Earthquake simulator testing of a steel model seismically protected with friction energy dissipators

In this research the study of an experimental reduced scale steel model of a medium-rise building structure is presented. The model was dynamically protected with energy dissipators installed on rigidization diagonals. These devices are passive control elements able to reduce the earthquake forces in buildings. The energy dissipators utilized in the experimental tests principally involve the steel-steel friction to dissipate energy and to lower the seismic response. When the structure undergoes interstory drifts the devices dissipate energy increasing the damping of the structure. A series of tests have been performed on a shaking table in the Applied Geophisics Laboratory of the Technical University of Catalonia, Barcelona, Spain. The model is a 3-D steel moment resisting frame with 5 stories. It is 1.70 m high, 1.44 m wide and 0.77 m deep. Along one direction there are two bays and in the other direction there is one. The experimental program consisted of identification tests (to determine the natural periods and the dynamic characteristics of the model) and earthquake simulation tests (to study the dynamic behaviour of the model with and without the dissipators). A numerical analysis has been performed to extrapolate some results also for other kinds of inputs. Results show the efficacy of the protection system.