高架简支箱梁与U梁车-轨-桥耦合振动分析

Analysis for vehicle-track-bridge coupling vibration of simply supported box-girder and U-girder

基于多体动力学与有限元法,利用多体动力学软件Simpack建立箱型梁及U型梁的三维车轨桥耦合振动仿真模型,对列车过桥时箱型梁、U型梁及轨道结构竖向和横向振动进行分析,得到桥梁振动空间分布情况,进一步研究扣件、板下弹性支承与桥梁支座参数对箱型梁和轨道结构的振动规律,并给出各参数的合理取值范围。研究结果表明:列车以80 km/h的速度过桥时,箱型梁与U型梁结构振动空间分布情况差异明显,应重点关注钢轨、轨道板以及箱梁翼板与腹板的竖向振动,U型梁翼缘处横向振动不容忽视;增大扣件刚度能明显减小钢轨变形,但过大的刚度会使箱梁与轨道结构的振动加剧,建议扣件竖向刚度取值为20~50 MN/m;增大板下弹性支承刚度可明显减小轨道板的振动,但过大的刚度会加强钢轨振动,建议板下弹性支承竖向刚度取值为(1.0~1.5)×10~3 MN/m;增大支座竖向刚度在一定范围内可减小轨道板与箱梁的振动,但过大的支座刚度反而会使桥梁振动加剧,不利于减振,建议支座竖向刚度取值为(3~4)×10~3 MN/m。

A three-dimensional model of vehicle-track-bridge coupling vibration was established by Simpack based on multi-body dynamics and finite element method.The vertical and lateral vibration of box-girder,U-girder and track structure were analyzed when the train passes through the bridge.For the box-girder bridge,the influences of parameters of fastener,elastic support under the track plate and support were analyzed,and the reasonable range of each parameter was given.The results show that when the train passes the bridge at 80km/h speed,the spatial distribution of vibration of box-girder and U-girder is obviously different.The vertical vibration of the rail,track plate and the flange and web of box-girder should be focused,and the lateral vibration at the flange of U-girder can not be ignored.Increasing the stiffness of the fastener can obviously reduce the deformation of the rail,but the excessive stiffness will aggravate the vibration of the box girder and track structure,the vertical stiffness of the fastener should be within the range of 20~50 MN/m.Increasing the elastic support stiffness can reduce the vibration of the track plate,but the excessive stiffness will strengthen the rail vibration,the vertical stiffness of elastic support under the track plate should be within the range of(1.0~1.5)103MN/m.Increasing the vertical stiffness of the support can reduce the vibration of the track plate and the box girder in a certain range,but the excessive stiffness of the support will make the vibration of the bridge increase,which is not conducive to the vibration reduction,the vertical stiffness of support should be within the range of(3~4)103 MN/m.