Lubrication performance characterization of axially grooved journal bearing considering random-interval hybrid uncertainties

Axially grooved journal bearings operate within a multidisciplinary environment and variable working conditions. Inevitably, many uncertain factors exist and affect the state of the journal bearing. This work presents a noninvasive analysis framework to characterize lubrication performance metrics of axially grooved journal bearings by considering random and interval mixed uncertainties, which can be adapted to different configurations and make full use of available statistical information. The corresponding performances of the journal bearing subject to pure random, pure interval and hybrid uncertainties are investigated, respectively. Moreover, accuracy validations of the established method are carried out by comparing it with the conventional sampling-based analysis method. It was found that the proposed method reduces nearly 99% of the time required in the sampling-based method while its error is below 3%. Specifically, the eccentric ratio and minimum film thickness are moderately deviated under mixed uncertainties as evidenced by their statistical moments of bounds. For the dynamic characteristics, the cross-term stiffness coefficients are heavily affected by the mixed uncertainties while all the damping coefficients have only some marginal variabilities. The findings of the current study can provide useful guidance in insightful characterizations of lubrication performances and serve as a powerful means of analyzing various axially grooved journal bearings with uncertainties.