1. Investigation of the effect of a bend on pipe inspection using microwave NDT.
- Author
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Chen, Guanren, Katagiri, Takuya, Song, Haicheng, Yusa, Noritaka, and Hashizume, Hidetoshi
- Subjects
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PIPE bending , *MICROWAVES , *NONDESTRUCTIVE testing , *INVESTIGATIONS , *PIPE , *COMPUTER simulation - Abstract
This study investigated the effect of a bend on microwave NDT (non-destructive testing) applied for rapid pipe inspections. The factors affecting the mode conversion of microwaves due to a bend were deducted theoretically and verified through numerical simulation. Both theoretical and numerical results revealed that the mode conversion at a bend was actually determined by the frequency normalized by the cut-off frequency of an arbitrary mode (f / f c), the ratio of the curvature radius to the inner diameter of the pipe (r / D) and the bend angle (α). Subsequent experimental evaluations were performed using four groups of pipes with different inner diameters and five different bends. The effect of a bend was quantitatively evaluated by comparing the reflection signals from pipe wall thinning in a straight pipe with those in a bent pipe. The results showed that the presence of a bend led to a decrease in the reflection signal behind the bend, and the extent of decrease also depended on r / D and α of the bend. Furthermore, the length or the depth of the pipe wall thinning did not noticeably affect the decrease in reflection signal, when the bend's dimensions were certain. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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