Quantitative method for surface crack of metal plate based on multi-point full-cycle magnetic field transient waveform

By directly measuring the magnetic field changes on the surface of a metal plate using a method based on multi-point, full-cycle magnetic field transient waveforms, the problem of magnetic field information loss in existing pulsed eddy current detection is solved, enabling accurate quantitative assessment of crack length and depth and expanding the application scope of the detection technology.

CN122361591APending Publication Date: 2026-07-10WUXI UNIV
View PDF 0 Cites 0 Cited by

Patent Information

Authority / Receiving Office
CN ยท China
Patent Type
Applications(China)
Current Assignee / Owner
WUXI UNIV
Filing Date
2026-04-17
Publication Date
2026-07-10

AI Technical Summary

Technical Problem

In existing pulsed eddy current detection technology, the use of induced voltage as the analysis object leads to the loss of some original magnetic field information, and the extraction of characteristic parameters is limited, making it difficult to achieve accurate quantitative assessment of cracks on the surface of metal plates.

Method used

A method based on multi-point full-cycle magnetic field transient waveforms is adopted. By cooperating with excitation coils and magnetic field detection units, the magnetic field changes on the surface of the metal plate are directly measured. The magnetic field detection unit records transient magnetic field signals at different positions, plots magnetic field-time change curves, identifies the crack extension length, and determines the crack depth by comparing with a pre-established relationship table.

Benefits of technology

It more completely preserves the details of magnetic field changes during the interaction between pulsed eddy currents and defects, and can extract more effective quantitative characteristic parameters, thus expanding the applicability of pulsed eddy current technology in quantitative crack assessment.

โœฆ Generated by Eureka AI based on patent content.

Smart Images

  • Figure CN122361591A_ABST
    Figure CN122361591A_ABST
Patent Text Reader

Abstract

This invention belongs to the field of nondestructive testing technology, specifically a method for quantifying surface cracks in metal plates based on multi-point, full-cycle magnetic field transient waveforms. The method includes: applying short-time pulsed eddy currents to the surface of the metal plate using an excitation coil, moving it step-by-step along a preset path above the crack region to acquire transient, full-cycle magnetic field signals at multiple measurement points; for each measurement point, extracting waveform features of transient magnetic field intensity changes within different time windows, and calculating the crack length along the surface by combining the spatial positional differences in magnetic field waveforms between adjacent measurement points with the movement step size; and performing waveform matching and similarity analysis between the transient magnetic field change curves acquired at the crack center measurement point and a pre-constructed magnetic field transient feature database to determine the actual crack depth. This invention uses the transient magnetic field response as the evaluation basis, which can more completely reveal the interaction mechanism between pulsed eddy currents and crack defects, providing rich feature parameters for the quantitative assessment of crack length and depth.
Need to check novelty before this filing date? Find Prior Art