著者

佐々木 幸太 Kota Sasaki

出版者

日本文学会

雑誌

日本文芸研究 (ISSN:02869136)

巻号頁・発行日

vol.66, no.1, pp.1-21, 2014-10

著者

佐々木 幸太 遊佐 訓孝 片桐 拓也 橋爪 秀利

出版者

日本AEM学会

雑誌

日本AEM学会誌 (ISSN:09194452)

巻号頁・発行日

vol.25, no.2, pp.266-272, 2017

被引用文献数

3

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<p>This study proposes long-range nondestructive inspection of the inner surface of a pipe without open end using microwave emitted by a probe attached to the pipe wall. Three-dimensional finite element simulations were conducted to evaluate how to propagate microwave effectively inside a pipe having an inner diameter of 19 mm. The simulations considered a coaxial cable penetrating the pipe wall to emit microwave inside the pipe. Experimental verifications were then carried out using a brass pipe with a total length of 4.5 m and a probe fabricated on the basis of the results of the numerical simulations. The experiment confirmed clear reflections due to artificial wall thinning 1 m away from the probe situated approximately at the center of the pipe. The experiment also revealed that directivity of the microwave depended on the frequency, which agrees with the results of the numerical simulations.</p>

著者

片桐 拓也 佐々木 幸太 遊佐 訓孝 橋爪 秀利

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集

巻号頁・発行日

vol.84, no.859, pp.17-00375-17-00375, 2018

被引用文献数

5

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<p>This study proposes nondestructive long-range inspection for axial cracks appearing at the inner surface of a metal pipe using microwave. Numerical simulations were conducted to design a mode converter that converts TEM into TE mode that is necessary to detect axial cracks. The simulations confirmed that situating coaxial cables circumferentially enables to propagate microwaves in TE mode inside a pipe. The results also revealed that the number and positions of coaxial cables affect the frequency range where microwaves propagate as TE₀₁ mode dominantly. A mode converter with four coaxial cables was fabricated according to the results of the simulations aiming at the propagation of microwaves as TE₀₁ mode. Experimental verification was conducted using a brass pipe with a total length of 11.6 m and an inner diameter of 19.0 mm, and having the mode converter at the center. The results showed significant difference between the signals with and without an artificial slit simulating a crack. This study also proposed a signal processing method to compensate for the dispersion of microwaves with an aid of a window function. The signal processing method gave the clearer signals corresponding to the slits to determine the predict position of the slit quantitatively using the time-of-flight of the signals.</p>