Stability of journal bearing-rotor systems with interval-bearing parameters

This paper addresses the stability problem of vibrating rotors supported by hydrodynamic journal bearings with interval parameters. Bearing oil film properties change considerably with changing operating conditions, and bearing clearance can only be known within a certain tolerance interval. This leads to substantial changes in the stability conditions of the underlying system. The considered vibrating system is modeled such that the oil film coefficients are intervals rather than single-valued quantities. Each stiffness and damping coefficient is given as a range of values. An interval analysis technique is applied to evaluate the stability of the system. Numerical simulations are presented to illustrate the results.