A PDEM-Based Research on the Impact of Stochasticity in the Inside Distance Between the Wheelset on the Vehicle-Turnout Coupling System

The inside distance between the wheelset is one of the most important influencing factors of the wheel-rail contact.By varying this factor, the corresponding comprehensive performance of a train passing through a turnout is hard to demonstrate through traditional methods.The application of stochastic theory is crucial.This paper constructs a stochastic field of variation of the inside distance between the wheelset.By employing the modal superposition method, a coupled vehicle-turnout multi-body dynamics system was built with rail flexibility considered via the ABAQUS-SIMPACK platform.The probability density function (PDF) of lateral displacement of the wheelset and the vertical wheel force were determined based on the generalized probability density equation (GDEE).The results show that the variation of inside distance between the wheelset can cause dispersion of lateral displacement of the wheelset in both the closure panel and the area behind the wheel load transition in the crossing panel.The vertical wheel forces in both the switch panel and the crossing panel present a more significant stochasticity while relatively concentrated in other areas.The maximum variation range is approximately 5 kilonewton (kN).Increase of the inside distance between the wheelset can exacerbate the lateral deviation of the wheelset towards the straight stock rail during wheel load transition in the switch panel, and can make the wheelset easier to align with the centreline of the track.The position of wheel load transition is advanced from about 240 to 250 mm in the switch panel, while that in the crossing panel hardly changes.