A phase-field regularized cohesive zone model for hydrogen assisted cracking

Being able to seamlessly deal with complex crack patterns like branching, merging and even fragmentation, phase-field fracture/damage models are promising in the modeling of localized failure in solids. This paper addresses a phase-field regularized cohesive zone model (PF-CZM) for hydrogen assisted cracking based on our previous work on purely mechanical problems. Two distinct hydrogen enhanced decohesion mechanisms are dealt with by introducing various implicitly defined (via the crack phase-field) hydrogen-dependent softening laws. The resulting models are then numerically tested and compared against several benchmark examples. It is found that, though the PF-CZM gives different results regarding various decohesion mechanisms, the global responses are insensitive to both the mesh discretization resolution and the incorporated length scale parameter even in the presence of hydrogen. (C) 2019 Elsevier B.V. All rights reserved.