Control strategy of semi-active nonlinear negative stiffness devices using optimal expansion ratio for base-isolated structures

Zhang, Yafei, Li, Ning, Hu, Yuchen, Zhou, Zihao and Sun, Li 2025. Control strategy of semi-active nonlinear negative stiffness devices using optimal expansion ratio for base-isolated structures. Journal of Building Engineering 103 , 112179. 10.1016/j.jobe.2025.112179 Item availability restricted.

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Abstract

High-intensity earthquake can cause excessive inter-story drift in base-isolated structures (BIS), potentially exceeding allowable limits which poses a serious threat to structural safety. This study proposes a novel displacement control strategy utilizing a semi-active nonlinear negative stiffness device (SA-NNSD). This approach leverages optimal expansion ratio derived from active nonlinear negative stiffness device control methodologies. The research implements this strategy on a two-degree-of-freedom BIS system, incorporating both a mechanical NNSD model of and a servo-hydro actuation facility that precisely regulates the NNSD spring extension ratio. Through nonlinear time history analysis, the study establishes the optimal nonlinear negative stiffness range of the NNSD, validating the effectiveness of the SA-NNSD control strategy. The resulting optimal nonlinear negative stiffness force and the corresponding range significantly reduce the displacement response of the isolation story across all different seismic events, especially when it comes to with high-damage potential. Quantitatively, up to 10% and 20% reductions for the mean values of the isolation story displacement and the top story absolute acceleration have been observed, respectively. Findings pave the way for improved seismic isolation strategies in earthquake-prone regions worldwide.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Schools > Engineering
Additional Information:	License information from Publisher: LICENSE 1: Title: This article is under embargo with an end date yet to be finalised.
Publisher:	Elsevier
ISSN:	2352-7102
Date of First Compliant Deposit:	24 February 2025
Date of Acceptance:	18 February 2025
Last Modified:	04 Mar 2025 15:00
URI:	https://orca.cardiff.ac.uk/id/eprint/176429

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