Extrapolation Analysis Of Load Spectrum And Stress Spectrum Of High-Speed Train Axle And Establishment Of Spectrum Of Experimental Bench

The axle is one of the most critical parts of the high-speed EMU,its fatigue structure reliability problem is directly related to the overall safe and stable operation of the train.The axle loading spectrum serves as the basis for fatigue reliability and life analysis,the preparation of the full-life loading spectrum and test bench loading spectrum are of great value to the fatigue life analysis of axle.This paper processes the line measured stress data of CRH2 A high-speed train axles,and combines the nonparametric nuclear density estimation technology to carry out the fitting extrapolation analysis of load spectrum and stress spectrum.The main research contents of this paper are as follows:First,carrying out the loading simulation calculation of the established wheel axle finite element model under three different line working conditions of straight line,curve and turnout.The force situation of the wheel axle under different working conditions is analyzed and the specific position of the key section of the axle is determined,and the force measuring wheel is verified.The rationality of the placement of the patch;analyze the results of the static calibration test of the axle,and calculate the axle vertical and lateral load stress transfer coefficients;Second,analyzing and processing the measured dynamic stress signal of the line obtained by the force measuring wheel pair,and combine the stress-load transfer coefficient to obtain the corresponding wheel axle load-time history;analyze the stress of the key section of the axle and the axle vertical under different line conditions And the time-domain signal change trend of lateral load,the rainflow counting method was used to compile the load spectrum and stress spectrum under different line conditions;the load spectrum and stress spectrum under different line conditions were analyzed and compared,and Compiled the load spectrum and stress spectrum of the entire wheel and axle measurement;Third,appropriate fitting sample data was selected,the parametric fitting method and the non-parametric kernel density estimation fitting method were compared and analyzed,and the non-parametric kernel density estimation method was used to fit and extrapolate the load spectrum and stress spectrum under the selected typical line In terms of probability density analysis,damage check and extreme value,the extended spectrum after linear extrapolation and fitting extrapolation is compared and analyzed with the measured whole spectrum,and the accuracy of the fitting extrapolation method is verified.The fitting method of non-parametric kernel density estimation is used to extrapolate the measured whole load spectrum and stress spectrum to the whole life load spectrum and stress spectrum,and compare and analyze with the whole life load spectrum obtained based on the time domain extrapolation method of POT model.Verify the accuracy of the kernel density estimation fitting extrapolation method;Fourth,based on the full-life extended load spectrum after fitting extrapolation,according to the Miner linear cumulative damage theory and using the non-equal interval ratio coefficient method to calculate the experimental platform spectral load amplitude,according to the principle of equivalent damage to complete the load The compilation of the 4-level load spectrum provides a test basis for further research on the optimization of wheel and axle structure and fatigue life.There are 64 pictures,34 tables and 51 references.