On the tribo-dynamics of lubricated point contacts: modeling and experiment

This study proposes a modeling methodology for the description of tribo-dynamic behavior of generic point contacts, considering surface defect/failure type of excitation. A twin-disk contact set-up is developed to experimentally determine the acceleration induced by lab-controlled groove surface feature present on one of the mating surfaces. The periodic passage of this artificial surface defect through lubricated contact zone leads to contact force fluctuation, and consequently normal direction dynamic relative displacement and relative velocity of the contact bodies. These dynamic responses impact the lubrication film thickness and flow, altering the tribological performance that governs the contact force. Implementing this interaction loop between dynamics and tribology, the computational simulations are shown to be able to yield fairly accurate predictions in comparison to the measured acceleration signals.