多层泡沫铝夹芯结构准静态压缩力学性能和吸能特性

Quasi-Static Compression Mechanical Properties and Energy Absorption Characteristics of Multilayer Aluminum Foam Sandwich Structure

采用闭孔泡沫铝和铝合金板制备单层夹芯板和6种多层夹芯结构。通过分析胞孔变形模式和宏观变形模式,研究了夹层板和芯层数量对结构准静态压缩力学性能和吸能特性的影响机制。结果表明:夹层板通过调节芯层间应力状态使芯层逐层坍塌,减少了由倾斜变形带形成和延伸所导致的多芯层同步变形、横向滑动以及两侧滑移,使结构具有更高的坍塌应力、平台应力、单位体积吸能量以及更小的致密应变;芯层数量的增加导致无夹层板结构中变形带的长度和数量增加,从而改变了其宏观变形模式,致使结构两侧滑移现象加剧,同时积累了有夹层板结构中多个芯层中的胞孔缺陷,因而影响了逐层稳定变形,导致致密应变增大,坍塌应力、平台应力和单位体积吸能量减小,致密应变处的吸能效率降低。与其他结构相比,三层泡沫铝夹层板具有最佳的抗压强度和吸能性能。

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 coll apse stress,platform stress,energy absorption per unit volume and smaller densification strain.The increase in the layer number leads to the increase in the length and number of the deformation bands in the structures without plate,and thus the macroscopic deformation mode changes,resulting in the aggravation of the slip phenomenon on both sides and the accumulation of cellular defects in the structures with plate,which affects the stable deformation and results in the increase in densification strain and the reduction of collapse stress,platform stress and energy absorption per unit volume,and thus the energy absorption efficiency at densification strain decreases.Compared with other structures,the three-layer structure with plates has the best compression resistance and energy absorption properties.