Abstract：By introducing a cohesive fracture model into the Mott[1] momentum diffusion analysis, Grady and Kipp[2] deduced a formula for predicting the average size of the fragments during a ductile fragmentation process. To quantitatively evaluate the accuracy of the Grady-Kipp formula, in this paper, we numerically simulated the fragmentation processes of an elastic-plastic bar undergoing initially uniform high strainrate tensile deformation. The key material parameters, including the fracture energy , the material density , and the strainrate sensitivity c, were varied intentionally for evaluating their effects on the fragmentation process. The average fragment sizes were calculated for a wide range of the prescribed strainrates and the material parameters. It was concluded that the Grady-Kipp model provides reasonably close predictions of the ductile fragment size, though slight deviations exist in the cases when the fundamental assumptions in the Grady-Kipp analysis do not apply.
2012, Vol. 33 
