Scattering of elastic waves in heterogeneous media with local isotropy

The scattering of elastic waves in heterogeneous media is discussed. Explic it expressions are derived for the attenuation of longitudinal and transver se elastic waves in terms of the statistics of the density and Lame paramet er fluctuations. The derivation is based upon diagrammatic methods with the problem posed in terms of the Dyson equation. The Dyson equation is solved for the mean field response. The results are given here in a straightforwa rd manner, in which the attenuations reduce to simple integrals on the unit circle. The medium is assumed statistically homogeneous and statistically isotropic. This model. with assumed local isotropic properties, is expected to apply to many materials. (C) 2001 Acoustical Society of America.