Influence of shear keys orientation on the shear performance of composite sandwich panel with PVC foam core: numerical study

The present study explores the effect of introducing shear key inserts between the face sheet and the foam core of the composite sandwich structure on the shear performance. Parametric finite element (FE) investigation using ABAQUS software has been performed to evaluate the effect of the shear key orientation (bi-axial model) on the shear response and the failure mode of the composite sandwich panel under in-plane shear load and comparing the results with the zero orientation shear key model (uni-axial). Polyvinylchloride (PVC) foam has been used as a core material which sandwiched between two thin strong face sheets of glass fibre reinforced polymer (GFRP) to build a high performance sandwich panel. Chopped strand glass fibre (CS) impregnated with epoxy resin was used as shear key material. A comprehensive material testing program was first carried out on the constituent materials in order to characterise its elastic response under different types of load. Different orientations of the shear keys, namely ±15°,±30°,±45°,±60° and 90/0°, have been investigated. The FE results showed an improvement in the initial stiffness and ultimate stress of the sandwich panel as a result of introducing the shear keys. The FE model precisely captured the failure mode and demonstrated that the model with ±60° was the most sustainable model among the other bi-axial models. In comparison with the bi-axial model, uni-axial model offered a remarkable enhancement in the shear performance compared with the bi-axial model and accordingly selected for the future investigation.