Damage characterization of titanium/GFRP hybrid laminates subjected to low-velocity impact

Low-velocity impact-induced damage in Ti/GFRP laminates as titanium-based Fibre-Metal Laminates (FMLs) was investigated to reveal the extent of internal damage in the in-plane direction and to evaluate the effects of titanium facesheets on impact damage in the GFRP core. It was found that interlaminar delamination in the GFRP layer expands widely due to crack initiation in the titanium layer on non-impacted side. However, matrix cracks and residual out-of-plane deformation are suppressed by energy absorption achieved by the bottom titanium layer. Furthermore, impact responses and damages obtained by finite element analysis with detailed modelling agree well with the experimental results. Thus, this study confirmed that the impact behaviour of the Ti/GFRP laminates is dominated by a fracture in the titanium layer on non-impacted side that fails in tension and that this layer plays a major role in preventing impact damages in the GFRP core.