On singular features of acoustic wave propagation in weakly dissipative anisotropic thermoviscoelasticity (Q1568142)

The authors study the propagation of bulk acoustic waves in an anisotropic body in the presence of weak dissipation due to thermal and viscous effects. The low loss approximation is seen to lead to significant effects in the neighborhood of acoustic axes not parallel to symmetry axes. These axes degenerate into pairs of directions of both phase speed and attenuation. The direction of wave-vector degeneracy is shown to admit a composite wave solution characterized by the linear dependence on spatial coordinates.