Periodic and Chaotic Motions of a Rotor-Active Magnetic Bearing with Quadratic and Cubic Terms and Time-Varying Stiffness

摘要: In this paper, we use the asymptotic perturbation method to investigate nonlinear oscillations and chaotic dynamics in a rotor-active magnetic bearings (AMB) system with 8-pole legs time-varying stiffness. The stiffness AMB is considered as time varying periodic form. Because of considering weight rotor, formulation on electromagnetic force resultants includes quadratic cubic nonlinearities. resulting dimensionless equations motion for rotor-AMB horizontal vertical directions are two-degree-of-freedom nonlinearities parametric excitation. used obtain averaged case primary resonance 1/2 subharmonic resonance. It found that there exist period-3, period-4, period-6, period-7, period-8, quasiperiodic modulated amplitude seen from numerical results phenomena multiple solutions soft-spring type hardening-spring frequency-response curves system. excitation, or produced by PD controller be controlling which can control response period n motion.