自體調諧質量阻尼系統動力反應最佳化於實務案例之可行性研究

Feasibility Study on Building Mass Damper Using Optimum Dynamic Response Control Algorithm for Practical Application

陳培榮(Pei-Rong Chen)

指導教授 ： 張國鎮

國立臺灣大學/工學院/土木工程學研究所/碩士(2016年)

https://doi.org/10.6342/NTU201601214

摘要

近年來隨著隔震設計之建築物蓬勃發展，其中基礎隔震設計須於基礎進行繁瑣伸縮縫施工，因此考量施工性較優之中間層隔震設計逐漸被廣泛應用，然而中間層隔震設計之高模態參與比例較高，恐造成隔震層下部結構反應放大。欲減少隔震層下部反應放大的問題，考慮傳統調諧質量阻尼系統為一有效之振動能量吸收器，其基本原理將調諧質量阻尼系統之自然頻率調整趨近於主要系統，使兩者於外力作用下產生反相位運動進而以調諧質量阻尼器消散外力擾動能量。
自體調諧質量阻尼(Building Mass Damper，BMD)系統將上部結構視為調諧質量，並利用橡膠支承墊與黏性阻尼器分別提供BMD系統所需之勁度及阻尼，結合中間層隔震與調諧質量阻尼器設計之優點，同時控制下部與上部結構反應。數值模型上，以一簡化三自由度模型分別模擬上部結構、控制層及下部結構，進而以三自由度之動力反應總和最小化作為控制目標，推導BMD最佳化系統參數。
基於前導研究已分別透過數值模擬及振動台實驗，驗證BMD設計於八層樓縮尺構架之可行性，故本研究將針對BMD設計於實際結構之可行性進行探討，因此將採用57層樓鋼構架作為空構架設計依據，在分析程序上，先根據2%鋼構架初始阻尼比分別設計TMD、BMD及OBMD構架，透過歷時分析上輸入六組不同特性之地震歷時，比較三種不同減震設計法之歷時反應，同時透過簡化三自由度之加速度轉換函數配合震波FFT頻涵圖，交互驗證其歷時行為；根據第一階段之歷時分析結論，分別設計一主結構阻尼比為4%之OBMD構架，以及一整體阻尼比為4%之消能減震構架，並重新對於空構架、消能減震構架及OBMD構架進行歷時分析，最後分別對於最大層間變位角及樓層最大加速度進行結果比較，以總結出BMD設計於實際案例應用之可行性。

關鍵字

調諧質量阻尼器 ； 中間樓層隔震 ； 自體調諧質量阻尼器 ； 目標函數 ； 數值分析 ； 實務案例應用

並列摘要

In a mid-story isolated building, the isolation system is incorporated into the mid-story rather than the base of the building. The effectiveness of mid-story isolation design in reducing seismic demands on the superstructure above the isolation system has been verified in many researches. But the response of substructure may be enlarged due to the flexibility and the contribution of the higher modes. Besides, tuned mass damper (TMD) system has been recognized as an effective energy absorbing device to reduce the undesirable vibrations of the attached vibrating system subjected to harmonic excitations. Therefore, the concept of building mass damper (BMD) design is to combine the tuned mass damper system and mid-story isolated design to control the seismic response of both substructure and superstructure. In BMD design, the superstructure serves as a tuned absorber mass whose stiffness and damping can be provided by the isolation system composed of elastomeric bearings and additional dampers, as the advantages of conventional tuned mass damper and mid-story isolation systems can be integrated.
A simplified three-lumped-mass structure model, in which three lumped masses are respectively assigned at the building mass absorber, the control layer, and the primary structure, is rationally assumed to represent a building structure with a BMD system. The reason for doing this is so that the inherent dynamic characteristics (fundamental modal characteristics of vibration) of both the building mass absorber and the primary structure can be considered comprehensively in the simplified structure model.
The feasibility of the optimum BMD (or OBMD) design method has been verified in previous studies. In this research, the 57-story steel frame is used to be a bare frame. According to 2% inherent damping ratios of the TMD, BMD and OBMD can be designed respectively. Six real earthquake records with distinct seismic characteristics adopted in this research are selected for the ground acceleration inputs along the longitudinal and transversal direction. On the other hand, the acceleration transfer functions of the simplified three-lumped-mass structural model and the FFT of each ground motion are used to describe the seismic behavior of the TMD, BMD and OBMD. Then, the seismic responses of the OBMD system are thoroughly investigated and the practicability and effectiveness of the OBMD system for seismic design are verified.

並列關鍵字

Mid-story isolation system ； Tuned mass damper ； Building mass damper ； Objective function ； Numerical analysis ； Practical application

參考文獻

1.李柏翰，自體調諧質量阻尼系統耐震行為與試驗研究，國立台灣大學土木工程學研究所博士論文，張國鎮教授指導，民國102年7月。

2.莊幃竹，自體調諧質量阻尼器動力反應最佳化之可行性研究，國立台灣大學土木工程學研究所碩士論文，張國鎮教授指導，民國103年6月。

3.郭仕璞，自體調諧質量阻尼器動力反應最佳化之振動台試驗研究，國立台灣大學土木工程學研究所碩士論文，張國鎮教授指導，民國104年7月。

8.汪向榮，中間樓層隔震建築之耐震行為分析與試驗研究，國立台灣大學土木工程學研究所博士論文，張國鎮教授指導，民國99年1月。

9.林孟慧，中間樓層隔震結構之模態耦合效應研究，國立台灣大學土木工程學研究所碩士論文，張國鎮教授指導，民國97年6月。