A procedure for the simulation of fatigue crack growth in adhesively bonded joints based on the cohesive zone model and different mixed-mode propagation criteria

This work deals with the simulation of the fatigue crack growth (FCG) in bonded joints. In particular a cohesive damage model is implemented in the commercial software Abaqus, in order to take into account for the damage produced by fatigue loading. The crack growth rate is evaluated with different Paris-like power laws expressed in terms of strain energy release rate. The crack growth rate is then translated into a variation of the damage distribution over the cohesive zone setting an equivalence between the increment of crack length and the increment of damage. The model takes also into account mixed mode I/II conditions. In this work the validity of the model is tested by comparison with theoretical trends for conditions of pure mode I, pure mode II and mixed mode loading. In the case of mixed mode conditions, different models are implemented for the crack growth rate computation. The results of the model are in very good agreement with the expected trends, therefore the model is adequate to simulate the fatigue crack growth behaviour of bonded joint.