The reliable identification of dynamic parameters in mechanical systems remains a big challenge, in particular for nonlinear systems. There is not a single mathematical model encompassing the universe of most systems. From a practical point of view, the identification of system parameters depends on the measurement data as well as on the reference model.
This paper presents a novel method for identifying the dynamic parameters of a gas bearing, whose force coefficients are strong functions of frequency. The method is based on the analysis of the phase diagram with the model assuming a mass-damper-spring system with time-dependent force coefficients. The phase diagram could be implemented electronically for on line monitoring and ready fault detection.