A multi-level matching transformation and optimization design method for complex sections of thin-walled structures in steel/aluminum vehicle body skeleton was proposed. The problems of lengthy body performance numerical analysis and low optimization efficiency were solved by the rapid collaborative optimization of simplified cross-sections and performance of the body skeleton. A complex cross-sections shape library of thin-walled structures in steel/aluminum body skeleton and formulas for solving section mechanical properties were established, which overcame the difficulty of translating simplified cross-sections of thin-walled structures in steel/aluminum body skeleton to actual complex sections. A precise optimization method for complex cross-sections of thin-walled structure controlled by proportional vectors was established, which solved the defect that it was difficult to precisely control the arbitrary change of complex cross-section shape, and provided a new way for lightweight optimization design of complex cross-sections. The proposed method achieved the rapid collaborative design of steel/aluminum body thin-walled structure with complex cross-sections and body skeleton performance through multi-level progressive cross-section matching transformation and optimization. A body skeleton model with actual complex cross-sections was established, and compared with the initial simplified structure, the weight reduction ratio of the body skeleton was up to 6.9 %, and the performance indicators of the body skeleton fully met the design requirements, which verified the effectiveness of the proposed method.

中文翻译：

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钢/铝车身骨架薄壁截面多层次结构优化

提出了钢/铝车身骨架薄壁结构复杂断面多级匹配改造与优​​化设计方法。通过车身骨架简化截面与性能的快速协同优化，解决了车身性能数值分析冗长、优化效率低的问题。建立了钢/铝车身骨架薄壁结构复杂截面形状库及截面力学性能求解公式，克服了钢/铝车身骨架薄壁结构简化截面转化为复杂截面形状库的困难。实际的复杂部分。建立了比例矢量控制的薄壁结构复杂截面精确优化方法，解决了复杂截面形状任意变化难以精确控制的缺陷，为轻量化优化提供了新途径复杂截面的设计。该方法通过多级递进截面匹配变换和优化，实现了复杂截面钢/铝车身薄壁结构和车身骨架性能的快速协同设计。建立了实际复杂截面的车身骨架模型，与初始简化结构相比，车身骨架减重比例高达6.9%，车身骨架的各项性能指标完全满足设计要求，验证了所提出方法的有效性。