Reworking a Simple Model for Deformable Projectile Penetration Into Thick Targets

Abstract

Target penetration by deformable projectiles is considered in the context of an established onedimensional theory based on the fundamental balance laws of continuum mechanics. The paper critically reviews the assumptions of this simple analytical model and discusses the material characteristics that influence resistance to penetration. A novel representation of the resisting force is introduced into the original analysis leading to the evaluation of the crater size in addition to other critical output such as depth of penetration and the time history of the impact force over a relevant range of impact energies. An algorithm for a time step integration of the resulting system of differential equations is proposed; this is numerically implemented through a FORTRAN code whose effectiveness and reliability are tested against experimental data from the technical literature. This comparison leads to rational and consistent estimates for the empirical factors adopted in the simplified modelling. The time histories of impulse provided by the computer implemented analysis can be used for the assessment of the effect of the transmitted shock on the supporting structure and its appendices.