The influence of operation variables on stress spectrum of high-speed train bogie frames

Dynamic load histories of vulnerable fatigue sites in structures are of paramount importance for safety design, and such load-time histories with long duration are usually lumped together to a load spectrum for safety assessment. In this paper, long-term field tests involving several operation variables, including track types, operation speeds, passenger lines, trains and their in-service time, were carried out to obtain stress-time histories of the bogie frame of high-speed trains. By comparing the stress spectra from different operation conditions, we identified the correlation between operation variables and the characteristics of stress spectra. It was found that both track type and operation speed play a prominent role in the magnitudes of stress spectra. Combined with the segmented Weibull model, we quantified the impact of operation variables on damage and confirmed that the inflection stress in the segmented Weibull model can be used as a measure of track status. The results revealed in this report could help obtain a systematic understanding of the fatigue performance of structures of complex dynamic systems like high-speed trains.