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Proceedings Paper

Modeling and signal processing of magneto-optic images for aviation applications
Author(s): P. Ramuhalli; James Slade; U. Park; Liang Xuan; L. Udpa
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Paper Abstract

Magneto-optic imaging (MOI) is a relatively new technology that produces analog images of magnetic flux leakage from surface and subsurface defects. An alternating current carrying foil serves as the excitation source and induces eddy currents in a conducting test specimen. Under normal conditions, the associated magnetic flux is tangential to specimen surface. Anomalies in the specimen result in generating a normal component of the magnetic flux density. The magneto-optic sensor produces a binary valued image of this anomalous magnetic field. The current system has two shortcomings. First, the presence of a textured background due to the domain structures in the sensor makes detection of third layer cracks and corrosion difficult. Second, the qualitative nature of the MO images does not provide a basis for making quantitative improvements to the MOI system. The availability of a theoretical model that can simulate the MOI system performance is extremely important for the optimization of the MOI sensor and hardware system. This paper presents a finite element model and its use in understanding the capabilities of the MOI system. In addition the paper also presents signal-processing methods for eliminating the background noise.

Paper Details

Date Published: 14 October 2003
PDF: 8 pages
Proc. SPIE 5062, Smart Materials, Structures, and Systems, (14 October 2003); doi: 10.1117/12.514759
Show Author Affiliations
P. Ramuhalli, Michigan State Univ. (United States)
James Slade, Michigan State Univ. (United States)
U. Park, Michigan State Univ. (United States)
Liang Xuan, Michigan State Univ. (United States)
L. Udpa, Michigan State Univ. (United States)

Published in SPIE Proceedings Vol. 5062:
Smart Materials, Structures, and Systems
S. Mohan; B. Dattaguru; S. Gopalakrishnan, Editor(s)

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