Adaptive finite element modeling of phase-field fracture driven by hydrogen embrittlement

Abstract

The effect of hydrogen on crack propagation has been studied extensively using various numerical algorithms. Recently, phase-field models have been developed that can predict crack propagation with very good resemblance of the crack paths with the experimental results. Solving the coupled equations of hydrogen transport, mechanical equilibrium and phase-field models is computationally expensive requiring a large number of time steps and high spatial resolution. Often, the spatial resolution is achieved a priori in known regions where the cracks may propagate. This leads to a large number of degrees of freedom to be solved for a large number of time steps for the coupled equations in simulating hydrogen-assisted cracking. In the present work, an adaptive refinement scheme is proposed that will remove the burden of very high uniform spatial resolution in non crack regions eventually leading to fewer degrees of freedom and hence decreases the computational cost. Several case studies are considered and the efficacy of the proposed method is demonstrated.