Title :
A model for inverting eddy-current data and reconstructing three-dimensional flaws embedded in anisotropic advanced composite materials
Author :
Barkeshli, S. ; Sabbagh, H.A. ; Radecki, D.J. ; Shamee, B.
Author_Institution :
Sabbagh Associates Inc., Bloomington, IN, USA
Abstract :
The authors present a three-dimensional linearized model for inverting eddy-current data to reconstruct flaws in advanced anisotropic composite materials, such as graphite epoxy. This problem is significant for enhancing the detection capability for the variety of failure modes in composites, such as delamination, fiber breakage, flaws, etc. The inversion scheme takes the form of an integral equation, which then is discretized by means of the method of moments. The measured data are then inverted by means of the conjugate gradient algorithm. Examples are shown in which a linear classifier is used to improve convergence of the conjugate gradient algorithm. As an example, a 0.11-in.-thick woven graphite epoxy material was simulated for the inversion algorithm.<>
Keywords :
composite materials; eddy current testing; 3D flaws reconstruction; anisotropic composite materials; conjugate gradient algorithm; convergence; delamination; eddy-current data; failure modes detection; fiber breakage; graphite epoxy; integral equation; inversion algorithm; inversion scheme; linear classifier; measured data; method of moments; three-dimensional linearized model; Anisotropic magnetoresistance; Character generation; Composite materials; Conductivity measurement; Current measurement; Electromagnetic measurements; Electromagnetic scattering; Integral equations; Slabs; Tensile stress;
Conference_Titel :
Antennas and Propagation Society International Symposium, 1989. AP-S. Digest
Conference_Location :
San Jose, CA, USA
DOI :
10.1109/APS.1989.135021
