MODELING OF INTERFACIAL VISCOPLASTIC SLIP COUPLED TO DAMAGE IN A POLYCRYSTALLINE MICROSTRUCTURE

The mesomechanics behavior of a poly crystalline microstructure subjec ted to creep and constant strain rate loadings is investigated. The an alysis is based on a Voronoi polygonization strategy for the generatio n of grains, that are bonded to each other via interfaces along the gr ain boundaries. A new constitutive model is proposed for the rate-depe ndent debonding along these interfaces, whereby damage is kinetically coupled to viscoplastic slip and dilatation. The paper may be viewed a s generalizing the rate-independent model used in Cannmo et al. (1995) .