Fatigue cracks in aluminum alloys structures detection using electromagnetic sensors array

Abstract

The paper presents the architecture of a new type of electromagnetic sensor in 2D structure designed and made in order to estimate the location of a discontinuity below the surface of a conductive material. The use of 2D emission reception architecture in configuration of 5x5 identical reception sensors excited by a surrounding emission coil is proposed. The analysis follows the way in which one or more linear fatigue cracks that intersect can affect the eddy current answers and the electromotive force induced in the reception coils. The study of the dependence of the field distribution on the number and position of the reception coils against the discontinuity was carried out using FDTD. Spatial resolution has been improved using a known super resolution algorithm. The 2D structure was tested for the detection of subsurface discontinuities induced in Al2024 samples subjected to cyclic loading.