Off-fault plasticity favors the arrest of dynamic ruptures on strength heterogeneity : Two-dimensional cases

Abstract : We study the effects of a plastic behavior of the volume around the fault on in-plane and anti-plane 2D rupture dynamics. Both rupture modes exhibit similar answer to off-fault yielding, in terms of modification of the kinematics of the rupture front, and in terms of energy lost outside the fault plane. We then compare the ability of the rupture to propagate through a barrier on the interface. The plastic behavior, responsible for a linear increase of the global fracture energy during dynamic crack growth, enhances the rupture front sensitivity to a static resistance increase on the fault. Consequently, the rupture arrest is more easily provoked in heterogeneous models that include a plastic yielding, even with relatively small variations of frictional resistance along the fault plane.