基於電流變液三明治樑之吸振器用於結構的振動控制

Vibration Control of a Structure Using a Vibration Absorber Based on an Electro-rheological Fluid Sandwich Beam

陳耿烽(Keng-Feng Chen)

指導教授 ： 林志哲

國立臺北科技大學/機電學院/自動化科技研究所/碩士(2012年)

摘要

本論文描述內含電流變液懸臂樑作為結構之吸振器的振動控制。吸振器是一種廣泛用來減少結構振動的設備，為了避免設備的主結構因振動損壞，故在不改變主系統的情形下加裝吸振器以達到減振的目的。本文使用三明治夾層懸臂樑作為吸振器的結構，在兩電極間以電流變液填充。電流變液屬於智慧型材料的一種，由不導電流體與介電懸浮微粒組成，經電場作用後懸浮微粒形成鏈結，造成剛性與阻尼產生變化，形態由牛頓流體轉變為近似Bingham塑性體，利用流體的黏滯性隨電場增強而增加造成剪切降伏應力改變的特性，做為吸振器中的可調式阻尼進行振動控制。本文量測三明治懸臂樑的動態特性，加上電場後其共振頻率會隨之提高，適合做為半主動吸振器的振動控制，當結構之振動恰為共振頻率時，控制電流變液樑吸振器之電場改變結構之共振頻率，藉以避免共振頻率下所帶來的振動。根據實驗量測結果，利用模糊控制理論建立模糊規則庫，利用CompactRIO控制器控制半主動可調變吸振器之振動，最後並與以模糊理論為基礎之自調變控制器之減振效果作比較。

關鍵字

電流變液 ； 模糊控制 ； 可調變吸振器

並列摘要

The main objective of this article is to present the achievements of controlling a sandwich cantilever beam embedded with electro-rheological fluid as a tunable vibration absorber. In this study, the sandwich beam filled with electro-rheological fluid inside regards as a structure of the vibration absorber. Electro-rheological fluids change to Bingham behavior from Newtonian flow under electric field. The field cause the suspended particles polarize and connect each other to form chain. The viscosity and the yield stress of the ER fluid increase as electric field so that it is applicable to be the adjustable damping of a tunable vibration absorber. This thesis describes the dynamic properties of the sandwich cantilever beam of which natural frequencies of the beam increase with the electric field. Therefore it is suitable to be the dynamic vibration absorber. According to the experimental results, we design a fuzzy controller to accomplish the tunable vibration absorber in semi-active vibration control. Then compare to the result of self-tuning control method.

並列關鍵字

Electro-rheological fluid ； Fuzzy control ； Tunable vibration absorber

參考文獻

[1] Duff, A.W., “The Viscosity of Polarized Dielectrics”, Phys. Rev. , pp. 23-38, 1896.

[2] C. J. Radcliffe, J. R. Lloyd, R.M. Andersland,J. B. Hargrove, “State feedback control of electrorheological fluids”, ASME International Congress and Exhibition, Nov., 1996 pp.17-22.

[4] W. M. Winslow , “Induced Fibration of Suspensions,” Journal of Applied Physics, vol. 20, 1949, pp.1137-1140

[7] R. Stanway, J. Sproston, A. El-Wahed, “Applications of electrorheological fluids in vibration control: a survey”, Smart Materials and Structures, vol. 5, 1996, pp.464-482.

[8] N. G. Stevens, J. L. Sproston, “An Experimental Study of Electro-Rheological Torque Transmission”. Journal of Mechanisms Transmissions and Automation in Design, 110 , 1988, pp. 182-188