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.

检测飞机多层结构中铆钉部位的腐蚀是确保飞机飞行安全的一项重要任务。由于对铆钉信号和结构中多个固定层的信号的影响，检测腐蚀非常具有挑战性。在这封信中，将电磁测试方法与主成分分析（PCA）结合使用以检测紧固件周围的腐蚀。使用多个霍尔传感器来有效测量铆钉部位的磁场分布。PCA在正交子空间中自动提取扫描的磁性图像的特征。所提出的方法显示了特征提取和腐蚀信号提取的潜在结果，可用于进一步开发多层工程结构中的电磁测试系统。