Application of Viscoelastic Tuned Mass Damper (VE-TMD) to control the Floor High-Frequency Micro-Vibration of High-Tech Factory

本文之主旨係以黏彈性諧調質量阻尼器(VE-TMD)做為減振機制，期減少高科技廠房樓版垂直向第一振態之振動量。所謂「黏彈性諧調質量阻尼器(VE-TMD)」係利用黏彈性材料提供諧調質量阻尼器之勁度與阻尼，亦即黏彈性阻尼器與質量塊之組合機構。本文之TMD其設計方法係依據Hartog’s method設計準則進行設計，藉由分析及試驗以檢視VE-TMD減少樓版垂直向振動量之可行性。是以，本文內容主要可分為兩部份，第一部份為樓版結構分析模擬之部份，分析所使用之軟體為SAP2000結構分析軟體，於SAP2000軟體中使用薄殼元素、固體元素及梁元素建立高科技廠房樓版結構分析模型，施加不同頻率之簡諧外力於樓版中央，以直接積分法對安裝TMD前、後之樓版進行動力反應之數值分析，進而求得樓版中央之振動反應(位移、速度及加速度)，比較樓版安裝TMD前、後之減振效果。第二部份內容為對現有之黏彈性阻尼器進行材料性質測試，本文提供一套簡單之材料性質試驗方法以做為參考，其試驗過程分為靜力試驗及動力試驗部份，靜力試驗之目的為，從現有之黏彈性阻尼器中篩選出最符合本文設計需求之樣品，將篩選出之樣品進行動力試驗，由動力試驗之結果求出黏彈性阻尼器其橡膠材料之勁度、自然頻率及阻尼比。本文使用之黏彈性阻尼器為受現有樣品之限制，樣品之材料性質無法完全適合本文廠房樓版之需求。但本文研究主旨目的係建立VE-TMD動力特性實驗架構與量測方法，以作為將來黏彈性阻尼之選擇與改善。This study investigates the mechanisms of viscoelastic tuned mass damper (VE-TMD) in reducing the floor vibrations in high-tech buildings of the first vertical mode. The so-called VE-TMD is a device composed of a viscoelastic damper and a mass block, in which the stiffness and viscous features of the device are offered by viscoelastic materials. In this study, the TMD is designed according to Hartog’s method, to verify the feasibility of reducing the vertical vibrations of floors through both numerical and experimental approaches. The content of this study is divided into two major parts. The first part is the numerical simulation part. With the commercial software SAP2000, the numerical models for the floors of high-tech buildings are set up with shell elements, solid element and beam elements. Applying harmonic loadings of different frequencies at the center of the floors and then comparing the dynamic responses (displacements, velocities, and accelerations) of the floors with and without TMD, the effects of TMD in reducing vibrations can be evaluated. The second part is the experimental verification part. A simple algorithm for testing the material properties of present viscoelastic dampers is presented in this study. The algorithm includes two tests: the static test and dynamic test. The purpose of the static test is to select a qualified viscoelastic damper that satisfies the design requirements out of several samples. The selected damper is then subjected to a dynamic test for the purpose of obtaining the properties of the rubber material in the damper, including the stiffness, natural frequency, and damping ratio. Although the material properties of the damper samples do not fully satisfy the design requirements for the building floors herein due to the limited number of samples available, the objective of this study in presenting an algorithm for testing the dynamic characteristics of the VE-TMD is achieved, hence offering a guideline for further improvements and selections in viscoelastic dampers