多胞薄壁结构优化及结构参数对耐撞性影响分析

Optimization of multi cell thin-walled structures and analysis of the impact of structural parameters on crashworthiness

为提高多胞薄壁结构的轴向耐撞性,基于动态拓扑优化得到薄壁结构在轴向冲击下的最优截面构型,设计了一种混合多胞薄壁结构(mixed multicellular thin-walled structure, MMTS)。运用有限元方法,对比了混合多胞薄壁结构与基于经验设计的窗型多胞结构及仿生树状分形结构在轴向冲击下的耐撞性能。为了进一步提高材料利用率,以结构尺寸为设计变量进行多目标优化。在此基础上,对结构进行水平截面一次变壁厚分析,获得耐撞性能随壁厚的变化趋势。研究结果表明:混合多胞薄壁结构相比等质量窗型多胞结构、树状分形结构耐撞性能大幅提高;与初始设计的MMTS相比,优化后比吸能增加了45.78%,质量降低7.14%,吸能过程更平稳。

In order to improve the axial crashworthiness of multi cell thin-walled structures,this paper proposes a hybrid multi cell Thin-walled Structure(MMTS)based on dynamic topology optimization to obtain the optimal cross-sectional configuration of thin-walled junctions under axial impact.The finite element method was used to compare the crashworthiness of hybrid multi cell thin-walled structures with window shaped multi cell structures and biomimetic tree shaped split structures designed based on experience under axial impact.In order to further improve material utilization,multi-objective optimization is carried out using structural dimensions as design variables.On this basis,a variable wall thickness analysis of the structure's cross-section is conducted to obtain the trend of impact resistance performance with wall thickness.The research results indicate that the collision resistance of mixed multi cell thin-walled structures is significantly improved compared to equal mass window type multi cell structures and tree shaped split structures.Compared with the initial design of MMTS,the optimized MMTS has increased specific energy absorption by 45.78%,reduced mass by 7.14%,and a smoother energy absorption process.