Code for the Modeling of Shaped Charge

Abstract

A shaped charge is an explosive device used to penetrate thick targets using a high velocity jet. A typical shaped charge contains explosive material behind a hollow cavity. The hollow cavity can be lined by a matching metallic shape the purpose of which is to focus the energy of expanding gaseous products released during the detonation of high explosive thereby propelling the liner elements hydrodynamically forming a coherent elongated jet of liner material. In this study shaped charge jet parameters are calculated using indigenously developed one dimensional code and using copper liner of conical geometry. Although many codes are available in literature to study this phenomenon, this code has distinctive features to model the motion of liner elements due to explosive loading, jet formation, elemental strain and strain rate developed on each liner element, jet breakup time and target penetration through application of a series of analytical approximations. The shaped charge liner was treated as a series of liner points. The code used Gurney formulation assuming polytropic expansion of gaseous detonation products to predict the velocity of each liner point. The collapse angle of the liner was calculated using a modified Taylor Angle formulation. The shaped charge jet parameters were calculated using the Pugh-Eichelberger-Rostoker jet/slug formulation theory. Non-steady state hydrodynamic theory of jet formation was used to develop the code[2]. The structure of the code is intended to provide flexibility in shaped charge design and modeling techniques. It has the capability of being customized from the user’s/designer/explosive processing perspective, warhead fabrication point, so that improvisation can be done at development stage itself. To ease the calculations and save the time the code was written in C language. Developed code was validated for various jet parameters with experimental data available in literature[5], [11], [14] and the results were within the range of +10%.