Dynamic study of viscoelastic rotor: Modal analysis of higher order model considering various asymmetries

The primary aim of this paper is to study modal analysis of higher order finite element model for a generally viscoelastic rotor supported by the journal bearing. The gyroscopic couple, internal damping and fluid film forces of journal bearings have a significant asymmetric influence on rotor dynamics. A complex modal coordinate creates a platform to indicate the directivity of modes and provides better information about the direction of the whirl. In which, study of natural modes and directional frequency response function are obtained for free and force vibration analysis. It also distinguishes the importance of higher order model over conventional second order model.