| Author: | Lao, Jiancong |
| Title: | Numerical study on a moment-resisting frame with SMA base isolators |
| Advisors: | Zhu, Songye (CEE) |
| Degree: | M.Sc. |
| Year: | 2020 |
| Subject: | Structural stability Earthquake resistant design Hong Kong Polytechnic University -- Dissertations |
| Department: | Department of Civil and Environmental Engineering |
| Pages: | iv, 86, 3 pages : color illustrations |
| Language: | English |
| Abstract: | Anti-seismic isolation systems are widely used to alleviate the seismic response of a structure by decoupling the ground motion and superstructure. But conventional isolators did not focus much on raising the resilience of isolators and the residual deformation after an earthquake event and thus, leaving a great many structures in a usability limit failure state. An innovative base isolator with shape memory alloy U-shaped dampers (SMA-UDs), namely SMA base isolator, was proposed in past papers. Thereinto, SMA-UDs are designed to provide a self-centering effect and moderate energy dissipation capacity to the isolator. This kind of isolator was proved to be an effective way to raise the performance of base isolators in the area of alleviating residual deformation by intrinsic shape memory effect in previous studies. Yet no attempt is made to study its seismic behavior when installed under a structure. To reflect the behavior and propose a simulate method, a numerical simulation using OpenSees is implemented in this study. Conventional lead rubber bearing and rubber bearing with steel-UDs equipped with SMA-UDs, namely SMA-LRB and SMA-SRB, are modeled with a two-story moment-resisting frame (MRF) upon as a representation to analyze the dynamic structural response under earthquake events, including a far-fault and a near-fault earthquake. Various configuration schemes of SMA base isolator are simulated to get the best configuration. The simulated result implies that, in all the SMAbase isolators, the post-earthquake residual displacement is greatly reduced with a small sacrifice in isolating efficiency. Wherein, SMA-LRB-1 and SMA-SRB exhibited a desirable performance in SC and vibration isolation efficiency within all the schemes. Slight deteriorated superstructure performance is observed in these two schemes compared to SRB-2. For SMA base isolators a bigger initial stiffness k1 and post-yielding stiffness k2 of both the energy dissipation devices and SMA-UDs can enhance the SC performance further without significant sacrifice in isolation effect. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| 5362.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 6.47 MB | Adobe PDF | View/Open |
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