Advances in Ritz Vector Identification
Publication: Journal of Structural Engineering
Volume 129, Issue 8
Abstract
Ritz vectors represent an alternative to mode shapes as suitable basis vectors for n-dimensional system analysis. In numerical studies, these vectors have been shown to offer superior performance in model reduction and time simulations. They also appear to be more sensitive to structural damage than traditional mode shapes. An approach to extract Ritz vectors from measured dynamic data has been developed, and the measured Ritz vectors have been shown to be identical to those obtained using analytical procedures. However, the identification process did not consider the effects of noise in the measured data or the presence of structural damping. In this paper, a new Ritz vector identification algorithm is developed which accounts for the presence of damping. It is shown for the case of proportional or modest structural damping that the new algorithm is able to recover the undamped Ritz vectors from damped structural responses. To address the issue of noise, the first Ritz vector accuracy indicator is developed. The “Twin Ritz Indicator” is shown to be a reliable measure of accuracy for identified Ritz vectors.
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Information
Published In
Journal of Structural Engineering
Volume 129 • Issue 8 • August 2003
Pages: 1131 - 1140
Copyright
Copyright © 2003 American Society of Civil Engineers.
History
Received: Oct 30, 2001
Accepted: Oct 21, 2002
Published online: Jul 15, 2003
Published in print: Aug 2003
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