Numerical simulation study on detonation effect of fragment impact covered explosive

In order to reveal the detonation effect and mechanism of covered explosive under fragment impact, based on one-dimensional shock wave theory, a theoretical model of fragment impact detonation of covered explosive is established. Combined with numerical simulation, the influence of key parameters such as fragment material, fragment shape and charge shell thickness on the detonation threshold velocity and the influence of fragment velocity on the detonation time and depth of covered explosive are obtained, and the mechanism of fragment on the detonation effect of covered explosive is revealed. The results show that the shock initiation effect of tungsten alloy fragments is better than that of 45# steel fragments. The shock initiation effect of cubic fragments is better than that of spherical fragments. When the thickness of charge shell is thin, it is the impact detonation mechanism. When the charge shell is thick, the impact detonation mechanism and the shear detonation mechanism coexist. The detonation time and detonation depth of explosives decrease with the increase of velocity, and the detonation time is proportional to the detonation depth.