研究了面内冲击载荷作用下胞元微拓扑结构对蜂窝材料动态冲击性能的影响。首先,在胞元边长、厚度一致的条件下,讨论了不同形状胞元、以及胞元形状相同但排列方式不同的蜂窝材料的动态冲击性能,并给出了试件及其微结构的动态演化过程。在此基础上,讨论了胞元微观排列方式对蜂窝材料的能量吸收能力的影响。计算结果表明,除了胞元基本结构参数(边长、壁厚等),胞元形状及排布方式也是影响蜂窝材料动态性能的重要因素。由于三角形单胞的稳定性,三角形填充蜂窝材料与四边形填充蜂窝材料相比,表现出更强的能量吸收能力。而交错排布则对应着更加均匀的变形和稳定的平台区。同时,局部拓扑结构的变化,交错排布的试件在冲击压缩的过程中表现出独特的颈缩现象。此结论将为蜂窝材料微结构的动力学优化设计提供指导和依据。
Effects of cell micro-topology on the in-plane dynamic crushing properties of honeycombs were numerically studied. The dynamic crushing of the honeycombs filled with the differently micro-arranged ceils was discussed in case of these cells with the same side length and thickness. The full-scale deformation of the specimen and the micro-structure dynamic evolution were given. Influences of the cell micro-arrangements on the energy absorption mechanism of the honeycombs were clarified. Results show that except for the basic structural parameters (e. g. side length and thickness) of the cells, the cell shape and its arrangement pattern are important to determine the dynamic responses of honeycombs. Due to the structural stability of triangular cells, the honeycombs with triangular cells display stronger energy absorption ability than those with square cells. Stagger arrangement of the ceils yields to more uniform deformation and stable plateau stresses. Owing to the variation of the micro-topology, the honeycombs with the staggerly-arranged cells reveal particular necking phenomena during the in-plane crushing.