基于虾螯的仿生多胞薄壁管耐撞性分析及优化

Crashworthiness investigation and optimization of bionic multi-cell tube based on shrimp chela

为提高薄壁吸能结构的耐撞性,基于雀尾螳螂虾螯的微观结构,提出了一种新型含“人”字形仿生单元的多胞薄壁管结构。通过有限元模型仿真分析了不同碰撞角度θ(0°、10°、20°和30°)条件下,仿生单元高宽比η(单元高度A与宽度λ的比值)对薄壁管耐撞性的影响。结果表明:轴向(θ=0°)和小角度斜向(θ=10°)载荷碰撞条件下,仿生薄壁管均呈现渐进折叠变形,且θ=10°的薄壁管具有较大的比吸能Es和碰撞力效率Cf,以及较小的初始峰值载荷Fp。通过复杂比例法评价了薄壁管的耐撞性,η值分别为0.6~1.0和1.5~1.7时的薄壁管具有较好的耐撞性,仿生单元高宽比η最优值为1.5。采用多目标优化方法和多目标粒子群优化算法对不同碰撞角度工况的薄壁管结构参数进行了优化,最优结果是壁厚t为0.75~1.2 mm、单元宽度λ为5.5~9.5 mm、初始峰值载荷为59.8 kN、比吸能最大值为13.28 kJ/kg,该薄壁管仿生设计方法和优化方法为吸能元件的轻量化设计提供了新思路。

In order to improve the crashworthiness of thin-walled absorber, a new type of bionic multi-cell tube was designed based on dactyl club microstructure of O. scyllarus. The crashworthiness of bionic multicell tubes with different herringbone ratios η(the ratio of herringbone height A and width λ) were comprehensively investigated under different loading angles(θ =0o, 10o, 20o and 30o, respectively). The bionic multi-cell tube presents progressive folding deformation mode under axial(θ=0o) and small oblique loading angle(θ=10o). Compared with axial loading condition, the bionic multi-cell tubes have larger speci fi c energy absorption Esand crush force ef fi ciency Cf, but smaller peak crush force Fpwhen θ is 10o. A complex proportional assessment method was applied to solve this multi-criteria decision problem. The result shows that the bionic multi-cell tubes have superior crashworthiness when their η ranges from 0.6 to1.0, and from 1.5 to 1.7, and η=1.5 was selected the best sectional configuration herein. Following such optimal selection, a metamodel-based multiobjective optimization method based on polynomial regression metamodel and multiobjective particle optimization algorithm were adopted for the dimensions design of the optimal selection. The optimal parameters of thickness t ranges from 0.75 mm to 1.2 mm, element width λranges from 5.5 mm to 9.5 mm, the initial peak crush force Fpand maximum specific energy absorption Es is 59.8 kN and 13.28 kJ/kg, respectively. The bionic design and optimization method in this work hope to provide a reference for the lightweight design of thin-walled energy absorber.