Arbitrary bi-dimensional finite strain cohesive crack propagation

摘要

In this paper, a systematic approach for elastic finite strain crack propagation with multiple cohesive cracks and self-contact is described. Crack paths are determined by the CTOD method and the advance criterion uses either the equivalent stress intensity factor or the tip-element stress. Crack intersections, coalescence and cohesive laws are accounted for, as is the formation of multiple particles. Globally-optimized mesh repositioning is used to minimize the least-square of all elements' inner-angle error. This is followed, in a staggered form, by a Godunov-based advection step for the deformation gradient. Several examples are presented showing the robustness and accuracy of the implementation, as well as the ability to represent crack face thickness variation in finite strains. Classical fracture benchmarks are solved and a problem of multiple crack evolution is proposed. Excellent results were observed in the effected tests.