A substructure replacement technique for the numerical solution of wave scattering problem

This paper is devoted to the numerical solution of wave scattering and diffraction problems. A substructure replacement technique is proposed for this purpose. By introducing an arbitrary auxiliary boundary, the scattering problem is solved as a simple radiation one. The proposed approach is effective for wave scattering and diffraction by surface irregularities, such as hills and valleys as well as by subsurface inhomogeneities, such as cavities, tunnels and pipelines buried in backfilled trenches. Irrespective of how complex the different types of surface irregularities and subsurface inhomogeneities are, the same input and the same treatment can be applied. It is equally applied to P, SV, SH and Rayleigh wave incidence. Results are validated by comparison with those available in the literature. A challenging test for rather higher frequency scattering of SH wave from a symmetrical shallow V-shaped canyon has been carried out. Well agreements have been achieved. The proposed technique is simple in theory and easy to implement numerically.