Abstract: The curving performance of a rail vehicle may be significantly enhanced by employing either active or forced steering bogies. Nevertheless, the transient dynamics at the transition curve differ between these two types of steering bogies due to their distinct steering mechanisms. Moreover, as both active and forced steering bogies alter the structure and physical topology of a conventional bogie suspension, the manner in which the same dynamic parameters influence curving performance might also exhibit discrepancies. To address these questions, active and forced steering vehicle dynamics models have been established in this study, followed by an analysis of the curving performance of both vehicles on two typical curves. Findings have revealed that a geometric inertia lag is experienced by the forced-steering bogie, thereby diminishing its curving performance during transitions curve. If the response lag of the active steering system remains below one third of the vehicle pitch and the maximum speed of movement does not fall short of 6.5 mm/s, the curving performance of the active steering bogie has been shown to surpass that of the forced steering bogie. Then a sensitivity analysis method has been employed, with the wear number utilized as an indicator, to comprehensively contrast the influence patterns of key dynamic parameters on the curving performance of conventional, active steering, and forced steering bogies. Results have demonstrated that the wheelset steering behavior is decoupled from the primary suspension stiffness by active and forced steering bogies, thereby enabling the elimination of primary suspension stiffness constraints on curving performance during parametric design, which brings convenient to bogie design.

Key words: steering bogie, dynamics, curving performance, sensitivity analysis