Modeling of Coupling Mechanism between Ballast Bed and Track Structure of High-Speed Railway

In this paper, a discrete and continuous body coupling algorithm is used to study the dynamic contact characteristics between ballasts and between ballasts and track structures. Firstly, the three-dimensional fine modeling of ballast particles is realized based on the three-dimensional laser scanning method, and then through the discrete and continuum coupling algorithm from the micro-macro point of view, a multiscale and unified particle-track structure coupling model is established. Based on the coupling model, the macro- and microdynamic characteristics of the ballast bed and the mechanical characteristics of the track structure under the dynamic load of high-speed trains with different driving speeds are studied. It is shown that the cumulative settlement of the ballast bed is directly proportional to the contact force and rotation speed of the ballast, and the faster the driving speed is, the greater the cumulative deposition speed and cumulative settlement of the ballast are. The contact force between the ballast and sleeper mainly comes from the bottom of the sleeper, and its contact force and contact strength increase with the increase of driving speed.