Challenges in the Application of Stochastic Modal Identification Methods to a Cable-Stayed Bridge |
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Authors: | Filipe Magalh?es Elsa Caetano álvaro Cunha |
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Affiliation: | 1Assistant, Faculty of Engineering of Univ. of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal. E-mail: filipema@fe.up.pt 2Associate Professor, Faculty of Engineering of Univ. of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal. E-mail: ecaetano@fe.up.pt 3Full Professor, Faculty of Engineering of Univ. of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal. E-mail: acunha@fe.up.pt
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Abstract: | This paper presents an analysis of the data collected in the ambient vibration test of the International Guadiana cable-stayed Bridge, which links Portugal and Spain, based on different output-only identification techniques: peak-picking, frequency domain decomposition, covariance-driven stochastic subspace identification, and data-driven stochastic subspace identification. The purpose of the analysis is to compare the performance of the four techniques and evaluate their efficiency in dealing with specific challenges involved in the modal identification of the tested cable-stayed bridge, namely the existence of closely spaced modes, the perturbation produced by the local vibration of stay-cables, and the variation of modal damping coefficients with wind velocity. The identified natural frequencies and mode shapes are compared with the corresponding modal parameters provided by a previously developed numerical model. Additionally, the variability of some modal damping coefficients is related with the variation of the wind characteristics and associated with a component of aerodynamic damping. |
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Keywords: | Stochastic models Vibration Bridges cable-stayed Portugal Spain |
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