Experimental and numerical study of low-velocity impact damage in sandwich panel with UHMWPE composite facings

This paper is concerned with the low-velocity impact (LVI) response behaviour of sandwich composite panels (SCPs) with ultra-high molecular weight polyethylene (UHMWPE) composite facings and Polyvinyl Chloride (PVC)/Polyethylene Terephthalate (PET) foam cores. A series of LVI tests with SCPs subjected to 50 J, 80 J and 110 J were conducted to examine their impact characteristics and damage mechanisms. LVI-induced internal damage in the SCPs were characterised by compute micro-tomography (mu CT) analysis. The effects of UHMWPE areal density and foam type on the LVI responses and associated failure modes of the panels were also examined. The experimental results showed that the SCP with a PET foam core exhibited higher impact strength and energy absorption performance than those of the panel with a PVC foam core. In addition, a finite element (FE) model incorporating the Puck's failure criteria, cohesive law and crushable foam plasticity model was developed and validated to predict the intra-and inter-laminar damages of SCPs. Finally, several failure mechanisms (fibre failure, matrix cracking and local delamination) of SCPs during LVI was thoroughly discussed. The results show the UH170-PET specimen has the best impact resistance and energy absorption performance. The parametric analysis of the areal density and foam type has revealed that these parameters can be optimised for the best LVI resistance of SCPs. These findings are helpful for designing lightweight foam-based sandwich composite structures with superior impact resistance.