Vibração analise dinamica

Hindawi Publishing Corporation Advances in Acoustics and Vibration Volume 2012, Article ID 659398, 8 pages doi:10.1155/2012/659398

Research Article Dynamic Analysis of Stockbridge Damper
Nilson Barbieri1, 2 and Renato Barbieri1
1 Mechanial

Engineering Department, Pontif´cia Universidade Cat´lica do Paran´ (PUCPR), Rua Imaculada Conceicao, ı o a ¸˜ 1155, 80215-901 Curitiba, PR, Brazil 2 Mechanial Engineering Department, Universidade Tecnol´ gica Federal do Paran´ (UTFPR), Rua Sete de Setembro, o a 3165, 80230-901 Curitiba, PR, Brazil Correspondence should be addressed to Nilson Barbieri, [e-mail] Received 9 April 2012; Accepted 18 May 2012 Academic Editor: Joseph C. S. Lai Copyright © 2012 N. Barbieri and R. Barbieri. 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. In this work a machine cam with five different profiles was used to investigate the linear and nonlinear dynamical behavior of asymmetric Stockbridge damper with excitation frequencies in the range of 5 ≤ f ≤ 17 Hz. The experimental vibration signals were acquired through accelerometers placed along the sample. The loss factor and the Young’s modulus were estimated through approximation of the experimental and numerical results using Genetic Algorithms (GAs). Linear and nonlinear mathematical models were used to adjust the data. The two parameters are dependent on the excitation frequency and the amplitude of the base displacement. The results are validated comparing typical impedance curves obtained in conventional testing using an electromechanical shaker.

1. Introduction
The Stockbridge damper is presently the most common type of transmission line damper. In general, the absorber consists of two weights attached to the end of stranded cables, which are known as messenger wires. A detailed mathematical description