Computing critical energy release rates for fracture in atomistic simulations

We describe a method for computing critical energy release rates for crack propagation in atomistic models and apply it to simulations of fracture in Ni. Our method relies on independent calculations of crack surface area and energy dissipated during fracture. We show that the critical energy release rate for fracture in Ni increases linearly with model size due to increasing energy dissipated through plastic deformation. We conclude with a discussion of prospects for direct comparisons of critical energy release rates computed from atomistic simulations to ones obtained from experiments.