Torsional mode magnetostrictive sensor, pipeline detection system and pipeline detection method

Abstract

The invention relates to a torsional mode magnetostrictive sensor, a pipeline detection system and a pipeline detection method, and belongs to the technical field of ultrasonic detection. The magnetostrictive sensor includes a coil array and a permanent magnet array. The coil array is formed by connecting a plurality of racetrack coils in parallel, and the racetrack coils are fixed surrounding theouter surface of a pipeline, and are uniformly distributed along the circumference of the pipeline; the permanent magnet array is formed by permanent magnets which are staggered in polarity and a magnet base, and is mounted on the outer side of the coil array, and a spacing between the axially adjacent permanent magnets is equal to the half wavelength of an excited torsional mode guided wave; andthe pipeline ultrasonic guided wave in a torsional mode is excited on the basis of a magnetostrictive mechanism under the coaction of an axial static bias magnetic field provided by the permanent magnet array and a circumferential dynamic magnetic field provided by the coil array. The torsional mode magnetostrictive sensor has the advantages of effectiveness in exciting and receiving ultrasonic guided waves in the torsional mode in a steel tube, single excited mode, high signal-to-noise ratio, and convenience in for realizing comprehensive detection of the pipeline.

Description

technical field [0001] The invention belongs to the technical field of ultrasonic nondestructive testing, and in particular relates to a torsional mode magnetostrictive sensor, a pipeline testing system and a method. Background technique [0002] Ultrasonic guided wave testing technology has the advantages of long ultrasonic propagation distance, low sound wave attenuation rate, and can cover most of the detection range in a short time. It has been widely used in the field of non-destructive testing of pipelines in recent years. Among them, the axisymmetric torsional mode is a more commonly used detection mode in the pipeline ultrasonic guided wave, and its advantage is that the propagation speed of the guided wave in this mode is basically not affected by frequency changes within a certain frequency range, that is, it has good The non-dispersive characteristics of the particle; the vibration direction of the particle is perpendicular to the propagation direction of the guid...

AI Technical Summary

Problems solved by technology

However, in engineering applications, there are still problems such as inconvenient installation and disassembly of sensors, unsatisfactory excitation signals, and low detection efficiency. Therefore, optimizing the design of existing magnetostrictive sensors or developing new magnetostrictive sensors is still a research topic in this field. One of hotspots and difficulties

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