DYNAMICS OF A FAULT STEADILY PROPAGATING WITHIN A STRUCTURAL INTERFACE

Analysis of propagation of a fault driven by a steadily moving shearing force through a structural interface reveals a channeling effect for the energy release. This effect implies that a steady-state solution for propagation exists, but, differently from the case of fault propagation in an infinite lattice, it turns out to always be unstable at low velocity and for fixed load, while stability can be achieved at high propagation velocity only if the amplitude load becomes a specially "designed" decreasing function of the velocity. With a proper choice of this load application law, the propagation can even be stopped. The disclosed behavior also contrasts with the solution for the propagation of a fracture in a homogeneous linearly elastic medium, where for fixed load the crack initially moves and later comes to a stop.