Eddy current inspection device based on resistance transducer of gigantic magnetism

Abstract

A vortex detection device based on huge magnetic resistance transducer is prepared as generating vortex by detected element when excitation coil is near to detected conduction structure based on electromagnetic induction principle and conversely influencing magnetic field generated by excitation coil by vortex, using probe of huge magnetic resistance transducer to detect out variation of magnetic field, sending said variation signal to two phase sensitive rectifiers and making output signal of said rectifier be close relation with parameter of detected element then driving out value of parameter to be detected.

Description

technical field [0001] The invention relates to an eddy current detection device based on a giant magnetoresistance sensor. Background technique [0002] At present, the military and civil aviation industry is developing very rapidly. A large number of in-service aircraft need to extend their service life as much as possible while ensuring safety. Therefore, the timely, rapid and automatic safety assessment of in-service aircraft and other aircraft has become a challenging issue that needs to be solved urgently. [0003] As we all know, the fuselage of the long-term use of the aircraft often has various defects such as corrosion, air gap, interlayer peeling, riveting, cracking and so on. Among the above-mentioned defects, the corrosion and cracks of the fuselage, especially the corrosion and cracks hidden in the multi-layer overlapping structure, will cause multiple damages to the fuselage, thereby affecting the safe flight of the aircraft. Therefore, it is urgent to deve...

AI Technical Summary

Problems solved by technology

[0005] Conventional eddy current detectors use coils as detection probes, which can solve some problems such as surface and subsurface defects, thickness measurement, etc., but it is difficult to detect deep defects, especially the small size hidden in the deep layers of multi-layer conductive structures such as aircraft fuselages. Defects such as cracks and corrosion, the main problem is that the sensitivity and spatial resolution of coil-type detection probes for internal defects in multi-layer structures are not high enough

In order to detect deep defects, it is necessary to reduce the excitation frequency of the detection system (low frequency), increase the diameter of the detection coil (large probe), etc., but this will lead to low sensitivity of the detection coil, low resolution, local detection signal Increased distortion, missed detection of defects smaller than the diameter of the detection coil, etc.

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