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Talks and Poster Presentations (with Proceedings-Entry):

H. Ecker, T. Pumhössel:
"Parametric excitation of a rotor system due to a periodic axial force";
Talk: 7th European Nonlinear Dynamics Conference ENOC 2011, Rom; 07-24-2011 - 07-29-2011; in: "Proceedings of the 7th European Nonlinear Dynamics Conference (ENOC 2011)", D. Bernardini, G. Rega, F Romeo (ed.); (2011), ISBN: 978-88-906234-2-4; 6 pages.



English abstract:
A mathematical model for a Laval-Jeffcott-rotor with periodic axial forcing is derived. This leads to a linear system of differential equations with time-periodic stiffness parameters, commonly termed as a parametrically excited system. For that system a stability analysis is carried out and well-known instabilities of the system, so-called "parametric resonances", are found. However, if the frequency of the axial forcing is chosen to be a combination of certain natural bending frequencies, then an increase of stability is noticed. The amount of increase depends in a nonlinear manner on the amplitude of the axial forcing. Due to parametric excitation an enhanced damping behaviour of the rotor system and an increased stability margin is observed, when forced at a non-resonant parametric combination resonance frequency. Several numerical studies demonstrate the effectiveness of the method, also in the presence of rotor unbalance. Time series of the rotor oscillations show the gain of damping by faster decay of the vibration signal.


"Official" electronic version of the publication (accessed through its Digital Object Identifier - DOI)
http://dx.doi.org/10.3267/ENOC2011Rome


Created from the Publication Database of the Vienna University of Technology.