Affiliations: Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, USA
Correspondence:
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Corresponding author: S. Morteza Safdarnejad, Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI 48910, USA. E-mail:safdarne@egr.msu.edu
Abstract: EC-GMR measurements have been applied for detection of sub-surface corrosion and cracks under fastener (CUF) head.
Generally, fastener signal amplitude is larger than the amplitude of the crack signal indication, rendering crack detection a challenging task.
Also, another challenge in the analysis of field signals is the stitching problem, commonly present in a raster scan of a row of fasteners.
We propose a method based on robust sparse coding (RSC) representation to alleviate the stitching problem and enhance defect detection capability.
For the dictionary, we simulate multi-layer geometries using finite element (FE) modeling.
Results on simulated and field data demonstrate the feasibility and robustness of the proposed algorithm.
Keywords: EC-GMR, crack under fastener, sparse coding
