During the design process of rolling bearing supported rotors, one of the most sensitive conditions to be regarded is the actual stiffness of these supports. The hertizian dry contact theory has long been used in order to approximate the behavior of rolling element bearings, once the ratio of load over the contacting area is very high on mostly non-conforming contacts. However, for some cases this approximation does not depict well the actual condition, as most of the applications would rely in a lubricated interface of such contacts. Hence, there is a need to introduce also the effects of a thin film lubrication to the actual bearing equilibrium. Given an elastohydrodynamic behavior of such contacts, the actual force-displacement relation will be greatly influenced by the oil film for a significant hydrodynamic condition of fully lubricated contacts. Nonetheless, to introduce such effects in a feasible simulation tool, through the integration of an EHD specific algorithm would be very time consuming and greatly computational intensive. A practical solution to such problem is to approximate such contacts by simpler analytical dynamic formulations, which could represent the actual force-displacement responses of the aforementioned contacts. In this work the authors propose a new insight to the non-linear dynamic behavior of such contacts, with a local linearization over the desirable displacement range. The effects of varying loads and velocities will be investigated over the previously proposed non-linear model and the extension of the valid linear range assessed. The effects of the load on the EHD linear stiffness will be examined and the presence of a non-zero force at zero equilibrium position discussed.
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