Wheel/rail adhesion wear investigation using a quarter scale laboratory testing facility

Abstract

A systematic large experimental test program of wheel/rail adhesion and wear was undertaken using the IIT wheel rail simulation facility of approximately 1/4 scale. This study was inspired due to the need of higher adhesion locomotives which are being designed and built at present. It was resolved, therefore, to determine the effects of axle load, adhesion coefficient, angle of attack (degree of curve), class of wheels (B and C), and mode of operation (braking and traction). All experiments were conducted using Hertzian simulation and DC traction. The experiments were conducted for clean/dry wheel and rail condition, ideal stiff track, constant rail speed, simulation of new 132 RE rail, and wheel creep corresponding to stable adhesion values. A total of twenty six tests were conducted. The range of loads corresponded from empty car to a locomotive. Adhesion coefficients from 0% to 50% were tested and angles of attack corresponding from tangent track to a 10 degree curve were used. Wear was measured by overlaying profiles of the wheel/rail surface at different stages of wear and measuring the change in the area of cross section. It was found that the hierarchy of influencing parameters for wheel/rail wear in order of priority are: (1) rail curves or angle of attack; (2) adhesion coefficient; and (3) axle loads. The curves increase the wear dramatically. The wear under traction and braking modes were comparable to each other. The wear of class B and class C wheels is also reasonably comparable, however, the rail wear produced by class C wheel was higher than that produced by class B wheels.