Dynamic Performance Analysis Of Wheel Lifter-Vehicle Coupling

Railway is not only a strategic and forward-looking major national infrastructure,but also an important part of our country’s transportation system.With the increase of vehicle service time and mileage,the probability of vehicle breakdown also gradually increases.In view of the situation that the vehicle can not run normally due to the failure of transmission gear stuck and bearing burn,a rescue equipment is developed,which is called "wheel lifter".As a temporary running device,the wheel lifter carries the faulty wheelset to run on the line,which is convenient for the faulty vehicle to recover its running capacity and drive off the line.In order to ensure the safety of the wheel lifter carrying the faulty vehicle,it is necessary to analyze the dynamic performance of wheel lifter–vehicle coupling model.Firstly,this thesis introduces the function and usage of the wheel lifter in railway accident rescue,and analyzes the structure and composition of the wheel lifter.The dynamics model of the vehicle,the dynamics model of the wheel lifter and the coupling dynamics model of the wheel lifter–vehicle were established by using SIMPACK software.Secondly,the influence of the three-direction positioning stiffness of wheel lifter on the stability,running stationarity,curve passing performance and turnout passing performance of the coupled model is calculated respectively.The dynamic indexes were evaluated according to relevant standards.The longitudinal positioning stiffness should be less than 30 MN/m.The value of lateral positioning stiffness should be less than 22 MN/m.The vertical positioning stiffness should be less than 14 MN/m.Then,the co-simulation of SIMPACK 2018 and the multi-objective optimization software Isight was implemented,and the integrated workflow was designed.In the meanwhile,the experimental design of the wheel lifter–vehicle coupling model was carried out.The radial basis function neural network proxy model was established by taking the threedirection positioning stiffness of wheel lifter as the input to design the variables,and the curve through the dynamic index as the output response.The model can be used for multi-objective optimization calculation,so as to obtain the optimal compromise solution of the three-direction positioning stiffness,which significantly improves the dynamic performance of the wheel lifter–vehicle coupling model.Finally,the influence of wheelbase on the running stationarity,curve passing performance and turnout passing performance of the coupling model was calculated,and the dynamics indexes were evaluated according to relevant standards.The results show that the wheelbase of wheel lifter should be 900～1350 mm.In order to ensure that the wheelbase of the wheel lifter is in the optimal range,the distance between the supporting axle of the wheel lifter and the small wheel of the wheel lifter of the general type of truck wheel lifter is 177～355 mm.For the general wheel lifter of passenger train,the distance between the supporting shaft and the small wheel of the wheel lifter is 164 ～ 339 mm.And this data in general electric locomotive wheel lifter is 116～280 mm.