Novel adaptive steel hysteretic damper for an enhanced seismic structural performance

Traditional Hysteretic Dampers (HDs) are installed in buildings to enhance their seismic performance by increasing the effective stiffness and damping and are usually designed to guarantee the structural safety for severe Ultimate Limit State (ULS) seismic events. As a negative consequence, only minimal damping is provided during weak but more frequent Serviceability Limit State (SLS) earthquakes since HDs mainly operate in their elastic regime. This can cause high Peak Floor Accelerations (PFAs) that are detrimental for sensitive non-structural components (NSCs), like electric network, elevators, and computers, whose integrity is crucial in high-technological buildings (e.g. hospitals, and emergency centers). In order to improve this unacceptable situation, a novel Adaptive Hysteretic Damper (AHD) was developed by the authors. The AHD can modulate its effective damping and stiffness to its actual deformation (i.e. PGA level) leading to: (i) reduced PFAs and enhanced building response to minor SLS earthquakes; (ii) not impaired structural safety under severe ULS events. The AHD force-displacement characteristics are experimentally assessed and nonlinear time-history analyses are carried out on a case-study structure to demonstrate the enhanced seismic performances compared to common HDs. © 2021 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin.