Influence of gradient metallic cellular core on the indentation response of sandwich panels

The characteristics of gradient metallic cellular materials vary along its thickness direction. Under quasi-static compression, the crushing stress of gradient cellular materials cannot be simplified as a constant before the cellular materials are all crushed. To calculate the crushing stress of gradient metallic cellular material, a new formula associate with strain hardening for gradient cellular materials is presented. Subsequently, an analytical model is developed to investigate the plastic indentation response of the sandwich panel with gradient metallic cellular core. Finite element (FE) simulation is carried out in order to verify the analytical results. Finally, the influences of gradient cellular cores with equivalent mass, in which two types of gradients: Linear mass density and linear plateau stress distributions are considered, on the response of sandwich panels are further investigated. And the results show that the plastic energy due to compressive deformation of the gradient cellular core with the linear mass density is larger than that of the gradient cellular core with linear plateau stress under the same indentation.