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Electrical and Computer Engineering
Electrical and Computer Engineering Faculty Research & Creative Works
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Full-Text Articles in Engineering
Disbond Thickness Evaluation Employing Multiple-Frequency Near-Field Microwave Measurements, Mohamed A. Abou-Khousa, R. Zoughi
Disbond Thickness Evaluation Employing Multiple-Frequency Near-Field Microwave Measurements, Mohamed A. Abou-Khousa, R. Zoughi
Electrical and Computer Engineering Faculty Research & Creative Works
Near-field microwave nondestructive evaluation (NDE) techniques have shown great potential for disbond detection in multilayer dielectric composite structures. The high detection capability associated with these techniques stems from the fact that near-field microwave signals are sensitive to minute variations in the dielectric properties and geometry of the medium in which they propagate. In the past, the sensitivity of the near-field microwave NDE techniques to the presence and properties of disbonds in multilayer dielectric composites has been investigated extensively. However, a quantitative disbond thickness estimation method has yet to be introduced. In this paper, we propose a maximum-likelihood (ML) disbond thickness …
High Resolution Millimeter Wave Inspecting Of The Orbiter Acreage Heat Tiles Of The Space Shuttle, Joseph Toby Case, Sergey Kharkovsky, R. Zoughi, Frank L. Hepburn
High Resolution Millimeter Wave Inspecting Of The Orbiter Acreage Heat Tiles Of The Space Shuttle, Joseph Toby Case, Sergey Kharkovsky, R. Zoughi, Frank L. Hepburn
Electrical and Computer Engineering Faculty Research & Creative Works
The physical cause of Space Shuttle Columbia's catastrophic failure was a breach in its thermal protection system, caused by a piece of external tank insulating foam (SOFI) separating from the external tank and striking the leading edge of the left wing of the orbiter. Consequently, there is an urgent need for a rapid, robust and life-circle oriented nondestructive testing (NDT) technique capable of inspecting the SOFI as well as the orbiter's protective heat tiles and its fuselage prior and subsequent to a launch. Microwave and millimeter wave NDT methods have shown great potential to achieve these goals using real focused …
Microwave And Millimeter Wave Nondestructive Testing And Evaluation -- Overview And Recent Advances, Sergey Kharkovsky, R. Zoughi
Microwave And Millimeter Wave Nondestructive Testing And Evaluation -- Overview And Recent Advances, Sergey Kharkovsky, R. Zoughi
Electrical and Computer Engineering Faculty Research & Creative Works
This article focuses on three recent applications of microwave and millimeter wave NDT&E techniques that involve novel instrumentation development and measurements, including: 1) disbond detection in strengthened concrete bridge members retrofitted with carbon fiber reinforced polymer (CFRP) composite laminates; 2) corrosion and precursor pitting detection in painted aluminum and steel substrates; and 3) detection of flaws in spray-on foam insulation and the acreage heat tiles of the Space Shuttle through focused and synthetic imaging techniques. These applications have been performed at the Applied Microwave Nondestructive Testing Laboratory (amntl) at the University of Missouri-Rolla.