Improving the mechanical performance and impact damage tolerance of glass composite laminates via multi-scales of hybridisation

The glass fabric composite laminates are widely used in the various applications compared to the non-crimp cross-ply laminates due to their high fracture toughness and better impact damage tolerance. However, their in-plane properties are limited owing to the interlacements of their warps and wefts. In this regard, an experimental investigation of the multi-scales hybridisation (i.e. yarns-hybridisation and hybrid layers methods) for improving the mechanical performance, and impact damage tolerance of continuous glass fibre-epoxy composite laminates has been presented. The two types of composite laminates that have intra yarns (i.e. hybrid yarns) and inter-ply (i.e. hybrid layers) with multi-stacking sequence were manufactured via vacuum infusion process and then compared with 2D hybrid fabrics and glass cross-ply composite laminates with respect to in-plane properties and impact damage tolerance respectively. The tensile strength properties and the low-velocity impact response of all laminates were identified by using tensile strength and drop-weight impact tests at different energy levels. The impact damage tolerance was studied by using compression-after-impact (CAI) strength tests, measuring the residual compressive strength of the damaged laminates. The damage characterisation based on impact and compression, and compression after impact was also examined using scanning electronic microscopy (SEM). The outcome of this investigation demonstrated that the intra- and inter-ply hybrid composite laminates showed higher tensile strength and modulus of elasticity, compared to hybrid fabric composites. Moreover, the impact damage tolerances of intra- and inter-ply hybrid laminates were found to be slightly higher than the non-crimp cross-ply glass laminates for certain-impact energy levels.