A fast method for determination of creep forces in non-Hertzian contact of wheel and rail based on a book of tables

The Kalker book of tables for non-Hertzian contact described in a previous work from the authors provides creep forces, but the moment generated in the contact patch is not available. The extended Kalker book of tables for non-Hertzian contact (KBTNH) presented in this paper provides creep forces, as well as the moment. The paper presents the simplified linear theory of rolling contact for a simple double-elliptical contact (SDEC) region used for regularisation of contact patches and, resulting from this theory, the full symmetry relations for creep forces and moment. The parameterisation of variables and structure of the extended book of tables are described. The extended Kalker book of tables of moderate volume has been computed in co-simulation Matlab-CONTACT. The creep forces and moment obtained from KBTNH have been compared to those obtained directly by CONTACT program and FASTSIM algorithm. The comparison shows that KBTNH is in good agreement with CONTACT for a wide range of creepage conditions and shapes of the contact patch, whereas the use of FASTSIM may lead to significant deviations from the reference CONTACT solutions. The presented example of application is a realistic case of a freight wagon curving simulation, where KBTNH has been used to assess the contribution of the moment into the unit frictional work dissipated in contacts of wheels and rails. The high calculation speed and good accuracy of determining creep forces for non-Hertzian wheel–rail contact make the proposed method a suitable tool for multibody system (MBS) simulation programs oriented for rail vehicle dynamics.