An Investigation of Velocity-Dependent Friction in Wheel-Rail Rolling Contact
Friction between sliding surfaces decreases as the velocity of sliding increases (‘falling friction’). This paper investigates the velocity-dependent friction relationships in non-Hertzian models of wheel-rail rolling contact. The effect of falling friction on tangential stress distribution and slip is examined. In otherwise steady rolling with constant creep, falling friction introduces a stick-slip oscillation to the trailing edge of the contact. This oscillation is increasingly unstable with increasing creep. The stick-slip behaviour at the trailing edge leads to sudden changes in the tangential stress distribution in the stick zone, including intermittent slip at the leading edge of the contact.
KeywordsSlip Velocity Rolling Contact Slip Zone Vehicle System Dynamics Normal Stress Distribution
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