Asymptotic study of the interfacial crack with friction

We study a model of interfacial crack in which contact of the crack faces o beys a Coulomb law of friction. For such cracks, the possibility that the s tress has a stronger singularity than r(-1/2) near the tip has been reporte d. In this paper, we demonstrate that these strong singularities can, in fa ct, be discarded, because they would assume a backward propagation of the c rack. In passing, we prove that near-tip slip is possible in one direction only, which is imposed by the sign of the elastic mismatch. The locking of the stress intensity factor during a non-monotonic cycle of loading is poin ted out, as well as the formation of a bubble near the tip under certain lo ading conditions. (C) 2000 Elsevier Science Ltd. All rights reserved.