A Parametric Study of Magneto-Optic Imaging Using Finite-Element Analysis Applied to Aircraft Rivet Site Inspection

Pulsed eddy current imaging and frequency spectrum analysis for hidden defect nondestructive testing and evaluation

“…Imaging technique can get the shape of a hidden defect and is more intuitive than traditional nondestructive testing methods. In recent years, some eddy current (EC) imaging methods are investigated to detect the defects in metal structures, such as Magneto-optical imaging [1,2], multi-frequency eddy current imaging [3], transient eddy current imaging [4], low-frequency eddy current imaging [5], and pulsed eddy current imaging [6]. In all these methods, pulsed eddy current (PEC) testing can be used not only to measure the parameters of metal, such as thickness and conductivity [7,8], but also in defect nondestructive testing and evaluation [9,10], such as crack measurements, crack depth estimation, and crack reconstruction [11][12][13].…”

Modeling for detecting micro-gap weld based on magneto-optical imaging

“…11(c) image. The median filer formula is expressed by [18] f (x, y) = median (s,t)∈sxy g (s, t) (12) where the g(s, t) expresses the original MO grey image, while thê f (x, y) expresses the image after filtering. Fig.…”

“…The magneto-optical (MO) detecting technique is usually being used in the large tested skin layer and subsurface stratum of the airframe's aluminum elements, as well as the flaw by corrosion and the fatigue cracks near rivets in the steel and titanium alloy constructions [10][11][12]. It also has been certified that MO imaging technology could be used in identifying detection and tracking micro gap weld [13][14][15].…”

Pulsed eddy current technique for defect detection in aircraft riveted structures

“…Tian GY et al presented a new feature called as rising point time to identify the different defect types and lift-off, which offers benefits such as independence of coil dimension and ability to evaluate a defect's depth regardless of its type or shape [9]. Zeng ZW et al presented a three-dimensional finite-element model of Maxwell's equation for numerical simulation of the Magneto-optic/eddy current imaging (MOI) operation which was useful to detecting surface and subsurface cracks at rivet sites [10]. Li S et al introduced development of differential probes in pulsed eddy current testing for noise suppression [11].…”