Damage cascade in an interface

A model describing the damage in an interface which is coupled to an elastic homogeneous block is introduced. The interface is loaded in mode I, through an imposed displacement. We look particularly to the transition between a homogeneous micro-cracking state in the interface and the apparition of a macro-crack. The elastic block is decomposed in a hierarchical model, that allows to take into account a mechanical redistribution when a crack appears. We use two modelisations for the interface: a continuum description, with a damage law, and a discrete description, based on the Daniels model. These representations allow to study the localization in the interface. In both cases, we show that the localization proceeds through a cascade of bifurcations. The damage is first spreading all over the interface, and then concentrates with the bifurcations into a narrow region, that leads to the apparition of a crack, and to the interface rupture. (orig.)