Stoneley Waves at an Interface Between Elastic Crystals

Results recently obtained by Currie for Rayleigh waves propagating along a traction-free surface of a semi-infinite anisotropic elastic body are here applied to interfacial (Stoneley) waves in an infinite body composed of two anisotropic elastic half-spaces in welded contact. It is first shown how the appropriate secular equation can be constructed directly from complex vectors provided by the analysis of free Rayleigh waves in the constituent half-spaces. We then prove that the secular equation reduces to a single real relation, thus confirming in full generality that when Stoneley waves exist they are not confined to discrete directions of propagation.