Dynamic Performance Evaluation Index Of Straddle-type Monorail And Analysis Of Influence Law Of Vehicle-bridge Coupling Vibration

As a new type of rail transit system,straddle monorail trains have been applied and developed in many cities.When a monorail vehicle runs on a flexible track beam,both the vehicle and the track beam will generate vibration under the coupling force.This coupling vibration directly affects the smoothness of the straddle monorail operation and the comfort of passengers inside the vehicle.Moreover,excessive coupling vibration can pose safety hazards to the vehicle’s operation.Therefore,in-depth research on the impact of cross seat monorail vehicle bridge coupling vibration is of great significance for the safe and stable operation of vehicles.This paper takes the project "Research on the Dynamic Characteristics of Straddle Monorail Trains under Vehicle/Track Beam Coupling Conditions" as the research object,establishes dynamic performance evaluation indicators suitable for Straddle Monorail Vehicles,and establishes a dynamic model to study and analyze the laws of vibration influencing factors of the Vehicle Track Beam Coupling System.The main research content of this article is as follows:(1)This article first compares the differences and outstanding characteristics between straddle monorail transit and traditional rail transit,and summarizes the research results of domestic and foreign scholars on the dynamic performance evaluation indicators of straddle monorail,flexible track beam research,bogie system,and vehicle bridge coupling system vibration so far.(2)By consulting a large number of relevant literature on dynamic performance evaluation indicators,the applicability of each dynamic performance indicator to straddle type monorail vehicles is summarized and analyzed.The relevant dynamic performance evaluation indicators of straddle type monorail vehicles are mainly constructed and analyzed from three aspects: smoothness,stability,and curve passing ability.(3)Briefly introduce the theoretical foundation and modeling theory of multi body dynamics,and draw a topology diagram of the straddle monorail model structure.Establish a vehicle system dynamics model on the UM modeling interface.Establish a suitable tire model.Establish a cross seat monorail vehicle bridge coupling dynamic model using UM-ANSYS.Based on the sixth level spectrum of track irregularity in the United States and the Japanese monorail irregularity spectrum,corresponding irregularity is added to the surface of the track beam as an external excitation.(4)Based on the above established straddle type monorail vehicle dynamics performance evaluation indicators,the UM dynamics software is used to simulate and analyze the dynamic model performance of the straddle type monorail vehicle bridge coupling system.Through the comparative analysis of the simulation results,it can be seen that although different evaluation indicators have certain rationality in evaluating the dynamic performance of the monorail,the evaluation results obtained are not the same,and the sensitivity and strictness of the evaluation indicators are also different.(5)Through UM simulation analysis,in-depth research was conducted on the impact of changes in structural parameters in flexible track beams and vehicle systems on vehicle bridge coupling vibration.The following regular understanding was obtained: as the bridge span and track beam surface roughness increase,the vibration response value of the vehicle bridge coupling system increases.As the height of the bridge increases,the coupled vibration response value of the vehicle bridge shows a slight decrease overall.The vertical force and lateral angle of the inner running wheel FR and outer guide wheel FL increase with the increase of curve superelevation rate,while the vertical force and lateral angle of the outer running wheel FL and inner guide wheel FR decrease with the increase of curve superelevation rate.The change of the vertical stiffness of the air spring mainly affects the mid span displacement response of the track beam.The changes in the vertical stiffness of running wheels and vehicle eccentricity also have a regular impact on the coupled vibration of the vehicle bridge.