重载列车作用下铁路钢桁梁桥的动力响应分析及疲劳寿命评估

摘要

以长东黄河大桥三跨连续钢桁梁为工程背景,采用ANSYS软件建立了有限元模型,对不同载重列车过桥时钢桁梁的动力响应进行了分析,并根据线性累计损伤理论,采用雨流法计数,对C80重载列车过桥时钢桁梁的疲劳损伤度及疲劳寿命进行了评估.主要结论为:列车车辆过桥时,随车辆轴重的增加,钢桁梁动挠度加大,但竖向加速度极值不严格随轴重的增加增大或减小；低速范围内随车辆速度的增加,钢桁梁动挠度变化不大,只有波动幅度增大,竖向加速度极值随车速的增加而增大.该钢桁梁在C80列车编组下的疲劳寿命约125 a,与C70列车编组下的疲劳寿命相差不大.%Based on the three-span continuous steel truss girder in ChangDong YellowRiver Bridge, the FE model is built using ANSYS software, the dynamic response when the trains with different axle load passing bridge are analyzed, and the fatigue damage degree and fatigue life are evaluated using linear accumulated damage theory and rain flow method. The results show that, with the axle loads increase, the maximum dynamic deflections enlarge, but the maximum vertical acceleration has no apparent raise; with the train speed increase, the maximum vertical acceleration increases, but the increase of maximum dynamic deflection is not apparent when the speed changes in the low speed range. Under the dynamic action of C80 marshalling, the fatigue life of this three-span continuous steel truss girder is 125 years, which is close to the fatigue life under the dynamic action of C70 marshalling.