In-plane shear behaviour of composite sandwich panel incorporated with shear keys methodology at different orientations: finite element study

The effect of introducing semi-circular shear keys in at the skin-core interface of the composite sandwich panels is illustrated numerically in the current study using ABAQUS software. Particularly, the effect of the shear keys orientation (shear grid), namely +/- 15 degrees, +/- 30 degrees, +/- 45 degrees, +/- 60 degrees and 90/0 degrees, on the shear response of the sandwich panel is introduced. Composite sandwich panels consisting of polyurethane foam core sandwiched between stiff glass fibre reinforced polymer skins were used, while chopped strand glass fibre impregnated with epoxy resin was utilized for the keys. The nonlinear finite element model was built to capture the shear response and the damage mode of the sandwich panel with the shear grid. The finite element model nominated the model with +/- 60 degrees grid orientation to be the most sustainable one among the other investigated models. In comparison to the model with shear keys in one direction (uni-axial model), the model with shear grid showed a significant reduction in the shear strength.