On a rigorous inverse scattering model for a three dimensional flaw embedded in anisotropic advanced composite materials

Inverse scattering models of the type that are often used to invert eddy current data are inherently nonlinear because they involve the product of two unknowns, the flaw conductivity and the true electric field within the flaw. Computational inverse models, therefore, often linearize the problem by assuming that the electric field within the flaw is known a priori. The authors describe a rigorous formulation of such an inverse scattering model. The model is based on coupled integral equations that are discretized by means of the method of moments. The linearized version of this model is also outlined. The measured data are inverted by means of the conjugate gradient algorithm. An example concerning the reconstruction of a flaw in a graphite-epoxy advanced composite using the linearized model is shown.<>