Assessments on seismic performance of self-centering hybrid damping systems under far-field and near-field ground motions. (May 2022)

• Record Type: Journal Article
• Authors: Li, Junlin; Wang, Wei
• Is Part Of: Journal of constructional steel research. Volume 192(2022)
• Publication Date: 2022-05
• Subjects: Self-centering -- Hybrid damping -- Ductility spectra -- Knee braces; Steel, Structural -- Periodicals; Building, Iron and steel -- Periodicals; Acier de construction -- Périodiques; Construction métallique -- Périodiques; 624.1821
• DOI: 10.1016/j.jcsr.2022.107209
• Languages: English
• ISSNs: 0143-974X

Abstract

Abstract : This research is conducted to perform the assessment on seismic performance of novel self-centering systems equipped with hybrid energy dissipaters, which are composed of hysteretic energy dissipaters in parallel with viscous energy dissipaters. The hybrid energy dissipating mechanism equips the self-centering system with significant energy-dissipating capacity. An equivalent self-centering damping ratio ξ SC is firstly proposed to quantify the energy-dissipating capacity from the two types of dampers, respectively. Single-degree-of-freedom systems (SDOF) with different dynamic parameters are then developed. Nonlinear response history analyses on SDOF are performed using a suite of far-field and near-field ground motions to make the assessment. It is shown that the near-field ground motions will lead to much more ductility demands and acceleration responses for the considered systems compared with far-field ground motions. Increasing the damping for the system will decrease the ductility demand but will lead to the dramatic acceleration amplification. Moreover, adjusting the equivalent self-centering damping ratio between the two types of damping will change dynamic response of the system. Increasing the proportion of hysteretic damping will decrease the ductility demand and increase the acceleration response of the considered system, especially under far-field ground motions. Ductility demand spectra of the considered system for seismic design are established based on results from SDOF analyses. Finally, system-level analyses are performed on a novel knee bracing frame with self-centering hybrid damping capacity to validate the practicability of ductility demand spectra, and conduct the assessment. Graphical abstract : Unlabelled Image Highlights : Equivalent self-centering damping ratio is proposed for self-centering hybrid damping systems. Seismic performance assessment of the considered systems based on equivalent self-centering damping ratio is performed. The ductility demand spectra for the considered system are established for seismic design. System-level analyses are performed to validate the practicability of ductility demand spectra, and conduct the assessment.