Elastic Wave Propagation in Strongly Anisotropic Solids

Abstract

In many branches of mechanics the study of waves gives much guidance to the understanding of unsteady phenomena. For example, in linear theories unsteady disturbances are commonly represented as superpositions of plane harmonic waves. A study of such waves reveals many important directional properties of the carrying medium — and the existence of an imaginary propagation speed is frequently taken to imply instability. For strongly anisotropic solids the propagation speed depends greatly on the direction of propagation, so that spreading wavefronts are far from spherical. This chapter will deal with some important features of the linear theory and will relate them to predictions for an ideally constrained solid. Some generalisations to acceleration waves in finite elasticity are also mentioned.