Model Expansion of Experimental Vibration Data for Numerical Acoustic Radiation Prediction

實驗振動數據模式展開對於數值聲響幅射預測之應用

Pierre Guisset ； Marc Brughmans

《中華民國振動與噪音工程學會論文集》 1995 (1995/06) Pp. 165-170

https://doi.org/10.30028/CSSVANNUAL.199506.0165

摘要

振動結構之聲響幅射預測傳統上都是利用聲學邊界元素法，假若對系統的動態行為非常了解，此種預測會有不錯的結果。本文即在說明實驗振動分析與數值聲響幅射預測之整合。此種方法包含三個步驟：(1)量測振動體表面之振動量，(2)以有限元素模式之模態資料將實驗數據展開至數值模式，(3)以邊界元素分析計算聲響幅射場。
由此整合，動態行為可以儘可能地被精確地定義，進爾邊界元素就可以應用於廣泛的範圍（如聲響分佈及敏感度分析等）。本文將以一個實際的應用實例（汽車引擎）來說明及驗證此一方法。

並列摘要

The prediction of the acoustic radiation of vibrating structures is traditionally based on the acoustic boundary element method. This approach leads to good predictions, provided that the dynamic behavior of the system is well known. This paper presents the integration of experimental vibration analysis with numerical acoustic radiation prediction. The developed methodology involves several steps: (i) measure the accelerations on the surface of a vibrating body, (ⅱ) expand these experimental data onto a numerical model, using the modal information of a finite element model, and (ⅲ) run a boundary element analysis to determine the acoustic radiated field.
This procedure presents the advantages that the dynamic behavior is as accurately as possible defined and that the boundary element approach opens wide results interpretation (contribution and sensitivity analysis...). A real-life application example (car engine) is shown to illustrate and validate the developed methodology.