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Full-Text Articles in Engineering
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.
Comparison Of Near-Field Millimeter-Wave Probes For Detecting Corrosion Precursor Pitting Under Paint, Mohammad Tayeb Ahmad Ghasr, Sergey Kharkovsky, R. Zoughi, Russell A. Austin
Comparison Of Near-Field Millimeter-Wave Probes For Detecting Corrosion Precursor Pitting Under Paint, Mohammad Tayeb Ahmad Ghasr, Sergey Kharkovsky, R. Zoughi, Russell A. Austin
Electrical and Computer Engineering Faculty Research & Creative Works
Aircraft structural components such as wings and fuselages are constantly exposed to harsh environments, which make them susceptible to corrosion initiation and growth. To complicate matters, corrosion is normally hidden under paint and primer and cannot be visually detected until significant corrosion has occurred, causing the paint to blister. Corrosion of this type is usually preceded by the presence of corrosion precursor pitting. Hence, early detection of pitting is a critical issue in the maintenance of an aircraft and its structural components. Near-field microwave nondestructive testing techniques have been successfully used for detection of corrosion under paint, including very small …
Microwave Nondestructive Detection And Evaluation Of Disbonding And Delamination In Layered-Dielectric Slabs, R. Zoughi, Sasan Bakhtiari
Microwave Nondestructive Detection And Evaluation Of Disbonding And Delamination In Layered-Dielectric Slabs, R. Zoughi, Sasan Bakhtiari
Electrical and Computer Engineering Faculty Research & Creative Works
A microwave nondestructive technique for detection and evaluation of disbonding and delamination in layered-dielectric-slabs backed by a conducting plate is discussed. The theoretical development begins by considering an incident wave illuminating such a medium and then formulating the characteristics of the wave reflected by the metal plate. An effective reflection coefficient is determined in this way whose phase characteristics are used in the detection and evaluation of delaminations in the media. The characteristics of this phase as a function of several parameters such as delamination dielectric constant and thickness, slab dielectric constant, and thickness and the frequency of operation are …