基于换挡力的换挡摇臂多目标结构设计优化

换挡摇臂是换挡执行机构的关键零件之一，其变形与疲劳寿命对于换挡执行机构的正常工作具有重要影响。文中以某型电控电动式换挡机构的换挡摇臂为研究对象，首先通过多体动力学仿真计算获取载荷谱，基于有限元仿真计算换挡摇臂的应力分布，从而计算出换挡摇臂的变形与疲劳寿命；然后基于变形和疲劳寿命分析结果，选取换挡摇臂关键几何参数为设计变量，以换挡摇臂质量和换挡摇臂变形为目标，以换挡摇臂疲劳寿命为约束条件，通过响应面法对换挡摇臂结构进行多目标设计优化。结果显示，在换挡摇臂质量减轻的同时，变形不增反减。这充分说明文中建立的模型和优化方法具有一定的工程应用价值，为换挡摇臂的设计提供了重要的理论支撑。

Multi-objective Structural Design Optimization of Shift Rocker Arm Based on Shift Force

The shift rocker arm is one of the key parts of the shift actuator. The deformation and fatigue life of the shift rocker arm have critical impact on the reliable and safe operation of the shift actuator. This paper focuses on the optimal design of the shift rocker arm of an electronically controlled electric shift mechanism. Firstly, the load spectrum is obtained through multi-body dynamics simulation, the stress distribution of the shift rocker arm is calculated based on the finite element analysis and the deformation and fatigue life of the rocker arm can be calculated. Based on the analysis results of deformation and fatigue life, the key geometric parameters of the shift rocker arm are selected as design variables, the mass and deformation of the shift rocker arm are taken as the minimization objectives, and the fatigue life requirement of the shift rocker arm is taken as the constraint. The multi-objective structure design optimization of the shift rocker arm is carried out by using the response surface method. The results show that the mass of the shift rocker arm is reduced, while the deformation does not increase but decrease. It fully shows that the optimization model and method proposed in this paper have certain engineering application value, which provides important theoretical supports for the design of rocker arm of shift mechanism.