A Weighted Absorbing Boundary for Wave Propagation in Poroelastic Media

An absorbing boundary condition is generally needed to model wave propagation in an unbounded domain in FEM analysis. Considering that the absorbing capabilities for the incident waves with large obliquity is commonly poor, a weighted absorbing boundary condition is presented and the computational formulae are derived based on the Fourier tranformation solution of wave propagation equations in poroelastic media. Its efficiency is compared with the results of G. Degrande and G. De Roeck in a numerial example by a study of the reflected wave amplitudes for waves—P1, P2 and SV at various angles of incidence. The results have shown that the weighted absorbing boundary is an improvement on the absorbing capabilities especially for P1 and P2 waves.