The effects of a random off-axis velocity component on the penetration achieved by long rod kinetic energy penetrators and shaped charge jets

Abstract

The impact of long rod kinetic energy penetrators and shaped charge jets on homogeneous targets is investigated. In particular the effects of a random off-axis velocity component on the penetration achieved are analyzed. The aim of this study is to consider the case where the off-axis velocity component takes a uniform value W along the rod or jet. It is assumed that penetration takes place according to the classical hydrodynamic penetration law, and that it continues either until the projectile material is exhausted or until a side wall collision occurs. The penetration is evaluated as a function of a reference coordinate q defined along the projectile, and the corresponding crater radius distribution R(q) calculated, on the assumption that W is zero. The locus of the penetration stagnation point S corresponding to the true value of W is then determined as a function of q and a revised crater profile is calculated with radius R(q), centred on S. We determine whether a side-wall collision occurs, and calculate the final penetration, P. The probability that P exceeds a given value P o is found. We then determine the expected value of P and investigate parameter variations to maximize this value.