The use of coupled nonlocal damage-plasticity to predict crack growth in ductile metal plates

A nonlocal coupled damage-plasticity model is presented for predicting crack growth within plates made from a ductile metallic alloy. The damage law is explicitly defined in terms of the accumulated nonlocal plastic strain ensuring efficient numerical implementation. On the basis of this model, a UMAT for the finite element (FE) package ABAQUS (implicit) is developed. Thin plates of different geometries were modelled and analysed using this model, and the numerical stability of the model has been verified. The model shows the ability to capture the post-peak softening behaviour, shows mesh independence, and requires calibration of parameters against experimental data. The suitability of the model for crack path prediction is discussed.