Establishment And Application Analysis Of CR400 High-Speed Wheel-set Stress Spectrum And Load Spectrum

As the train running speed increases,the fatigue strength and fatigue life of the axles are particularly important as the important moving parts of high-speed trains,especially when the axles are defective,which poses a great threat to the safety of high-speed trains.In this paper,the axle of the CR400 is taken as the research object,and the crack initiation spectrum and crack initiation life of the axle load spectrum and the notched axle are analyzed.The main work is as follows:(1)Static calibration test:Explain the principle of continuous measurement of wheelsets,briefly describe the scheme and working conditions of the calibration test.The calibration data is fitted by the least squares method,and the vertical load transfer coefficient and the lateral load transfer coefficient of the wheel and rail force are obtained after analyzing the influence of loading position and loading angle to the instrumented wheel-sets bridge based on the principle of quasi-static method.(2)Compilation of the measured axle load spectrum of the line:The data collected by the line test and test is analyzed and processed,and the load spectrum showing the load amplitude and corresponding frequency of the axle during the test is obtained.The rules of train operation under different speed grades and different load conditions are analyze.d.(3)Estimation of the crack initiation life:Three different shapes of notches are introduced at one of the three measuring points of the finite element model of the axle,and the stress concentration factor of the notch is calculated by finite element simulation,and the corresponding fatigue notch coefficient is obtained.The notched S-N curve was estimated by a smooth sample S-N curve in combination with the coefficients mentioned above.The notch S-N curve is applied to the Miner linear cumulative damage calculation method The crack initiation life of the axle under different shape notches is calculated,and the influence of the notch shape on the crack initiation life is analyzed.(4)Prediction of crack propagation life:The gap used in the previous calculation is simplified as a crack and introduced into a measuring point on the axle.The Paris equation is combined with Newman's interpretation of the effective stress intensity factor.After inputting the measured load spectrum,the remaining life of the axle corresponding to the cracks of three different shapes is calculated.