The Electric Current Injection (ECI) method of nondestructive evaluation is applied to materials that are electrically conductive but not magnetically permeable, such as aluminum, magnesium, and titanium. 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. However, these solutions are limited to only a few problems with very simple geometries. This paper presents a boundary integral equation (BIE) formulation, which allows arbitrary two-dimensional plate and flaw shapes to be modeled, providing a much greater flexibility to the measurement model. Also, since only l-D boundary elements are required, this approach has a significant computational advantage over finite element methods (FEM) for solving problems that can be regarded as two-dimensional

The next section describes the BIE formulation, followed by a sample calculation for a square aluminum plate, and a comparison with the results given by a commercial finite element method software. Also, the procedure needed to simulate a thick conductive plate is described.