A hybrid T matrix/boundary element method for elastic wave scattering from a defect near a non-planar surface

Artikel i vetenskaplig tidskrift, 2012

The in-plane P-SV scattering of elastic waves bya defect and a close non-planar surface is considered. A hybrid T matrix/boundary element approach is used, where a boundary integral equation is used for the non-planar surface and the Green’s tensor in this integral equation is chosen as the one for the defect and thus incorporates the transition (T ) matrix of the defect. The integral equation is iscretized by the boundary element method in a standard way. Also models of ultrasonic probes in transmission and reception are included. In the numerical examples the defect is for simplicity chosen as a circular cavity. This cavity is located close to a non-planar surface, which is planar except for a smooth transition between two planar parts. It is illustrated that the scattering by the cavity and the non-planar surface becomes quite complicated, and that shielding and masking may appear.