A seismic‐resistant steel frame with energy‐dissipating, chevron‐type braces is proposed. The braces are equipped with replaceable hourglass‐shaped pins made of duplex stainless steel. Under design seismic loading, energy is dissipated through inelastic deformations confined in the replaceable pins while the other members remain essentially elastic. As a result, the frame exhibits high post‐yield stiffness due to the inherent properties of the stainless‐steel pins. A Eurocode‐8‐based design methodology is adopted for the frame and assessed following the Eurocode‐8‐compatible INNOSEIS approach. Specifically, the overstrength factor is evaluated through nonlinear pushover analysis while the behaviour factor is assessed through incremental dynamic analysis considering high and medium seismicity site‐specific ground motion suites. The determined behaviour factor satisfies the global collapse prevention and life safety objectives while also keeping the maximum residual inter‐storey drifts below 1/300 to permit an easy substitution of the damaged pins after the design level earthquake.

Structures may be subjected to earthquake sequences after major mainshock (MS) events in seismically active sites within a short time. As a result, they may be susceptible to damage accumulation, which may hinder their performance under consecutive seismic loading. This study evaluates the effects of earthquake sequences on the seismic performance of seismic‐resistant concentrically braced steel frames designed to Eurocode‐8. The frames under investigation have concentric chevron‐type braces with replaceable hourglass‐shaped pins made of duplex stainless steel. The seismic energy is dissipated through inelastic deformations concentrated in the pins while keeping the other members elastic. The stainless‐steel pins provide the frame with high‐post‐yield stiffness to reduce the residual drifts after a seismic event. The seismic behaviour of the frame is assessed using site hazard‐specific mainshock‐consistent‐aftershock (MS‐AS) sequences selected for a site in Terni, Central Italy. Nonlinear back‐to‐back dynamic analyses are performed at multiple intensity levels while adopting detailed numerical nonlinear models created in OpenSees. We show that the implemented behaviour factor satisfies the life safety assurance objective while keeping the maximum residual inter‐storey drifts below 1/300 to permit an easy substitution of the damaged pins after the design‐level earthquake without being curtailed by the potential following events. We then develop prediction models for the damage accumulation in the pins, considering different energy‐based intensity measures and we show that the cumulative absolute velocity‐based model is the most efficient predictor in this particular case. Finally, the damage accumulation in the pins is evaluated, confirming their superior low‐cycle fatigue capacity under earthquake sequences.