Elastic waves in inhomogeneously oriented anisotropic materials

Ray theory is developed for elastic waves propagating in inhomogeneously or iented anisotropic solids. These are materials of uniform density with modu li which are uniform up to a rotation of the underlying crystalline axes ab out a common direction, the degree of rotation varying smoothly with positi on. The ordinary differential equations governing the evolution of a ray ha ve a simple form, and involve the angle of deviation between the slowness a nd wave velocity directions. The general theory is demonstrated for the cas e of SH waves in a transversely isotropic medium. The equations required fo r the description of SH Gaussian beams are derived, including the transport equation and the wavefront curvature equation. The theory is combined with an equivalent complex-source representation to generate an approximation t o a time harmonic point source. (C) 2001 Elsevier Science B.V. All rights r eserved.