Perforation of FRP laminates under impact by flat-nosed projectiles

A theoretical study is performed herein on the perforation of fibre-reinforced plastic laminates subjected to impact by flat-nosed projectiles in a wide range of velocities. Ballistic impact on FRP laminates is a very complex problem and it can be generally classified into two categories, i.e. global deformation with local rupture and wave-dominated local failure. Simple analytical models for both global deformation failure as well as wave-dominated local failure are first given, and a shear failure criterion is employed to predict the perforation of FRP laminates which fail in global deformation mode. By combining the wave-dominated local failure model and the concept of Von Karman’s critical impact velocity, a condition for the transition of the above mentioned two failure modes is obtained. It is shown that the model predictions are in good agreement with available experimental observations in terms of ballistic limits and critical conditions for the transition of failure modes.