Diffraction of SH waves by Griffith cracks or rigid strips lying in a laterally and vertically non-homogeneous infinite medium

Abstract

The problem of diffraction of obliquely incident SH waves by one Griffith crack in an infinite non-homogeneous elastic medium is solved. The problems of diffraction of normally incident SH waves by two coplanar cracks or by two coplanar rigid strips in an infinite non-homogeneous elastic medium are also solved. Approximate expressions are derived for the displacement component and the stress intensity factors. The modulus of rigidity (μ) and the density (ρ) of the material are assumed to vary both in the horizontal ( x) and vertical ( z) directions, and the ratio μ ρ is assumed to be constant. The numerical values of the stress-intensity factors are displayed graphically to show the effect of non-homogeneity of the material. The results for the corresponding problems for an isotropic, homogeneous, elastic medium are derived as particular cases.