應用非線性流體系統於隔振之研究

Analyses and Applications of Nonlinear Liquid Systems on Vibration Isolation

魏聿彥(Yu-Yen Wei)

指導教授 ： 黎文龍

國立臺北科技大學/機電學院/自動化科技研究所/碩士(2010年)

https://doi.org/10.6841/NTUT.2010.00288

摘要

使用一些軟非線性元件對於振動的抑制是有效的。然而，大多數的應力應變經驗公式並不精確且有著材料以及尺寸上的侷限。因此值得發展他種的非線性隔振器來改善。吾人希望該系統效應類似於具有軟性回復力之系統，進一步在一定程度上可自由地設計各式各樣的軟彈簧效應。特別是流體將用於構成此隔振系統。
在本研究中介紹了三種型態的非線性流體系統(NLS)，分別是浮力型、交換型以及承載型，實際上他們有些為變動質量系統。本研究也推導了這些系統運動方程式以驗證其非線性。本研究採用一些範例造型進行數值模擬與分析，結果顯示NLS在特定條件下具有軟彈簧效應。
本研究展示了一種承載型非線性流體系統的實驗架構以驗證其軟效應。然而，實驗結果顯示可能會有來自液體及預期固定之架構帶來的振動干擾。這使得驗證本研究之組態非線性系統是困難的。本研究對使用非線性流體系統作為隔振器提出一些指引與建議。

關鍵字

流體 ； 非線性 ； 軟彈簧 ； 變動質量 ； 隔振器

並列摘要

Softening nonlinear elements are usually effective for vibration reduction. However, most stress-train relations of structural systems are not exact and have limitation of materials and scale. One is desirable to develop nonlinear isolators to improve vibrations. Anticipating the effect of such a system is similar to a system with softening restoring force, one can have a certain extend to design diverse kinds of softening effects. Especially, liquid is used to build isolation systems.
Three types of nonlinear liquid system (NLS) are introduced in this study, which are the buoyance, exchange and loading types. In fact, some of them are variable mass systems. The equations of motion of these systems are also derived to verify their nonlinearities. Numerical simulations and analyses are followed for several example shapes. The experimental results reveal that NLSs have softening spring effects with specific conditions.
An experimental model of NLS-L is displayed to verify its softening spring effects. However, the experiments results show that there’re may be some vibration noises from the motion of liquid and the static structure one expects. It’s hard to verify the configuration nonlinear system, at least the NLS-L designed in this study. The present research gives guidelines and suggestions for using NLS as vibration isolators.

並列關鍵字

Liquid System ； Nonlinear System ； Soft Spring ； Variable Mass ； Vibration Isolator

參考文獻

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