Operational modal analysis of the Braga Sports Stadium suspended roof

Abstract

This paper describes the application of three output-only modal identification techniques to the data collected during an ambient vibration test performed at the Braga Sports Stadium suspended roof. The identified natural frequencies and modes shapes are compared with the ones predicted by a finite element model that took into account the geometrical non-linear behavior and the construction process. On the other hand, the estimated modal damping coefficients are compared with the ones obtained in previously developed forced/free vibration tests. These comparisons allowed evaluating the accuracy of the results provided by the experimental and numerical tools used.