汽车工程 ›› 2023, Vol. 45 ›› Issue (11): 2157-2164.doi: 10.19562/j.chinasae.qcgc.2023.11.017

所属专题: 车身设计&轻量化&安全专题2023年

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副车架静刚度修正方法及多层级拓扑优化

苏永雷1,2,张志飞1()   

  1. 1.重庆大学机械与运载工程学院,重庆 400030
    2.上海小米智能技术有限公司,上海 200000
  • 收稿日期:2023-03-22 修回日期:2023-05-24 出版日期:2023-11-25 发布日期:2023-11-27
  • 通讯作者: 张志飞 E-mail:z.zhang@cqu.edu.cn
  • 基金资助:
    国家自然科学基金(51875060)

Correction Method of Static Stiffness and Multi-level Topology Optimization for Subframe

Yonglei Su1,2,Zhifei Zhang1()   

  1. 1.College of Mechanical and Vehicle Engineering,Chongqing University,Chongqing  400030
    2.Shanghai Xiaomi Intelligent Technology Co. ,Ltd. ,Shanghai  200000
  • Received:2023-03-22 Revised:2023-05-24 Online:2023-11-25 Published:2023-11-27
  • Contact: Zhifei Zhang E-mail:z.zhang@cqu.edu.cn

摘要:

本文构造副车架静刚度与K&C性能的并行仿真流程,提出考虑多学科性能耦合的副车架静刚度目标修正方法,并系统地建立一体式空心铸铝副车架分层级设计优化方法。首先,建立副车架计算模型并改进加载方法,提出局部坐标系下的静刚度计算方法,并集成副车架静刚度分析、模型缩减分析、K&C性能分析3种工况,执行多样本分析并通过实验设计矩阵转换,构建K&C性能与静刚度性能的组合代理模型,基于组合代理模型利用K&C性能修正静刚度目标;其次,开展多性能约束的副车架多层级拓扑优化,通过第1层级拓扑优化完成等壁厚主体结构设计,通过第2层级拓扑优化完成变壁厚结构设计。结果表明:经过多层级拓扑优化的副车架1阶、2阶扭转模态分别提升39.3%、14.9%,静刚度及K&C性能满足目标要求,其他各项性能指标均得到显著提升且实现轻量化。本文可为副车架静刚度性能目标制定、K&C性能提升及副车架结构优化提供参考。

关键词: 副车架, 静刚度, K&C性能, 拓扑优化, 多性能约束

Abstract:

Based on the construction of the parallel simulation process of the static stiffness and K&C performance of the subframe, a correction method for static stiffness of subframe considering the coupling of performance is proposed, and a hierarchical design optimization method for the aluminum hollow subframe is systematically established. Firstly, a subframe calculation model is established and the loading method is improved, with a new static stiffness calculation method in a local coordinate system proposed. Three subcases including static stiffness analysis, flexibility model analysis and the K&C performance analysis are integrated and synchronously driven, and an ensembled surrogate model of K&C performance and static stiffness performance is constructed based on the multi-sample analysis and experimental design matrix conversion. The ensembled surrogate model is used to modify the static stiffness target according to the K&C performance index. Secondly, the multi-level topology optimization of the subframe under multi-performance constraints is carried out, using the first-level topology optimization to complete the main structure design with equal wall thickness, and the second-level topology optimization to complete the structure design with variable wall thickness. The results show that the first order and second order torsion modal increases by 39.3% and 14.9% respectively after multi-level topology optimization, with the static stiffness and K&C performance meeting the target requirements, on the premise of ensuring lighting-design and the other performance indicators significantly improved, which can provide a reference for the formulation of static stiffness performance targets of the subframe, the improvement of K&C performance and the optimization of the subframe structure.

Key words: subframe, static stiffness, K&C performance, topology optimization, multi-performance constraints