The authors present an original eddy current imager (ECI) designed for the fast and accurate non-destructive evaluation of defects buried next to rivets in aeronautical lap-joints. The ECI is associated to a signal processing method based on a principal component analysis (PCA) followed by a maximum likelihood (ML) approach. The PCA was implemented using EC images obtained with selected excitation frequencies. These images are considered as resulting from a linear mixing of different sources including the presence of rivets and defects, and the PCA is used to separate these sources thanks to an eigen decomposition of the EC data covariance matrix. As a result, the defect signatures are enhanced and used to implement an automatic defect characterization. This characterization is carried out by the means of an ML approach which allows the length and depth of the defects to be estimated. The method was implemented for the evaluation of a laboratory made riveted lap joint mock-up featuring buried defects. It was experimentally optimized and successfully implemented for the characterization of calibrated defects ranging from 2 to 10 mm in length and 2 to 8 mm in depth.


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    Title :

    Characterization of subsurface defects in aeronautical riveted lap-joints using multi-frequency eddy current imaging


    Additional title:

    Charakterisierung von Fehlern unterhalb der Oberfläche in Luftfahrt-Nietverbindungen mittels Mehrfrequenz-Wirbelstromabbildung


    Contributors:

    Published in:

    NDT&E International ; 42 , 2 ; 133-140


    Publication date :

    2009


    Size :

    8 Seiten, 12 Bilder, 1 Tabelle, 17 Quellen




    Type of media :

    Article (Journal)


    Type of material :

    Print


    Language :

    English






    A computational technique for automated recognition of subsurface cracks in aeronautical riveted structures

    Morozov, M. / Rubinacci, G. / Tamburrino, A. et al. | Tema Archive | 2004


    Strength of riveted joints

    Bowen, I.G. | Engineering Index Backfile | 1945


    Tests of riveted joints

    Engineering Index Backfile | 1890