Research On Vibration Characteristics Of Rubber Floating Slab Track In Metropolitan Rapid Rail

The metropolitan rapid rail is a relatively new type of rail transit that provides convenient public transport services between the city’s central and suburban areas.With the development of the metropolitan rapid rail,the environmental vibration problems caused by train operation are also increasingly apparent.In order to reduce the vibration,rubber floating slab rails were laid in the high-damper vibration section of the metropolitan rapid rail.However,after the application of the floating slab track in this new type of rail transit,the dynamics of parameter influence and vibration propagation characteristics are not sufficient.In this paper,aiming at the parameter influence and vibration propagation in the rubber floating slab track of the metropolitan rapid rail,the dynamics model of the railway-rubber floating slab track-subgrade coupling dynamics and dynamic simulation is established.Firstly,the system parameters analysis of the dynamic response of the rail system is carried out.Then the sensitivity of the parameters to different dynamic indexes is quantitatively studied.The influence of the randomness of the sensitive parameters on the probability distribution of the dynamic indicators is discussed.Finally,considering the randomness of vibration propagation,the laws of propagation and distribution of subgrade vibration are further studied.The conclusions of the study will provide some theoretical guidance for the vibration reduction design,maintenance and maintenance of the metropolitan rapid rail.The main work and conclusions of this paper are as follows:1.Based on the theory of vehicle-rail coupling dynamics,the dynamic model of the rail-subgrade coupling of the metropolitan rapid rail train-rubber floating slab track is established,and the correctness of the model and the solution method is verified.The train model is based on multi-body dynamics theory;the rubber floating slab track-subgrade model is based on finite element theory;the vehicle-rail coupling is realized by self-programming using the vehicle-rail coupling solution method.Finally,the theoretical results are compared with the field test results to verify the correctness of the model and the solution method.2.From the perspective of time domain and frequency domain,the system analyzes the effects of vehicle speed,fastener stiffness,damping pad stiffness and vehicle axle weight on vehicle body vertical acceleration,wheel-rail vertical force,vertical displacement of track structure and acceleration.Increasing the speed of the vehicle will cause the vertical acceleration of the vehicle body to increase significantly;Increasing the stiffness of the fastener will cause the vertical displacement of the rail to decrease significantly,and the vertical acceleration of the base slab and subgrade will increase significantly.Increasing the stiffness of the damping pad will cause the vertical acceleration of the vehicle body,the vertical displacement and acceleration of the rail and the track slab to be significantly reduced,and the vertical acceleration of the base slab and the subgrade will increase significantly.Increasing the axle load of the vehicle will cause the vertical force of the wheel and rail,and the vertical displacement of the rail and the track slab to increase significantly.3.From the point of view of the randomness of the parameters,firstly,the sensitivity of parameters to different dynamic indexes is quantitatively tested.Then,the displacement safety and vibration control of the track structure are mainly considered.The influence of the randomness of the damping pad stiffness and the fastener stiffness on the probability distribution of different dynamic indicators is discussed.The randomness of the stiffness of the damping pad will cause the vertical displacement amplitude of the rail and track slab to exhibit obvious normal distribution characteristics,and the vertical acceleration amplitude of the base slab and subgrade will show discrete and irregular distribution;the randomness of the fastener stiffness will cause the vertical displacement amplitude of the rail to exhibit a more obvious normal distribution.4.From the perspective of the randomness of vibration propagation,considering the vector characteristics of vibration acceleration,the characteristics of submarine vibration propagation,space and probability distribution are studied.During the train running,the direction of the vibration acceleration of the subgrade will continue to rotate and the vertical component will become more prominent and the vibration will show continuous rotation in the space.The subgrade vibration will be obviously enlarged at the position of the base slab joint and the track slab joint and will be attenuated from the enlarged area to the periphery,but will be attenuated and then increased along the lateral direction of the subgrade;the statistics of the vibration acceleration of the subgrade level have obvious normal distribution characteristics,while the statistics in the cross section have no obvious distribution characteristics.