A method to determine the two-point contact zone and transfer of wheel-rail forces in a turnout

A practical method to determine the zone of two contact points and the transfer of wheel-rail forces between two rails in a turnout is presented in this paper. The method is based on a wheel-rail elastic penetration assumption and used to study a turnout system for a 200 km/h high-speed railway in China. Rail profiles in a number of key sections in the turnout are identified first, and profiles in other sections are then obtained by interpolation between key sections. The track is modelled as flexible with rails and sleepers represented by beams and the interaction between the vehicle and turnout is simulated for cases of the vehicle passing the turnout. Results are mainly presented for two-point contact positions and the characteristics of the wheel-rail forces transference. It is found that the heights of the switch and crossing rail top have significant effects on the wheel-rail contact forces. Finally, the optimised top height for the crossing rails is proposed to reduce the system dynamic force in the turnout system.