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dc.contributor.advisorNikravesh, Parviz E.en_US
dc.contributor.authorWang, Dexin*
dc.creatorWang, Dexinen_US
dc.date.accessioned2013-04-25T10:06:05Zen
dc.date.available2013-04-25T10:06:05Zen
dc.date.issued1999en_US
dc.identifier.urihttp://hdl.handle.net/10150/284350en
dc.description.abstractThis study presents novel approaches for direct damage identification of structures in the frequency domain. Relations between structural stiffness variations and measured system responses are formulated, thus opening the possibility of locating structural damage in terms of the reduction in the local stiffness when analytical baseline models are not available. After this, the related identifiability is discussed under the noise-free condition. In identifying damage in structural points, generic joint elements with only translational degrees of freedom are defined to parameterize the stiffness variations in the joints. Since ill-conditioning is a common problem in system identification and damage detection, a solution regularization based on parameter subset selection is proposed and used with least squares methods. A substructure-based parameter-recursive algorithm is developed for selecting parameter subsets to make use of the fact that the damage is local in structures. The proposed methods are verified by various simulated examples in which systematic modeling errors are present. Finally, the methods are also applied to the degradation identification of a vehicle structure.
dc.language.isoen_USen_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.subjectEngineering, Civil.en_US
dc.subjectEngineering, Mechanical.en_US
dc.titleStructural damage identification in the frequency domainen_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
thesis.degree.grantorUniversity of Arizonaen_US
thesis.degree.leveldoctoralen_US
dc.identifier.proquest9927513en_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineAerospace and Mechanical Engineeringen_US
thesis.degree.namePh.D.en_US
dc.identifier.bibrecord.b39569974en_US
refterms.dateFOA2018-09-06T02:56:49Z
html.description.abstractThis study presents novel approaches for direct damage identification of structures in the frequency domain. Relations between structural stiffness variations and measured system responses are formulated, thus opening the possibility of locating structural damage in terms of the reduction in the local stiffness when analytical baseline models are not available. After this, the related identifiability is discussed under the noise-free condition. In identifying damage in structural points, generic joint elements with only translational degrees of freedom are defined to parameterize the stiffness variations in the joints. Since ill-conditioning is a common problem in system identification and damage detection, a solution regularization based on parameter subset selection is proposed and used with least squares methods. A substructure-based parameter-recursive algorithm is developed for selecting parameter subsets to make use of the fact that the damage is local in structures. The proposed methods are verified by various simulated examples in which systematic modeling errors are present. Finally, the methods are also applied to the degradation identification of a vehicle structure.


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