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Experimental Identification of Generalized Proportional Viscous Damping Matrix.

Authors :
Adhikari, S.
Phani, A. Srikantha
Source :
Journal of Vibration & Acoustics; Feb2009, Vol. 131 Issue 1, p011008:1-011008:12, 12p, 1 Chart, 1 Graph
Publication Year :
2009

Abstract

A simple and easy-to-implement algorithm to identify a generalized proportional viscous damping matrix is developed in this work The chief advantage of the proposed technique is that only a single drive-point frequency response function (FRF) measurement is needed. Such FRFs are routinely measured using the standard techniques of an experimental modal analysis, such as impulse test. The practical utility of the proposed identification scheme is illustrated on three representative structures: (1) a free-free beam in flexural vibration, (2) a quasiperiodic three-cantilever structure made by inserting slots in a plate in out-of-plane flexural vibration, and (3) a point-coupled-beam system. The finite element method is used to obtain the mass and stiffness matrices for each system, and the damping matrix is fitted to a measured variation of the damping (modal damping factors) with the natural frequency of vibration. The fitted viscous damping matrix does accommodate for any smooth variation of damping with frequency, as opposed to the conventional proportional damping matrix. It is concluded that a more generalized viscous damping matrix, allowing for a smooth variation of damping as a function of frequency, can be accommodated within the framework of standard finite element modeling and vibration analysis of linear systems. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
10489002
Volume :
131
Issue :
1
Database :
Supplemental Index
Journal :
Journal of Vibration & Acoustics
Publication Type :
Academic Journal
Accession number :
37308367
Full Text :
https://doi.org/10.1115/1.2980400