考虑轮对弹性的车轮振动及车轮多边形化对轮轨力影响研究

摘要

In order to study the influence of wheelset elasticity on wheel vibrations,wheel polygonization and wheel-rail forces of linear metro vehicles,on the basis of making modal analysis on a single wheelset,the rigidflexible coupling dynamic model of the complete vehicle system was established,where the wheelsets were considered as the elastic body and the remaining parts were treated as the rigid body.The results show as follows:Taking into consideration wheelset elasticity,the bending vibration frequencies of the elastic wheelset will couple with the vibration frequencies of the linear motor and so increase the amplitude of wheelsets vibrations,thus reflecting changes of wheelsets vibrations and wheel-rail forces more realistically;wheel polygonization will produce larger vertical wheel-rail forces which are closely related to the wheel polygon amplitude,phase difference,harmonic order and vehicle running speed,and the influence of wheel polygonization on wheel-rail forces can be reflected more accurately in the case of the wheelsets being taken as the elastic body;in actual operation of metro vehicles,if the dominant order of wheel polygonization is known,we should try our best to avoid the running speed corresponding to coupling between excitations generated by wheel polygonization and vertical bending vibration frequencies of the flexible wheelset.%为研究直线电机地铁车辆轮对弹性对车轮振动、车轮多边形化及轮轨相互作用的影响,在对单轮对进行模态分析的基础上,建立完整的车辆系统刚柔耦合动力学模型,模型中将轮对视为弹性体,其余部件按刚体处理.研究表明:考虑轮对弹性之后,轮对的弯曲振动频率会与直线电机的沉浮与点头振动频率相耦合,从而加大轮对的振动幅度,因此考虑轮对弹性可以更加真实地反映车轮的振动与轮轨力的变化.车轮多边形化会引起较大的轮轨垂向力,并与车轮多边形化的波深、相位差、谐波阶数及车速有密切关系,而将轮对考虑为弹性体将会更加准确地反映出车轮多边形化对轮轨力的影响.在车辆实际运用过程中,如果已知车轮某阶多边形占主导,应尽量避开该阶多边形化车轮产生的激励与车轮垂向弯曲频率相耦合时的车辆运行速度.