Scattering of SH guided wave by a circular cavity in a strip with the serrated boundary

Abstract

The problem of dynamic stress concentration in anti-plane motion of a single circular cavity in a serrated boundary strip medium is studied. Firstly, the scattering of SH wave by a circular cavity defect in the straight line boundary strip medium is analysed based on guided wave theory. The scattering of waves around a circular cavity is expressed as series form by the employed wave function expansion method, and compatible scattering guided waves resulting from the reflection of waves off the boundaries of the elastic strip is constructed by repeated image superposition. The coefficients of the wave function expansion are determined based on the stress free condition of circular boundaries with pre-given incident guided waves. Then the center of the cavity is respectively moved to the upper and lower boundaries to form a depression, and the scattering of the SH-wave by the cavity in the strip with the depression is analyzed. The results of finite element method and analytical method are used to verify each other. A number of depressions are set up at the boundary to simulate a serrated boundary. Then the finite element method is used to analyze the SH wave scattering problem in the serrated boundary strip.