Simulation of ductile crack initiation and propagation by means of a non-local Gurson-model

In the present study a non-local GTN-model in an implicit gradient-enriched formulation is employed to simulate ductile crack growth under small-scale yielding conditions numerically. The problem in handling full material failure in a non-local damage model is pointed out. An approach is presented to deal with this problem and a numerical implementation is derived. This technique allows to simulate large amounts of crack growth. The results show that the model captures correctly the states of initial crack tip blunting, crack initiation and crack propagation if a sufficiently fine mesh is used. A systematic parameter study is performed. On this basis, a procedure to determine the model parameters from experiments is proposed.