以調控形狀記憶合金線軸向力之可用調式振動吸震器設計及結構減振應用

A Tunable Vibration Absorber Having SMA Wires with Adjustable Axial Force and Its Application in Vibration Reduction of Platform Structure

林佳宏(C.H. Lin) ； 廖允廷(Y.T. Liao) ； 吳美雯(M.W. Wu) ； 李春穎(C.Y. Lee)

《中華民國振動與噪音工程學會論文集》 2015 (2015/06) Pp. 145-151

摘要

因應高科技廠所要求的高精密製程，機台的振動也成為一項自動化生產機台所需要克服的重點之一。本研究致力於應用可調式振動吸振器（tunable vibrationabsorber, TVA）於機台結構之減振，使用形狀記憶合金線於相變化所產生之軸向變形的特性，來調變吸振器結構之軸向力，以使吸振器之自然頻率配合到主結構之外力激振頻率產生減振效果。研究中除了推導吸振器之動態數學模型，作為設計吸振器之依據，也以實驗量測形狀記憶合金吸振器動態特性隨軸向力之改變情形，並實際將吸振器架設在一實驗平台結構上，進行不同頻率下主結構減振效果之探討。結果顯示在設定之預張力及加熱電流之控制下，吸振器自然頻率可以從15 Hz調控至38Hz，達到153.3%的頻率改變量。另外，平台結構的第一模態振動可由吸振器之作動而降低約80%的振動振幅，最後並調整電流加熱之方式，將此吸振器之作動速度作有效的提升。

關鍵字

可調式振動吸振器 ； 形狀記憶合金 ； 初始張力

並列摘要

Recently, because of the increasing demand on high quality products, the mechanical industries have been evolving from traditional machining to developing high-precision machinery to deal with the required high-precision manufacturing process. The machinery which manufacture the high-precision products always face the challenging problem of vibration. In this thesis, we focus on applying the tuned vibration absorber (TVA) to reduce the vibration of primary structure. The design of this vibration absorber with tunable property in constituent material has different types and the most common form of vibration absorber reported in the literature is basically a beam-type configuration. In this study, we focus on controlling the axial force yielded by SMA wires due to its phase transformation to tune the natural frequency of the absorber to the excitation one. Theoretical formulation on the dynamic characteristics of the absorber and experimental measurement on its tunability by axial force were conducted. Moreover, the vibration reduction on a spring-supported platform structure using this absorber was demonstrated experimentally. The results revealed that the control of absorber's natural frequency from 15 Hz to 38 Hz, i.e. an increment of 153.3%, was obtained. More than 80% reduction in vibration amplitude was also demonstrated using this absorber in the first mode vibration of a platform. The possible improvement on the response speed of the absorber and other research aspects were mentioned at the end of this paper.

並列關鍵字

Tunable vibration absorber ； Shape memory alloy ； Initial tension