On small-displacement waves in prestressed bodies with isotropic incremental elasticity tensor

We consider a body at rest in a prestressed configuration kappa which responds elastically to small incremental displacements from kappa; the incremental elasticity tensor is supposed isotropic. On the basis of the paper [1] we characterize the conditions for the propagation of longitudinal, transverse, and oblique small-displacement waves superimposed to kappa. Formulae for the propagation speeds of these waves are written in terms of the prestress components and Lame parameters. The amplitudes of longitudinal and transverse waves are eigenvectors for the prestress.