仿生树状分形薄壁结构的耐撞性研究

Crashworthiness of bionic tree-liked fractal thin-walled structures

为提高薄壁管结构的耐撞性,受树枝生长规律的启发,设计了两类树状分形的薄壁多胞结构。根据简化的超折叠单元理论,针对轴向压缩工况,建立仿生薄壁管的平均冲击力理论模型,采用有限元数值模拟技术,研究分形结构对薄壁结构耐撞性的影响。结果表明:理论模型可以有效地预测仿生薄壁管的平均冲击力,树状分形设计能够促进薄壁结构的变形稳定,高阶仿生薄壁管在比吸能、载荷效率等方面优于单胞方管,且随着分形阶数的增加,仿生管的能量吸收能力和变形稳定性进一步提升。

To improve the crashworthiness of thin-walled tube structures,two kinds of tree-like fractal thin-walled multicellular structures were designed,inspired by the growth law of branches.Based on the simplified super folding element theory,the theoretical model of the average impact force of bionic thinwalled tube is established for the axial compression condition.The influence of fractal structure on the crashworthiness of thin-walled structures is studied by finite element numerical simulation.The results show that the theoretical model can well predict the mean crash forces of the bionic thin-walled tubes,and high-order bionic thin-walled tubes are superior to the traditional square tube in terms of specific energy absorption and load efficiency,and the energy absorption capacity and deformation mode of the bionic tube are further improved with the increase of the fractal order.