Title: Dynamic damage identification using complex mode shapes
Abstract: Structural Control and Health MonitoringVolume 27, Issue 12 e2632 RESEARCH ARTICLE Dynamic damage identification using complex mode shapes E. Lofrano, Corresponding Author E. Lofrano [email protected] orcid.org/0000-0003-3254-3977 Structural and Geotechnical Engineering, ‘La Sapienza’ University of Rome, Rome, Italy Research group GNFM, National Group of Mathematical Physics, Rome, Italy Correspondence Egidio Lofrano, Structural and Geotechnical Engng. University ‘La Sapienza’, Via Gramsci 53, Rome 00197, Italy. Email: [email protected] for more papers by this authorA. Paolone, A. Paolone Structural and Geotechnical Engineering, ‘La Sapienza’ University of Rome, Rome, ItalySearch for more papers by this authorG. Ruta, G. Ruta Structural and Geotechnical Engineering, ‘La Sapienza’ University of Rome, Rome, Italy Research group GNFM, National Group of Mathematical Physics, Rome, ItalySearch for more papers by this author E. Lofrano, Corresponding Author E. Lofrano [email protected] orcid.org/0000-0003-3254-3977 Structural and Geotechnical Engineering, ‘La Sapienza’ University of Rome, Rome, Italy Research group GNFM, National Group of Mathematical Physics, Rome, Italy Correspondence Egidio Lofrano, Structural and Geotechnical Engng. University ‘La Sapienza’, Via Gramsci 53, Rome 00197, Italy. Email: [email protected] for more papers by this authorA. Paolone, A. Paolone Structural and Geotechnical Engineering, ‘La Sapienza’ University of Rome, Rome, ItalySearch for more papers by this authorG. Ruta, G. Ruta Structural and Geotechnical Engineering, ‘La Sapienza’ University of Rome, Rome, Italy Research group GNFM, National Group of Mathematical Physics, Rome, ItalySearch for more papers by this author First published: 02 September 2020 https://doi.org/10.1002/stc.2632Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Summary Damage, be it a material or a geometric degradation, modifies some features of the response foreseen by the original structural design. These variations, once the dependence on the damage causing them is established, can be used for identification purposes. In the literature, vibration-based approaches usually compare some responses of linear elastic structures with dissipative properties that are assumed proportional to the mass and stiffness measures. However, such an assumption is reasonable for new, undamaged structures, but can be unreliable in existing, potentially damaged structures, particularly for damages localised in narrow areas. The eigenmodes of a proportionally damped system can be reduced to the real ones of the relevant ideal undamped system. On the other hand, non-proportional damping exhibits complex eigenmodes that cannot be reduced to those of the ideal, or of the proportionally damped, structure. Thus, we may assume the complexity of the eigenmodes as a measure of non-proportional damping, hence of damage. On this basis, some contributions in the literature verified the relationship among presence of damage and amount of complexity. Here, we propose a perturbation approach and an objective function able to identify presence, location and amplitude of localised damages, intended as sources of non-proportionality in viscously damped linear systems. A prototype naturally discrete structure with four degrees-of-freedom is chosen to test and show capability and accuracy of the proposed method. Volume27, Issue12December 2020e2632 RelatedInformation