Investigation of the asperity point load mechanism for thermal elastohydrodynamic conditions

Department of Solid Mechanics, KTH – Royal Institute of Technology

^* Corresponding author: cmev@kth.se

Abstract

The rolling contact fatigue damage called pitting or spalling develops more frequently in surfaces with negative than positive slip. Since normal line loads do not cause any tensile surface stresses this investigation considers the effects of small point shaped asperities. Shear traction causes tensile stresses at the trailing edge of asperities entering the contact at negative slip. At positive slip the tensile stresses appear at the leading edge when the asperities exit the contact. It was found that the trailing edge of the asperity breaks through the lubrication film at contact entry. This causes negative slip to be more detrimental than positive slip. At negative slip the location of large frictional shear stresses and tension stresses from normal asperity contact coincide.