基于路谱频域的车身疲劳分析

针对车身疲劳分析中静载法无法考虑结构动力学响应,瞬态分析法无法求解过长时间域的问题,将这2种方法与频域法进行比较,发现用频域法对大规模有限元模型进行动态疲劳分析相对容易,并能完全描述动力学响应过程.根据频域法进行振动疲劳分析的理论和计算过程,给出基于路谱频域的车身疲劳分析流程.基于功率谱密度（Power Spectral Density,PSD）载荷谱的传递函数法求解某车关键部件的疲劳寿命,求解结果与疲劳试验结果比较一致.结果表明基于路谱频域的振动疲劳分析方法在汽车结构疲劳计算中的应用可行.

Vehicle body fatigue analysis based on frequency domain of road spectrum

As to vehicle body fatigue analysis, a structure dynamics response can not be considered in static loading method, and transient analysis method can not be applied on the solution with an overlong time domain. The comparison of the two methods with the frequency domain method shows, that it is relatively easy to use frequency domain method to perform dynamic fatigue analysis on large scale finite element models, and dynamics response process can be described completely. According to the vibration fatigue analysis theory and analysis process using frequency domain analysis method, the vehicle body fatigue analysis process based on road spectrum frequency domain is proposed. Based on the transfer function method of load spectrum of Power Spectral Density(PSD), the fatigue life of some critical parts is solved for a vehicle body, and the results are relatively consistent with fatigue test results. It is feasible to use vibration fatigue analysis method based on road spectrum to calculate automobile structure fatigue.