Issues in modelling the penetration of thick targets by rigid long rods

Abstract

The spherical cavity expansion model has been widely implemented in approximate methods for penetration analysis. These penetration methods include simplifying assumptions, and provide a simple and fast means to predict the deceleration, velocity and depth of a penetrating projectile. Several of these methods include empirical parameters that should be calibrated with test data, and others do not require any calibration. In a recent paper, Warren presented a complete analytical derivation of a model with emphasis on the importance of the target inertia and its effect on the total target resistance to penetration. In recent years, Rosenberg et al. have presented another approximate approach, stating that the target resistance to penetration is constant and denied the contribution of target inertia to the total resistance. Rosenberg et al. criticize other approaches, and attempt at demonstrating the flaws in the other methods and prove the superiority of their approach.This paper aims at examining the key features of Warren's and Rosenberg et al. approaches, and address the key critical remarks, in order to clarify issues under dispute and contribute to the ongoing discussion on this important topic. This study refutes Rosenberg et al. remarks and raises doubts regarding the key assumptions of their approximate approach.