High strain rate damage sensing in intra-ply hybrid composites under dynamic shear loading

Abstract

An experimental study is performed to investigate the damage sensing in intra-ply glass/carbon hybrid composites at high strain rate shear loading conditions. A unique four circumferential probe measuring technique is used to measure the electrical response during dynamic shear loading. Double-notch specimen geometry is considered to investigate the electrical and shear behavior of composites. A split Hopkinson pressure bar apparatus in conjunction with high-speed imaging is used to conduct dynamic shear characterization. Glass fiber (GF) reinforced composites demonstrated elastic buckling and had a delayed crack initiation. However, no buckling is observed for intra-ply hybrid composites and the crack initiated much earlier than the GF composite. Orientation of glass and carbon fibers in intra-ply composites considerably influenced the dynamic shear strength and piezo-resistance sensitivity. Among the four intra-ply layups, alternating (+45o/-45o) layup of intra-ply composites show a high resistance sensitivity, and it improved significantly with an increasing strain rate.