Noise and Vibration Suppression Using an Array of Weak Radiating Panels

瀏覽統計 Email 通知 RSS Feed

簡歷

基本資料

Project title

Code/計畫編號

NSC102-2221-E019-020

Translated Name/計畫中文名

應用弱輻射嵌板陣列之噪音與振動制抑

Project Coordinator/計畫主持人

Yih-Hwang Lin

Funding Organization/主管機關

National Science and Technology Council

Department/Unit

Department of Mechanical and Mechatronic Engineering

Website

https://www.grb.gov.tw/search/planDetail?id=3088744

Year

2013

Start date/計畫起

01-08-2013

Expected Completion/計畫迄

01-07-2014

Bugetid/研究經費

1075千元

ResearchField/研究領域

機械工程

"本研究之目的係在探討應用弱輻射嵌板陣列之噪音與振動制抑。題材涉及複雜的結構動力問題。相對於傳統的消減噪音的方法，使用昂貴與寬敞的非接觸包覆外殼，本研究考慮使用隔音嵌板陣列直接連接至振動結構體。使用此策略可顯著減少成本和所需之空間。然而直接連接嵌板陣列將造成困難的噪音和振動問題，有待解決。首先，主結構的基座激振可從直接連接處傳遞，可能導致共振而造成災難性的失敗。其次，嵌板陣列可以表現出多種振動模式，各小組嵌板之組合振動模態將含蓋寬廣範圍並包含單一嵌板設計時之目標頻率。第三，嵌板陣列所造成之隔離空間可能引起聲音共鳴，而大幅降低嵌板的隔音性能。在本研究中我們將解決基座激振問題，設計具振動隔絕的隔音嵌板，使之可從主結構之寬頻激振中存活下來。這需要設計一個軟嵌板使其前幾個自然頻率數倍低於基本激振頻率。嵌板同時也必須具有足夠的剛性，使其振動模態與各個強迫激振頻率有效區隔。此外，將分析各小組嵌板之組合振動模態特性，以確保設計的嵌板振動頻率與激振頻率不重疊。主結構和隔音嵌板封閉空間之潛在聲音共鳴問題將進行查驗，並探討噪音吸收或空間分隔以量身訂製嵌板設計，避免共振問題。本研究將在各個階段進行實驗以確認理論之預測，將進行實驗模態分析以確立主結構和所設計嵌板的振動模態。利用操作振形以獲得整體系統的操作振動樣式，使得該系統的關鍵指標可以有效識別，以確保適當的設計。另將進行聲音量測，以確立系統噪音特質，並展現隔音嵌板在主結構各個激振頻率的隔音性能。" "The purpose of this study is to investigate noise and vibration suppression using an array of weak radiating panels. The subject matter involves complex structural dynamics problems. As opposed to the traditional noise abatement approach in using an expensive and spacious enclosure panels, the present study considers a direct attachment of sound insulation panel array onto the vibrating structure. A significant reduction in cost and space can be achieved in using the proposed strategy. However, the direct attachment of the panel array results in more difficult noise and vibration problems to be tackled. Firstly, base excitation from the main structure can now be transmitted from the direct attachment, which may result in resonance leading to catastrophic failure of the treatment. Secondly, the panel array can exhibit numerous vibration modes within vibrating sub-group panels, with natural frequencies populated around the target frequencies as designed using a single panel. Thirdly, the panel array creates isolated air space which may induce further acoustic resonance and degrade significantly the sound insulation performance of the panel. In this study, we shall tackle the problem of base excitation by designing a vibration isolated sound insulation panel, which can survive the broad band excitation from the main structure. This requires a design of a soft panel with the first few natural frequencies several times below the fundamental excitation frequency. At the same time, the panel must also be rigid enough to survive the various excitation frequencies by tailoring the vibration modes to be well separated from the forcing frequencies. Furthermore, the characteristics of the vibrating sub-group panels will be analyzed to ensure that the vibration modes of the designed panel do not coincide with any of excitation frequencies. The potential acoustic resonance in the air space enclosed by the main structure and the sound insulation panel will be examined to tailor the panel design and additional treatment for noise absorption or air space partition to alleviate the resonance problem will be investigated. Experiments will be carried out at various stages of this study to confirm the theoretical predictions. Experimental modal analysis (EMA) will be performed to characterize the vibration modes of the main structure and the designed panels. Operating deflection shapes (ODS) will be utilized to obtain the vibration pattern of the entire system in operation so that the key indicator of the system can be identified to ensure a proper design. Acoustic measurement will be conducted to characterize the system’s noise behavior to demonstrate the performance of the sound insulation panel for various excitation frequencies of the operating main structure."

DSpace CRIS

Noise and Vibration Suppression Using an Array of Weak Radiating Panels

基本資料

Description