Fracture Modelling of Crack Propagation in Steel

In the present study, an interface element with softening and hardening series springs is used to model crack growth in steel. These series spring elements are developed to obtain the strain energy release rates based on the virtual crack closure technique (VCCT). Two nonlinear springs are proposed to be placed between interfacial node pairs. A spring element with softening behaviour and another spring element with hardening behaviour are placed in series at the crack tip between two nodes to calculate the internal forces. Therefore, with these springs, strain energy release rates can be calculated directly. Also, with the implementation of fracture criteria, crack growth can be also analyzed. The model decreases computational time and complexity for analysing discrete cracks. The model is easy, accurate, and independent of the mesh size.