Finite element and analytical computation of flash temperature

Abstract

When sliding occurs due to over-braking of a vehicle, intense heat is generated at the rail-wheel interface due the rollingsliding motion. Sliding means a moving frictional heat source. The resulting “flash” temperature greatly influences the course of proceedings on the contact patch. A thorough analysis of the wheel/rail contact requires a FEM-based model which is able to follow the thermo-mechanical processes in close neighborhood of the contact area. In order to validate whether the mesh in the FE model is suffciently refined, analytical solutions were set up. After having performed the initial thermal finite element analysis, an analytical solution was developed for the same load case. The FE mesh was refined based on a comparison of the FE and analytical results. The effects of FE mesh size on the computational results were investigated. In certain cases, the analytical formulae derived were found to be more effective than FEM.