2 BASIC WAVE-PROPAGATION PROBLEMS FOR THE NONUNIFORM MOTION OF DISPLACEMENT DISCONTINUITIES IN A HALF-PLANE

The splitting of elastic materials is often achieved by, effect, moving more rigid solids into the surface of the material or by causing a shear tearing characterized by the relative slip of adjacent material points. Therefore, both processes involve the motion of displacement discontinuities. This article examines basic wave propagation problems for the non-uniform motion of two arbitrary displacement discontinuities in an elastic half-plane along paths normal to the surface. The discontinuities impose relative displacements which are, respectively, normal to and along the path. Complete solutions are derived in forms which allow identification of each component of the reflection-complicated wave pattern, Moreover, the dependence of these components on specific aspects of the discontinuity behavior can be noted. Finally, two physical examples, the motion of a rigid wedge and the motion of edge dislocations in the half-plane, are studied. © 1979.