Development of spatial vehicle-track coupled dynamic model for rack railway

To understand the basic dynamic characteristics of the rack vehicle and improve the rack vehicle dynamics theory, based on gear system dynamics and vehicle-track coupled dynamics, an advanced rack vehicle-track(rack) coupled dynamic model (RVTM) is established in this paper. Moreover, effectiveness and accuracy of RVTM is validated by engineering test. Finally, based on RVTM, the basic dynamic characteristics of rack vehicle are studied. Results show that the RVTM established in this paper is effective and has high calculation accuracy. The predominant frequencies of vertical and lateral acceleration of carbody are mainly in the range of 1–3 Hz, and the lateral acceleration is smaller. Wheel-rail contact force includes low frequency component of 3–4 Hz caused by carbody vibration and high frequency component caused by wheel-rail deformation coupled resonance. The vibration frequency of vertical acceleration is 6–7 Hz, which is mainly caused by track irregularity. The main frequency of gear-rack meshing force is distributed in 60–70 Hz. The maximum nonlinear Hertz pressure is low frequency of 28–35 Hz and medium-low frequency of 55–69 Hz. RVTM can be well applied to the research on the dynamic characteristics, dynamic stability and the influence of system parameters on the dynamic characteristics of rack vehicle system, and also has reference value for engineering application design.