Influence of Realistic Lubricant Density-Pressure Dependence on the Stiffness of Elastohydrodynamic Lubricated Contacts

Abstract

The analysis of the dynamic response of elastohydrodynamic lubricated contacts has often invoked a universal law for lubricant density–pressure dependence, even though the densities of many lubricants exhibit a substantial deviation from this widely adopted law. The current work investigates the influence of real lubricant density–pressure behavior on the stiffness of elastohydrodynamic lubricated contacts. It is shown that accounting for the real lubricant density–pressure dependence is crucial for an accurate estimation of the oil film stiffness, under steady-state considerations. The influence on the overall stiffness of the contact is found to be negligible though. Finally, an analytical correction procedure is provided, allowing a correction of oil film stiffness predictions that are based on the universal law for lubricant density–pressure dependence (or any other unrealistic law), to account for the real lubricant density–pressure response.