An improved method for magnetic identification and localization of cracks in conductors

Conductivity Imaging in Plates Using Current Injection Tomography

“…The magnetic field may be decomposed into two portions: contributions from the current densities at the boundaries of the conductor, and contributions from volume currents which have curl [8,9]. In this particular case of the rectangular conducting plates, the contributions of the edge currents to the magnetic field can be removed by a current cancellation technique [10]. The only remaining contributions to the magnetic field are from the currents in the area of the plate which have curl.…”

Boundary Integral Equations for Modeling Arbitrary Flaw Geometries in Electric Current Injection NDE

“…As Vis harmonic, it must satisfy Laplace's equation, (2) From Green's second identity, a boundary integral equation that solves this harmonic potential problem can be derived [6] (3)…”

“…It consists of detecting current-flow anomalies due to voids, nonmetallic inclusions and open cracks in the conducting material, through distortions introduced in the magnetic field generated by the sample [1]. Several 2-D analytical solutions have been derived to simulate the magnetic field produced by a flaw in a conductor for direct current injection [2][3] [4]. Scans of standard flaw specimens have validated these models experimentally.…”

Automation of Electric Current Injection NDE by Neural Networks

“…In the future an automated positioning system will be added to the measurement system, so the points will be already equally spaced, exempting the need of interpolation. As the plates being measured are not infinite, there is a ramp shaped signal added to the peculiar dipolar pattem due to the flaws [4]. In order to remove this effect, we first calculate the mean curve of the measurements taken from the unflawed plate, and then subtract this mean signal from all measured signals.…”