Seismic performance of an innovative dissipative replaceable components bracing steel frame (DRBrC)

The structural performance of a steel Concentrically Braced Frame (CBF) equipped with replaceable dissipative seismic components, called DRBrC, is presented. X-diagonal CBFs are an efficient structural solution for buildings in seismic prone areas, being conceived to dissipate the energy stored during the earthquake through plastic deformation of bracing elements; all the other components remain in the elastic field thanks to opportune design criteria. Of course, structural damages, even if voluntarily located in specific regions, need to be repaired after the seismic event to restore the functionality of the building, leading to relevant economic (and time) effort since the full replacement of damaged dissipative components is necessary after irreversible plastic deformations. Recently, research activities have been widely carried out to provide repairability of steel buildings by means of easily replaceable dissipative components. The Research Fund for Coal and Steel (RFCS) of European Commission, for instance, promoted and funded the research project DISSIPABLE - Fully dissipative and easily reparable device for resilient buildings with composite steel-concrete structure”, with the aim of designing, producing, optimizing and testing several dissipative components for steel structures having, as fundamental feature, the full repairability after the earthquake without impacting on other components. In the present paper, the seismic performance of a steel braced frame equipped with a specific typology of dissipative replaceable device at the ends of braces is presented by means of nonlinear analyses.