Independent analytical technique for analysis of the flexural behaviour of the composite sandwich panels incorporated with shear keys concept

The current investigation presents an independent fibre-modelling approach for the analysis of the composite sandwich panels reinforced with shear keys methodology under static bending load. The sandwich panel under investigation is composed of glass fibre reinforced polymer skin with polyvinylchloride and polyurethane foam core, while the semi-circular shear keys inserts are made of chopped strand glass fibre impregnated with epoxy resin. The constituent materials were investigated through a series of quasi-static tests, while the flexural response of the sandwich panel with and without shear keys has been evaluated under four-point bending test. The experimental stress-strain curves of all the constituent materials were considered in the analytical model, while the total deflection is assumed to comprise two main components, one due to flexure and the other due to shear deformation. An incremental approach is used, where the concepts of force equilibrium and strain compatibility are satisfied in every loading step. The numerical procedure was executed using MATLAB code programming with the predictions of the damage mode. A significant improvement in the flexural stiffness and strength of the panel incorporated with shear keys accompanied with a good correlation with the analytical results were observed.