Scuffing Theory Modeling and Experimental Correlations

Abstract

The scuffing behavior for contacts operating in the partial elastohydrodynamic lubrication regime is shown to be greatly affected by the asperity contact temperatures and the lubricant pressures inside the elastohydrodynamic lubrication conjunction. A scuffing model which takes into account the temperature and pressure effects for predicting the onset of scuffing failure has been developed. This model is based on the lubricant molecule physisorption theory and is capable of predicting the scuffing failures for general contact conditions including the boundary lubrication contacts and the elastohydrodynamic lubrication (ehl) contacts. A preliminary investigation into this model showed a good correlation existing between the theory and some scuffing experiment results conducted on a twin disk machine. However, more experimentation is necessary to further ascertain the validity of this new model. To validate the new scuffing theory, a method for calculating the asperity flash temperatures is formulated. The flash temperature calculations were performed using the actual digitized run-in surface profiles of the mating bodies. The necessary informations for calculating the flash temperatures such as, the real areas of contact and the asperity contact pressures were all determined using a recently developed rough surface contact simulation model.