PLANE-ELASTIC-WAVE SCATTERING FROM AN ELASTIC SPHERE

The scattering of elastic waves from a spherical inclusion of arbitrary size in an infinitely extended elastic medium is investigated. The spherical scatterer and the exterior medium are isotropic, homogeneous, and linearly elastic, but of arbitrarily differing material parameters, with compressional and shear waves supported in both media. Exact expressions for scattered and transmitted fields caused by an incident plane compressional or shear wave of unit amplitude are calculated analytically and general expressions for extinction and scattering cross-sections are derived. In the Rayleigh-wave range for small scatterers, agreement with the approximate solution of Truell is established. In this range of wavelengths the lowest modes have cross-sections proportional to the fourth power of the wave number.