Impact damage characteristics in reinforced woven natural silk/epoxy composite face-sheet and sandwich foam, coremat and honeycomb materials

This research is interested in the impact toughness of a reinforced composite face-sheet and cores materials used in lightweight sandwich panels. It investigated the degrees of damage inflicted on the contact surface, through thickness and rear surface of the sandwich panels. The sandwich specimens were prepared in configurations of natural silk (NS)/Epoxy/Foam, NS/Epoxy/Coremat, NS/Epoxy/Honeycomb and reinforced NS/Epoxy serving as referral. For all experiments, drop weight impact test was carried out under low velocity impact energies of 32 J, 48 J and 64 J. Parameters measured were load bearing capability, energy absorption capability and damage fragmentation of the specimen with regards to increasing impact loads. Dominant deformation modes were seen as upper face-sheet compression failure, lower face-sheet delamination and lower face-sheet tensile failure.

► We examined the impact response of woven natural fibre sandwich. ► Load bearing, energy absorbing capabilities and failure mechanisms were investigated. ► Dominant deformation modes involved face-sheet failure. ► Mechanism of failure was combination of fibre-matrix debonding, fibre breakage and interlaminar matrix cracking.