竖弯涡振作用下桥上列车行车安全舒适性研究

Research on Train Traveling Safety and Comfort on Bridge Under Vertical Vortex-Induced Vibrations

为研究高速铁路桥梁竖弯涡振对桥上列车行车安全舒适性的影响,以某大跨公铁两用斜拉桥和CRH2型动车组为背景,进行风-车-轨-桥耦合系统振动分析。基于ANSYS与SIMPACK联合仿真平台,引入桥梁涡激力数值模型,建立风-车-轨-桥耦合系统振动模型,对比10 m/s平均风速下主梁发生与未发生竖弯涡振时桥梁和列车的动力响应,并分析不同列车速度的影响。结果表明:竖弯涡振会加剧桥梁和列车的竖向响应,而列车的存在会使发生竖弯涡振时的桥梁竖向位移和加速度分别降低31.8%和42.4%,对主梁竖弯涡振具有一定的抑制作用;主梁发生竖弯涡振时列车行车安全性指标峰值和竖向舒适性指标(竖向加速度和竖向Sperling指标)峰值明显大于未发生竖弯涡振时,并均随着车速的增大而增大;当车速超过230 km/h时,列车轮重减载率超过安全限值0.6,当车速超过200 km/h时,桥上列车竖向加速度超过安全限值1.3 m/s^(2)。

Based on a long-span rail-cum-road cable-stayed bridge and CRH2 EMU,the train traveling safety and comfort on high-speed railway bridge under the action of vertical vortex-induced vibrations is studied.With an ANSYS-SIMPACK joint simulation platform,the numerical model of vortex-induced forces on bridge was built up and the wind-vehicle-track-bridge coupling vibration model was established,to compare the dynamic responses of bridge and train when vertical vortex-induced vibrations occurred and did not occur on bridge at an average wind speed of 10 m/s.And the train traveling speeds were analyzed.It is shown that vertical vortex-induced vibrations can intensify the vertical responses of bridge and train,while the existence of train would cause the vertical displacement and acceleration of the bridge to reduce by 31.8%and 42.4%,respectively,when there are vertical vortex-induced vibrations on bridge,which can,to a certain extent,suppresses the vertical vortex-induced vibrations.When the main girder is subjected to vertical vortex vibration,the peak values of the train traveling safety and vertical comfort index(vertical acceleration and vertical Sperling index)are obviously greater than the scenario where there are no vertical vortex-induced vibrations observed,and the faster the train,the greater these peak values.When the train speed exceeds 230 km/h,the wheel load reduction rate surpasses the safety limit value of 0.6.When the train traveling speed is over 200 km/h,the vertical acceleration of train on the bridge is above the safety limit value of 1.3 m/s^(2).