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

► Effect of impact loading on micro-deformation of asperities in elliptical EHL contacts is disclosed. ► The high pressure produces the micro-groove in ridges. ► The micro-groove is formed by two different mechanisms. ► Effects of ridge size, shape and orientation, initial impact gap and loading speed on the micro-groove formation are elucidated.