Study of concrete de-bonding assessment technique for containment liner plates in nuclear power plants using ultrasonic guided wave approach

Lee, Yonghee; Yun, Hyunmin; Cho, Younho

doi:10.1016/j.net.2021.09.040

Cited by 4 publications

(1 citation statement)

References 17 publications

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“…Among the NDT techniques, ultrasonic testing (UT) and echo impact (EI) techniques are the most widely used. The UT technique has the advantage of accurately measuring the thickness of a plate by contact with an ultrasonic probe, but has the disadvantage of consuming a significant amount of time when a large area is being inspected because it requires a contact point [7,8]. The EI technique can identify resonance frequencies in the frequency domain of the vibration signals acquired using the fast Fourier transform (FFT), and, through this, information about voids in concrete can be acquired [9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Lateral Heat Distribution Characteristics of CLP S275 Using Gaussian FFT Algorithm in Optical Thermographic Testing

Lee,

Chung,

Kim

et al. 2024

Applied Sciences

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In general, when using infrared thermography (IRT) techniques to excite a heat source on the surface of an inspection object, the heat source is focused on the center of the image of the infrared (IR) camera. If the object to be inspected is small, uniform excitation of the heat source is possible, but if the area is large, the heat source is concentrated locally, resulting in uneven heat distribution. Therefore, in this study, heat distribution was analyzed after inducing a non-uniform heat source by exciting the heat source at different locations. Additionally, the fast Fourier transform (FFT) algorithm with Gaussian filtering was applied to resolve the non-uniform distribution of the heat sources. Excellent results were obtained from the amplitude image, and the effectiveness of the FFT algorithm was verified using the Otsu algorithm. Finally, the signal-to-noise ratio (SNR) was calculated, and the detection ability according to each thinning rate was analyzed.

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