DETERMINATION OF SURFACE-WAVE VELOCITIES IN A PRESTRESSED ANISOTROPICSOLID

In this paper, the velocities of surface waves propagating in a prestr essed anisotropic crystal are determined both theoretically and experi mentally. The Barnett-Lothe's integral formalism, which is fast and ef ficient in determining the surface wave velocities, is extended to sol ve 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 formalis m, the surface wave velocities of the prestressed anisotropic body can be determined. In the experiment, the surface wave velocity of a magn esium oxide (MgO) single crystal with (001) orientation under compress ive stress is measured. A uniaxial compression in the [100] direction is applied to the crystal, and the corresponding phase velocities of t he 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 1.0 GHz. Copyright (C) 1996 Elsevier Science Ltd.