Elastic wave reflection from liquid-anisotropic substrate interfaces

We derive analytical expressions for the reflection and transmission coefficients from the interfaces of liquid-anisotropic half-spaces possessing up to as low as monoclinic symmetry. Also we present expressions for the distributions of stresses and displacements throughout the fluid-solid system. Solutions are obtained for an acoustic wave impinging the interface at an arbitrary angle θ from the normal as well as at any azimuthal angle ø. By examining the behavior of the reflection coefficient we are able to identify all of the propagation characteristics that influence the distribution of the reflected field. These include the possible existence of secondary (pseudo-surface) modes besides those associated with the normal surface ones. We also deduce the variations of phase velocity and beam shifting parameters with azimuthal angles. Material systems of higher symmetry, such as orthotropic, transversely isotropic, cubic and isotropic are contained implicitly in our analysis. We present numerical results drawn from several examples of materials belonging to these symmetry groups.