Adhesion-creep Curve Characteristics of Wheel/Rail under Various Conditions

Abstract

Abstract：The wheel/rail adhesion-creep curves under different surface conditions and normal forces are measured on a wheel/rail rolling contact apparatus through a continuous varying creep ratio test method.The peak positions and initial slopes of the measured adhesion-creep curves in different tests are investigated through two numerical fitting strategies.The results indicate that there are big differences of the adhesion-creep curves under different conditions.Compared to the dry condition, water and oil conditions not only drop the adhesion coefficient obviously but also move the peak points to the left of the curves.Sanding under water or oil condition could efficiently improve the degraded adhesion coefficient and lead the right movement of the peaks in the curves.Under dry condition, the increase of normal force affects little on the adhesion coefficient and peak position, but could descend the initial slopes of the adhesion-creep curves.Under water and oil conditions, the increase of normal force leads the left movement of the peaks in the curves.In addition, significant decrease of adhesion coefficient could also be observed with the increased normal forces under water condition.After sanding, both the adhesion coefficient and the peak position are less affect by the increased normal force, while the initial slopes of the adhesion-creep curves are reduced obviously.The combination of this experiment and numerical strategies to achieve the character parameters of the adhesion-creep curves could make good references for future studies.