Adhesion experiment on a wheel/rail system and its numerical analysis

Abstract

The experiment on the adhesion coefficient of a wheel-rail system has been carried out by means of a full-scale test facility under the condition of different axle loads and rolling speeds. The effects of the condition of the wheel-rail contact surfaces, such as a clean and dry surface, water and oil contamination and slip, on the adhesion coefficient have been investigated in the experiment. The experimental results show that, when the rolling speed of the wheelset increases, the adhesion coefficient decreases under the condition of the constant creepage and water contamination on the contact surfaces, but it increases for oil contamination. Using the data obtained by statistics and analysis of the experimental results and Kalker's rolling contact theory with Hertzian form modified by the present authors, a numerical analysis concerning the effect of wheelset rolling speed on the adhesion coefficient and the distribution of the stick-slip area in the contact area has been made. The numerical results are in good agreement with those obtained by experiment. They are very useful in designing the traction power of a locomotive at higher speeds.