Analysis of Rolling Contact between Wheel and Rail in Switch Area

In order to study the wheel-rail matching relationship and applicability of the classical wheel-rail contact theory in turnout area, the finite element model of the wheel-rail contact in switch area was established, and several calculation programs of the normal force and tangential force on switch were compiled. By taking the typical section of the No. 18 high-speed switch rail area and the switch frog area as an example, the contact patch area and contact stress in the rolling contact theories of the Hertz, semi-Hertz, Kalker three-dimensional non-Hertz and the finite element model are compared in the normal direction. The creep forces calculated by the FASTSIM algorithm based on Hertz and semi-Hertz, the Polach model and CONTACT are compared under different working conditions. The calculation results show that as the stress-strain characteristics of the wheel-rail material is considered in the finite element model, the result is closer to the actual working conditions. The maximum difference between the contact patch areas of Hertz, semi-Hertz, Kalker non-Hertz and finite element method 50.42%, 17.83% and 24.78%. The maximum difference in contact stress is 60.28%, 25.25% and 32.37%. Under the different working conditions, the creep force of the four tangential force models shows the same trend with the varying creep rate. Under the same working condition, the maximum difference between the creep forces calculated by CONTACT, FASTSIM algorithm based on Hertz and half Hertz and the Polach model are 8.08%, 5.19%, and 9.70%. According to the calculation accuracy of the switch in the normal and tangential directions and computational efficiency, the semi-hertz contact theory combined with the FASTSIM algorithm has advantages in large-scale data processing.