Coupling Vibration Characteristics Of Straddle-type Monorail Train And Bridge And Riding Condition Assessment

Among the many rail transport systems,the cross-seat monorail system has been widely noted for its unique adaptability and economy.As the pace of urban development continues to increase,more and more urban rail network planning schemes have begun to adopt this form,with significant success.The current study of vehicle-bridge coupling for cross-seat monorails is oriented towards the demand for medium capacity and medium driving speed,and factors such as the deviation of the track beam alignment on the comfort of train driving are not considered.In this paper,based on a monorail project interval track beam,the coupled vibration dynamic equations of the cross-seat monorail bridge are derived and established based on the iterative idea of the bridge subsystem,and a MATLAB and ANSYS interactive bridge coupling analysis program is developed and verified;the influence of factors such as track beam alignment on the vibration of the monorail train and the track beam is studied on the basis of the verified reasonable,and the comfortable driving is determined.The effects of earthquakes on the vibration characteristics of the cross-seat monorail bridge system are investigated.The main research work and results include the following:(1)A study on the numerical analysis method of the coupled vibration of a cross-seat monorail vehicle and bridge.Firstly,based on the idea of iteration of the vehicle-bridge subsystem,the monorail train whole vehicle dynamic system model and the bridge finite element system model are established respectively;then from the mechanical vibration characteristics of the pneumatic tyre,combined with the characteristics of the cross-seat monorail train and the independence between the components,the contact wheel pairs of the train and the track beam and their contact states are simulated,the D’Alembert principle is applied to derive the action force of each group of wheel pairs of the train,and establish Finally,a numerical calculation program for the dynamic interaction analysis of the train-rail beam system is prepared using MATLAB and ANSYS language.(2)Validation of the numerical analysis procedure for the coupled vibration of cross-seat monorail bridges.The comparison and verification of the simulation data results with literature and test and inspection data information shows that the numerical calculation results are in good agreement with the measured results,which verifies the rationality of the monorail axle coupling theory and the validity of the numerical analysis procedure established in this paper.Further analysis of the effect of two different models of single and dual axle cars on the axle system shows that different models have different body mass and tyre dynamic characteristics,so they have different degrees of influence on the vibration response of the whole train-rail beam system,of which the smaller body mass and better tyre dynamic characteristics of the single axle car make the vibration effect of the car body and the rail beam smaller.(3)A study on the control criteria of track girder alignment deviation based on traffic comfort.The results show that:(i)track alignment control parameters such as track flatness level,beam deflection,abutment elevation deviation and bearing deviation have a significant impact on the acceleration safety limit of the bridge system,the running quality of the vehicle and ride comfort.The level is not more than B,the deflection span ratio is not more than1/2000,and the deviation at the pier elevation and bearing is not more than 5mm.(ii)Various alignment parameters have a more significant impact on the vibration characteristics of the bridge system and the comfort of the vehicle driving under high speed driving conditions,and more stringent alignment control standards need to be developed to ensure the comfort and smoothness of driving.(4)Analysis of the dynamic response of a cross-seat monorail-rail girder bridge system under seismic action.The results show that the lateral response of the bridge is significantly increased by the earthquake,because the unique wheel-rail contact relationship between the straddle monorail and the rail girder makes it possible to guarantee the safety of the train under different intensity levels of earthquakes,and that the continuous rigid rail girder has better The continuous rigid track beam has better comfort and safety than the simple-supported track beam.