An advanced train-slab track spatially coupled dynamics model: Theoretical methodologies and numerical applications

Train-slab track spatial interactions generally deal with system vibrations in vertical, lateral and longitudinal directions. In the majority of conventional dynamics models, vertical-lateral coupling effects are of main concern, and great progress has also been achieved in the field of train longitudinal dynamics in recent years. However, for modelling strategies of track structures, longitudinal coupling effects are always neglected and lateral vibration of track slab is assumed as rigid behavior. To this end, the classical vehicle-track coupled dynamics theory is extended in this paper by thoroughly implementing the track flexibility and advanced coupling relations into a three-dimensional train-slab track system. Rail axial, torsional and bending vibrations, as well as in-plane and flexural vibrations of track slab based on Kirchhoff or Mindlin plate theory, are simultaneously taken into account. Eigenvalues and forced vibrations of the track slab for both in-plane and flexural vibrations are tackled by a set of powerful trigonometric series serving as the unified trial functions. Moreover, wheel-rail, rail-track slab and track slab-base interactions are partially re-deduced due to the participation of foregoing new degrees of freedom (DOFs). The reliability of proposed dynamics model has been verified by the previous literature, ANSYS software and co-simulation technique. Comparisons between the presented model (PM) and conventional model (CM) indicate that dynamic responses are sensitive to the longitudinal coupling effects and slab in-plane vibration which should be paid adequate attention for more accurate evaluations on train-slab track interactions.