Theoretical Analysis on Shock Initiation of Performed Fragment to Uncovered Explosive

To research the laws of spherical, cylindrical, and regular prismatic preformed fragments initiating uncovered explosives, we adopted Mathcad software and the u²d criterion of Held to do the theoretical calculation and analysis.Influences of the preformed fragments' quality, density, shape, length to diameter ratio, and the number of edges were intercompared emphatically and were compared with the simulation results of AUTODYN.The results show that, for spherical fragments, when the diameter is certained, the initiating ability enhances as the density (or mass) of fragments increases; for spherical fragments and cylindrical fragments with a length to diameter ratio of 1, with the same material and diameter, the initiating ability of cylindrical fragments is better than that of spherical ones; for cylindrical and prismatic fragments of the same density and quality, as the length to diameter ratio increases, the fragments' initiating ability decreases; as the number of edges of regular prism fragment increases, the initiating ability decreases, when the edge number approaches infinite, its initiating ability converges with that of the corresponding cylindrical fragment.