风攻角对强风下大跨度斜拉桥车-桥耦合振动的影响

Influence of wind attack angle on vehicle-bridge coupling vibration for long-span cable-stayed bridge during strong wind

为研究风攻角对强风作用下大跨度斜拉桥车-桥系统耦合振动的影响,通过风洞试验得到不同风攻角条件下桥梁主梁和桥上不同位置处列车的三分力系数;在此基础上,依据弹性系统动力学总势能不变值原理,进一步建立风-车-桥耦合系统振动方程,求解方程并就风攻角对桥梁和列车的动力响应的影响进行分析研究。研究结果表明:风攻角对桥梁和列车的气动三分力系数影响较大;桥梁跨中处的横向振动位移在攻角为-12°时有最大值,竖向振动位移在攻角为-6°时有最大值,极大值均未在攻角为0°时出现;风攻角对车辆动力响应的影响较大,但各项动力响应受风攻角影响而出现变化的趋势并不相同;列车的脱轨系数、轮重减载率和横向力在负向攻角时比正向攻角时的大,且随负向攻角绝对值的增大有增大趋势。

In order to study the effect of wind attack angle on the coupling vibration of train-bridge system for long-span cable-stayed bridge during strong wind,by using wind tunnel tests,three-component force coefficients of the bridge girder and the train at different positions of the bridge deck and different wind attack angles were obtained.According to the principle of the total potential energy with stationary value in elastic system dynamics,the coupling vibration equation of the wind-train-bridge system was established.The vibration equation was solved and the effect of wind attack angle on the dynamic response of the bridge and train was analyzed.The results show that three-component coefficient of the bridge and train is greatly influenced by the wind attack angle.The transverse vibration displacement at the middle span of the bridge has a maximum value when the attack angle is?12°,and the vertical vibration displacement has a maximum value when the attack angle is?6°,and the maximum values do not appear when the attack angle is 0°.The wind attack angle has a great influence on dynamic responses of the train,but the changing trend of various dynamic responses under the influence of wind attack angle is not the same.Derailment factors,offload factors and lateral forces of the train are larger in the negative attack angle than those of the positive attack angle,and they increase with the increase of the absolute value of negative attack angle.