Non-contact electromagnetic ultrasonic energy transducer capable of generating torsion guide wave and detection method thereof

Abstract

The invention discloses a non-contact electromagnetic ultrasonic energy transducer capable of generating torsion guide wave and a detection method thereof. The non-contact electromagnetic ultrasonic energy transducer comprises a coil, a permanent magnet and a detected steel pipe, the coil is in a runway shape, and the permanent magnet employs magnetic poles arranging at a linear part of the runwaycoil in a periodical interlace mode; a transducer array composed of several runway coils and the permanent magnets is placed at one end close to a steel pipe as an excitation energy transducer, and asame coil-permanent magnet array arranged at the other end close to the steel pipe is taken as a reception energy transducer. The permanent magnet is used for providing the bias magnetic field, eddycurrent is induced from the detected steel pipe by the runway coil, the moved electrons are subjected to Lorentz force effect in the magnetic field, crystal lattice in the steel pipe is bumped, so that the vibration of the wall of the steel pipe is generated, the force is circumferentially and periodically changed along a pipeline, so that the torsion guide wave is generated, wave packet can be displayed by using an oscilloscope at a receiving end, and the defect position can be determined according to the arriving time to the wave packet and the propagation wave velocity of the guide wave inthe pipeline.

Description

technical field [0001] The invention belongs to the field of non-destructive testing research, and in particular relates to a non-contact electromagnetic ultrasonic transducer capable of generating torsional guided waves and a testing method, which can realize online testing of pipeline health conditions. Background technique [0002] Because the environment in which the pipeline is generally relatively harsh, it is easy to adversely affect the health of the pipeline itself, and it is easy to induce catastrophic events caused by defects such as pipeline corrosion, cracks, and damage. Therefore, pipeline defect detection technology has always been an important research direction. [0003] Existing non-destructive testing technologies for pipeline defects (in terms of testing methods) mainly include: magnetic particle testing, eddy current testing, ultrasonic testing, ray testing and ultrasonic guided wave testing. Among them, the advantages of ultrasonic guided wave testing ...

AI Technical Summary

Problems solved by technology

In the patent "An Electromagnetic Ultrasonic Transducer" applied by Yan Chongqiang, Qian Hongliang and others, the design is to add a magnetic permeability layer between the coil and the permanent magnet, but this does not change the magnetic permeability of the tested material itself.

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