Dynamic analysis of heavy-haul train-track-bridge system in curved section considering friction wedge of wagon

Dynamic interactions in heavy-haul train-track-bridge systems (HTTBS) are significantly influenced by the curvature of a railway line on the bridge, which could intensify structural vibrations and even jeopardize train running safety. This study investigates the coupling dynamics features of the HTTBS in curved sections, incorporating the nonlinear friction behavior of wedges in the secondary suspension of wagon, a factor often overlooked in the previous studies. Firstly, a coupled dynamics model for HTTBS is developed using the D’Alembert principle and finite element method, with its accuracy validated by a field test of a heavy-haul train passing through a curved bridge. The phenomenon of integer-multiple frequencies of bridge vibrations is captured and analytically clarified. Subsequently, the effects of nonlinear friction wedge and equivalent linear damping models on HTTBS dynamic performance are compared, revealing significant differences in system responses—particularly the linear model’s underestimation of bridge low-frequency vibrations. Finally, the effects of train speed and track superelevation on curved HTTBS dynamics are investigated. Results demonstrate that speed influences almost all the discussed dynamic responses, while superelevation primarily affects safety and lateral deformation indices. The research results emphasize the importance of controlling speed and superelevation for heavy-haul trains traversing curved bridge sections.