Penetration and perforation of FRP laminates under normal impact by ogival-nosed projectiles

The penetration and perforation of FRP laminates impacted by ogival-nosed projectiles at normal incidence were examined. Based on the assumption that the deformation is localized and that the mean pressure offered by the laminate targets to resist the projectiles can be decomposed into two parts: one part is a cohesive quasi-static resistive pressure due to the elastic-plastic deformation of the laminate materials and the other is a dynamic resistive pressure arising from velocity effects, a new formulation is developed by extending Wens model by assuming that the target resistance is no longer a constant, but a function of the penetration velocity. Equations are obtained for predicting the depth of penetration in the FRP laminate targets, the residual velocity and the ballistic limit in the case of perforation. It is shown that the theoretical predictions are in good correlation with available experimental data.