Research on characterization methods for track irregularities

Abstract The characterization of track irregularities is crucial in railway dynamics, as track irregularities are the primary source of internal excitation in railway systems. In this paper, three mathematical models are proposed to characterize the track irregularities under different circumstances. The first model is a novel explicit track spectrum function, which performs better in reflecting the inherent periodic components of track irregularities than the existing track spectra. On this foundation, the second model, a parameterized track spectrum random model, is proposed to represent the vast measured track irregularities from the probabilistic perspective. Finally, the third model, an imprecise track spectrum interval model based on a neighborhood uniform sampling Bootstrap method, is presented to identify the confidential interval of the track spectra when the track irregularity data are limited. Three examples are illustrated to demonstrate the feasibility of the three track irregularity models in characterizing the track irregularities in different conditions. This research can help capture the railway deformation status and optimize track maintenance strategies.