Fragments dispersion characteristics of the casing with the mismatched shell under internal explosive loading

The shell of the conventional casings filled with explosives is often in a good matching state with the charged explosive, but the conventional casings cannot meet the needs of the design of innovative warheads. To further improve the control capability for fragment dispersion characteristics of fragment warheads, the concept of the casing with the mismatched shell is proposed and studied in this paper. This kind of casing is composed of a cylindrical explosive and an asymmetric shell. A typical casing with the mismatched shell is designed, and the fragment dispersion characteristics of the casing are experimentally obtained using X-ray radiography technology and witness target test technology. It is found that the flying direction of fragments from the casing is consistent with the normal direction of the shell, and the fragment dispersion density in a direction is significantly improved. The particular fragment dispersion characteristic of the casing is verified, and the effects of eccentric initiation and shell strength on the fragment dispersion characteristics of the casing are analyzed by numerical simulation. The numerical results show that the shell strength has little effect on the special fragment dispersion characteristics of this kind of charged casing. By controlling the position of the initiation point, the fragments in a specific direction can be concentrated to achieve the fragment directional killing. The findings herein could serve as a solid foundation for the engineering design of innovative fragment warheads and could also be a reference for the hazard assessment of Improvise Explosive Devices (IEDs).