Abstract
Reliable detection of cracks on slanted metal surfaces and through irregular insulation/coating is critical in many inspection applications. Microwave non-destructive testing (NDT) techniques have proven to be effective for crack detection and characterization. However, the utility of conventional microwave NDT techniques for challenging inspection scenarios which involve cracks on slanted surfaces, or cracks under relatively thick, and possibly, irregular insulation has been limited. In this paper, a polarimetric microwave imaging approach is employed for the detection of cracks in such inspection cases. The detection concept using interrogation with dual polarized wave to suppress the background is presented. It is established herein that the cross-polarization measurement is independent to irregular surfaces, and therefore, it constitutes an effective mean for reliable crack detection even if the background is not uniform or if the metal surface is slanted. This fact is further corroborated by numerical electromagnetic simulations and measurements. The efficacy of the proposed method is demonstrated using imaging results of various samples spanning the abovementioned scenarios. © 2023 Elsevier Ltd
Original language | American English |
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Journal | NDT and E International |
Volume | 140 |
DOIs | |
State | Published - 2023 |
Keywords
- Crack detection
- Electromagnetic simulation
- Imaging systems
- Insulation
- Polarimeters
- Polarization
- Radar imaging
- Synthetic aperture radar
- Circular aperture
- Destructive testing techniques
- Dual-polarizations
- Metal surfaces
- Microwave imaging
- Non destructive testing
- Slanted surface
- Surface cracks
- Thick insulation
- Nondestructive examination