Numerical validation of a new energetic fracture criterion in elastic-plastic fracture mechanics for aluminium alloys

The paper deals with numerical studies of two-dimensional quasi-static crack growth problems, for elastic-plastic materials with isotropic harening behaviour. In particular, the fem analyses regard centre-cracked panel, CCP, specimens, made of Al2024-T3 alloy, subjected to monotonic increasing load histories, without any constraint about the intensity of the deformation. The main result of these studies is a new fracture criterion, based on the fracture property of the Energy Momentum Tensor; during a quasi static crack propagation, the trace of the Energy Momentum Tensor, evaluated at the current crack tip, reaches a value independent of the crack length. Based on this property, the proposed fracture criterion allows us to describe the crack growth resistance curve (load versus crack extension) of aluminium alloys, in a good agreement with experimental tests.