Abstract: The influence of the wheel axle bending stiffness to the wheel/rail vertical dynamical load and wheelset vertical vibration was investigated on a vehicle of the Beijing metro railway. Based on the general multi-body dynamics model and the two kinds of elastic wheelset models, combined with BM3000 type wheelset and the wheelset adopted by the vehicles of the Beijing metro railway, a comparison is carried out between the wheelset vertical vibration and the wheel/rail vertical contact force which adopted the rigid and elastic wheelset model. Simulation results show that the wheelset vibration and the wheel/rail contact force of the elastic wheelset model is different with that of the rigid wheelset model; this is due to the BM3000 type wheelset not having high enough bending stiffness, the deviation between the two models increases with running speed. In contrast, the results of the elastic wheelset model of the wheelset of the Beijing metro railway vehicle is quite similar to the results of the rigid model and both the wheelset vibration value and frequency exhibit an obvious decrease since it has a larger bending stiffness. Consequently, the wheelset vibration and wheel/rail contact force can be improved by increasing the wheel axle bending stiffness which will improve wheel/rail dynamic contact conditions.

Key words: Vertical acceleration, Wheel axle stiffness, Wheel/rail force, Wheelset