Bone and joint changes in pneumatic drillers : M. J. Burke,E. C. Fear and V. Wright 1977 Annals of Rheumatic Diseases36, 276–279. (4 pages, 2 figures, 13 references)

Propagation of waves in linear anisotropic non-homogeneous thermoviscoelastic media is investigated by employing the basic ideas of the theory of singular surfaces and of ray theory. The characteristic equation governing the wave velocities, and the decay and growth equations describing the change of the strength of the discontinuity as the wave front moves in the medium are obtained. The results then are reduced to the case of isotropic materials. The decay and growth equations for this case are integrated along the rays and the general solutions are obtained. The factors affecting the decay and growth, namely the effects of inhomogeneity, geometry of the wave front, material internal friction and thermomechanical coupling, are discussed.