Damage localization as a possible precursor of earthquake rupture

Based on the concepts of statistical mesoscopic damage mechanics, the ruptu re of a heterogeneous medium is investigated in terms of numerical simulati ons of a network model, subjected to simple shear loading. The heterogeneit ies are simulated by varying the sizes and fracture strains of the elements of the network. Progressive damage is governed by a damage field equation and a dynamic function of damage (DFD). From the damage field equation, a c riterion for damage localization can be derived, and the DFD can be extract ed from the simulations of the network. Importantly, the DFD intrinsically governs the damage localization. Both stress-free and periodic boundary con ditions for the network are examined. It is found that damage localization may be the underlying mechanism of eventual rupture and thus could be used as a possible precursor of earthquake rupture.