低地板有轨电车异常振动分析

Abnormal Vibration Analysis of Low-floor Tram

针对五模块100%低地板有轨电车在40 km/h速度运行时车体垂向平稳性指标出现异常的问题,探究其产生的原因,并进行线路试验研究,认为车轮偏心频率和整车固有模态频率共振是造成垂向平稳性指标异常的原因。采用PolyMAX算法进行模态参数识别,得到车体主频为5.85 Hz的垂向固有模态,表现为五模块车体间的点头与浮沉。通过建立车辆动力学模型,分析轮对偏心量的影响。对车间纵向减振器和二系垂向减振器进行参数优化,也可以达到抑制异常振动的效果;当二系垂向减振器的阻尼取24 MN·s/m和节点刚度取20~30MN/m时,垂向平稳性指标约为1.9,基本可消除异常振动的影响。

For the 100% low-floor tram with five modules,the vertical stability index was abnormal at 40 km/h speed.In order to explore the cause,the field test was carried out.The test result indicated that the eccentric frequency of the wheel resonates with the natural modal frequency of the tram.Then the PolyMax algorithm was used to identify the modal parameters,and the vertical natural mode with the main frequency of 5.85 Hz was obtained,which was presented as the nodding and floating between the five car-bodies.By establishing a vehicle dynamics model,the influence of the wheel on the different eccentricity is analyzed,and the vertical ride comfort is greatly improved by optimizing parameters of inter-vehicle longitudinal damper and secondary vertical damper.When the damping is 24 MN·s/m and the node stiffness is 20~30 MN/m in the secondary vertical damper,the vertical stability index is about 1.9,which can basically eliminate the influence of abnormal vibration.