Finite Element Simulation of Rotor-Bearing Systems With Internal Damping

Abstract

The implementation of finite element simulations for the study of rotor dynamic systems has been the subject of recent publications. Since the finite element offers obvious modeling advantages, particularly in modeling large-scale systems, this study extends the linear finite element concept to provide a detailed evaluation of damped rotor stability. In this work the effects of both internal viscous and hysteretic damping have been incorporated into the finite element model. Both produce circulatory terms in the generalized equations of motion which encourages the destabilization of this nonconservative system. Results are presented for both hysteretic and viscous forms of damping. Both forms of internal damping destabilize the rotor system and induce nonsynchronous forward precession. The stabilizing effects of anisotropic bearing stiffness and external damping are also demonstrated.