Fatigue Strength Research On High-Speed Bogie Frame

With the continuous improvement of the running speed of railway vehicles, the condition of the actual service of the components of railway vehicles becomes more and more severe, therefore, the safety and reliability requirements of which are higher and higher. High-speed bogie frame is one of the most important part of the emu, and the vibration of the frame will also affect the security of the train. In this paper, taking a new high-speed bogie frame as the research object, the fatigue life of the bogie frame under the random vibration excitation is analyzed.In this paper, the evaluation theory of fatigue vibration lifeis introduced, and the processof random vibration fatigue by using the frequency domain method and the time domain analysis is discussed. The different algorithms in the frequency domain method are made comparative analysis, and the fatigue lifeof the bogie frame by using the three interval method in frequency domain algorithm is assessed.The working modes of the bogie frame are obtained through the line experimental test, and then the modes of the bogie frame using the finite element method under the different boundary conditions are calculated. Based on the comparative analysis of the calculated modes and the working modes, more accurate finite element model is obtained.The information of random vibration excitation acceleration of the bogie frame is got by the line experiment in the time domain, and the random vibration excitation power spectrum of the bogie frame is got by Fourier Trans. The random vibration of the bogie frame for the simulation calculation is conducted by using the modal superposition method; According to the theory of Miner linear damage accumulation and the method of three interval method proposed by Steinberg, the fatigue damage of the bogie frame is predicted and the damage value at the maximize weld stress of the bogie frame under the line measured excitation is got. By analyzing the bogie frame damage under different direction random vibration excitation, the vertical excitation has the greatest influence on the lifeof the bogie frame, and the transverse excitation is the second, and the longitudinal excitation has the least influence.The damage of the bogie frame under the testing cyclic loading at the maximize weld stress are obtained through the bogie frame fatigue test. Comparison standard, the damage value of the bogie frame fatigue test and the damage value of simulation calculation are close to.