AbstractFriction is the bond linking the tangential and normal forces at the wheel-rail interface. Modeling friction is the precondition for the wheel-rail adhesion calculation. In this work, the critical role of friction in the calculation of wheel-rail adhesion is discussed. Four types of friction models (Coulomb model, linear model + Coulomb model, rational model and exponential model) which are commonly used for the calculation of wheel-rail adhesion are reviewed, in particular with regard to their structural characteristics and application state. The adhesion coefficients calculated from these four friction models using the Polach model are analyzed by comparison with the measured values. The rational model and the exponential model are more flexible for defining the falling friction, and the adhesion coefficient calculated by these two models is highly consistent with the measured one. Though the rational model and exponential model describe the falling friction well, the existing friction models are not applicable for calculating adhesion after considering more realistic factors, such as thermal effect, contaminants and so on. Developing a novel and practical friction model to accurately describe the wheel-rail friction behavior is still an essential but challenging and significant task. This review provides a reference for the selection of existing friction models and generates fresh insights into developing novel and practical friction models.
A Review on the Application of Friction Models in Wheel-Rail Adhesion Calculation
