Effect of shear keys diameter on the shear performance of composite sandwich panel with PVC and PU foam core: FE study

The present paper addresses the most dominant failure mode of composite sandwich panels with foam core, where the prevention and limitation of debonding failure between skin and core is highly important design issues. This paper presents a semi-circular shear keys inserting between the skin and the foam core to improve the shear performance and skin–core debonding resistance for sandwich panels with foam core. Polyvinylchloride (PVC) and polyurethane (PU) foam core are chosen for the current study and sandwiched between glass fibre reinforced polymer (GFRP) skins, while the chopped strand (CS) glass fibre impregnated with epoxy resin is used for the shear key. A parametric investigation on the effect of the shear keys diameter on the in-plane shear performance has been performed numerically. In order that, a comprehensive experimental testing program was performed on the constituents to obtain the basic parameters used in the finite element (FE) model. The FE model of the ordinary sandwich panel was validated experimentally and proved its capability to represent the shear response of the sandwich panel. The suggested design was numerically investigated to select the most effective diameter for the shear key under in-plane shear load. For all investigated sandwich model configurations the suggested shear keys were able to stop skin–core debonding and to redirect it to diagonal orientation with a significant improvement in the overall shear performance.