Effects analysis of curve geometric parameters on wheel/rail dynamic interactions between different freight bogies

The 27 t axle load side-frame cross-braced bogie and sub-frame radial bogie are the two heavy haul freight bogie developed recently in China. In order to comparatively study the curving performance of the two bogies， and analyze the influence characteristics of the curve geometric parameters and the excitation of track spectrum on wheel-rail dynamic interaction of different freight bogies， the heavy haul freight vehicle-track coupled dynamic model and the parameterized curved track model are established，where the structure， the technical parameters of the bogies and the related requirements of heavy haul curved track are comprehensively considered. The results indicate that ， the sub-frame radial bogie has relative advantages of curving performance on small radius curves （R≤800 m）， and the smaller the curve radius is， the more advantage it has， but the increase of curve radius and track spectrum excitation will weaken the advantage. The dynamic responses of the two bogies to the changes of rail superelevation and length of transition curve are basically the same， the comprehensive wheel/rail dynamic responses of both bogies are small within the deficient superelevation value （0~15 mm）. There is an inflexion point for the length of transition curve， and the inflexion values of both bogies are almost the same. When the speed is 80 km/h and the curve radius is 800 m， the calculated inflexion value is about 50 m， which is consistent with the minimum length of transition curve specified in the standard of Code for Design of Heavy Haul Railway （TB 10627—2017）.