Abstract: With the continuous improvement of train operating speed, the sanding device connected at the end of the bogie frame of a high-speed train is subjected to complex loads and vibrates violently during service, which easily leads to vibration fatigue failure. To study the vibration fatigue damage of the sanding device, the finite element model is established by ANSYS software to analyse the modal characteristics and vibration transfer law of the sanding device and the frame end. Combined with the Dirlik method and Miner linear cumulative damage law, the structural damage under the standard acceleration spectrum and line acceleration spectrum is simulated, and verified by bench tests. The vibration fatigue damage calculation process is established to predict the damage of 15 million km. The results show that the first-order modal frequency of the sanding device is close to the first-order dominant frequency of the bench sweep test, and the error is 2%. From the frame end to the sanding device, the displacement response under unit acceleration excitation is magnified and the vibration is intensified. Under two kinds of acceleration spectrum, the fatigue damage error obtained by simulation and bench tests is less than 20%, and the larger damage position is mainly distributed at the outer welding seam of the axle box spring cap barrel at the frame end and the circular base metal of the upper part of the sanding device. The maximum damage of the structure at 15 million km under the line acceleration spectrum is 0.71, which is much higher than the standard acceleration spectrum. Therefore, when designing and evaluating the end and connecting parts of the bogie frame, the influence of line conditions and structural modes should be fully considered to avoid the occurrence of insufficient service life caused by standards design and evaluation only.

Key words: sanding device, random vibration, power spectral density, frequency domain characteristics, fatigue damage