Browsing by Author "Özbey, B."

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    Wireless monitoring of a structural beam to be used for post-earthquake damage assessment
    (IEEE, 2018-05-06) Özbey, B.; Kurc, O.; Demir, Hilmi Volkan; Ertürk, Vakur B.; Altıntaş, Ayhan
    Wireless monitoring of a standard reinforced concrete beam is shown in a simply supported beam experiment. The passive nested split-ring resonator (NSRR) probes are attached on the reinforcing bars (rebars) within the beam, and an antenna interrogates the probes from outside the beam. The results of the experiment show that the plastic deformation region strain/displacement can be detected by the wireless sensing system. The data collected by the system constitutes an important input for the assessment of the damage that can be observed after earthquakes.
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    Wireless sensing in complex electromagnetic media: construction materials and structural monitoring
    (Institute of Electrical and Electronics Engineers Inc., 2015) Özbey, B.; Demir, Hilmi Volkan; Kurc, O.; Ertürk, V. B.; Altıntaş, A.
    In this paper, wireless sensing in the presence of complex electromagnetic media created by combinations of reinforcing bars and concrete is investigated. The wireless displacement sensing system, primarily designed for use in structural health monitoring (SHM), is composed of a comb-like nested split-ring resonator (NSRR) probe and a transceiver antenna. Although each complex medium scenario is predicted to have a detrimental effect on sensing in principle, it is demonstrated that the proposed sensor geometry is able to operate fairly well in all scenarios except one. In these scenarios that mimic real-life SHM, it is shown that this sensor exhibits a high displacement resolution of 1 μm, a good sensitivity of 7 MHz/mm in average, and a high dynamic range extending over 20 mm. For the most disruptive scenario of placing concrete immediately behind NSRR, a solution based on employing a separator behind the probe is proposed to overcome the handicaps introduced by the medium. In order to obtain a one-to-one mapping from the measured frequency shift to the displacement, a numerical fit is proposed and used. The effects of several complex medium scenarios on this fit are discussed. These results indicate that the proposed sensing scheme works well in real-life SHM applications. © 2001-2012 IEEE.