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Advances in Acoustics and Vibration
Volume 2009, Article ID 319538, 7 pages
Research Article

Center Impedance Method for Damping Measurement

1Department of Mechanical Engineering, Vibration and Acoustics Center, Northern Illinois University, DeKalb, IL 60115, USA
2The Daubert Chemical Company, 4700 S. Central Avenue, Chicago, IL 60115, USA

Received 3 June 2009; Revised 5 October 2009; Accepted 18 November 2009

Academic Editor: Kim Meow Liew

Copyright © 2009 D. Malogi 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.


Damping materials are used extensively for reduction of vibration and noise. These damping materials have viscoelastic characteristics and are used by automotive and other industries. Testing of these materials is important in order to predict their performance and traditionally the damping properties are measured by the Oberst method. This paper discusses an alternate method called the Center Impedance method where force and response are measured directly and the damping properties are obtained. The Center Impedance method is easy to use requiring only standard vibration equipment for excitation, namely, shaker, and is easy to control the experiment for repeatability. Results of beams tested by both Oberst and Center Impedance methods are presented in order to validate this test method.