Re-polarization of elastic waves at a frictional contact interface—I. incidence of an SH wave

This paper examines the interaction of an incident SH wave with a frictional contact interface between two solids which are pressed together. The incident wave is assumed strong enough to break friction so that localized slip takes place. It is also assumed that the solids are loaded by both anti-plane and in-plane sheafing tractions which lead to a global sliding motion. An important and interesting phenomenon is that the incident SH wave is re-polarized at the interface so that the in-plane waves are induced because of the existence of the in-plane shearing traction. The present problem is indeed a nonlinear boundary value problem since the mixed boundary conditions involve unknown intervals (the slip and stick zones). Using Fourier analysis, we manage to reduce the problem to a set of algebraic equations coupled with simple integral equations. An iterative procedure is developed based on the solution to the welded interface. The locations and sizes of the slip zones, the interface shearing tractions, the slip velocities, the global sliding velocity and the energy dissipation and partition are displayed for the case of two identical materials. The present analysis is limited to the sub-critical angle incidence. © 1998 Elsevier Science Ltd