City Research Online

Abstract

In recent years, the passive tuned mass damper inerter (TMDI) has been widely considered in the literature for the seismic demand mitigation of building structures. Its effectiveness relies on careful design/tuning of the TMDI stiffness and damping properties, while its performance improves with the increase of the inertance property, which is readily scalable, as well as with spanning several floors when placed to the top of buildings. Nevertheless, TMDI configurations spanning several floors may be impractical for ordinary structures. This paper addresses the above issue by presenting a novel hybrid energy dissipation system, termed rooftop isolated tuned mass damper inerter (RI-TMDI). The RI-TMDI comprises an additional seismically isolated floor with a TMDI placed atop of buildings, making it applicable for seismically retrofitting of existing structures as well as for enhancing the seismic performance of new structures. The motivation of the RI-TMDI is based on the fact that the vibration control potential of TMDIs improve as the floor they are installed to is designed to be more flexible. Herein, a three degree of freedom (3-DOF) structural system is put forward to study the potential of RI-TMDI for seismic response mitigation of buildings, modelled as linear damped single degree of freedom structures, in which isolator bearings are modelled through the Bouc-Wen model. Statistical linearization is applied to expedite optimal RI-TMDI tuning such that the input energy dissipated by the TMDI is maximized under white noise excitation. A pilot parametric numerical investigation is undertaken to assess the influence of the isolator flexibility and damping properties and of the TMDI inertance to the tuning and performance of the RI-TMDI under white noise excitation. Further, results from nonlinear response history analyses for four recorded GMs applied to optimally tuned RI-TMDI systems are reported. It is found that the efficacy of RI-TMDI for suppressing seismic structural displacement demands improves as the effective post-yielding flexibility of the isolators increases, provided that the TMDI is equipped with sufficiently high inertance. However, this improvement comes at the cost of increased deflection of the isolators. To this end, it is shown that by increasing inertance both building and isolator displacements may be reduced.

Publication Type:	Conference or Workshop Item (Paper)
Additional Information:	This paper has been published by ICONHIC2022.
Publisher Keywords:	hybrid passive vibration control, tuned mass damper inerter, seismic isolation, optimal design
Subjects:	T Technology > TA Engineering (General). Civil engineering (General) T Technology > TH Building construction
Departments:	School of Science & Technology > Engineering

Export

Downloads