Operational modal analysis and finite element model correlation of the Braga Stadium suspended roof

The paper presents the most relevant results obtained from the application of different output-only modal identification methods to data collected in dynamic tests of the new Braga Sports Stadium suspended roof and the subsequent finite element model correlation analysis. This experimental work allowed the validation of the numerical modelling of the suspended roof, which takes into account the geometric non-linear structural behaviour and the progressive application of loads during the construction phase. Particular attention was given to identification of modal damping ratios, due to the necessity of analysing the susceptibility of the suspended roof to buffeting effects. Modal damping ratios were estimated from data provided by free, forced and ambient vibration tests, using an improved implementation of the Enhanced Frequency Domain Method and the Stochastic Subspace Identification Methods: SSI-DATA and SSI-COV.