考量位能效應之可變勁度隔震系統研發與應用

Abstract

台灣地處環太平洋地震帶，在集集大地震過後隔減震研究更受到重視。傳統隔震系統面臨近域地震時，會造成隔震層位移有嚴重放大之問題。為解決此問題，本研究致力開發考量位能特性之智慧型半主動結構控制律。研究首先以過去發展之隔減震控制律為基礎，增加考慮位能特性及位能權重，使能量考量更為全面，以研發出更具效益之智慧型半主動控制律。在數值模擬與試驗部分，受限於控制箱之通道數量，本研究使用單自由度構架模擬上部結構並置於隔震層之上。研究已開發完成半主動控制理論，其成效與傳統控制律相比，本研究提出之控制律可有效降低隔震層位移，且加速度反應亦具有更為良好之成效。振動台試驗顯示近域地震情況下隔震位移可降至原反應的71%，且各控制律理論模擬與實驗情形相符。

In recent years, a study of semi-active isolation system named Leverage-type Stiffness Controllable Isolation System (LSCIS) was proposed. The main concept of the LSCIS is to adjust the stiffness in the isolator for the fundamental period of the superstructure by a simple leverage mechanism. Although great performance has been achieved with the support of an algorithm considering the least input energy in far-field earthquakes, some result still reveal that the proposed system is not suitable in application for near-fault strong ground motion. To overcome this problem, an upgraded algorithm is proposed by considering the potential energy effect in the semi-active structural control system in this study. Firstly, the new algorithm is developed with the combination of the potential energy and the kinetic energy as the control objective to reduce the structural displacement responses efficiently. The optimal weightings between the potential and kinetic energy are then determined through a series of near-fault earthquake simulation. In order to demonstrate the performance of the proposed algorithm, a single-degree-of-freedom structure is used as a benchmark in both numerical simulation and experimental verification. The results have shown that the dynamic response of the structure can be effectively alleviated by the proposed algorithm under both far-field and near-fault earthquakes, while the structural responses by the original algorithm may be worse than the pure passive control. The feasibility of implementing the proposed system has also been experimentally verified.