Point Focus Acoustic Materials Signature V(z) of Anisotropic Solids

The purpose of this paper is to show that point focus V(z) signals obtained on anisotropic solids are dominated by a small number of principal surface wave rays, which correspond to directions in which the surface wave slowness is stationary. In consequence, the inverse problem becomes more manageable. As an example, the computed V(z) curve for the (001) surface of Cu is analyzed, and is found to be the superposition of 4 dominant periods. Two of these are associated with the RW, one corresponding to the [100] direction where the RW slowness is a maximum, and the other to an oblique direction where the RW slowness is a minimum. The other two periods correspond to a maximum and a minimum in the PSAW slowness