A weighted sparse reconstruction-based ultrasonic guided wave anomaly imaging method for composite laminates

• Published in: Composite structures Vol. 209; pp. 233 - 241
• Main Authors: Xu, Cai-bin, Yang, Zhi-bo, Zhai, Zhi, Qiao, Bai-jie, Tian, Shao-hua, Chen, Xue-feng
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2019
• Subjects: Anomaly detection; Composite laminates; Structural health monitoring; Ultrasonic guided wave; Weighted sparse reconstruction; Composite laminates; Structural health monitoring; Weighted sparse reconstruction; Ultrasonic guided wave; Anomaly detection
• ISSN: 0263-8223; 1879-1085
• DOI: 10.1016/j.compstruct.2018.10.097

Ultrasonic guided wave is a promising tool for structural health monitoring and nondestructive testing. Numerous signal processing methods have been proposed to detect and localize anomalies based on ultrasonic guided waves for plate-like structures. However, imaging performance is limited in these methods, such as large spot size and significant artifacts. To achieve a better imaging performance of Lamb waves, a weighted sparse reconstruction-based anomaly imaging method is proposed for plate-like structures. Scattering signals are sparsely decomposed in a dictionary pre-constructed from Lamb wave propagation and scattering models. The pixel value at each location of the imaging region can be obtained by solving a weighted sparse reconstruction problem. To verify the accuracy and effectiveness of the proposed method, experiments on a carbon fiber reinforced plastic with and without additional mass are conducted. The experimental results show that the proposed method can achieve anomaly imaging with smaller spot size and fewer artifacts.