Electromagnetic Testing of Corrosion at Rivet Sites via Principal Component Analysis

Detection of corrosion at rivet sites in a multilayer structure of an aircraft is an essential task to ensure the flight safety of an aircraft. It is challenging to detect the corrosion due to the influence on the signal of the rivet and the multiple fastened layers in the structure. In this letter, an electromagnetic testing method is used in conjunction with principal component analysis (PCA) to detect corrosion around fasteners. Multiple Hall sensors were used for efficient measurement of the magnetic field distribution at the rivet sites. The features of the scanned magnetic image were automatically extracted by the PCA in orthogonal subspaces. The proposed method shows potential results of features extraction and corrosion signal extraction for further development of electromagnetic testing systems in multilayer engineering structures.