MECHANICAL PROPERTY CHARACTERIZATION OF FOAM-FILLED HIERARCHICAL ORTHOGONAL CORRUGATED SANDWICH STRUCTURE

The static mechanical properties of foam-filled hierarchical orthogonal corrugated sandwich structure were investigated through theoretical analysis and finite element (FE) simulation. Based on the representative volume element (RVE), the relative density of the sandwich core was calculated. An analytical model was developed in order to predict mechanical properties of the sandwich structure under out-of-plane compressive and in-plane shear loadings. Considering effects of geometric dimensions of the sandwich cores, FE model of the foam-filled hierarchical orthogonal corrugated sandwich structure was established and FE simulations were performed. The analytical predictions are in good agreement with FE simulations. It is shown that both equivalent stiffness and equivalent yield strength of the sandwich structure increase with the corrugation angle, while decreasing with increasing foam core thickness. The equivalent buckling strength, however, increases with both inclination angle and core thickness of corrugated sandwich structure. A competition between the yield and the buckling failure modes was observed. The failure of the sandwich structure under tensile-shear loading is dominated by the yield, whereas the compression-shear loading may lead to the buckling failure. These results will provide a significant theoretical basis for the optimization designs of key parameters of the foam-filled hierarchical orthogonal corrugated sandwich structure.