Novel Microwave Method for Detection of Finite Surface Cracks in Metals
An electromagnetic model for finite surface crack detection is presented. An open-ended waveguide sensor is used to scan a cracked metal surface. The crack is modelled as a large waveguide feeding a smaller one. The characteristics of the standing wave set up in the waveguide is altered when the waveguide is terminated by an imperfect short circuit load (crack surface). This is due to the generation of higher order modes as a result of the presence of the crack. Strategic probing of the standing wave properties is used to indicate the presence of a crack. A Fourier boundary matching technique is used to satisfy the boundary conditions at the waveguide aperture and the crack boundaries. The behavior of crack characteristic signals as a function of crack size and location within the sensor aperture is also studied. A finite fatigue crack is finally detected at 38 GHz to demonstrate the practical feasibility of this technique.
C. Yeh and R. Zoughi, "Novel Microwave Method for Detection of Finite Surface Cracks in Metals," Proceedings of Advanced Microwave and Millimeter-Wave Detectors (1994: San Diego, CA), vol. 2275, pp. 103-111, SPIE--The International Society for Optical Engineering, Jul 1994.
The definitive version is available at https://doi.org/10.1117/12.186707
Advanced Microwave and Millimeter-Wave Detectors (1994: Jul. 25-26, San Diego, CA)
Electrical and Computer Engineering
Keywords and Phrases
Boundary Conditions; Cracks; Fourier Transforms; Metals; Sensors; Surfaces; Waveguides; Electromagnetic Models; Standing Waves; Microwave Devices
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Article - Conference proceedings
© 1994 SPIE--The International Society for Optical Engineering, All rights reserved.
01 Jul 1994