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Experimental study of resonant vibrations of suspended steel cables using a 3D motion analysis system / Jiazhu Hu in Journal of engineering mechanics, Vol. 138 N° 6 (Juin 2012) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 138 N° 6 (Juin 2012) . - pp.640- 661 Titre : Experimental study of resonant vibrations of suspended steel cables using a 3D motion analysis system Type de document : texte imprimé Auteurs : Jiazhu Hu, Auteur ; P. Frank Pai, Auteur Année de publication : 2012 Article en page(s) : pp.640- 661 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Cable  Vibration  Resonance  Nonlinear  response  Experimentation Résumé : This paper presents the results of an experimental study of regular resonant vibrations of steel cables using a camera-based three-dimensional (3D) motion analysis system. The cable had one fixed end, and the other end was subjected to harmonic vertical excitation. Retroreflective markers were fixed to the cable and evenly distributed along it. The 3D motion analysis system was used to obtain 3D time traces of all marker vibrations; these traces were then entered into other programs for further signal processing. Time-varying modal coordinates were extracted from the trajectories of the markers using a modal decomposition technique. The resonant vibrations observed include isolated and simultaneous 1∶1, 2∶2∶1, 1∶1∶2∶2, and 4∶2∶4∶2 internal resonances. Subharmonic and superharmonic resonances, period-doubling bifurcations, hardening nonlinearity effect, and complex traveling vibrations were observed and studied. The resonant vibrations were characterized by examining time-varying vibration profiles, vibration modal coordinates and their frequency spectra, single-point vibration trajectories, Poincaré sections, etc. Using the 3D motion analysis system, this experimental study offers a distinctive interpretation of the characteristics of nonlinear resonant vibration of cables in the spatial domain (based on mode-shape information of the entire cable), in addition to one in the time domain (based on real-time traces of one single point). Detailed experimental result analyses were made on the responses within certain excitation intervals (responses of intervals) and those of similar characteristics in the entire excitation frequency (responses of branches). This paper follows a previously published article by the same authors, in which the detailed description of the test as well as details on the modal identification process can be found. ISSN : 0733-9399 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29EM.1943-7889.0000374 [article] Experimental study of resonant vibrations of suspended steel cables using a 3D motion analysis system [texte imprimé] / Jiazhu Hu, Auteur ; P. Frank Pai, Auteur . - 2012 . - pp.640- 661. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 138 N° 6 (Juin 2012) . - pp.640- 661 Mots-clés : Cable  Vibration  Resonance  Nonlinear  response  Experimentation Résumé : This paper presents the results of an experimental study of regular resonant vibrations of steel cables using a camera-based three-dimensional (3D) motion analysis system. The cable had one fixed end, and the other end was subjected to harmonic vertical excitation. Retroreflective markers were fixed to the cable and evenly distributed along it. The 3D motion analysis system was used to obtain 3D time traces of all marker vibrations; these traces were then entered into other programs for further signal processing. Time-varying modal coordinates were extracted from the trajectories of the markers using a modal decomposition technique. The resonant vibrations observed include isolated and simultaneous 1∶1, 2∶2∶1, 1∶1∶2∶2, and 4∶2∶4∶2 internal resonances. Subharmonic and superharmonic resonances, period-doubling bifurcations, hardening nonlinearity effect, and complex traveling vibrations were observed and studied. The resonant vibrations were characterized by examining time-varying vibration profiles, vibration modal coordinates and their frequency spectra, single-point vibration trajectories, Poincaré sections, etc. Using the 3D motion analysis system, this experimental study offers a distinctive interpretation of the characteristics of nonlinear resonant vibration of cables in the spatial domain (based on mode-shape information of the entire cable), in addition to one in the time domain (based on real-time traces of one single point). Detailed experimental result analyses were made on the responses within certain excitation intervals (responses of intervals) and those of similar characteristics in the entire excitation frequency (responses of branches). This paper follows a previously published article by the same authors, in which the detailed description of the test as well as details on the modal identification process can be found. ISSN : 0733-9399 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29EM.1943-7889.0000374