将车辆系统在随机轨道谱激励下的动力响应与疲劳强度理论结合起来，以客车及ＲＤ３轴为例，进行了客车的随机响应计算与车轴响应谱的建立，并在此基础上，运用局部应力应变法和累积损伤理论进行了车轴疲劳寿命估算和可靠性分析，为新型车辆结构的随机疲劳寿命估算和可靠性设计提供了一种有应用意义的方法和途径。 Combining the dynamic response of the vehicle system under the excitation of random orbital spectrum with the theory of fatigue strength, taking bus and RD3 axis as an example, the random response calculation and axle response spectrum of passenger car are established. Based on this, local stress Strain method and cumulative damage theory are used to estimate the fatigue life and reliability of the axle, which provides a meaningful method and method for the estimation and reliability design of the new type of vehicle structure.