Abstract: Based on virtual simulation research, the fatigue life of the suspension lower control arm of an sport utility vehicle (SUV) in a certain city is analyzed. A three-dimensional model is used to establish a rigid flexible coupling dynamic model of the entire vehicle. The load spectrum of the lower control arm under the suspension and the ultimate load under actual driving conditions are obtained using this model. The finite element model of the control arm under suspension is established, and the boundary constraint of the control arm is established by the load of the vehicle in the ultimate condition. Based on statistical analysis of force load spectrum and Miner cumulative damage rule, the fatigue life and damage cloud maps of the lower control arm are analyzed and calculated in the fatigue analysis software Ncode. The results show that the total life of the lower control arm of a certain city SUV suspension is 4.78×105 h, which meets the requirements of use.

Key words: Adams/Car; MacPherson suspension; Lower control arm; Force load spectrum; Fatigue life analysis

摘要： 基于虚拟仿真研究分析了某城市运动型多用途汽车（SUV）悬架下控制臂疲劳寿命问 题，结合三维模型建立整车刚柔耦合动力学模型，利用该模型得到悬架下控制臂力载荷谱以 及实际行驶工况下的极限载荷。建立悬架下控制臂有限元模型，以整车极限工况载荷建立下 控制臂的边界约束，并运用模态分析证实了模型的可靠性。基于统计分析力载荷谱和 Miner 累计损伤法则，在疲劳分析软件 Ncode 中分析计算得到下控制臂的疲劳寿命云图与损伤云图， 结果表明，某城市 SUV 悬架下控制臂的总寿命为 4.78×105 h，满足使用要求。

关键词: Adams/Car；麦弗逊悬架；下控制臂；力载荷谱；疲劳寿命分析