Impact Elastohydrodynamics in Point Contacts

Abstract

When an elastohydrodynamically lubricated conjunction is subjected to pure impact, two types of oil entrapments can be generated; one is the central dimple and the other is the peripheral dimple. This article presents some numerical analyses to simulate laboratory experiments and study the influence of input parameters on the two types of oil entrapments. It has been found that the film profile (oil entrapment) in the central contact region is mainly determined by the loading speed at the initial stage but the film profile in the peripheral region is determined by the late stage of the loading. The central dimple shifts to the peripheral dimple as the loading speed increases. The amount of oil entrapped in the elastohydrodynamic lubrication conjunction increases as the loading speed and the maximum load increase. The results also indicated that a critical viscosity exists in the formation of the oil entrapment. The film thickness obtained by numerical simulations was well correlated with the experimental results.