The scattering of ultrasonic waves by polycrystals. II. Shear waves

The theory of ultrasonic propagation in polycrystals presented in a previous paper is used to calculate the scattering coefficient and the phase and group velocities of plane shear waves in polycrystals of cubic symmetry with randomly orientated grains. The calculation was done in second-order perturbation theory using the assumption that the changes in the elastic constants and in the density from grain to grain are small. The asymptotic values at low κa (Rayleigh scattering) are exactly the same as the well-known results from Bhatia and Moore. Numerical calculations are carried out for some examples.