Imposing a Speed Limit to Crack Propagation in Phase Field for Fracture

Abstract

High-speed fracture is typically a strain-rate dependent phenomenon, and it isgenerally accepted that the fracture energy is a function of the speed at which a crack propagates. Importantly, most experimental observations seem to indicate that crack tip speed limits are lower than the bulk wave speed for a given material. This means the coupling between fracture and elastodynamics is dependent on the limiting speed, and developing models that capture this limit accurately is desirable.This thesis presents a thermodynamically consistent modification to the popularphase field for fracture framework, which includes a dissipative term that is intended to impose a limiting speed on propagating cracks. Additionally, it highlights the extent to which modifications to the existing theory are permissible.