Unit:
Κατεύθυνση Σχεδίασης Ολοκληρωμένων ΚυκλωμάτωνΠληροφορική
Supervisors info:
Ευαγγελία Καραγιάννη, Αναπληρώτρια Καθηγήτρια, ΣΝΔ
Χρήστος Βαζούρας, Επίκουρος Καθηγητής, ΣΝΔ
Original Title:
Ανίχνευση ρωγμών σε μεταλλική πλάκα με μικροκυματική μέθοδο
Translated title:
Detection of cracks in metal plate by microwave method
Summary:
The main purpose of this thesis is to detect cracks on a metal surface using the microwave method through a probe to select the appropriate frequency. The microwave-assisted waveguide technique is one of the non-destructive materials testing techniques to evaluate and confirm their durability and effectiveness. Initially there is an introduction to all the categories of Non-Destructive Methods used to detect cracks and defects in general.
Next, important points in the theory of electromagnetism are mentioned, with a greater emphasis on microwaves since they are essential for understanding the mode of operation of waveguides, one of the key tools used in experimental conduct.
Following is the experimental procedure in which a metal sample having a straight crack of 1.3mm to 3mm depth was used. Along the cracks, a 3x4cm waveguide was placed in a transmit antenna and an 8-10GHz source was wave formed to measure reflectors. After many tests, at different frequencies, by placing the waveguide vertically or parallel to it, it was found that for shallow cracks, the 8.5 GHz frequency gave the highest reflections, with a wave of 10mV - which is clearly detectable. Similarly, for the 3mm depth crack the most appropriate frequency is 8.2 GHz. The most appropriate positioning of the waveguide was in the vertical dimension with respect to the crack. Finally, the results of the measurements, the conclusions and the confirmation that the microwave method is effective for detecting cracks on a metal surface are presented.
Main subject category:
Science
Keywords:
Non Destructive Control, Failure, Crack, Microwave, Waveguide, Reflected Radiation, Metal, Slit
