Crack extension energy rate and energetic approaches in elastic - plastic fracture mechanics

In this paper, an overview on energetic approaches in Elastic -Plastic Fracture Mechanics is given, based on the energy balance proposed by Griffith. This energy balance was originally applied to obtain the Energy Release Rate at the incipient crack propagation for elastic/brittle materials and, later on, adapted to elastic materials with small scale yielding by Irwin. The theoretical bases of these approaches are discussed, remarking possible drawbacks when used as crack-driving force during quasi-static crack growth in ductile materials.