Fragment Distribution of Prismatic Casings under One-End Detonation Conditions

As a typical non-cylindrical structure, prismatic casings with semi-preformed fragments are significantly important for the structural design and damage efficiency evaluation of innovative warhead. The velocity and scattering angles of the fragments are important parameters in warhead design and safety protection. However, the vast majority of existing fragment velocity formulas have been proposed for cylindrical casing, and few formulas exist for calculating the scattering angle applicable to prismatic casing. In this study, through theoretical analysis, the fragment velocity formula for prismatic casing was derived, and further, the fragment scattering angle formulas were proposed, which include both the radial scattering angle and the axial scattering angle. Then the rationality of the formulas were validated by numerical results which had been verified experimentally. Finally, on the basis of the formulas and orthogonal analysis, the influence laws of dimensionless geometric parameters on the scattering angle and specific kinetic energy of the fragments were obtained, and the primary and secondary orders of the influence of each parameter on the scattering angle and the specific kinetic energy were determined, respectively. The results in this work provided an important foundation for further research on the prismatic metal casing and other kinds of asymmetric casings. It was also a reliable reference for engineering design of innovative warheads.