On Competing Failure Modes in Rolling Contact

Abstract

Rolling contact failures are classified according to their failure mode as (a) wear, (b) plastic flow, (c) fatigue, and (d) bulk failures, with the last class arising outside the immediate contact area. The wear failures are subdivided into mild wear by loose particle removal and smearing involving metal transfer. Plastic failures may arise due to overload or to temperature imbalance. Fatigue is of the spalling or the surface distress type. An analysis of the stress conditions in a rolling contact is sketched; the stepwise refinements of the contact model are considered, starting from Hertz theory, and progressively including surface traction, plasticity, elastohydrodynamic lubricant films, surface microtopography, and the inhomogeneities of real metals, Each failure mode is associated with the relevant severity parameters of the contact stress condition, and a description of its mode of formation is given. Guidelines are provided for the identification of that failure mode which, among competing modes, i...