Penetration and perforation of FRP laminates struck transversely by conical-nosed projectiles

A theoretical study is presented herein on the penetration and perforation of fibre-reinforced plastic (FRP) laminates struck normally by conical-nosed projectiles over a wide range of velocities. The formulations are based on the assumption that the deformation is localized and that the pressure offered by the laminate targets to resist the projectiles is velocity dependent which can be divided into two parts: a quasi-static part due to the elastic–plastic deformation of the laminate materials and a dynamic part due to penetration velocity. Equations are obtained for the depth of penetration, residual velocity, and ballistic limit. Transient response is solved numerically in terms of time-histories of displacement/penetration, velocity and deceleration. It transpires that theoretical predictions are in good agreement with available experimental results.