Predicting the Penetration and Perforation of Targets Struck by Projectiles at Normal Incidence*

Engineering models are presented in this paper to predict the penetration and perforation of a range of targets struck normally by projectiles with different nose shapes over a wide range of impact velocities. The projectiles are either rigid or eroding and the targets are made of metallic materials as well as other materials such as fibre-reinforced plastics and concrete. The approach is based on the assumption that the mean pressure offered by the target materials to resist the projectiles can be decomposed into two parts. The first is a cohesive quasi-static resistive pressure due to the elastic–plastic deformation of the target materials. The second is a dynamic resistive pressure defined as a velocity-dependent enhancement factor applied to the quasi-static resistance. Equations are obtained for predicting the depth of penetration in the targets and the ballistic limits in the case of perforation. It is shown that the model predictions are in good agreement with available experimental data in the case of rigid missiles and that, in the case of eroding projectiles, the model correlates well with the experimental results for the nondimensional parameter (ρ/σ y )1/2 V i ranging from 3 to 7, which corresponds to initial impact velocities ranging from 1 km/s to 2.5 km/s, approximately.