Defect Detection for the Insulation Layer of Bent Aircraft Cables Based on Ultrasonic Guided Waves

The damage of aircraft cables is a major issue in the aerospace industry, which usually starts from insulation layer defect and can lead to serious casualties and financial losses. In this article, a method for defect detection for the insulation layer of bent aircraft cables is proposed, which is based on ultrasonic guided waves (UGWs). The propagation characteristics of UGWs in bent cables were studied by simulation and experiments, and wavelet packet decomposition (WPD) was used for feature extraction of the detection signals to distinguish bending and defects in the insulation layer. The experimental results show that the method is able to detect and locate both bending and defects (abrasion and cut) in the insulation layer. The maximum relative error in bending and defect localization does not exceed 0.3%.