基于验证模型的枕梁疲劳寿命预测虚拟实验

为了研究地铁车辆枕梁服役安全性问题，考虑到大量疲劳实验耗时长且成本高，利用虚拟实验方法对枕梁结构疲劳寿命进行评估，根据EN12663-1标准设计枕梁静力实验，获得枕梁表面特征点的应力值和位移值；然后对枕梁进行有限元建模并仿真，对比静力实验结果，调整后获得与枕梁实际结构相符的有限元模型；最后利用Monte Carlo方法，进行地铁车辆枕梁在恒幅载荷与变幅载荷作用下的虚拟疲劳实验. 研究结果表明:在标准规定的恒幅载荷作用下，该地铁车辆枕梁寿命大于1 000万次载荷循环的可靠度约为0.73；在变幅载荷作用下，寿命大于1 000万次载荷作用的可靠度约为0.81；因此，该地铁车辆枕梁完全满足设计与使用要求. 

Virtual Experiments to Predict Bolster Fatigue Lifetime Based on FEM Model Validated by Static Tests

To study the service safety of a metro train bolster, a virtual experiment method was used to evaluate fatigue lifetime, avoiding time-consuming and expensive fatigue tests. A static test of the bolster was designed based on the EN12663-1 standard, and the stresses and displacements on its surface were measured. An FEM model of the bolster was then established and analysed for comparison with the static test results; an FEM model that is consistent with the actual structure was thus determined. Finally, virtual experiments of the bolster under constant amplitude loads and variable amplitude loads were conducted using a Monte Carlo method. It is concluded that the fatigue reliability of this bolster with 107 loads cycles is 0.73 under constant amplitude loads and 0.81 under variable amplitude loads. This metro train bolster therefore meets the design and service requirements.