Investigation on effect of the pitch of shear keys on the in-plane shear performance of sandwich panels with PU foam core: FE study

The main problem associated with using composite sandwich panels with foam core is their ability to withstand shear load. The techniques currently available to improve the shear performance and the skin-core debonding resistance of the sandwich structure, necessary for efficient and reliable design, have the drawback of significantly reducing the in-plane mechanical properties of the whole structure. The aim of the present work is to investigate the effects induced by inserting a semi-circular shear keys between the skin and the foam core to improve the in-plane shear response of the sandwich structure. Tension, compression and shear tests were performed for a complete static mechanical characterisation of the constituents of the sandwich. The mechanical properties of each component were used as input data in the finite element (FE) analysis using ABAQUS software. Parametric investigation using the FE analysis to select the most suitable pitch of the shear keys taking into consideration the material nonlinearity and the complex interaction between all the mating surfaces is performed. Five different pitches have been investigated namely 15, 25, 35, 45 and 55 mm. The results showed that the model with 45 mm pitch represents the most sustainable model among the others.