Experimental analysis of a full-scale steel frame with replaceable dissipative connections

This work presents the experimental campaign performed on a full-scale 6-storey steel concentrically braced frame equipped with the so-called Dissipative Replaceable Braced Connection (DRBrC) made with plates of mild steel and high-strength steel. Such component, constituting the brace-column joint, is capable of dissipating large amounts of energy through wide hysteretic loops, while providing the possibility of being easily replaced after the building undergoes medium-high intensity earthquakes. To reduce the costs and, at the same time to obtain a representative response of the full frame, hybrid simulation tests were employed, in which only the ground floor was physically built in the laboratory. In contrast, the remainder of the structure was numerically simulated. The innovative frame was subjected to three different natural ground motions at the Damage Limitation (DL), Significant Damage (SD) and Near Collapse (NC) limit states, respectively. The outcomes highlighted the high potential of the DRBrC component in dissipating large amounts of energy and, at the same time, in protecting the remaining parts of the structure, by exhibiting very small residual displacements that enhance self-centring and repairability capabilities. Moreover, the numerical models were calibrated by including the non-negligible effect introduced by the bolt-hole clearances. All results are thoroughly described in the manuscript.