Research On Guided Wave Monitoring Method Of Aircraft Structure Corrosion

The corrosion damage of aircraft structures can significantly reduce the safety performance of aircraft structures and endanger the flight safety.In this paper,an aircraft structure corrosion damage probability reconstruction algorithm based on guided wave is proposed to monitor the corrosion damage of aircraft structures.Targeted at structurally real corrosion damage,in this paper,the correlation between the Lamb wave reference signal and the monitoring signal is characterized by the spectrum amplitude difference damage index,which is used as the image reconstruction parameter in the reconstruction algorithm for probability inspection of damage(RAPID).According to the imaging results of the RAPID method,a fusion damage index method is proposed to evaluate the corrosion depth,and the structural corrosion damage depth measured by the ultrasonic C-scan system is compared with the above method.The experimental results show that the proposed method can effectively locate the corrosion damage and evaluate the corrosion depth.It is of great significance to guide the corrosion maintenance of aircraft structures.The main contents of this paper are as follows:(1)The propagation characteristics of guided waves in structures and the influence of corrosion damage on the propagation of guided waves are studied and analyzed.Combining the excitation of Lamb waves by piezoelectric sensors in the structure,the Lamb wave mode and excitation Center frequency,through the experimental method to study the five different damage indexs on the corrosion damage monitoring ability.(2)The corrosion damage on the structure was studied by nondestructive testing with ultrasonic C-scan method.The results of corrosion damage imaging on the structure surface were obtained by ultrasonic C-scan method.Meanwhile,the depth of corrosion was measured by ultrasonic C-scan method.(3)The corrosion damage on the structure surface has been studied by using the reconstruction algorithm for probabilistic inspection of damage(RAPID).The structural corrosion depth assessment function was obtained by using the fusion damage index method,the experimental verification of corrosion damage positioning and depth assessment results.