Void growth and damage models for predicting ductile fracture in welds

This study reports on a numerical and experimental investigation of ductile tearing using a local approach to fracture. Two models have been analysed: (i) the Rice-Tracey (RT) void growth model; and (ii) the Rousselier contin uum damage theory. The effects of the model parameters, including the mesh size, on the crack growth behaviour have been analysed, and a significant i nfluence on both the J-values and the slopes dJ/dn has been noted. The crac k propagation in an overmatched welded joint has also been investigated. Fo r the RT model, crack propagation has been simulated using the release node technique. Because this method requires one to previously assign the crack propagation path, using such a model is somewhat restrictive. This problem vanishes when dealing with Rousselier's model (and more generally with cou pled models) because the elements which are damaged automatically give the crack path.