Scattering of elastic waves by a movable rigid sphere embedded in an infinite elastic solid

Abstract

Scattering of an elastic wave by a rigid but movable spherical obstacle is studied, its oscillation being taken into account. The scattered wave, the oscillation of the rigid sphere and the scattering cross section are calculated for an incident longitudinal or shear wave. These calculations reveal the differences between the scattering by a movable rigid sphere and that by an immovable one, especially in the Rayleigh limit. The scattering cross section in this limit is shown to depend on the inverse of the fourth power of the wavelength, while it was reported to be independent of the wavelength for an immovable rigid sphere.