仿生多胞薄壁管耐撞性分析及优化

为提高薄壁管结构耐撞性，以雀尾螳螂虾螯为仿生原型，结合仿生学设计方法，设计一种含正弦胞元的多胞薄壁管结构。以初始峰值载荷、比吸能和碰撞力效率为耐撞性指标，通过有限元数值模拟分析了不同碰撞角度（0o、10o、20o和30o）条件下，仿生胞元数对薄壁管耐撞性的影响，通过多目标的复杂比例评估法获取仿生薄壁管的最优胞元数。基于不同碰撞角度权重因子组合，设置了4种单一角度工况和3种多角度工况，采用多目标粒子群优化方法获取了不同工况下薄壁管结构最优胞元高宽比和壁厚。复杂比例评估结果表明，胞元数为4的薄壁管为最优晶胞数仿生薄壁管。优化结果表明，单一角度工况下，最优结构参数高宽比的范围为0.88～1.50，壁厚的范围为0.36～0.60 mm，碰撞角度为0o和10o的最优高宽比明显小于碰撞角度为20o和30o的；多角度工况下，最优高宽比范围为1.01～1.10，壁厚范围为0.49～0.57 mm。

Crashworthiness analysis and optimization on bio-inspired multi-cell thin-walled tubes

To improve the crashworthiness of thin-walled tube structures, a series of bio-inspired multi-cell thin-walled tubes with sinusoidal cells (abbreviated BSTs) were designed based on the dactyl club microstructure of Odontodactylus scyllarus (O. scyllarus) using bionic design methods. By taking initial peak load, specific energy absorption and crushing force efficiency as crashworthiness indexes, the influences of cell numbers on the crashworthiness of the BSTs under different impact angles (0o, 10o, 20o and 30o) conditions were analyzed under low-velocity impact condition using the nonlinear finite element (FE) method through LS-DYNA. The optimal number of bionic cells was obtained using complex proportion assessment. A complex proportional assessment (COPRAS) method was used to select the optimal number configuration under multiple loading angles. Base on the combination of weight factor values of different impact angles, four single-angle cases (1–4) and three multi-angle cases (5–7) were set. A metamodel-based multi-objective optimization method based on polynomial regression (PR) metamodels and a multi-objective particle optimization (MOPSO) algorithm were employed to optimize the dimensions of the optimal cell number configuration, where the initial peak load, specific energy absorption and crushing force efficiency were taken as objectives and the height-width ratio and thickness were regarded as the design variables. According to the results of the COPRAS method, the BST with four sinusoidal cells was determined to be the best design based on the multi-criteria process. The optimization results of single-angel cases show that, the optimal height-width ratio ranges from 0.88 to 1.50, and the optimal thickness ranges from 0.36 mm to 0.60 mm. The optimal height-width ratios of cases 1–2 are significantly smaller than those of cases 3–4 . The BST with four sinusoidal cells has the maximum optimal thickness of 0.6 mm when the impact angles is 0o. For multi-angel cases, the optimal height-width ratio ranges from 1.01 to 1.10, and the optimal thickness ranges from 0.49 mm to 0.57 mm. The results above are helpful for exploring the lightweight design of new thin-walled tube structures and providing new ideas for their application in energy absorption and crashing field.