Optimal design of multi-DOF viscoelastic dynamic neutralizers for passive vibration control in rotordynamics

Abstract

Passive vibration control using viscoelastic dynamic absorbers is acknowledged as robust and cost-effective solutions for vibration control. However, research on viscoelastic dynamic neutralizers (VDN) applied to reduce lateral vibrations in rotordynamics is incipient. The articles written in the area use the state-of-the-art fractional derivative model for viscoelasticity and the generalized equivalent parameters method to achieve an accurate prediction of the dynamic of the composed system and a low computational cost. However, none of those articles consider using more than one DOF in the design of VDN. Thus, the goal of this article is to develop the equations for the optimal design of a VDN with different number, type, and combination of DOF and then to evaluate its vibration suppression efficiency. This article is also aiming to perform a comparison between the most efficient multi-DOF VDN found in the present article and the most efficient multi-DOF VES (viscoelastic support) presented in the literature. Additionally, this article presents an analysis of the detuning phenomenon together with an approach to mitigate this issue. The fractional derivative model combined with the generalized equivalent parameters technique and a hybrid optimization technique constitutes the methodology used in the present work. The results are presented and discussed, from which it is possible to acknowledge the most effective combination of DOF in a VDN to achieve the best results in vibration suppression, and the most effective solution between multi-DOF VDN and the multi-DOF VES.