Journal of Theoretical
and Applied Mechanics

55, 3, pp. 751-763, Warsaw 2017
DOI: 10.15632/jtam-pl.55.3.751

Stability analysis and dynamic behaviour of a flexible asymmetric rotor supported by active magnetic bearings

Molka Attia Hili, Slim Bouaziz, Mohamed Haddar
The objective of this work is to show the influence of dynamic characteristics of Active
Magnetic Bearings (AMBs) on the stability and dynamic response of an asymmetric and
unbalanced rotor. Indeed, AMBs have been successfully applied in several industrial machinery
facilities. Their main advantages are the contactless working principle, frictionless suspension
and operation in very high speeds. Firstly, the AMBs dynamic support parameters
have been obtained through electromagnetic theory. Then, a generalized system equations of
motion have been derived using the finite element method. The motion of a rotor the shaft
cross-section of which is asymmetric is generally governed by ordinary differential equations
with periodic coefficients. Floquet’s theory is used to investigate the stability of this system
of equations. Finally, numerical simulation results are presented and discussed.
Keywords: asymmetric rotor, finite element, Floquet’s theory, dynamic coefficients, stability