中低速磁浮车岔耦合振动研究

Coupled Vibration Between Low-Medium Speed Maglev Vehicle and Turnout

为研究中低速磁浮道岔主动梁关键参数对车岔耦合振动的影响,进行了各工况下磁浮道岔主动梁的模态测试,并建立了考虑道岔主动梁弹性振动的车岔耦合动力学模型,对悬浮稳定性进行了分析.通过仿真与试验对比,对道岔主动梁的模态特征进行了修正,并基于修正后的车岔耦合动力学模型,研究了磁浮道岔主动梁不同设计参数对悬浮稳定性的影响规律.研究结果表明:中间台车采用50 MN/m的弹性约束进行等效,能够达到比较理想的误差要求;二台车支撑方案相比三台车支撑方案,更容易避开磁浮车岔耦合的共振频率;随着主动梁一阶垂向弯曲频率的不断增大,悬浮控制参数的稳定区间越小,当道岔主动梁垂向弯曲频率大于12 Hz时,更容易出现车岔耦合振动现象;随着道岔主动梁刚度的增加,悬浮控制参数的稳定范围越小;增加道岔主动梁结构阻尼比不能解决车岔耦合共振问题,只能降低振动幅值大小;随着道岔主动梁线密度的增大,越不容易出现车岔共振现象,当线密度低于1 500 kg/m时,悬浮稳定区间将急剧下降;中间台车的等效支撑刚度越大,控制参数的稳定区间越小,但影响幅度不大.

In order to study the influence of key parameters of the main beam of a low-medium speed maglev turnout on the coupled vibration of the vehicle-turnout system, modal tests of the main beam of maglev turnout are carried out in various conditions, and a vehicle-turnout coupling dynamic model considering the elastic vibration of the main beam of turnout is established for numerical simulation analysis of the levitating stability.First, the modal characteristics of the turnout main beam are modified through comparisons between simulation and experiment. Based on the modified vehicle-turnout coupling dynamic model, the influence of different design parameters of the maglev turnout main beam on levitating stability is then studied. The results obtained are as follows: The intermediate bogie can be equivalent to a 50 MN/m elastic constraint to meet the ideal error requirements, and the two-bogie support scheme is easier to avoid the resonance frequency between vehicle and turnout than the three-bogie support scheme. With the increasing of the first-order vertical bending frequency of the main beam, the stability range of the levitating control parameters becomes smaller;when the first-order vertical bending frequency of the main beam of turnout is greater than 12 Hz, the phenomenon of vehicle-turnout coupled vibration is more likely to occur. As the stiffness of the turnout main beam increases, the stability range of the levitating control parameters becomes smaller. Besides, increasing the structural damping ratio of the turnout active beam can only reduce the vibration amplitude but cannot solve the coupling resonance problem between vehicle and turnout. It is also found that the higher the linear density of the turnout main beam, the less likely the vehicle-turnout resonance is to occur;when the linear density is lower than 1500 kg/m, the levitating stability range drops sharply. In addition, a greater equivalent support stiffness of the intermediate bogie leads to a smaller stability range of the control parameters, but the influence range is small.