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Updated: Jan 28, 2026
05:30
Crack Monitoring in Resonance Fatigue Testing of Welded Specimens Using Digital Image Correlation
Published on: September 29, 2019
8.7K
Fundamental wave amplitude difference imaging for detection and characterization of embedded cracks
Sylvain Haupert1, Yoshikazu Ohara2, Ewen Carcreff3
1Sorbonne Université, CNRS UMR 7371, INSERM UMR S 1146, Laboratoire d'Imagerie Biomédicale, Paris, France.
Ultrasonics
|March 6, 2019
Summary
A new ultrasonic technique, fundamental wave amplitude difference (FAD), effectively images nonlinear scatterers like cracks. FAD offers superior crack detection specificity and contrast compared to conventional ultrasound imaging.
Area of Science:
- Non-destructive testing
- Materials science
- Ultrasonic imaging
Background:
- Conventional ultrasonic imaging struggles to detect certain defects like partially-closed cracks.
- Nonlinear scatterers require advanced imaging techniques for reliable detection.
Purpose of the Study:
- To evaluate the capabilities of the fundamental wave amplitude difference (FAD) ultrasonic technique for imaging nonlinear scatterers.
- To compare FAD imaging with conventional ultrasound for crack detection in metallic samples.
Main Methods:
- The fundamental wave amplitude difference (FAD) method involves sequential ultrasonic acquisitions using different element subsets.
- Images are reconstructed by subtracting subset responses from the full-aperture response.
- Two metallic samples with fatigue or thermal cracks were inspected using FAD and conventional ultrasound.
Main Results:
- FAD demonstrated higher crack detection specificity and better contrast than conventional ultrasound.
- Linear and nonlinear scatterers were found to be mostly non-co-localized, providing complementary information.
- FAD exhibited resolution characteristics similar to conventional ultrasonic techniques.
Conclusions:
- FAD is a promising and reliable tool for real-time imaging of nonlinear scatterers.
- The technique can be implemented on conventional ultrasound devices, facilitating industrial adoption.
- FAD allows for parametric studies to investigate signal distortion mechanisms.
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