scholarly journals Assessment of qualitative and quantitative S0 guided wave tomography of sharp thickness loss defects in the isotropic membrane regime

2021 ◽  
Vol 149 (3) ◽  
pp. 1475-1487
Author(s):  
William Cailly ◽  
Henri Walaszek ◽  
Sébastien Brzuchacz ◽  
Fan Zhang ◽  
Philippe Lasaygues
Keyword(s):  
Guided Wave ◽  
Qualitative And Quantitative ◽  
Thickness Loss ◽  
Wave Tomography

Accurate Thickness Inversion of Corrosion Using A1 Lamb Wave

2021 ◽  
Author(s):  
Min Lin ◽  
Yang Liu
Keyword(s):  
High Resolution ◽  
Oil And Gas ◽  
Residual Life ◽  
Early Stage ◽  
Corrosion Damage ◽  
Oil And Gas Industry ◽  
Forward Modeling ◽  
Guided Wave ◽  
Velocity Inversion ◽  
Wave Tomography

Abstract Corrosion is one of the most critical issues in the oil and gas industry, leading to severe environmental and economic problems. Due to the high cost and serious safety risk of corrosion, it is essential to improve current corrosion testing techniques to detect corrosion damages at an early stage. Guided wave tomography (GWT) demonstrates its great potential to inspect and quantify the corrosion damage. GWT is capable of determining the residual life of corrosion structures by quantifying the remaining wall thickness. In this paper, an accurate guided wave tomography technique incorporating full waveform inversion (FWI) and higher-order Lamb waves (A1 mode) is presented for plate-like structures, which is able to get high-resolution reconstruction results. The technique consists of three steps: forward modeling, velocity inversion and thickness reconstruction. The forward modeling is computed by solving the elastic full-wave equations in 2-D time domain by using the finite difference method. High-resolution phase velocity inversion can then be obtained by minimizing the waveform misfit function between simulated and recorded data using a second order optimization method, which updates the velocity model from low to high frequencies iteratively. Finally, the velocity variations can be transformed into depth profiles by using the dispersive characteristics of ultrasonic guided waves; therefore, the thickness reconstruction can be obtained. The numerical simulations are performed on an aluminum plate with a complicated corrosion defect. By comparing the thickness reconstruction maps using both A1 and A0 modes, the results demonstrate that FWI with A1 mode can achieve significantly better resolution of corrosion imaging than that with A0 mode.

Field trials results of guided wave tomography

2015 ◽  
Author(s):  
Arno Volker ◽  
Tim van Zon ◽  
Edwin van der Leden
Keyword(s):  
Field Trials ◽  
Guided Wave ◽  
Wave Tomography

Guided wave tomography based on least-squares reverse-time migration

2019 ◽  
Vol 19 (4) ◽  
pp. 1237-1249 ◽  
Author(s):  
Jiaze He ◽  
Daniel C Rocha ◽  
Paul Sava
Keyword(s):  
Experimental Data ◽  
Least Squares ◽  
Guided Wave ◽  
Circular Array ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Damage Site ◽  
Time Migration ◽  
Damage Imaging ◽  
Wave Tomography

A key to successful damage diagnostics and quantification is damage imaging through ultrasonic guided wave tomography. We propose the implementation of least-squares reverse-time migration in a circular array for damage imaging in an aluminum plate. The theory of least-squares reverse-time migration is formulated for guided wave applications along with the summary of an efficient optimization algorithm: the conjugate gradient method. Numerical simulation and laboratory experiments are used to evaluate its performance with a circular array setup. In order to improve the data processing efficiency, the concept of using a limited number of actuators but a relatively large number of sensors is tested. Studies are conducted on three numerical cases, including a rectangular-shaped damage site, a complex-shaped damage site, and six other damage sites varying in size. As an inversion-based method, least-squares reverse-time migration shows significantly improved shape reconstruction with the amplitude quantification capability, compared to conventional reverse-time migration. Our experimental data are generated by piezoelectric wafers as actuators, measured by a scanning laser Doppler vibrometer to form a circular array on an aluminum plate, with a rectangular notch located in the inner region of the array. The damage images using experimental data show consistency in both the simulations using Born scattering and in altered material properties in the damaged region. According to the comparison, least-squares reverse-time migration for guided wave tomography is a promising technology to provide high-resolution large area damage imaging for plate-like structures.

scholarly journals Structure of the San Andreas Fault at SAFOD from P-wave tomography and fault-guided wave mapping

2006 ◽  
Vol 33 (13) ◽  
Author(s):  
Peter Malin ◽  
Eylon Shalev ◽  
Heather Balven ◽  
Catherine Lewis-Kenedi
Keyword(s):  
San Andreas Fault ◽  
Guided Wave ◽  
P Wave ◽  
San Andreas ◽  
Wave Tomography

Ultrasonic guided wave tomography for ice detection

Ultrasonics ◽  
2016 ◽  
Vol 67 ◽  
pp. 212-219 ◽  
Author(s):  
Xiang Zhao ◽  
Joseph L. Rose
Keyword(s):  
Guided Wave ◽  
Ultrasonic Guided Wave ◽  
Wave Tomography ◽  
Ice Detection

scholarly journals Nonlinear Guided Wave Tomography for Detection and Evaluation of Early-Life Material Degradation in Plates

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5498
Author(s):  
Chengwei Zhao ◽  
Sunia Tanweer ◽  
Jian Li ◽  
Min Lin ◽  
Xiang Zhang ◽  
...  
Keyword(s):  
Early Life ◽  
Guided Waves ◽  
Lamb Waves ◽  
Tone Burst ◽  
Guided Wave ◽  
Material Degradation ◽  
Third Order Elastic Constants ◽  
Metal Plates ◽  
Wave Tomography ◽  
Aluminum Plates

In this paper, the possibility of using nonlinear ultrasonic guided waves for early-life material degradation in metal plates is investigated through both computational modeling and study. The analysis of the second harmonics of Lamb waves in a free boundary aluminum plate, and the internal resonance conditions between the Lamb wave primary modes and the second harmonics are investigated. Subsequently, Murnaghan’s hyperelastic model is implemented in a finite element (FE) analysis to study the response of aluminum plates subjected to a 60 kHz Hanning-windowed tone burst. Different stages of material degradation are reflected as the changes in the third order elastic constants (TOECs) of the Murnaghan’s model. The reconstructed degradations match the actual ones well across various degrees of degradation. The effects of several relevant factors on the accuracy of reconstructions are also discussed.

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