Fracture propagation solved with a primal-dual active set phase-field technique

Prof. Thomas Wick

Sept. 17, 2014, 1:45 p.m. S2 416

In this talk, we consider phase-field-based fracture propagation in elastic and poroelastic media. The main purpose is the development of a robust and effcient numerical scheme. To enforce the entropy condition; namely, crack irreversibility, we use a robust primal-dual active set strategy. This is merged with the outer Newton iteration for the variational inequality of the fully-coupled nonlinear partial differential equation system, resulting in a single, rapidly converging nonlinear iteration. In addition, it is well known that phase-field models require fine meshes to accurately capture the propagation dynamics of the crack. Because traditional estimators based on adaptive mesh refinement schemes are not appropriate, we present a predictor-corrector scheme for local mesh adaptivity to reduce the computa- tional cost. Our proposed approach is substantiated with different numerical tests for crack propagation in elastic media as well as pressurized fractures.