An eddy current radar defect detection, quantification and imaging method and system

Abstract

The invention discloses an eddy current radar defect detection, quantification and imaging method and system. The system uses excitation signals of different modes such as pulse, sine, frequency modulation, and modulation to drive the eddy current sensor, and induce eddy current in the detected object. The output signal of the eddy current sensor is used as the time domain response signal, and the time domain response signal of the defect-free area is used as the reference signal. The cross-correlation algorithm is implemented on the time-domain response signal and the reference signal to obtain the cross-correlation amplitude and phase. Extract the eigenvalues ​​from the cross-correlation amplitude and phase for defect detection; establish the quantitative correspondence between the eigenvalues ​​and the depth through the standard specimen test, and realize the quantification of the defect depth; display the cross-correlation amplitude of each detection point on the scanning path value and phase for B-scan imaging; with the help of a scanning mechanism to detect a certain area, use eigenvalues ​​for C-scan imaging. The method and system have the advantages of high signal-to-noise ratio, accurate depth quantification, good anti-interference performance and the like, and can be applied in the field of non-destructive testing.

Description

technical field [0001] The invention belongs to the technical fields of equipment nondestructive testing, material characterization evaluation, structural health monitoring and product quality control, and in particular relates to an eddy current electromagnetic nondestructive testing method and system. Background technique [0002] With the development of modern science and industrial technology, non-destructive testing technology has become a necessary means to ensure product quality and equipment operation safety. At present, representative non-destructive testing technologies mainly include radiographic testing, ultrasonic testing, penetrant testing, magnetic particle testing, eddy current testing (ECT), and rapidly developing technologies such as thermal imaging testing and dislocation speckle interference. [0003] Eddy current testing technology is a non-destructive testing method based on the principle of electromagnetic induction, which is suitable for conductive ma...

AI Technical Summary

Problems solved by technology

[0007] The current eddy current testing technology also has some deficiencies, mainly in: 1) The signal-to-noise ratio of the signal is low due to the influence of electromagnetic field attenuation and noise interference; 2) The quantitative accuracy of the depth of internal defects is not high, and it is difficult to judge the distance between defects 3) The C-scan imaging mainly relies on the time-domain eigenvalue and the position of the detection point, and the anti-interference is poor

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