Experimental and numerical assessment of a steel frame equipped with Dissipative Replaceable Bracing Connections

In the last decades, high priority has been given by the research community to the development of low-damage structures, and reparability has become fundamental for minimizing the environmental and economic impact of reconstruction. In this context, the European Research Fund for Coal and Steel (RFCS) project DISSIPABLE was carried out, with the aim to test large-scale structures where the dissipation is concentrated on replaceable components introduced in the structure. In this paper, the performance of a six-storey braced steel frame with dissipative systems is analysed. The capacity of withstanding seismic actions relies on Dissipative Replaceable Bracing Connections (DRBrC), used for the brace-column joints. The energy dissipation is ensured by wide hysteresis loops experienced by DRBrC, whose configuration enables an easy replacement after a medium-high intensity earthquake. Results of a wide experimental test campaign on full-scale structures and numerical analyses on refined models are presented and compared. In particular, experimental data were used to validate and to calibrate the simplified numerical laws used to represent the cyclic performance of the dissipative components and it was proved the effectiveness of using a simplified formulation from both a theoretical and a practical point of view.