Phase-field modeling of fracture and crack growth in friction stir processed pure copper

The present work aims to predict the fracture mechanism of a friction stir processed (FSPed) copper. In particular, a phase-field model integrated with finite element model is developed for ductile fracture modeling. The phase-field evolution governed by the nonlinear coupled system comprising the linear momentum equation and the diffusion-type equation is solved concurrently through a Newton–Raphson approach. The proposed fracture model is established by correlating the phase-field degradation function with a scalar measure of the plastic strain, and assuming that the fracture takes place once the accumulated plastic strain reaches a critical value. The numerical simulation results are validated with experimental investigations. The results show that the proposed model is capable of capturing the experimentally observed sequence of elastoplastic base material behavior, FSP deformation, and fracture phenomena in specimens.