Influence of differential deterioration of random track irregularity at different wavelengths on high-speed train safety

To reveal the influence of differential deterioration of random irregularity at different wavelengths on train safety. Based on the vehicle-track coupling dynamics and the optimized wavelet theory, irregularity samples of typical wavelengths with different deterioration degrees are reconstructed, Henceforth, the postures of the vehicle during the whole derailment process is simulated, during which the derailment risks are revealed. The research shows that the wavelength range of most potential threat to train safety is less than 1 m and greater than 32 m to speed-up line. Train derailment posture is sudden and the safety margin of Nadal criterion is appropriate when the wavelength of track irregularity is less than derailment posture mutation wavelength (DCMW). By contrast, when the wavelength is greater than DCMW, derailment posture is a gradual process, and the safety margin of Nadal criterion is too large. The results can provide theoretical guidance for the fine maintenance and safety monitoring of track geometric.