非線性黏性阻尼器建築結構受近斷層地震作用之振動台試驗與分析

Experimental and Analytical Study of a Structure with Supplemental Nonlinear Viscous Dampers Subject to Near-Fault Ground Motions

龔琬茜(Wan-Chien Kung)

指導教授 ： 黃尹男

國立臺灣大學/工學院/土木工程學研究所/碩士(2017年)

https://doi.org/10.6342/NTU201703120

摘要

減震系統的設計，常應用阻尼折減係數，其定義為單自由度結構5%阻尼比反應譜值與某目標阻尼比反應譜值之比。過去已有學者研究發現在近斷層地震作用下，阻尼折減係數和結構物之自然週期與近斷層地震脈衝週期之比值(T/Tp)有關，但現行規範之阻尼折減係數僅為阻尼比及結構週期之函數，並未特別考慮遠域與近斷層地震地表加速度歷時紀錄不同之特性。
　　本研究以一座安裝非線性液態黏性阻尼器的三層樓立體抗彎鋼構架進行振動台試驗，進而驗證阻尼折減係數與T/Tp之相關性，並配合SAP2000結構程式軟體進行數值分析。測試用之鋼構架未安裝阻尼器時第一模態自然週期約1秒。試驗結果證實近斷層地震脈衝週期Tp與結構物週期之比值確實會影響阻尼器對結構反應的折減效果。對於第一模態主控之結構物，當結構物週期接近脈衝週期時，阻尼器會有較好的地震反應折減效果，最佳地震反應折減落在T/Tp介於0.7至0.9之間。

關鍵字

近斷層地震 ； 速度脈衝 ； 脈衝週期 ； 阻尼折減係數 ； 非線性液態黏性阻尼器

並列摘要

Energy dissipation system is about a structure installed with dampers. These dampers raise the damping ratio and increase the energy dissipation capability of structure. In seismic design code, the damping reduction factor (DRF) is used to divide the 5% damped spectral value to obtain the spectral values corresponding to various damping ratios. Under the near-fault ground motion, the DRF has been discovered that it has a relationship with the vaule of T/Tp which is the ratio of natural period of a structure to the pulse period of near-fault ground motion.
　　In order to proof the correlation between DRF and T/Tp, this study would perform shaking table tests on a three-story steel structure with supplemental nonlinear viscous dampers. The natural period of first mode of the test structure was around 1 seconds. In addition, numerical analysis used SAP2000 to compare with experimental results.
　　The results show that T/Tp is an important parameter for DRF. When the T/Tp is close to 1, the dampers are more effective in reducing responses of displacement and acceleration. The range of T/Tp between 0.7 and 0.9 presents the most effective reduction.

並列關鍵字

near-fault ground motion ； velocity pulse ； pulse period ； damping reduction factor ； nonlinear viscous damper

參考文獻

23. 劉家仁 (2015)，「近斷層地震對結構隔減震系統效益之影響研究:單自由度系統」國立臺灣大學土木工程學研究所，碩士論文，黃尹男教授指導，台北，台灣。

22. 游豐碩 (2016).，「近斷層地震對結構減震系統效益之影響研究」國立台灣大學土木工程學研究所，碩士論文，黃尹男教授指導，台北，台灣。

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