Dynamic vehicle response on horizontal curves equivalent to turnout curves through Swedish UIC60 turnouts

Abstract

In conjunction with an evaluation of vehicle dynamics on horizontal curves where transition curves are not used, the Swedish turnout geometries have been evaluated. The study quantifies the dynamic vehicle response on alignments according to Swedish UIC60 turnouts and compares it with vehicle response on limiting cases according to applicable track standards. Vehicle dynamics is quantified where there are curves in opposite directions, as in crossovers with 4.5 m track distance. Vehicle dynamics is also illustrated where there are circular curves in the same direction, connected by a short intermediate straight. When a vehicle enters a circular curve, there will be a transient change from the lateral steady-state position on the straight to a new steady-state position on the curve. The simulations show that this transient change in position increases the dynamic lateral wheel/rail forces at the wheel/rail interface compared to the steady-state values on the circular curve. For each curve entry, there is an unfavourable peak load. Such peak loads occur both on circular curves in opposite directions and on circular curves in the same direction that are connected with a short intermediate straight.