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H. Ecker, A. Tondl:
"Suppression of self-induced vibrations by a strongly non-linear parametric excitation";
Talk: 9th International Conference on Motion and Vibration Control, Munich; 2008-09-15 - 2008-09-18; in: "Proceedings-CD MOVIC 2008", (2008), Paper ID 1170, 12 pages.

A mechanical system with two degrees of freedom is investigated. Due toa self-excitation mechanism the system is unstable in the first vibrational mode, but it can be stabilized by parametric stiffness excitation. This excitation is realized by an electromechanical actuator with open-loop stiffness control. The stiffness generated by this device is a function of the deflection and therefore a strong non-linearity is introduced to the system. Almost all previous studies have assumed a linear parametric excitation and little is known how parametric stabilization is affected by nonlinearities. Numerical simulation is employed to investigate and compare results for linear and non-linear parametric excitation. It is shown that a cubic restoring function with no constant component cannot stabilize the system. On the other hand, even a strong non-linearity has no adverse effect on the capability of the linear parametric excitation to fully suppress self-induced vibration of the system.