Simulation of dynamic interaction between train and railway turnout

Abstract

Dynamic train–track interaction is more complex in railway turnouts (switches and crossings) than that in ordinary tangent or curved tracks. Multiple contacts between wheel and rail are common, and severe impact loads with broad frequency contents are induced, when nominal wheel–rail contact conditions are disturbed because of the continuous variation in rail profiles and the discontinuities in the crossing panel. The absence of transition curves at the entry and exit of the turnout, and the cant deficiency, leads to large wheel–rail contact forces and passenger discomfort when the train is switching into the turnout track. Two alternative multibody system (MBS) models of dynamic interaction between train and a standard turnout design are developed. The first model is derived using a commercial MBS software. The second model is based on a multibody dynamics formulation, which may account for the structural flexibility of train and track components (based on finite element models and coordinate reduction methods). The variation in rail profile is accounted for by sampling the cross-section of each rail at several positions along the turnout. Contact between the back of the wheel flange and the check rail, when the wheelset is steered through the crossing, is considered. Good agreement in results from the two models is observed when the track model is taken as rigid.

Keywords:

• Dynamic train–turnout interaction
• Switches and crossings
• Wheel–rail contact geometry
• Contact forces
• Multibody dynamics

Acknowledgements

This work was performed at the Department of Applied Mechanics, Chalmers University of Technology in Gothenburg, Sweden. It forms part of the activities within the Centre of Excellence CHARMEC (CHAlmers Railway MEChanics). The partners in CHARMEC are Abetong Teknik, Banverket, Bombardier Transportation Sweden, Duroc, Green Cargo, Interfleet Technology, Lucchini Sweden, SAB WABCO, SL Infrateknik and voestalpine Bahnsysteme. Financial support is also provided by the government agency VINNOVA. Mr Heinz Ossberger and Mr Erich Scheschy of the turnout manufacturer VAE provided input data on rail cross-sections in the turnout. Mr Ingemar Persson of AB DEsolver assisted with advice on modelling in GENSYS.