F轨对中低速磁浮列车-桥梁系统竖向耦合振动的影响研究

为了探讨F轨对中低速磁浮列车-桥梁系统竖向耦合振动响应的影响，以某中低速磁浮试验线20m预应力混凝土简支梁为研究对象，考虑基于位移-速度-加速度反馈的PID主动悬浮控制，采用SIMPACK和ANSYS联合仿真，分别建立了考虑F轨和不考虑F轨两种中低速磁浮列车-桥梁系统耦合振动模型，结合现场动载试验，将仿真值与实测值分别在时域与频域内进行对比与验证，着重考察竖向耦合振动响应。结果表明：考虑F轨时，仿真结果与实测结果更为接近|F轨在50~65Hz范围内的局部振动密集，考虑F轨时，桥梁竖向加速度的仿真值与实测值均在此频率范围内出现峰值，而不考虑F轨时在此频率范围内未出现峰值|F轨的局部变形较明显，更类似于短波不平顺，使得磁浮间隙与磁浮力的波动范围更大，导致车辆动位移和振动加速度更大|增加F轨的竖向刚度，可减小桥梁和车体的竖向动力响应值。

Study on the influence of F-rail in vertical coupling vibration of low-medium speed maglev train-bridge system

In order to study the influence of F-rail in vertical coupling vibration of low-medium speed maglev train-bridge system, two coupling vibration models, in which one considered the F-rail and the other did not, were built respectively using the joint simulations of SIMPACK and ANSYS for a 20m prestressed concrete (PC) simply-supported girder in one low-medium speed maglev test line, considering the PID active control based on the feedback of displacement-velocity-acceleration. Then, the field dynamic test was carried out, and simulation results of the two models were compared and verified based on the field test data in time-domain and frequency-domain, respectively, with special emphasis on the vertical coupling vibration responses. Analysis results show that: when considering the F-rail, the simulation results are closer to the experimental results| the local vibration of F-rail is intensive within the range of 50~65Hz| when considering the F-rail, the simulation and measured values of vertical acceleration of bridge have peaks within the frequency range (50~65Hz), and without considering the F-rail, the peaks do not appear| the local deformation of F-rail is relatively remarkable, which resemble the shortwave irregularity, leading to the larger fluctuation  of magnetic levitation gap and magnetic levitation force and the greater dynamic displacement and acceleration of train| increasing the vertical stiffness of F-rail may reduce the vertical dynamic responses of bridge and carriage.