Transmission and Polarization of Elastic Waves in Irregular Structures

Abstract

Propagation of elastic waves in an infinite elastic medium containing a finite array of circular cylindrical cavities is considered. It is assumed that the cavities are equally spaced within each layer, but the cylinder radii, as well as the distance between the layers, may vary from layer to layer. Our objective is to analyze the effect of such an irregularity on scattering properties of the system. Using the method of multipole expansions we evaluate for the case of normal incidence the reflection and transmission matrices for a stack of layers, and find a range of frequencies for which polarization or complete reflection of an incident wave takes place. Presented results highlight the effect of variation in radii and distance between the layers on propagation of elastic waves in such structures.