Experimental evaluation of the seismic performance of steel MRFs with compressed elastomer dampers using large-scale real-time hybrid simulation

Abstract

Real-time hybrid simulation combines experimental testing and numerical simulation, and thus is a viable experimental technique for evaluating the effectiveness of supplemental damping devices for seismic hazard mitigation. This paper presents an experimental program based on the use of the real-time hybrid simulation method to verify the performance-based seismic design of a two story, four-bay steel moment resisting frame (MRF) equipped with compressed elastomer dampers. The laboratory specimens, referred to as experimental substructures, are two individual compressed elastomer dampers with the remainder of the building modeled as an analytical substructure. The proposed experimental technique enables an ensemble of ground motions to be applied to the building, resulting in various levels of damage, without the need to repair the experimental substructures, since the damage will be within the analytical substructure. Statistical experimental response results incorporating the ground motion variability show that a steel MRF with compressed elastomer dampers can be designed to perform better than conventional steel special moment resisting frames (SMRFs), even when the MRF with dampers is significantly lighter in weight than the conventional MRF.

Seismic structural and non-structural performance evaluation of highly damped self-centering and conventional systems

“…Lin and Chopra [14] showed that brace flexibility has negligible effect on the peak responses of elastic systems for practical applications where braces are designed to have stiffness more than 5 times larger than the story stiffness (e.g., design cases of steel MRFs with dampers in [22][23]). …”

“…Dampers are placed between successive floors of a building by using supporting braces which are designed to be stiff enough so that story drift produces damper deformation rather than brace deformation [22][23]. Lin and Chopra [14] showed that brace flexibility has negligible effect on the peak responses of elastic systems for practical applications where braces are designed to have stiffness more than 5 times larger than the story stiffness (e.g., design cases of steel MRFs with dampers in [22][23]).…”

“…Occhiuzzi analyzed different examples of frames with passive dampers found in literature and showed that values of the 1 st modal damping ratio higher than 20% seem to trade off a minor reduction of interstorey drifts with a significant increase of total floor accelerations [21]. Compressed elastomer dampers with viscoelastic behavior under small amplitudes of deformation and friction behavior under large amplitudes of deformation were designed and tested by Karavasilis et al [22][23]. When combined with flexible steel MRFs of reduced strength, these dampers were found capable of significantly reducing drifts and inelastic deformations without increasing total floor accelerations.…”

Collapse Risk Evaluation of Self-Centering Steel MRFS With Viscous Dampers in Near-Fault Regions

“…Steel moment-resisting frames (MRFs) equipped with passive dampers are another class of resilient structures. Previous analytical and experimental research showed that steel MRFs with passive dampers can be designed to be lighter and perform better than conventional steel MRFs under the design basis earthquake (DBE) and the maximum considered earthquake (MCE) [26][27]. A study shows that supplemental viscous damping does not always ensure adequate reduction of RDs [26][27][28].…”

“…Previous analytical and experimental research showed that steel MRFs with passive dampers can be designed to be lighter and perform better than conventional steel MRFs under the design basis earthquake (DBE) and the maximum considered earthquake (MCE) [26][27]. A study shows that supplemental viscous damping does not always ensure adequate reduction of RDs [26][27][28]. A recent work evaluates the seismic collapse resistance of steel MRFs with linear viscous dampers and shows that supplemental viscous damping does not always guarantee a better seismic collapse resistance when the strength of the steel MRF with dampers is lower or equal to 75% of the strength of a conventional steel MRF [29].…”