Numerical Model of the Railway Brake Disk for the Temperature and Axial Thermal Stress Analyses

Increases in speeds and traffic density in railway sector impose challenges on the modern disk-pad brake systems such as higher temperatures and stresses resulting in hot-spots and a degraded system performance. The prediction of disk thermal behavior under challenging conditions has become an important engineering issue. In this study, a model is developed using the finite difference method (FDM) with realistic time-dependent boundary conditions and experimental convection correlations with non-uniform time-step size features. A previous numerical/experimental study on the thermal behavior of railway disc brake is partly adopted and enhanced. The results of the developed model agree well with the results of the previous study. A practical prediction method for thermal stresses in the disk is applied using the axial temperature distributions at several time instants from locations with highest temperature. Furthermore, same configuration of the disc with the pad is modelled in Simcenter STAR-CCM+ which is a validated commercial CFD software to compare the results and computation times with that of the developed model. Using this model, an investigation has been conducted on the effect of temperature-dependent material properties on thermal behavior. The developed numerical model can simulate the conditions experienced by a railway disk in a relatively new standard considering the transient thermal behavior and axial thermal stress distribution with relatively low computational time and reasonable accuracy. Also, valuable insights are obtained on the effect of variable thermal properties of the disk and convection correlations on the disk thermal behavior.