Appraising Kirchhoff approximation theory for the scattering of elastic shear waves by randomly rough defects
File(s)
Accepted version
Author(s)
Haslinger, Stewart G
Lowe, Michael JS
Huthwaite, Peter
Craster, Richard
Shi, Fan
Type
Journal Article
Abstract
Rapid and accurate methods, based on the Kirchhoff approximation (KA), are developed to evaluate the scattering of shear waves by rough defects and quantify the accuracy of this approximation. Defect roughness has a strong effect on the reflection of ultrasound, and every rough defect has a different surface, so standard methods of assessing the sensitivity of inspection based on smooth defects are necessarily limited. Accurately resolving rough cracks in non-destructive evaluation (NDE) inspections often requires shear waves since they have higher sensitivity to surface roughness than longitudinal waves. KA models are attractive, since they are rapid to deploy, however they are an approximation and it is important to determine the range of validity for the scattering of ultrasonic shear waves; this range is found here. Good agreement between KA and high fidelity finite element simulations is obtained for a range of incident/scattering angles, and the limits of validity for KA are found to be much stricter than for longitudinal wave incidence; as the correlation length of rough surfaces is reduced to the order of the incident shear wavelength, a combination of multiple scattering and surface wave mode conversion leads to KA predictions diverging from those of the true diffuse scattered fields.
Date Issued
2019-11-10
Date Acceptance
2019-07-26
Citation
Journal of Sound and Vibration, 2019, 460, pp.1-16
ISSN
0022-460X
Publisher
Elsevier
Start Page
1
End Page
16
Journal / Book Title
Journal of Sound and Vibration
Volume
460
Copyright Statement
© 2019 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000485026200005&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
EP/M020207/1
Subjects
Science & Technology
Technology
Acoustics
Engineering, Mechanical
Mechanics
Engineering
Diffuse scattered field
Elastic shear waves
Randomly rough surface
Kirchhoff approximation
Non-destructive evaluation
SEISMIC-WAVES
SURFACES
PROPAGATION
SIMULATIONS
SMOOTH
Publication Status
Published
Article Number
UNSP 114872
Date Publish Online
2019-08-02