Study On Load Spectrum Of 400 Km/h EMU Bogie Frame

In order to meet the development requirements of China high-speed railway,build a world-class independent brand with Chinese characteristics,at the same time as the higher speed train passenger equipment reliability evaluation and fully meet the relevant standard equipment for fatigue reliability design of key technology research put forward the need to upgrade,we bring forward research on key technology of high speed passenger transport equipment with more than 400 kilometers per hour.Bogie frame is the key bearing part of train.It plays a decisive role in vehicle running gear.Fatigue strength evaluation and reliability design must be carried out.The load borne by the frame is the basis for fatigue strength evaluation.Therefore,this paper mainly studies the load of the 400 km/h bogie frame,which provides reference and guidance for the design,research and test of the 400 km/h bogie frame.Since the 400 km/h bogie frame load is still unable to get through the line measure,therefore China standard EMU as the research object,using the structure load and the measured damage data of the typical line at the 240km/h-380km/h speed level of Zhengxu passenger dedicated line,through the load spectrum distribution fitting,establish the function relation between the load of the frame with the speed of 400 kilometers per hour,so as to obtain the bogie frame load spectrum.First,the load and strain transfer coefficient and the load stress transfer coefficient of the frame are obtained through the calibration test.Then the line tests are carried out on the Zheng Xu passenger dedicated line at different speeds,and the load time history of the frame under different speeds is obtained through data processing.Combined with speed and gyroscope signal,load characteristics of main load and local load under straight speed and curvilinear working conditions are analyzed.The load types that are sensitive to straight curve and speed are obtained,which lays the foundation for the establishment of 400 km/h bogie frame load spectrum.At the same time,the load spectrum of the speed 350km/h bogie frame is set up,Which is used as an example to calibrate the damage consistency,the damage calculated by the established load spectrum covers the actual damage of the key points of the frame.We choose 6 kinds of bogie frame load which are sensitive to speed,and study their characteristics of loading spectrum under different speeds of line and curve respectively.Then use Weibull distribution to fit to it,and the Weibull fitting parameters of these 6 load spectra are obtained.Fitting the parameters and velocities of Weibull fitting with quadratic polynomial,we get the function relation between speed and Weibull fitting parameters,and get the Weibull distribution parameter of 400 km/h bogie frame load spectrum.The same with quadratic polynomial to determine the 400 km/h bogie frame of the load spectrum of the maximum value,divided into 16 equal parts,after determining the load spectrum of the total frequency,By using the inverse solution of Weibull distribution function,the frequency of each load amplitude corresponding to each level is obtained,and the load spectrum of the 400 km/h bogie frame is obtained.