Low-velocity Impact Behaviour of 3-D Glass Fibre Hollow Integrated Core Sandwich Composites

In the current work, 3-D glass fibre woven fabric-reinforced composites were fabricated by impregnating epoxy resin in a hand lay-up procedure for the hollow integrated core sandwich structure. Four types of 3-D structures were investigated in terms of the impact properties as a function of the z-direction fibre length (5, 6 and 7 mm) and covered skins (covered with aluminium) in core structures. Impact properties including peak load, time to peak load, and absorbed energy were evaluated. It was found that the 3-D hollow integrated core sandwich composites covered with aluminium skin considerably enhanced the impact resistance. Photographs of the impact damage taken after impact tests were analyzed and discussed in terms of a hollowing on the front face sheet against the load applied, and whitening spread in the impact point on the back face sheet of the composites was also studied.