仿生类弧形层级蜂窝结构的耐撞性研究

Crashworthiness of Bionic Arc-Like Hierarchical Honeycomb Structure

蜂窝结构是目前应用最广泛的吸能结构之一,以益母草根茎、四方竹及蛛网为仿生原型,仿生设计一种类弧形层级蜂窝结构。采用简化超折叠单元理论推导出仿生类弧形层级蜂窝结构在轴向冲击载荷下平均碰撞力的解析值,通过数值模拟的方法验证了理论值的准确性,分析了层级数量与尺寸参数对结构耐撞性的影响。研究结果表明,增加层级数量可以有效降低类弧形蜂窝结构的峰值碰撞力,同时也可大幅度提高结构的平均碰撞力,1级与2级结构的平均碰撞力相比0级提升明显,分别提高了25.46%和29.98%;增加壁厚与壁长可以明显改善结构的耐撞性,其中,壁厚对结构平均碰撞力和比吸能的影响更加显著。

Honeycomb structure is one of the most widely used energy-absorbing structures.In this study,a bionic arclike hierarchical honeycomb structure is designed using motherwort rhizome,quadrangular bamboo,and spider web as bionic prototypes.The simplified super-folded unit theory is used to derive the analytical value of the average collision force of the bionic arc-like hierarchical honeycomb structure under axial impact load,and the accuracy of theoretical value is verified by numerical simulation to analyze the influence of layer number and dimensional parameter on the structural crashworthiness.The results show that the increase in layer number can effectively reduce the peak collision force of the arc-like honeycomb structure and greatly improve the mean collision force of the structure,and the mean collision force of the primary and secondary structures can be improved significantly by 25.46% and 29.98%,respectively,compared with that of the zero-level structure.The increase of the wall thickness and wall length can significantly improve the mean collision force of the structure,in which the wall thickness has more significant influence on the mean collision force and the specific energy absorption of the structure.