Study of linear shaped charge (LSC) jet penetrating layered targets

Abstract

This paper presents the results of an experimental and numerical study conducted to investigate the mechanism of penetration of linear shaped charges (LSCs) into double layered targets. A type of LSC causing less collateral damage in terms of jet residues was studied. The LSC consisted of a linear liner and case with the depth to diameter aspect ratio of 2.0. Anti-theft doors and spaced steel plates were used to represent double layered targets. The anti-theft door and the equivalent targets were penetrated with little jet residues behind the exit crater. The experiments were simulated using the commercially available software AutoDYN as a 2-D planer symmetry FEM model of the LSC penetrating a double layered target. An Eulerian mesh was used to model the LSCs whilst the double layered target was modelled using a Lagrangian mesh. A fully coupled algorithm was used for two different meshes. The data from the experiments (the shape of the breach and jet residues) were used to validate the numerical model. The validated numerical model was used to gain insights into the penetrating mechanisms of the LSC. The numerical results indicated that the penetration mechanisms of the two layers target were different. The first layer was penetrated by a continuous jet typical of a high-speed jet whereas the second layer was perforated by both a jet tip and slug characterized by a low-impact velocity projectile (slug).