Related Experiment Video
Updated: May 17, 2026
11:34
Subsurface Defect Localization by Structured Heating Using Laser Projected Photothermal Thermography
Published on: May 15, 2017
3D imaging of Sub-Millimeter defects using Laser-Generated broadband surface waves and Multi-Band Space-Wavenumber
Min Sheng1, Chuanyu Lu2, Hao Chen3
1Key Laboratory of Nondestructive Testing, Ministry of Education, Nanchang Hangkong university, Nanchang 330063, China.
Ultrasonics
|May 15, 2026
Summary
This study introduces a new 3D imaging technique using laser-generated surface waves for precise defect detection and crack monitoring. The method achieves high-resolution 3D reconstruction of submillimeter defects and enables accurate crack propagation analysis.
Area of Science:
- Materials Science
- Non-destructive Testing
- Wave Physics
Background:
- Submillimeter-scale defects pose challenges for traditional 3D imaging.
- Monitoring submillimeter crack propagation requires high-resolution techniques.
Purpose of the Study:
- To develop a novel 3D imaging method for submillimeter defects and crack monitoring.
- To investigate surface wave interaction with defects using finite element modeling.
Main Methods:
- Laser-generated broadband surface waves and multi-band space-wavenumber analysis.
- Finite element modeling to study surface wave attenuation with defect depth.
- Two-dimensional Fourier transform (2D-FFT) for defect depth assessment via cut-off frequency.
- Sliding window and 2D-FFT for local wavenumber estimation and 3D image reconstruction.
Main Results:
- Accurate 3D reconstruction of defects as small as 2 mm × 0.2 mm × 0.1 mm.
- Clear 2D morphologies for defects with lengths 2-4 mm and inclination angles 15°-45°.
- Maximum length measurement error below 5%, demonstrating potential for crack monitoring.
Conclusions:
- The proposed method effectively suppresses noise and enhances detection resolution.
- Enables high-precision 3D reconstruction and multi-scale characterization of submillimeter defects.
- Validates potential for precise submillimeter crack propagation monitoring.
