FEM analysis of bulk wave scattering at an inclusion

摘要

Elastic waves scattering at dissimilar inclusions are theoretically analyzed for Rayleigh scattering and Kirchhoff approximation. For the situation where the wavelength and size of inclusion are comparable, analytical solution is found only for very special boundary conditions. Therefore, we have to rely on numerical analysis for real boundary conditions. Boundary element method is widely used for analysis of wave scattering, particularly for voids and cracks. However, the method loses the simplicity for the inclusion problem, because of the consideration of the refracted wave into the inclusion. In principle, finite element method can analyze such problems. The conventional FEM solver for static structural analysis does not work well for elastic wave scattering, in which fine mesh and small time increment are required. We have developed an explicit finite element method with a simple data structure of the stiffness matrix where only nonzero components are stored. In the present paper, the method is applied for bulk wave scattering under plane strain at a solder cylinder imbedded in a an aluminum block.