by the strong backwall reflection. These methods can be applied easily with few tuning parameters or little prior knowledge. The performances of the proposed imaging techniques are validated in both simulation and experiments, and the results show the effectiveness of the developed methods to eliminate the artefacts caused by the backwall reflections when imaging near backwall defects.
Egerton JS, Lowe MJS, Huthwaite P, et al., 2017, Ultrasonic attenuation and phase velocity of high-density polyethylene pipe material, JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA, Vol: 141, Pages: 1535-1545, ISSN: 0001-4966
Egerton JS, Lowe MJS, Huthwaite P, et al., 2017, A multiband approach for accurate numerical simulation of frequency dependent ultrasonic wave propagation in the time domain, JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA, Vol: 142, Pages: 1270-1280, ISSN: 0001-4966
Haith MI, Ewert U, Hohendorf S, et al., 2017, Radiographic modelling for NDE of subsea pipelines, NDT & E INTERNATIONAL, Vol: 86, Pages: 113-122, ISSN: 0963-8695
Haith MI, Huthwaite P, Lowe MJS, 2017, Defect characterisation from limited view pipeline radiography, NDT & E INTERNATIONAL, Vol: 86, Pages: 186-198, ISSN: 0963-8695
Quintanilla FH, Lowe MJS, Craster RV, 2017, The symmetry and coupling properties of solutions in general anisotropic multilayer waveguides, JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA, Vol: 141, Pages: 406-418, ISSN: 0001-4966
Shi F, Lowe M, Craster R, 2017, Diffusely scattered and transmitted elastic waves by random rough solid-solid interfaces using an elastodynamic Kirchhoff approximation, PHYSICAL REVIEW B, Vol: 95, ISSN: 2469-9950
Elastic waves scattered by random rough interfaces separating two distinct media play an important role in modeling phonon scattering and impact upon thermal transport models, and are also integral to ultrasonic inspection. We introduce theoretical formulas for the diffuse field of elastic waves scattered by, and transmitted across, random rough solid-solid interfaces using the elastodynamic Kirchhoff approximation. The new formulas are validated by comparison with numerical Monte Carlo simulations, for a wide range of roughness (rms σ≤λ/3, correlation length λ0≥ wavelength λ), demonstrating a significant improvement over the widely used small-perturbation approach, which is valid only for surfaces with small rms values. Physical analysis using the theoretical formulas derived here demonstrates that increasing the rms value leads to a considerable change of the scattering patterns for each mode. The roughness has different effects on the reflection and the transmission, with a strong dependence on the material properties. In the special case of a perfect match of the wave speed of the two solid media, the transmission is the same as the case for a flat interface. We pay particular attention to scattering in the specular direction, often used as an observable quantity, in terms of the roughness parameters, showing a peak at an intermediate value of rms; this rms value coincides with that predicted by the Rayleigh parameter.
Shi F, Lowe MJS, Craster RV, 2017, Recovery of correlation function of internal random rough surfaces from diffusely scattered elastic waves, JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS, Vol: 99, Pages: 483-494, ISSN: 0022-5096
Van Pamel A, Sha G, Rokhlin SI, et al., 2017, Finite-element modelling of elastic wave propagation and scattering within heterogeneous media, PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, Vol: 473, ISSN: 1364-5021
Choi W, Skelton EA, Pettit J, et al., 2016, A Generic Hybrid Model for the Simulation of Three-Dimensional Bulk Elastodynamics for Use in Nondestructive Evaluation, IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL, Vol: 63, Pages: 726-736, ISSN: 0885-3010
Egerton JS, Lowe MJS, Halai HV, et al., 2016, Improved FE Simulation of Ultrasound in Plastics, 42nd Annual Review of Progress in Quantitative Nondestructive Evaluation (QNDE), Publisher: AMER INST PHYSICS, ISSN: 0094-243X
Haith MI, Ewert U, Hohendorf S, et al., 2016, Modelling Based Radiography for NDE of Subsea Pipelines, 42nd Annual Review of Progress in Quantitative Nondestructive Evaluation (QNDE), Publisher: AMER INST PHYSICS, ISSN: 0094-243X
Huthwaite P, Lowe M, Cawley P, 2016, Guided Wave Tomography Performance Analysis, 42nd Annual Review of Progress in Quantitative Nondestructive Evaluation (QNDE), Publisher: AMER INST PHYSICS, ISSN: 0094-243X
Leinov E, Lowe MJS, Cawley P, 2016, Ultrasonic isolation of buried pipes, JOURNAL OF SOUND AND VIBRATION, Vol: 363, Pages: 225-239, ISSN: 0022-460X
Leinov E, Lowe MJS, Cawley P, 2016, Investigation of guided wave propagation in pipes fully and partially embedded in concrete, JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA, Vol: 140, Pages: 4528-4539, ISSN: 0001-4966
Quintanilla FH, Lowe MJS, Craster RV, 2016, Full 3D dispersion curve solutions for guided waves in generally anisotropic media, JOURNAL OF SOUND AND VIBRATION, Vol: 363, Pages: 545-559, ISSN: 0022-460X
Seher M, Huthwaite P, Lowe MJS, 2016, Experimental Studies of the Inspection of Areas With Restricted Access Using A0 Lamb Wave Tomography, IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL, Vol: 63, Pages: 1455-1467, ISSN: 0885-3010
Shi F, Lowe MJS, Xi X, et al., 2016, Diffuse scattered field of elastic waves from randomly rough surfaces using an analytical Kirchhoff theory, JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS, Vol: 92, Pages: 260-277, ISSN: 0022-5096
Van Pamel A, Huthwaite P, Brett CR, et al., 2016, Numerical simulations of ultrasonic array imaging of highly scattering materials, NDT & E INTERNATIONAL, Vol: 81, Pages: 9-19, ISSN: 0963-8695
Van Pamel A, Nagy PB, Lowe MJS, 2016, On the dimensionality of elastic wave scattering within heterogeneous media, JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA, Vol: 140, Pages: 4360-4366, ISSN: 0001-4966
Ewert U, Tschaikner M, Hohendorf S, et al., 2015, Corrosion Monitoring with Tangential Radiography and Limited View Computed Tomography, 42nd Annual Review of Progress in Quantitative Nondestructive Evaluation (QNDE), Publisher: American Institute of Physics (AIP), ISSN: 1551-7616
Accurate and reliable detection of subsea pipeline corrosion is required in order to verify the integrity of the pipeline. A laboratory trial was conducted with a representative pipe sample. The accurate measurement of the wall thickness and corrosion was performed with high energy X-rays and a digital detector array. A 7.5 MV betatron was used to penetrate a stepped pipe and a welded test pipe of 3 m length and 327 mm outer diameter, with different artificial corrosion areas in the 24 mm thick steel wall. The radiographs were taken with a 40 x 40 cm² digital detector array, which was not large enough to cover the complete pipe diameter after magnification. A C-arm based geometry was tested to evaluate the potential for automated inspection in field. The primary goal was the accurate measurement of wall thickness conforming to the standard. The same geometry was used to explore the ability of a C-arm based scanner in asymmetric mode for computed tomography (CT) measurement, taking projections covering only two thirds of the pipe diameter. The technique was optimized with the modelling software aRTist. A full volume of the pipe was reconstructed and the CT data set was used for reverse engineering, providing a CAD file for further aRTist simulations to explore the technique for subsea inspections.
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