Effect of Penetrator Size on Dynamic Failure Response of Woven Graphite Epoxy Composites around the Critical Perforation Energy

Abstract

Dynamic tests were carried out on plain weave carbon epoxy composite plates of different thicknesses, namely, 12, 16, and 24 layers (0.21mm∕layer) using a Penetrating Split Hopkinson Pressure Bar (P-SHPB). Protruding spherical penetrators of different sizes (3/16, 7/32 and 1/4-in.) were used to determine the perforation threshold energies for each woven specimen. The specimen damage thresholds considered in this paper are: below perforation limit (BPL), at perforation limit (PL), and above perforation limit (APL). Perforation limits (energy that must be exceeded to perforate or completely penetrate the specimen) were experimentally determined using P-SHPB. The results show that sample thickness and penetrator size play significant roles in the nature or extent of damage. The results also show that strain rate depends on both the striker impact energy, penetrator size, and the target thickness. Cracks were found to propagate faster in thin specimens in all the damage thresholds.