Abstract
This study proposes a new type of self-centering damper equipped with novel buckling-restrained superelastic shape memory alloy (SMA) bars. The new solution aims to address some critical issues related to degradation and loss of superelasticity observed in existing tension-only SMA-based self-centering devices, and in addition, to encourage enhanced material utilization efficiency. The cyclic tension-compression behavior of individual SMA bars is experimentally studied first, and subsequently, two proof-of-concept self-centering dampers are manufactured and tested. A simple yet effective numerical model capturing the flag-shaped response of the dampers is then established, and a preliminary system-level analysis is finally conducted to demonstrate the effectiveness of the proposed damper in structural seismic control. The individual SMA bar specimens show asymmetrical flag-shaped hysteretic responses with satisfactory self-centering capability and moderate energy dissipation. Through a specially designed configuration, the proposed damper shows desirable symmetrical and stable hysteretic behavior, and maintains excellent self-centering capability at 6% bar strain. The system-level dynamic analysis indicates that the dampers, as a means of retrofitting, could effectively reduce both the peak and residual inter-story drift ratios of a six-story steel frame. In particular, the mean residual inter-story drift ratio is reduced from over 0.5% to below 0.2% under the maximum considered earthquake, implying elimination of necessary structural realignment even after strong earthquakes.
Original language | English |
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Article number | 035009 |
Journal | Smart Materials and Structures |
Volume | 29 |
Issue number | 3 |
DOIs | |
Publication status | Published - Jan 2020 |
Keywords
- buckling-restrained
- damper
- retrofitting
- seismic resilient
- self-centering
- shape memory alloy (SMA)
- tension-compression
ASJC Scopus subject areas
- Signal Processing
- Civil and Structural Engineering
- Atomic and Molecular Physics, and Optics
- General Materials Science
- Condensed Matter Physics
- Mechanics of Materials
- Electrical and Electronic Engineering