Abstract:Single-layer sandwich panels and six kinds of multilayer sandwich structures were prepared using closed-cell aluminum foam and aluminum alloy sheets. The cellular and macroscopic deformation modes were analyzed to study the influence mechanism of the plates and layer number on the quasi-static mechanical properties and energy absorption characteristics. The results show that the plates can adjust the stress state and make the cores collapse layer by layer, which reduces the multilayer synchronous deformation, lateral and bilateral slip caused by the formation and extension of the inclined deformation bands, so that the structure has higher collapse stress, platform stress, energy absorption per unit volume and smaller densification strain. The increase of the layer number leads to the increase of the length and number of the deformation bands in the structures without plate, thus changes the macroscopic deformation mode, results in the aggravation of the slip phenomenon on both sides, leads to the accumulation of cellular defects in the structures with plate, affects the stable deformation, results in the increase of densification strain, the reduction of collapse stress, platform stress and energy absorption per unit volume, and the decrease of energy absorption efficiency at densification strain. Compared with other structures, the three-layer structure with plates has the best compression resistance and energy absorption properties.