Mathematical Problems in Engineering
Volume 2011 (2011), Article ID 340235, 14 pages
http://dx.doi.org/10.1155/2011/340235
Research Article

Vibration Attenuation in Rotating Machines Using Smart Spring Mechanism

Aldemir Ap. Cavalini Jr.,1 Thiago Vianna Galavotti,2 Tobias Souza Morais,1 Edson Hideki Koroishi,1 and Valder Steffen Jr.1

1Laboratory of Mechanics and Structures, (LMEst) School of Mechanical Engineering, University of Uberlândia, Uberlândia, MG, Brazil
2Group of Smart Materials and Structures, (GMSINT) Mechanical Engineering Department, Engineering Faculty of Ilha Solteira, UNESP, Ilha Solteira, SP, Brazil

Received 9 July 2010; Accepted 13 October 2010

Academic Editor: Marcelo Messias

Copyright © 2011 Aldemir Ap. Cavalini et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

This paper proposes a semiactive vibration control technique dedicated to a rotating machine passing by its critical speed during the transient rotation, by using a Smart Spring Mechanism (SSM). SSM is a patented concept that, using an indirect piezoelectric (PZT) stack actuation, changes the stiffness characteristics of one or more rotating machine bearings to suppress high vibration amplitudes. A Genetic Algorithm (GA) optimization technique is used to determine the best design of the SSM parameters with respect to performance indexes associated with the control efficiency. Additionally, the concept of ecologically correct systems is incorporated to this work including the PZT stack energy consumption in the indexes considered for the optimization process. Simulation carried out on Finite Element Method (FEM) model suggested the feasibility of the SSM for vibration attenuation of rotors for different operating conditions and demonstrated the possibility of incorporating SSM devices to develop high-performance ecologic control systems.