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Fourier Expansion to Elastic Vector Wave Functions and Applications of Wave Bases to Scattering in Half-Space

Published online by Cambridge University Press:  22 March 2012

P.-J. Shih ,
T.-J. Teng  and
C.-S. Yeh
P.-J. Shih*
Affiliation:
Department of Civil and Environmental Engineering, National University of Kaohsiung, Kaohsiung, Taiwan 81148, R.O.C.
T.-J. Teng
Affiliation:
National Center for Research on Earthquake Engineering, Taipei, Taiwan 10671, R.O.C.
C.-S. Yeh
Affiliation:
Department of Civil Engineering and Institute of Applied Mechanics, National Taiwan University Taipei, Taiwan 10617, R.O.C.
*
*Corresponding author (pjshih@nuk.edu.tw)
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Abstract

This paper proposes a complete basis set for analyzing elastic wave scattering in half-space. The half-space is an isotropic, linear, and homogeneous medium except for a finite inhomogeneity. The wave bases are obtained by combining buried source functions and their reflected counter-waves generated from the infinite-plane boundary. The source functions are the vector wave functions of infinite-space. Based on the source functions expressed in the Fourier expansion form, the reflected counter-waves are easily obtained by solving the infinite-plane boundary conditions. Few representations adopt Wely's integration, but the Fourier expansion is developed from it and applied to decouple the angular-differential terms of the vector wave functions. In addition to the scattering of the finite inhomogeneity, the transition matrix method is extended to express the surface boundary conditions. For the numerical application in this paper, the P- and the SV- waves are assumed as the incoming fields. As an example, this paper computes stress concentrations around a cavity. The steepest-descent path method yielding the optimum integral paths is used to ensure the numerical convergence of the wave bases in the Fourier expansion. The resultant patterns from these approaches are compared with those obtained from numerical simulations.

Keywords

Fourier expressionElastic half-spaceScattering
Type
Articles
Information
Journal of Mechanics , Volume 28 , Issue 1 , March 2012 , pp. 19 - 39
Copyright
Copyright © The Society of Theoretical and Applied Mechanics, R.O.C. 2012

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