動態吸振器於樑結構之減振分析

Vibration Reduction Analysis of Dynamic Vibration Absorber in Beam Structure

蔡定江(Ting-Chiang Tsai) ； 張璽良(His-Liang Chang)

《中華民國振動與噪音工程學會論文集》 2018 (2018/06) Pp. 159-166

摘要

本文以連續系統（Continuous System）樑結構作為動態吸振器（Dynamic Vibration Absorber）並對樑結構進行減振分析。文中首先利用能量法推導出受分佈外力及基座激振之樑結構運動方程式，參考雙自由度之動態吸振器模型，衍生為連續系統之動態吸振器模型，再利用傳遞矩陣法（Transfer Matrix Method）分析動態吸振器對具黏滯阻尼樑結構之減振效果。研究針對樑結構前兩個模態進行減振，分析動態吸振器影響效應之參數，包括質量比與阻尼比，當動態吸振器共振頻率與基座激振頻率相同時，求得樑結構自由端振幅為最小，最後在樑結構與動態吸振器最大彎矩處加上黏滯阻尼，即可達到減緩共振時產生之大量變形。

關鍵字

動態吸振器 ； 樑結構 ； 傳遞矩陣法

並列摘要

In this paper, based on continuous system beam structure as a dynamic vibration absorber and analyzed the vibration reduction of beam structure. The equation of motion of the beam structure with base excitation is derived by using energy principle. The dynamic vibration absorber model of the continuous system is derived from the dynamic vibration absorber model with two-degree of freedom, and then the effect of vibration absorber on the structure of viscous damped beam is analyzed by Transfer Matrix Method. The influence of design parameters, which are the mass ratio and damping ratio, is analyzed to research the vibration reduction of the first two modes of the beam structure. When the resonance frequencies of the vibration absorber are the same as the excitation frequencies of the base, the amplitude of the free end of the beam structure is the smallest. Finally, the results show that the viscous damping is located on the maximum bending moment of the beam structure or absorber can reduce the amount of displacement in the resonance.

並列關鍵字

Dynamic Vibration Absorber ； Beam Structure ； Transfer Matrix Method