SURFACE-ROUGHNESS INDUCED ATTENUATION AND CHANGES IN THE PROPAGATION VELOCITY OF LONG RAYLEIGH-TYPE WAVES

The propagation of long Rayleigh waves on a rough surface is studied theoretically by Rayleigh method and for the free rough surface of a homogeneous and isotropic elastic half-space. The frequency dependence of the propagation velocity and attenuation is analysed under the assumption that the frequency is real. Moreover, the changes in the propagation velocity induced by the surface roughness are expressed in terms of the square of the ratio of the root-mean-square departure of the surface from flatness to the correlation length of the distance between successive peaks and valleys in the rough-surface profile.