Impact Damage Modes and Residual Flexural Properties of Composites Beam

The damage evolutions under low velocity impact were investigated using epoxy composite beams reinforced by S-2 glass, basalt, and Twaron 1000 fiber (identified as GFRP, BaFRP, and AFRP, respectively). GFRP showed a mutational damage mode, while BaFRP and AFRP represented a progressive one. The damage modes, the reductions in flexural strength and modulus in the direction of the impact face and the back face were compared based on the difference in fiber properties combined with fractography. The dominant factors for damage evolution were analyzed. There existed critical impact energy for initial damage, standing for the change in damage mode and dividing the post-impact flexural properties variation into two linear parts.