The effect of rolling speed on lateral adhesion at wheel/rail interface under dry and wet condition.

A rolling contact two disk test rig is used to measure the lateral adhesion ratio under dry and wet conditions, and the results show that after the application of water the lateral adhesion ratio decreases. This effect is especially evident for low speed at large angle of attack, and the reduction rate is almost up to 50%. In contrast, the effect of water application on the lateral adhesion ratio at high speed is almost negligible. In this research, the effect of rolling speed on the lateral adhesion ratio under dry and wet conditions are also investigated. It is found that the lateral adhesion ratio decreases with rolling speed under dry conditions; while after the application of water, the measured results show an opposite trend. Furthermore, a model of wheel/rail contact mechanics is developed based on previous models and experimental measurements. Using this model, the simulated friction creep curves shift down with the increase of rolling speed. In comparison with previous mathematicla models, the correlations of this theoretical model with measured lateral adhesion ratios at various rolling speeds are much improved. Hereby, the authors would like to highlight the following innovations and contributions of this paper. ● The lateral adhesion ratios at various yaw angles and rolling speed are measured under dry and wet condition, and the effect of water application is investigated. ● The effect of rolling speed on lateral adhesion ratio under wet condition is investigated and illustrated, and the effects of low speed and high speed are compared. ● A theoretical model for wheel/rail contact in the lateral direction based on the contact theory of Kalker is developed and its correlation with experimental measurements is much improved. [ABSTRACT FROM AUTHOR]