A novel 3D evaluation method for surface defects using broadband laser-generated Rayleigh waves with wavenumber...

Area of Science:

• Materials Science
• Non-Destructive Testing
• Acoustic Wave Propagation

Background:

• Traditional surface defect imaging methods struggle with small defects and depth evaluation.
• Local wavenumber estimation for surface defect imaging faces challenges with accuracy and depth assessment.

Purpose of the Study:

• To propose a novel three-dimensional (3D) evaluation method for surface defects using broadband laser-generated Rayleigh waves and wavenumber analysis.
• To overcome limitations in imaging small defects and evaluating defect depth.

Main Methods:

• Established a finite element model to simulate Rayleigh wave interaction with surface defects.
• Investigated wavenumber changes in Rayleigh waves upon encountering defects.
• Developed a 3D evaluation method involving frequency-wavenumber analysis and space-frequency-wavenumber analysis.
• Estimated defect depth by analyzing the maximum amplitude of the Rayleigh wave.

Main Results:

• Rayleigh wave interaction with defects generates mode-converted scattered waves with lower wavenumbers.
• A linear relationship exists between defect depth and maximum Rayleigh wave amplitude.
• The proposed method effectively suppresses noise and achieves high-precision imaging of small surface defects.

Conclusions:

• The novel 3D evaluation method offers improved precision for small surface defect imaging.
• The method enables accurate defect depth evaluation through amplitude analysis.
• This research provides a potential application for advanced 3D surface defect assessment.