Analysis And Simulation Of Coupling Vibration Between Medium-low Speed Maglev Vehicle Andactive Switch Beam

As a new force in urban rail transit,Mid-low speed maglev transportation has developed rapidly at home and abroad in recent years.Although the technology of Mid-low speed maglev transportation has been relatively mature at present,many engineering problems have been exposed in its application stage.Coupled vibration of switch is one of the most urgent problems to be solved.It occurs when the vehicle passes slowly or hangs statically on the switch beam,which affects the normal magnetic levitation.is one of the main obstacles to operational reliability.Therefore,it is of great significance to study the basic characteristics and laws of coupling vibration between vehicle and switch beam and reveal the internal mechanism of switch coupling vibration.Firstly,on the basis of introducing the basic structure and working principle of medium and low speed maglev switch,this paper takes the active beam of medium and low speed maglev switch in Qingyuan Maglev Travel Demonstration Line as the object,the model of medium and low speed maglev switch beam by using finite element software ANSYS was established.The finite element modal analysis of rigid and elastic restrained maglev switch active beam under two and three trolley support modes were analyzed.The analysis,combined with the field test results of the natural frequency,determines the reasonable restraint mode of the switch active beam,and verifies the rationality of the switch active beam model.Secondly,the coupling dynamic model of low-speed maglev vehicle-switch beam including active suspension control and its distributed collaborative simulation analysis platform were established.Based on this platform,the dynamic response of the vehicle passing through the switch beam at a low speed of 30 km/h is simulated,and the basic characteristics of the coupling vibration response of medium-speed maglev vehicle-switch beam are obtained.Finally,the effects of main parameters such as driving speed,suspension stiffness of secondary system,structural damping of switch beam and rigidity of switch beam on the vibration law of Maglev vehicle-switch coupling system are studied.The results show that with the increase of driving speed,the acceleration response of the car body,suspension frame and beam basically decreases first and then increases,and the coupling vibration of the switch is stronger when the vehicle passes through the switch at low speed;the vertical stiffness of the air spring mainly affects the vibration of the car body,and the larger the vertical stiffness of the air spring,the smaller the vertical acceleration of the car body,the weaker the impact on the suspension frame,and the switch.The vibration response of the beam system has little influence;with the increase of the damping ratio of the switch structure,the vibration response of the switch beam decreases,and there is a negative correlation between them.The effect of the switch damping on the vertical vibration acceleration of the switch beam is significant,and the low damping of the steel structure switch is one of the main reasons for the strong coupling vibration of the switch at low speed.The amplitude decreases with the increase of the switch beam stiffness.Under the condition of two trolley support and low stiffness,strong resonance occurs in the magnetic levitation vehicle-switch-control system at about 9Hz.In view of this resonance phenomenon,some suggestions were put forward,which includes improve the switch beam stiffness and quality,increase the switch damping and improve the suspension control parameters.