Tribo-dynamic effects of machining caused surface waviness on a line contact

Considering an elastohydrodynamic lubrication line contact, this study investigates the tribo-dynamic effects introduced by surface waviness. These waviness profiles are inevitable during various machining processes, such as grinding, and are on a larger scale than roughness. The waviness feature excites vibratory motions of contact bodies, and influences the lubrication performance through dynamic contact force and periodic squeezing. In this work, a tribo-dynamic formulation is implemented to examine such impact on film thickness, contact pressure, friction, and movement of the contact components. Owing to the presence of subharmonics, waviness introduced tribo-dynamic behavior cannot be eliminated within the adopted operating speed range. However, it is shown to be feasible to implement engineered waviness profile for lubrication performance improvement, providing a new and effective technique for friction/power-loss reduction, for instance.