Abstract: In this paper,dynamic elastic-plastic FEM analyses of a double notch thir plate subjected to the experimentally measured tensile pulse are presented.An invariant finite domain integral expression J(t)employed as dynamic energy release rate is calculated. The analysis demonstrate that J(t)integral can be regarded as the crack tip characterizing parameter for the double notch specimen used in Ref.1. we also calculate the value of the J_(dc)(t)integral from the measured load-calculated displacement curve by us...