An atomistic-based interphase zone model for crystalline solids

In this paper, we present an atomistic-based interphase zone model (AIZM), discuss its physical foundation, and apply it to simulate fractures at small scales. The main technical ingredients of the atomistic-based multiscale finite element method are: (1) a colloidal crystal model to describe material interface degradation including slip planes, grain boundaries, cracks, and inhomogeneities; (2) implementation of the reduced integration and hour-glass model control technique to avoid locking inside the interphase element, and (3) introduction of a novel concept of “element stacking fault energy”, which can be utilized in simulations to distinguish ductile and brittle failures at small scales. In particular, AIZM provides an interface description that is consistent with the bulk material properties, and it can capture microstructure-based mixed-mode interfacial fracture automatically. The method may provide a mesoscale solution for polycrystalline solids by bridging the gap between fine scale molecular dynamics and macroscale continum dynamics.