高速动力车轴应力谱分析及疲劳寿命可靠性预测

结合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,以"中华之星"高速动力车轴为例,建立了动车系统的非线性动力学模型,仿真车辆在典型线路上的运行特性,获取作用于轮轴上的随机载荷谱。引入车轴材料的非线性本构关系,进行轮轴的有限元分析,得到车轴关键部位的应力时间历程,对其进行统计分析后得到各危险点的应力谱。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,得到不同可靠度下的疲劳寿命。当可靠度为0.9时,其疲劳寿命为16年。

Stress spectrum analysis and fatigue life prediction about wheel axle of high-speed power car

Combining the dynamic response of vehicle under the excitation of track spectrum with fatigue strength theory,the wheel axle of China Star high-speed power car was taken as example,the nonlinear dynamics model of the power car was set up,the running property of vehicle on typical railway was simulated,and the random loads acted on vehicle wheelsets were obtained.Based on the nonlinear random cyclic constitution of the axle material,the finite element model of the wheelset was established,the stress time history of key region of the wheelset under the random loads was calculated,and the stress spectrum of hazard sections of the axle was obtained by statistical analysis.Using fracture mechanics theory and accumulative damage theory,the fatigue life of the axle was predicted,and its reliability was analysed.When the reliability was 0.9,the fatigue life was 16 years.7 tabs,4 figs,15 refs.