Effect of Powder Liner’s Density Distribution on Perforation Performance

In order to study the influence of the density distribution of the liner on the jet velocity gradient and the penetration performance, two numerical models of the typical density distribution of the powder liner were established. One is the uneven distribution of the axial density of the powder liner, and the other is the uneven distribution of circumferential density of the powder liner. The LS-DYNA software was used to calculate the multi-condition numerical values, and the shape, velocity gradient distribution and penetration depth of the jet are obtained. The jet velocity and the depth of the perforation are calculated and analyzed in combination with the quasi-steady theory of fluid mechanics and the virtual origin concept. The results show that the axial density of the powder liner has a certain increase on the jet shape and penetration depth. The density of the powder liner is unevenly distributed in the circumferential direction, and the jet has a tendency to deflect toward high density. Introduction As the core component of the shaped charge warhead, the powder liner is of concern for the quality and end effect of the jet under the explosive load. For example, delaying the breaking time of the jet [1], the petroleum perforating bullet has no corpus callosum and high penetration depth [2], increasing the mass ratio of the jet-type mask and increasing the driving ability of the powder liner. [3]. The design of the powder liner is close to the bottleneck, and the potential for excavation is small. Therefore, researchers at home and abroad have turned their attention to the application of new materials and new processes in the formation of the powder liner. The powder metallurgy liner is widely concerned because of its flexible material ratio, simple processing technology, high jet penetration depth and large pore surface area [4], and largely avoiding the phenomenon of plugging. However, the powder liner prepared by the pressing process generally has a problem of uneven density distribution in the axial/circumferential direction. In this paper, based on the above background, the axial/circumferential density distribution of the powder liner is uneven. The LS-DYNA finite element analysis software was used to carry out numerical simulation research, in order to provide theoretical basis for the shape, velocity gradient and penetration performance of the jet caused by uneven density distribution of the powder liner, and to provide reference for other related research. Theoretical Analysis According to the Allison and Vitalit hypothesis [5], there is a virtual source as the starting point of all jets, the jet velocity is linearly distributed along the axis, and the velocity of the jet micro-element does not change during the motion [6]. Therefore, the calculation formula for the penetration depth of the jet is International Conference on Modeling, Analysis, Simulation Technologies and Applications (MASTA 2019) Copyright © 2019, the Authors. Published by Atlantis Press. This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/). Advances in Intelligent Systems Research, volume 168