Dynamical surface response of a semi-infinite anisotropic elastic medium to an impulsive force

The dynamical surface response to an impulsive point source or line source at any location on the free surface of an anisotropic half-space is solved. The calculation of the Green's functions of the elastic homogeneous medium is based on the Cagniard-de Hoop method. This theoretical study models the generation-detection of transient surface acoustic waves with a point source-point receiver or with a line source-point receiver. An inspection of singular points in the complex plane of the phase slownesses points out the striking phenomena due to anisotropy of surface wave propagation. As a result, the propagation of the Rayleigh wave, of the surface skimming waves, and of the pseudosurface wave are studied as well as the wavefronts focusing. In addition, the diffraction effects by the cusps are emphasized. (C) 1998 Acoustical Society of America.