荣兵+肖攀+周建文+蔡川+张建民

摘 要：将汽车试验场实测载荷谱，按各路面载荷谱在频域下主要集中频段的高低划分为低频和高频路面载荷谱。对于高频路面载荷谱采用基于六分力测试信号的虚拟迭代方法进行分解，对于低频路面采用基于陀螺仪测试信号的方法计算车身姿态，再结合六分力测试信号的方法进行分解，且两种方法均要控制实测与仿真的轴头加速度、弹簧位移等信号的相对损伤比在0.5～2.0范围内。基于载荷分解得到后桥接口点的动态载荷，利用有限元和疲劳分析理论，对其进行疲劳寿命分析预测，反映了后桥在前期开发中存在的疲劳风险，同时进行相应的结构改进优化，分析表明，其寿命满足疲劳性能目标并通过了强化耐久试验的验证。

关键词：载荷谱；载荷分解；相对损伤；疲劳分析

中图分类号：O346.2文献标文献标识码：A文献标DOI：10.3969/j.issn.2095-1469.2016.03.08

Abstract：Based on the measured proving ground data， the road load spectrum was divided into low and high frequency bands. The virtual iterative method was used based on wheel forces to get the dynamic load components for high-frequency road spectrum. The vehicle body attitude was calculated from the gyroscope signal and the wheel forces were used to obtain the dynamic load components for low-frequency road spectrum. Both methods must ensure the relative damage range for the spindle acceleration and spring displacement is between 0.5 and 2.0. Based on dynamic load for the rear axle the fatigue analysis was conducted， and the fatigue risk was found in the early development phase. Finally the optimized structure has met the requirements of fatigue performance and passed the durability test.

Keywords：road load spectrum； load cascading； relative damage； fatigue analysis

在汽车开发过程中，结构部件的疲劳耐久性能开发是一个关键和核心的技术领域。近年来，轴头六分力测试以及相应内部载荷测试技术的发展和普及，将车辆所受的随机载荷转化为可见的数字信号，让开发工作者能在车辆开发过程中了解到车辆所受的外界动态载荷，进而具备了车辆部件疲劳研究的基础。基于实测载荷谱得到各零部件接口点外界动态载荷的方法，主要是建立车辆动力学模型进行载荷分解，具体的分解方法包括以下两种：（1）约束车身，直接加载六分力载荷进行分解。……