Measurement of structural intensity using boundary element method-based nearfield acoustical holography

Area of Science:

• Acoustics
• Structural Mechanics
• Numerical Methods

Background:

• Accurate measurement of structural intensity (SI) is crucial for understanding vibration transmission and noise radiation.
• Traditional methods using nearfield acoustical holography (NAH) struggle with noise amplification due to spatial derivative calculations.
• Existing regularization techniques for SI measurement are often limited to fast Fourier transform (FFT)-based NAH.

Purpose of the Study:

• To propose and validate a modified regularization method for structural intensity measurement using boundary element method (BEM)-based NAH.
• To address the limitations of noise amplification in spatial derivative calculations inherent in SI measurement.
• To leverage the advantages of BEM-based NAH, such as avoiding aperture replication, for improved measurement accuracy.

Main Methods:

• The study modifies a previously introduced regularization method for SI measurement.
• The modified method is applied within the framework of BEM-based NAH.
• Experimental validation is performed to demonstrate the effectiveness of the proposed technique.

Main Results:

• The proposed regularization method effectively mitigates the amplification of high-wavenumber noise components during SI measurement.
• BEM-based NAH allows for a smaller measurement aperture compared to FFT-based NAH, simplifying experimental setups.
• Experimental results confirm the successful application and accuracy of the modified regularization method for SI measurement.

Conclusions:

• The developed regularization method is effective for accurate structural intensity measurement using BEM-based NAH.
• This approach offers a robust solution to noise contamination issues in SI measurements.
• The findings pave the way for more precise acoustic analysis and diagnostics in structural systems.