Identification of surface crack profile in metallic structures through ACFM data using first and second order fuzzy approximation

One of the most fundamental problems in industries is the initiation and growth of fatigue cracks before their destructive results. Consequently, various nondestructive evaluation techniques are proposed to eliminate mentioned concern. Although several accurate crack depth estimation methods have been proposed, they are not able to determine the error rate of theirs. Known upper bound error rate not only determines the maximum accuracy of a method, but also it would be feasible to arrange the least computational complexity based on desire error rate. Accordingly, as a result of the robustness of fuzzy methods over accessing to a closed-form of problems which have complex and empirical nature, a first and second fuzzy system is utilized to estimate the surface crack depth profile of an arbitrary crack in metallic structures based on ACFM signals, and employed to surmount mentioned drawbacks. Finally, to prove the advantages of the presented method in this paper comparing several common methods and analyzing its difficulties, numeric results of different simulations would be revealed in analytical and experimental forms.