Determination of surface wave velocities in a prestressed anisotropic solid

In this paper, the velocities of surface waves propagating in a prestressed anisotropic crystal are determined both theoretically and experimentally. The Barnett-Lothe's integral formalism, which is fast and efficient in determining the surface wave velocities, is extended to solve the surface wave problem of a prestressed anisotropic material. The governing equations and boundary conditions of the wave superposed on a prestressed elastic body are derived by acousto-elasticity, and the effective wave propagating constants of the finite deformed body are determined. As the effective constants are determined and utilized to replace the elastic constants in the Barnett-Lothe's integral formalism, the surface wave velocities of the prestressed anisotropic body can be determined. In the experiment the surface wave velocity of a magnesium oxide (MgO) single crystal with (001) orientation under compressive stress is measured. A uniaxial compression in the [100] direction is applied to the crystal, and the corresponding phase velocities of the surface wave propagating on the (001) surface are measured by the V(z) curves of a line focused scanning acoustic microscope (SAM) with a frequency 1.0GHz. Copyright © 1996 Elsevier Science Ltd.