Time-Frequence Analysis And Prediction Study On Track Irregularities

The track irregularity has a very important influence on railway vehicle system. Firstly, track irregularity is the excitation source to the wheel-rail system, and is the main causes of the locomotive and rolling stock vibration and the dynamic force of wheel-rail. It has an important influence on the transportation safety, steady, ride quality, lifecycle of the vehicles and the track component as well as the circumstance noise. Track irregularity is the primary factor in track aspect to limits train speed. Secondly, the condition of track irregularity indicates the synthetic performance and bearing capacity of the track structure. The condition of track irregularity is an important index for the railway administration department to advise the service plan.Therefore, it has important theory and practical value for railway safety to study on the track irregularity. Based on the recent research results, this paper focuses on three main aspects of track irregularity, which are the track spectrum, time-frequency analysis and trend predicting.(1) The track irregularity data from China railway, such as the Jing-Guang, Jing-Ha, Jing-Hu, Long-Hai railway and so on, were analyzed. Simultaneously, the track spectra of non ballast track irregularity and the compound track irregularity were analyzed.(2) Based on the domestic and foreign track spectrum model and a mass of tested calculation, the fitting model of track spectrum which indicates the character of China railway was proposed. The optimization parameters of fitting track spectrums were educed by nonlinear curve-fitting in the least-squares sense.(3) In order to study the unified formula of national track spectrum, the track spectra was fitted. The research showed that the proposed track spectrum formula in this paper could fit well recent track spectrum. Based on the calculation of track spectrum, the form of general track spectrum was debated. Meantime, a set of Chinese general track spectrum which was divided into three levels according to the railway speed grade was proposed. The upper and lower limits track spectra of the 200km/h, 160km/h and 120km/h railway lines were proposed to evaluate the track spectrum.