Uncertainty propagation of correlated lubricant properties in gear tribodynamic system

An uncertain gear tribodynamic model considering correlation is proposed. Based on this model, uncertainty propagation of correlated lubricant properties in the gear tribodynamic system is investigated for the first time. Compared with previous tribodynamic models ignoring uncertainty correlation, this model contributes to a much more accurate prediction towards the uncertain domain of responses. The effects of uncertainty level, correlation coefficient, and operating conditions on the uncertain responses including vibration, flash temperature and fatigue life are discussed. The results show that large uncertain level of lubricant properties and positive correlation between them deteriorate the tribodynamic performance. Moreover, high speed and large torque magnify the response uncertainties and result in less correlated responses generally.