The indirect boundary element method to simulate elastic wave propagation in a 2-D piecewise homogeneous domain

Abstract

A method is presented to simulate the propagation of elastic waves in a 2-D piecewise homogeneous domain composed of several regions of arbitrary shapes. The regions can be isolated within an elastic background or also embedded among themselves. The method is based on the indirect boundary element method (IBEM) in which the diffracted field is obtained as the contributions of distributed sources along the regions boundaries. This is somehow reminiscent of Huygens's Principle for wave fronts. The fields emitted by the sources are computed in frequency domain using analytical expressions of Green's functions for displacements and tractions. This approach is validated, in the antiplane case, by comparing against a semi-analytical solution for a basin composed of concentric semi-circular layers and embedded in a half-space. Finally, an example of in-plane wave propagation is given for a complex configuration involving five interlocked regions.