Tuned Mass Damper Inerter with Structural Modifications for Seismic Protection of Buildings

Abstract

Tuned mass damper enhanced with inerter (TMDI) presents promising potential for improving seismic performance of multi-story buildings over the conventional passive tuned mass damper (TMD) under non-pulse-like earthquake excitations. However, its effectiveness in mitigating structural response under near field pulse-like ground motions (PLGMs) remains underexplored. This study therefore numerically investigates the effectiveness of combining the TMDI with local structural modification to mitigate structural response to PLGMs. To this aim, a novel PLGM-based optimal TMDI tuning is put forth for structural displacement response minimization which leverages a simplified two-degrees-of-freedom (2-DOF) model focusing on the fundamental vibration mode of the primary structure, as well as the Mavroeidis and Papageorgiou pulse excitation model. Numerical simulations are conducted to analyse the response of the system and optimize the stiffness and damping properties of the TMDI for various TMDI inertia properties and local structural modifications. The proposed PLGM-based tuning is compared with standard H2 tuning of the TMDI assuming frequency neutral (i.e. white noise) excitation. Performance assessment in terms of peak absolute response and root-mean-square (RMS) response indicate that TMDI in the grounded inerter configuration exhibits superior performance over the ungrounded inerter configuration when subjected to analytical pulses. With inerter in the latter configuration, structural modification employed in conjunction with TMDI contained within a single storey effectively reduces the response of the system when exposed to actual pulse-like ground motions, while with grounded inerter the performance improvement depends on the tuning methodology adopted.

Date of Award	7 May 2024
Original language	American English
Supervisor	Giaralis (Supervisor)