A critical elastic strain energy storage-based concept for characterizing crack propagation in elastic–plastic materials

•The elastic strain energy storage concept is extended to characterize crack propagation in elastic–plastic materials.•A continuous loading–unloading method is utilized to eliminate plastic dissipation in designed experiments.•The critical elastic strain energy storage decreases linearly with the increase of crack length. This paper provides a new insight on the problem of crack propagation in elastic–plastic materials from the perspective of the critical elastic strain energy release rate Ge. Specifically, Ge is derived from the power balance during crack propagation with the elimination of plastic dissipation and is assumed available for new crack formation. To validate this assumption, a series of experiments are carried out. The results show that the critical elastic strain energy storage decreases linearly with the increase of crack length. Therefore, Ge is believed as a more intrinsic parameter to describe the crack propagation in elastic–plastic materials.