Simulation of train–turnout interaction and plastic deformation of rail profiles

Abstract

Railway turnouts (switches and crossings) require more maintenance than other parts of the railway network. Multiple wheel–rail contacts are common, and impact loads with large magnitudes are generated when the conventional wheel–rail contact conditions are disturbed at various locations along the turnout. The dynamic interaction between train and turnout is simulated in order to predict the forces and creepages in the wheel–rail contacts, and the sizes and locations of the contact patches. Furthermore, the change in rail profile because of plastic deformation is calculated by finite element analysis at a selected position along the switch rail. Contact loads and contact locations, taken from the vehicle dynamics simulation, are then used as input data in the finite element analysis. The objective of the study is to gain knowledge about the influence of different damage mechanisms on the life of a turnout. This is useful in an optimization of turnout geometry with the purpose to improve vehicle ride dynamics and to decrease maintenance costs.

Keywords:

• Dynamic train–turnout interaction
• Plastic deformation
• Ratchetting
• Switches and crossings
• Wheel–rail contact geometry

Acknowledgements

This work was performed as part of the activities within CHARMEC (CHAlmers Railway MEChanics). Docents Jens Nielsen and Magnus Ekh at the Department of Applied Mechanics, Chalmers University of Technology are acknowledged for their valuable comments on this study. Mr Heinz Ossberger and Mr Erich Scheschy of the turnout manufacturer VAE provided input data on rail cross-sections in the turnout. Mr Alexander Santos at SL Infrateknik is acknowledged for carrying out the Miniprof measurements.