含非線性黏性阻尼器結構之位移設計法與實驗研究

Abstract

現今之耐震需求單靠結構發揮韌性來抵禦地震力已稍嫌不足，結構控制概念的加入，可運用消能裝置或隔震系統來降低結構物因地震力傳入之反應，結構物不致發揮太大韌性而造成嚴重破壞，使得在震後仍可正常使用。位移設計法在設計過程中，主要是控制結構物之頂層位移，設計者可根據結構物之功能性或規範規定之容許層間相對位移來設定目標位移，強度及勁度不再是設計中之變數，而是設計結果，且在結構整體或區域之位移變形上，位移設計比強度設計更能清楚洞察到結構損壞及極限破壞之情況。 本文之重點乃在多層結構物上加裝非線性黏性阻尼器，應用位移設計法以控制結構頂層位移，並檢核其加速度，利用平均消散能及平均儲存能推導出結構之等效線性系統：等效勁度、等效阻尼比；同樣以平均消散能提出非線性黏性阻尼器之等效線性阻尼比，並評估結構單、多模態位移貢獻對等效阻尼之影響，以及比較與Constantinou提出之等效阻尼比在位移設計法上之差異，最後以三層樓鋼構架加裝非線性黏性阻尼器進行振動台試驗，將實驗、位移設計結果與非線性歷時分析互做比較。

Displacement-base design is the method that used displacement of the structure as the major design parameter. It can also check the acceleration of the roof. In this design procedure, strength and stiffness are no longer the variable. This method specifies the target displacement first, and designs the essential properties of the energy dissipation device. Passive energy dissipation is a technique that offers extra damping to raise the performance of the structure during an earthquake. This paper is concerned with the modeling of nonlinear viscous damper and the displacement-base design of structures for seismic retrofit purposes. In this paper, the equivalent damping ratio of the nonlinear viscous damper is determined by the proposed model of equivalent linear viscous damper. The model also expresses the equivalent stiffness and equivalent damping ratio of the equivalent linear system in accordance with the average store energy and average dissipation energy. The proposed design method has been verified by shaking table test.