Stability of steady frictional sliding at an interface between two elastic layers

Abstract

Instabilities in dynamic antiplane frictional sliding on a planar interface between two elastic layers with dissimilar elastic properties are studied. At the interface, a rate- and state-dependent friction law with a positive instantaneous dependency on slip velocity and velocity weakening behaviour in the steady state is assumed to be in effect. The linearized response of the sliding of the two elastic layers to a Fourier mode perturbation along the interface is studied. A key aspect of the problem is that interfacial waves exist for the problem in both freely slipping and bonded contact. The growth rate of slip instabilities and their phase velocities are obtained numerically. The stability of both rapid and slow slip is analyzed. The results show that one mechanism for instabilities is the destabilization due to friction of interfacial waves in freely slipping contact and in bonded contact. The effect of layer thickness on the stability results is also studied.