线路纵断面设置对千米级高铁悬索桥动力学行为的影响

Influence of Track Profile Setting on Dynamic Behavior of High-Speed Railway Suspension Bridge with Kilometer Span

以高速铁路悬索桥五峰山长江大桥为背景,运用多体动力学方法和有限单元法,建立车-线-桥动力相互作用模型,研究线路纵断面设置对千米级高铁悬索桥动力学行为的影响。结果表明:桥上纵断面坡段变化对行车安全性指标基本无影响,纵断面变坡点数量增加对车体垂向加速度有一定影响,但对运行舒适性影响不明显,大跨度桥上坡段长度可调整到200 m及以上;车-桥动力相互作用引起的悬索桥动态刚度不平顺易造成车体加速度呈现周期性振动,在进出竖曲线位置易与离心力引起的振动产生车体振动叠加效应;线路竖曲线半径从30000 m减小到25000和20000 m时,对应的车体加速度分别提高0.00341g和0.00827g,对应的轮重减载率分别增加0.00359和0.00898。

Based on the high-speed railway suspension bridge Wufengshan Yangtze River Bridge,the train-track-bridge dynamic interaction model was established by using multi-body dynamics method and finite element method,and the influence of track profile setting on the dynamic behavior of high-speed railway suspension bridge with kilometer span was studied.The results show that the change of longitudinal profile slope on the bridge basically has no influence on the indexes of train operation safety.The increase in the number of longitudinal profile slope changing points has a certain effect on the vertical acceleration of car body,but the influence on the running comfort is not obvious.The length of the uphill section of the long-span bridge can be adjusted to 200 m or more.The dynamic stiffness irregularity of suspension bridge caused by vehicle-bridge dynamic interaction is prone to cause the periodic vibration of car body acceleration,and it tends to produce superposition effect of car body vibration with the vibration caused by centrifugal force at the position of the entrance and exit of vertical curve.When the vertical curve radius of the track decreases from 30000 m to 25000 and 20000 m,the corresponding car body acceleration increases by 0.00341 g and 0.00827 g respectively,and the corresponding wheel load reduction rate increases by 0.00359 and 0.00898 respectively.