Research On Load Characteristics Of Standard EMU Bogie Frame Based On Tracking Test

With the on-line operation of the standard EMU,it marks the maturity of the nine key technologies of the EMUs independently developed by China and has been successfully put into use.One of the key technologies is the high-speed bogie,which is used for carrying,guiding and damping during the operation of the vehicle,and is also the final actuator for traction and braking.The frame is the main component of the bogie and is the carrier that connects the wheelset to the car body.Whether the fatigue strength of the frame meets the requirements is directly related to the operational safety of the vehicle.This paper takes the normal operation of the A-type and B-type standard EMUs on the Beijing-Guangzhou line as the research object,and participates in the tracking test for a long time.Based on the load data of the bogie frame obtained by the line test,the main research contents of this paper are as follows:(1)Using nCode software to process the measured data of the two vehicles,obtain the equivalent stress and equivalent load amplitude of each measuring point according to the linear cumulative damage theory and the equal damage principle,and compare with the fatigue allowable stress value of the welded joint.The result indicates the structure.The fatigue life meets the design requirements of the EMU 15 million kilometers.Comparing the structural characteristics of the two-vehicle frame,the reasons for the difference in the stress of the two-vehicle frame are analyzed,and the floating-sink,roll,torsion and lateral load of the two-vehicle frame under five typical conditions are compared and analyzed.(2)Counting and counting the 11 loads time history of the two-vehicle frame respectively,compiling the load spectrum and fitting the Weibull distribution,using the r-test to test the curve fitting effect,and obtaining the Weibull of each load spectrum distribution of three parameter values x0,xa,b.(3)Select 27 one-way test samples in one round cycle as the total sample,and use W test to judge whether the distribution fitting parameters of each load obey the normal distribution.Under the 95%confidence level,the homogeneity test and the T test are performed on the normal distribution population,and the non-parametric test is performed on the non-normal population to determine the minimum number of samples that can reflect the population selected for the segment,and finally all the loads.The maximum of the minimum number of samples in the fitted parameters is taken as the minimum number of samples in the population.In order to achieve the purpose of shortening the test time and saving the test cost.(4)Establishing the vehicle dynamics model of the standard EMU,and obtaining the time history of the floating and sinking,load,torsion and lateral load of the frame under straight and curved conditions,and comparing with the measured load,which proves the feasibility of dynamic simulation.Set the super-high volume of different orbits and analyze the influence of super-high volume on the frame load.103 figures,26 tables,62 references.