臺灣博碩士論文加值系統

本論文主要討論三明治樑阻尼於不同層數、不同長度下頻率響應的差異性，由有限元素軟體COMSOL對三明治阻尼機構進行模擬，利用對頻率響應的觀察，可觀察出三明治阻尼的自然頻率位置、共振峰值，並應用FORTRAN電腦程式將多層三明治阻尼曲線圖轉換出m、c、k、 值，計算出每根三明治阻尼桿在不同層數不同長度的質量m值、阻尼c值、彈簧常數k值、阻尼的損失係數 值；本研究藉由數據探討阻尼長度及層數對桿件m、c、k參數的影響，並找出三明治桿件之最佳尺寸參數，以作為設計者的基礎設計的依據。

The paper presents an approach of transforming the multi-layer sandwich beams into spring-mass-damper systems. The frequency responses of multi-layer sandwich beams are determined through exercising the finite element code COMSOL. After determining the static deflection, damped resonant frequency and peak amplitude at resonant frequency from the frequency response curve, the corresponding parameters of a spring-mass-damper system, including mass, spring constant and damping coefficient can be obtained through the developed approaches. Traditionally, there are two fundamental concepts to simulate the damping performance of a sandwich beam, including structure damping, and viscous damping which can be classified into peak amplitude method and half power method. The differences between these methods are compared and examined. The spring constant, mass and damping coefficient of the damped sandwich beam in different lengths, different amounts of damping layers are investigated. Results show that the damping coefficient and is inverse proportional to the length of the beam. The mass and the spring constant are proportional to the length of the beam. It is noticed that the damping performance of the five damping layers is more than twenty times of the single damping layer.

摘要……………………………………………………………………Ⅱ
目錄……………………………………………………………………Ⅲ
表錄……………………………………………………………………Ⅴ
圖錄……………………………………………………………………Ⅵ
第一章、 緒論
1.1文獻回顧………………………………………………1
1.2 研究動機與目的…………………………………………3
1.3 本文架構…………………………………………………4
第二章、理論分析
2.1 理論模型……………………………………………5
2.2樑振動理論……………………………………………6
2.3 單一自由度系統黏滯阻尼之頻率響應…………………10
2.4 單一自由度系統結構阻尼之頻率響應…………………12
2.5 單一自由度系統之等效阻尼……………………………13
第三章、繞線系統模擬
3.1 彈簧常數與質量之參數轉換…………………………16
3.2 阻尼常數值之參數轉換……………………………………17
3.3 損失係數之參數轉換………•••••……………………………17
3.4 程式流程解說………………………………•…………………18
3.5 三明治阻尼器之質量參數轉換(層數固定長度改變)•……… 19
3-6 三明治阻尼器之彈簧常數參數轉換(層數固定長度改變)•••20
3-7 三明治阻尼器之阻尼參數轉換(層數固定長度改變)•••••••24
3-8 三明治阻尼器之損失係數之參數轉換(loss factor)•••••••••27
3-9 三明治阻尼器之質量參數轉換(長度固定層數改變)•••••••29
3-10 三明治阻尼器之彈簧常數參數轉換(長度固定層數改變)•••35
3-11 三明治阻尼器之阻尼參數轉換(長度固定層數改變)•••••••41
3-12 三明治阻尼器之損失係數參數轉換(長度固定層數改變)•••47
3-13 三明治阻尼之結構阻尼參數轉換(長度固定層數改變)•••••53
3-14 三明治阻尼之 、 值參數轉換(長度固定層數改變)••••• 59
第四章、誤差分析••••••••••••••••••••••••••••••••••••••••• 65
第五章、未來展望…………………………………………………… 70
參考文獻……………………………………………………………… 71
附錄(A)…………………………………………………………………72
附錄(B)……………………………………………………………… 117
附錄(C)……………………………………………………………… 120

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