Formation of micro-grooves under impact loading in elliptical contacts with surface ridges

This paper is focused on the effect of impact loading on micro-deformation of asperities in elliptical elastohydrodynamic contacts. Based upon isothermal Newtonian numerical analyses, it is elucidated that a micro-groove, which appears in the ridge under impact loading in elliptical contacts, is brought about by two different mechanisms. One is the smooth surface local pressure difference across the virtual ridge and the other is the macroscopic pressure difference along the ridge. The formation of the micro-groove due to the former mechanism is influenced by the shape, size and orientation of the ridge, and the smooth surface pressure distribution depending on the initial impact gap and loading speed, and that due to the latter is markedly influenced by the loading speed.