The propagation of surface waves in bodies with material boundaries

Abstract

A study is made of the propagation of Love and Rayleigh waves in elastic bodies whose boundaries support surface stresses, such as crystals cleaved in vacuo or bodies upon which are deposited extremely thin films. The surfaces of such bodies are herein modelled as two-dimensional elastic continua that adhere without slipping to their substrates and in which is located residual stress. The corresponding boundary condition gives rise to behaviour which is contrasted with that occurring in the absence of surface stress. The results are also related to previous studies of surface waves in thin strata superposed on elastic half-spaces, from which the present theory differs by taking into account residual stress. The behaviour is shown to be sensitive to the relative values of the residual stress, elastic moduli, and density of the surface. Attention is drawn to the relevance of the study to those signal-processing devices which utilize surface waves in thin films.