On the acoustoelasticity of polycrystalline materials.

A linear relation between the strains and stresses of a crystallite within a polycrystal is used to homogenize the polycrystal's elastic properties. The homogenization parallels the self-consistent method that is used for estimating the polycrystal's linear elastic properties. Acoustoelasticity for a macroscopically isotropic polycrystal is then formulated using a homogenized constitutive equation with initial stress. Simple expressions are given for the phase velocities and polarization directions for a uniaxially stressed polycrystal. The present model is compared with the model of Man and Paroni [J. Elast. 45, 91-116 (1996)]. Strong anisotropy of the crystallite elastic constants causes the present model to differ noticeably from the model of Man and Paroni.