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Reflection and transmission coefficients for guided waves reflected by defects in viscoelastic material plates
Bernard Hosten1, Ludovic Moreau, Michel Castaings
1Laboratoire de Mécanique Physique, Université Bordeaux 1, UMR C.N.R.S. 5469 351 cours de la Libération, 33405 Talence Cedex, France. b.hosten@lmp.u-bordeauxl.fr
The Journal of the Acoustical Society of America
|June 8, 2007
Summary
This study introduces a Fourier transform method to analyze guided wave scattering from defects in viscoelastic materials. The technique accurately quantifies reflection, transmission, and mode conversion, crucial for structural health monitoring.
Area of Science:
- Materials Science
- Mechanical Engineering
- Signal Processing
Background:
- Guided waves are vital for inspecting viscoelastic materials.
- Defects like notches can alter wave propagation, causing scattering and mode conversion.
- Accurate quantification of these effects is essential for structural integrity assessment.
Purpose of the Study:
- To develop and validate a Fourier transform-based signal processing procedure.
- To quantify reflection, transmission, and mode conversion of guided waves diffracted by defects.
- To assess the method's precision using numerical simulations and comparison with existing techniques.
Main Methods:
- Fourier transform-based signal processing.
- Finite element (FE) code simulation of guided wave propagation and diffraction.
- Energy balance computation for validation.
- Comparison with an orthogonality relation-based processing method.
Main Results:
- The procedure successfully quantifies reflection and transmission coefficients.
- Mode conversion effects due to notches were accurately captured.
- Validation through energy balance confirmed the method's precision.
- Results showed good agreement when compared to the orthogonality relation method.
Conclusions:
- The proposed Fourier transform method is a valid and precise tool for analyzing guided wave-Lamb wave scattering in viscoelastic materials.
- This technique enhances the capability for non-destructive evaluation (NDE) of defects.
- The study provides a reliable approach for quantifying wave-defect interactions, including mode conversion.
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