Abstract: To address the engineering challenge of balancing multiple conflicting performance objectives with lightweight requirements in the design of automotive rear hub brackets, this paper proposes a multi-objective topology optimization method based on the compromise programming approach. A maximum design space model is constructed based on suspension hardpoints, and a multi-objective optimization model is formulated with volume fraction and critical hardpoint stiffness as constraints, aiming to simultaneously minimize structural compliance and maximize the first natural frequency. Unlike conventional weighted sum methods, the compromise programming approach effectively resolves the non-convex conflicts between stiffness under multiple load cases and natural frequency by seeking a compromise solution with the shortest distance to the ideal point, thereby enabling rational material distribution. The optimization is performed using OptiStruct, followed by structural reconstruction and iterative design in Siemens NX. The validation results show that the optimized bracket exhibits superior stiffness at all hardpoints compared to the benchmark model, with a maximum stress of 201 MPa under extreme conditions, satisfying strength requirements. The mass is reduced from 5.27 kg to 3.15 kg, achieving a 40.2% weight reduction. The proposed method provides a transferable engineering pathway for the synergistic design of high performance and lightweight in critical chassis components.

Key words: rear hub bracket; multi-objective optimization; compromise programming approach; topology optimization; lightweight

摘要： 针对汽车后轮毂支架设计中多性能目标冲突与轻量化需求并存的工程难题，文章提出 一种基于折衷规划法的多目标拓扑优化设计方法。在悬架硬点布局基础上，构建最大设计空 间模型，以体积分数与关键硬点刚度为约束，建立同时最小化结构柔度与最大化第一阶固有 频率的多目标优化模型。区别于传统加权和法，折衷规划法通过求解与理想解距离最小的折 衷解，有效协调不同工况下刚度与频率间的非凸冲突，实现对材料分布的合理规划。在 OptiStruct 中完成求解后，基于优化结果在 Siemens NX 中开展结构重构与迭代设计。验证结 果表明，优化后支架在各硬点方向刚度均优于对标车型，极限工况下最大应力为 201 MPa， 满足强度要求；质量由 5.27 kg 降至 3.15 kg，减重 40.2%。该方法为底盘关键部件在高性能与 轻量化之间的协同设计提供了可推广的工程路径。

关键词: 后轮毂支架；多目标优化；折衷规划法；拓扑优化；轻量化