OPTIMIZATION OF THE SLIP FORCE IN A NOVEL FRICTION-BASED CONNECTION FOR THE E-CLT TECHNOLOGY

The European Union has sponsored the development of a new friction dissipating system, for improving seismic behaviour of existing buildings. The proposed system consists of CLT-elements connected to the external beams of existing reinforced concrete building using steel profiles. Each of the steel profiles consists of two separate plates connected by a friction connection made by preloaded bolts in elongated holes. The authors carried out the experimental testing of the friction connection by estimating the corresponding hysteresis curve. A Duhem-like mechanical model, matching with the experimental results, simulates the cyclic response of the connection. The authors investigate the seismic performance of a structural archetype, a plane RC frame with CLT shear walls equipped with this sort of friction dampers. It is assessed the optimum preload condition to achieve an optimal seismic performance according to the Italian seismic scenario by the fragility assessments. A selected suite of earthquakes is the basis of Incremental Dynamic Analysis (IDA) of the structural archetype, without and with the friction device. The optimum preload of the dissipating systems descends by optimizing the structural performance: maximizing the dissipated energy by preventing damage to the CLT panel and the reinforced concrete frame.