On the non-linear dynamic behavior of elastohydrodynamic lubricated point contact

The complex dynamic concepts of mechanical systems are regarded each day as new barriers to be overcome. One of the most complex systems, despite its common construction design, is the rolling element bearings. The interactive dynamic interfaces of such bearings are normally disregarded by engineering analysis on the day to day basis due to its complexities. This paper intends to propose a new approach to the characterization of the elastohydrodynamic lubricated point contacts on such components, in order to fully depict its non-linear dynamic behavior, avoiding the use of rough hypothesis on a systemic procedure. A multi-level method was used to solve the coupled lubrication-deformation problem, alongside a Newmark-beta integrator of the motion equation for the contact system. A range of dynamically similar contacts were evaluated, so as to characterize its nonlinear dynamic behavior. A least-squares method was applied to the multi-level algorithm results, fitting the displacements-force relation to a linear and also to a third order polynomial stiffness. The fitting results were compared, clearly showing the nonlinear behavior of such contacts. Also, the oil film damping was regarded as viscous, leading to good overall response. Some peculiarities of the proposed adjust method are also considered. (C) 2010 Elsevier Ltd. All rights reserved.