Pseudo-dynamic testing of a full-scale two-storey steel building with RBS connections

The paramount role of beam-to-column joints on the seismic response of MRFs is universally recognised and many studies have been devoted to the improvement of their ductility and energy dissipation capacity, mostly after the seismic events of Northridge and Kobe. Nevertheless, while much experimental work has been already carried out on the seismic behaviour of beam-to-column sub-assemblages, the available experimental results on full-scale structures are still quite limited. Aiming to provide a contribution to fill this knowledge gap, an experimental program has been planned at the STRENGTH Laboratory of the University of Salerno concerning the pseudo-dynamic testing of a full-scale two-storey steel building equipped with five different connection typologies. In this paper, the results of the first series of tests, dealing with MRFs with RBS connections, are presented. The mock-up has been subjected to a sequence of seven accelerograms and the results have shown that, if properly designed, RBS connections provide large energy dissipation capacity and plastic rotation supply. Nevertheless, the failure of welds due to damage accumulation can be still possible, even adopting full penetration butt joint welding details conforming to Eurocode 3 and Eurocode 8 provisions. The test results are complemented with a numerical model developed with the software SeismoStruct. The comparisons between the numerical simulations and the experimental results show that the applied mixed distributed and concentrated plasticity approach, based on the adoption of phenomenological spring models, can capture accurately the global response of the structure, but it predicts with lower accuracy the local response parameters.