Development of button shear keys to improve the debonding resistance of sandwich composite panel

Abstract

Abstract In the composite sandwich panel, debonding between the foam core and face sheet is due to its inability to withstand shear loads. In the present study shear resistance capability of sandwich panel is enhanced by introducing button shaped shear key inserts in between facesheet and foam core. The sandwich panel is composed of glass fibre reinforced polymer (GFRP) skin with PVC (Polyvinylchloride) foam core impregnated with epoxy resin while the button keys are made up of chopped strands. By using the present methodology, the bonding of the facesheet and foam core of sandwich model will be improved by the participation of the core through button keys. Also, the button shapes distribute the stress concentration uniformly on the inner layer of the foam surface. Parametric finite element (FE) investigation using ANSYS software has also been performed to evaluate the foam core performance by the introduction of button shaped grooves in the foam material. The shapes of the button keys comprising of hemisphere, frustum and cylindrical shapes are analysed numerically and compared with experimental results.