Penetration and perforation of thick FRP laminates

Analytical equations are given for the prediction of the penetration and perforation of thick FRP laminates struck normally by missiles over a wide range of impact velocities. The missiles have different nose shapes (i.e. truncated, conical, flat, ogival and hemispherical). The formulation is based on the assumption that the deformations are localized and that the mean pressure offered by the FRP laminate targets to resist the missiles consists of two parts. One part is a cohesive quasi-static resistive pressure due to the elastic-plastic deformation of the laminate materials. The other is a dynamic resistive pressure arising from velocity effects. Analytical equations are derived for the depth of penetration (DOP) in the FRP laminate targets and the ballistic limits in the case of perforation. It is shown that the theoretical predictions are in good correlation with available experimental data. Glass-polyester composites are example.