兆赫兹磁致伸缩超声导波管道检测系统的研制

研制的扭转模态磁致伸缩管道检测系统采用排线式磁致伸缩传感器时，可在管道中激励出低频T（0，1）模态超声导波，并有效检测出管道中截面缺失率为3％的通孔缺陷。为拓展检测系统的工作频率范围，设计出一款柔性印刷感应线圈，对其进行的实验验证结果表明，柔性线圈式磁致伸缩传感器可在管道中激励出兆赫兹T（0，1）模态超声导波，传感器的中心频率达1．30MHz，有望进一步提高磁致伸缩传感器的缺陷检测灵敏度。柔性印刷线圈无需使用适配器，可直接卷曲贴覆在管道表面，易于拆装。由此，研制的磁致伸缩管道检测系统的频率范围可覆盖几十千赫兹到兆赫兹，适合应用于实际工程检测。

Magnetostrictive-based Megahertz-range Torsional Guided Wave Inspection System for Pipeline

A torsional guided wave pipeline inspection system using the magnetostrictive sensor （MsS） was presented. The flexible flat cable （FFC） -based MsS was employed to excite kilohertz-range T （0,1） mode in pipe, which was able to detect the signal reflected from a through-hole flaw with 3% of cross section area of pipe. An innovative flexible printed coil （FPC） was designed for the MsS to expand operation frequency range. Frequency sweeping tests were conducted to the FPC-based MsS. The results showed that the FPC-based MsS could generate megahertz-range T（0,1 ） mode guided wave in the pipe, having a central frequency of 1.30 MHz. Thus, the sensitivity of the MsS to small defect was expected to be further improved. Meanwhile, the FPC can be wrapped onto the pipeline surface without requiring any adaptor. With its capacity from kilohertz-range to megahertz- range applications, the inspection system has great potential for in-situ inspection.