GFRP materials under high-velocity impact loading

Depth of penetration experiments with long rods impacting GFRP blocks of different thicknesses with high velocities yield residual penetrations in a steel-backing which indicate the ballistic performance of the investigated target. The material-related ballistic protection performances of three composites are compared with those of ductile and brittle target materials. One of the major aims of this investigation is to separate the dependence of the material of a target layer on the protective power from the influence of its environment, e.g. confinement. A formerly introduced ballistic material parameter, called ductile limit of the equivalence factor, sufficiently describes the protective power of brittle and ductile target materials. This approximation is successfully applied to GFRP's. It has been found that the ballistic resistance of a thick GFRP block grows with increasing penetration depth. The penetration behaviour of these composites differs completely from that of ductile or brittle materials and thus makes GFRP materials interesting for light-weight armour applications. Additionally a material-related explanation for the growing ballistic resistance is given.