Research on short-wave irregularity spectrum of urban rail surface
Addressing the issue of vibration-induced noise in urban rail transit, this study investi-gates the short-wave irregularities of rail surfaces. Initially, preprocessing is applied to the mea-sured short-wave irregularity data from Shanghai's urban rail transit lines, involving zero aver-aging, outlier removal, and trend item elimination. Then, utilizing an enhanced covariance method, the power spectrum of short-wave irregularities on rail surfaces is computed. The study analyzes the impact of track types, curve radius, and rail joints on the distribution patterns of power spectra related to short-wave irregularities. Moreover, employing a nonlinear least squaremethod, a fitting is performed on the short-wave irregularity spectrum of the rail surface. Fi-nally, a statistical expression for the short-wave irregularity spectrum of urban rail transit rail surfaces in China is proposed. The results show that the power spectral density curve of short-wave irregularities on rail surfaces in straight joint sections exhibits numerous characteristic peaks across the entire wavelength range. There is little difference in the distribution characteris-tics and values of short-wave irregularity spectral density between the upper and lower frequen-cies in the straight joint area, indicating a fundamentally consistent irregularity state in both di-rections. The wear degree of the rail is negatively correlated with the curve radius, and the dis-parity in power spectral density between the inner and outer rail surfaces decreases with increas-ing curve radius, highlighting curve radius as a principal factor influencing rail surface irregulari-ties. The impact of line type on the short-wave irregularity power spectrum of rail surfaces is marginal, while distinctions are evident for various curve radius and welded joints. When con-ducting track maintenance, attention should be directed towards the irregularity states in sec-tions characterized by small curve radius and welded joints.
万方数据
维普
