Research And Development Of New High-speed Turnout Structure And Its Mechanical Behavior

As an indispensable part of railway transportation,turnout is the main factor determining the speed and safety of driving.However,with the increase of railway operation speed,the problems of complex structure,poor integrity and easy damage of No.18 standard turnout switch are becoming more and more prominent,which seriously affects the safety and stability of the train when passing through the turnout.Therefore,this paper develops a new type of high-speed turnout switch structure to reduce the harm to traffic.Based on the vehicleturnout coupling dynamics theory,the dynamic characteristics of the train passing through the two turnout structures are studied.The purpose is to provide a theoretical basis for the improvement and application of the new turnout structure.The main research contents and results of this paper are as follows :(1)Aiming at the problems of complex structure,poor integrity and easy damage of No.18 standard turnout switch,a new turnout switch structure without sharp rail and with the same rail head section as the basic rail is developed by using the bending property of rail without changing the full length of No.18 standard turnout.The structure composition and working principle of the structure are described in detail.(2)Based on the structure size,section position and related mechanical parameters of No.18 standard turnout and new turnout,the models of No.18 standard turnout and new turnout were established in UM software.According to the position relationship between the components of the vehicle and the related mechanical parameters,the single vehicle model of CRH2 vehicle is established.Finally,the vehicle-standard turnout and vehicle-new turnout dynamic analysis models are generated respectively,and the correctness of the model is verified by comparing with the literature results.(3)In the ideal track state and random irregularity state,the dynamic characteristics of the train passing through the two turnout structures are compared and analyzed.The results show that when the train passes through the No.18 standard turnout,the wheel-rail vibration in the frog area is more intense than that in the switch area.When the train is running in the switch area of the new turnout,the stability of the vehicle is better than that of the standard turnout,and the risk of derailment of the train is slightly higher than that of the standard turnout.However,the maximum value of the derailment coefficient in the switch area is 0.2,which is less than the excellent limit of the derailment coefficient 0.6,which meets the requirements of driving safety.(4)Under the ideal track state and random irregularity state,the dynamic characteristics of the train side passing through the two turnout structures are compared and analyzed.The results show that when the train passes through the turnout,the influence of the guide curve on the lateral vibration of the car body is stronger than that of the inherent irregularity and random irregularity of the structure.When the train runs in the switch area of the new turnout,the stability of the vehicle is better than that of the standard turnout,and the derailment risk of the train is slightly higher than that of the standard turnout.However,the maximum wheel load reduction rate in the switch area is 0.2,which is less than the second limit(safer)limit of wheel load reduction rate 0.6,which meets the requirements of driving safety.