Development of a real-time wheel/rail contact model in NUCARS^®1and application to diamond crossing and turnout design simulations

Abstract

A new, stable, multi-point penetration wheel/rail (w/r) contact algorithm has been developed for the NUCARS ® vehicle/track interaction multi-body simulation program. This algorithm resolves previous problems with integration instabilities during wheel flange contact. Contact geometry comparisons using both the standard rigid and new penetration contact models show that the new penetration model correctly calculates the constrained contact geometry for a range of wheel diameters and contact angles. The critical conditions for multiple solutions for w/r profile combinations with steep flanges and the methodologies to account for this problem in NUCARS are also discussed.Applications of the new w/r contact algorithm to diamond crossing and turnout design simulations are presented and compared with test data. These results show that the revised real-time w/r penetration contact model and the flexible track model with rail profile variation capability in NUCARS provide a promising tool for the advanced analysis of special track work.

A new rolling contact method applied to conformal contact and the train–turnout interaction

“…E. Kassa et al [10] simulated the vehicle-turnout interaction; they accounted for random deviations from the nominal track geometry, but FASTSIM was also used as the wheel-rail contact model. Shu et al [11] performed simulations for vehicles in turnouts. Their model was able to detect multiple-point contact and calculate the penetration depth, but the tangential contact problem which is necessary for wear prediction was ignored.…”

Method for evaluating the performance of railway crossing rails after long-term service

“…The dynamic wheel/crossing interaction can be analyzed using the multi-body dynamics (MBD) method, the finite element (FE) method or some combination of the two. In the MBD model, the vehicle and track components are simplified as a combination of rigid or flexible bodies, springs and dampers [7][8][9][10][11][12]. The MBD method requires a limited number of degrees of freedom, and thus the computation procedure is fast.…”

Fast estimation of the derailment risk of a braking train in curves and turnouts

“…Other authors have focused on the wheel-rail contact in turnouts, which is complex due to the profiles of the switch blade and the crossing. Wiest et al [16] and Shu et al [17] focused on the normal contact problem, while Burgelman et al [18] considered the tangential problem. To the authors' knowledge, all the models in the literature to date have included a single vehicle coasting through a turnout.…”