Vehicle-track random vibrations considering spatial frequency coherence of track irregularitives
Lei Xu, Yongsheng Zhao, Zixu Zhu, Zheng Li, Hubing Liu, Zhiwu Yu
Abstract
To disclose the possible dynamic behaviours of vehicle-track systems subject to an entire railway network, random vibration analysis is of great concern in railway engineering due to the system geometric and parametric uncertainties. In this work, an emphasis is therefore put on the highly efficient simulation and numerical analysis of track geometry excitation and its induced system uncertain behaviours. Considering the spatial variability, frequency coherence and constant evolution of track irregularities, the random analysis of track irregularities belongs to a big data analysis scope. By introducing practical tools of power spectral density (PSD), frequency coherence analysis and correlated variable random simulation method, a strategy for obtaining representative and realistic track irregularity PSD samples is proposed. Besides, the modelling method of vehicle-track interactions, where versatile programming tactics to couple the track slab and subgrade elements with incompatible elemental sizes, is introduced. By combining the simulation methods of track irregularities and vehicle-track dynamic interaction, the dynamic performance of vehicle-track systems can be evaluated efficiently, and the full view of system dynamics is revealed with probabilistic characteristics.