Achievement Journal NDT&E Int. Student

論文掲載決定 (NDT&E International誌)!!



本年度初のジャーナルアクセプトです。非破壊検査に関する学術論文誌、NDT&E Internationalに"Detection of Cracks with Arbitrary Orientations in a Metal Pipe Using Linearly-Polarized Circular TE11 Mode Microwaves (TE11モードのマイクロ波を用いた、任意の方向を向いた管内壁割れの検出)"とのタイトルで投稿した論文が受理されました。筆頭著者はD2の陳冠任君です。

論文の内容は、マイクロ波を使って配管の広域一括検査を行う技術に関するものです。これまでの研究で、当該技術においては、特に表面割れを対象とした場合、 これまでに用いていたTM01及びTE01というモードのマイクロ波では、 割れが管軸方向を向いているか周方向を向いているかにより、検出性に大きな差異が生ずるということが明らかとなっていました。より具体程には、TM01モードを使った場合、周方向を向いた割れは検出できるものの軸方向を向いた割れの検出は難しく、TE01モードの場合はその逆、というようにです。本論文はこのような状況を鑑みて実施された研究結果をまとめたものでして、新しくTE11モードのマイクロ波を管内に伝播させる方法を見出し、その有効性、即ちTE11モードのマイクロ波を使うことによって、軸方向、周方向いずれを向いた割れも感度よく検出できる、ということを見出した、ということを報告したものです。



A new journal entitled ' Detection of Cracks with Arbitrary Orientations in a Metal Pipe Using Linearly-Polarized Circular TE11 Mode Microwaves ' was recently accepted, now it is received for production. The information is shown as below:

Information on the article to be published

The other authors are Mr. Takuya Katagiri, Mr. Haicheng Song, Dr. Noritaka Yusa and Prof. Hidetoshi Hashizume.

The first author Mr. Guanren Chen will cook some dishes for other lab members to celebrate the acceptance in a near future.

This study proposed a long-range non-destructive pipe inspection approach using linearly-polarized circular TE11 mode microwaves, enabling rapid detection of both axial and circumferential cracks on the inner surface of a metallic pipe. The applicability of the TE11 mode microwaves for crack detection was discussed in the light of the currents induced on the inner surface of a pipe due to the propagation of the TE11 mode microwaves. A dual-bend structured mode converter was designed to propagate linearly-polarized TE11 mode microwaves inside a pipe with a certain inner diameter, based on the theoretical and numerical analysis of mode conversion due to a bend. A 3.5 GHz working bandwidth of the mode converter was achieved with a conversion efficiency of the TE11 mode of over 90%. Experimental verification was conducted using stainless-steel pipes with an inner diameter of 23 mm and a total length of 7 m. An axial and a circumferential slit were introduced to simulate cracks. The experimental results confirmed reflections from both the axial and circumferential slits, indicating that the TE11 mode microwaves are applicable to crack detection. The results also confirmed the correlation between TE11 mode polarization and its detection sensitivity toward slits with different orientations along the circumferential direction. Furthermore, the axial and circumferential slits situated at different longitudinal and circumferential locations in the pipe were successfully detected by orthogonally deploying the mode converter to change the polarization of the TE11 mode by 90°.

  1. 図の使用は出版社の許可を取っています、もちろん。

-Achievement, Journal, NDT&E Int., Student

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