Theoretical Study on the Penetration and Perforation of FRP Laminates Struck by Cone-Nosed Projectiles

The penetration and perforation of FRP laminates struck transversely by cone-nosed projectiles has been theoretically investigated. Based upon the assumption that the deformation is localized, 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. Furthermore, Wen's model has been developed by assuming that the resistance of the FRP laminate is no longer a constant, but a function of penetration velocity. Equations are obtained for predicting the depth of penetration, the residual velocity and the ballistic limit in the case of perforation. It transpires that the theoretical predictions are in good correlation with available experimental data in terms of penetration depth, residual velocity and ballistic limit.