开放磁路式磁致伸缩导波传感器原理的实验研究

磁致伸缩导波技术具有单点激励即可实现长距离检测的优点,但在检测非铁磁性构件或端部外露构件时面临难题.在分析已有磁致伸缩导波传感器检测原理的基础上,提出首先利用磁致伸缩效应在铁磁性波导管中产生导波;然后通过端部将其传入构件实现检测的原理,构建了开放磁路式磁致伸缩导波传感器原理的研究实验平台.采用270 kHz的纵向模态导波,在长2800 mm,壁厚2.5mm的Φ25 mm低碳钢钢管上可检测出0.5mm深刻槽和Φ5 mm的通孔缺陷,且在长2800 mm,壁厚2.5mm的Φ25mm不锈钢钢管上可得到明显的端部回波信号,从而为该传感器进一步应用于非铁磁性或端部外露构件检测提供了依据.

Experimental research on principle of open magnetic circuit magnetostrictive guided wave sensor

Magnetostrictive guided wave technology can realize long distance testing with single point excitation, however, it faces challenges when testing non-ferromagnetic components or components with exposed ends. On the basis of analyzing testing principle of existing magnetostrictive guided wave sensors, firstly, propose using magnetostrictive effect to generate guided wave in ferromagnetic waveguide tube ; and then transfers the wave to component to be tested, and also laboratory platform for principle research on open magnetic circuit magnetostrictive guided wave sensor is built. Longitudinal mode waveguide of 270 kHz is used to detect the notch with 0.5 mm thickness and through-hole defect of φ5 mm in a 25 mm-diameter,2.5 mm-wall thickness ,2800 mmlength low carbon steel pipe, and the sensor also can receive obvious end echo signal in a 25 mm-diameter, 2.5 mm-wall thickness, 2 800 ram-length stainless steel pipe, which provides basis for further application in detection of non-ferromagnetic or end-exposed component.