Defect identification of layered adhesive structures based on dynamic time warping and simulation analysis
Jiyang Zhang, Jiaoyiao Ren, Lijuan Li, Jian Gu, Dandan Zhang
Abstract
Layered adhesive structures are widely used in the aerospace field, and thus their defect detection is a critical part of quality control. Hence, this paper proposes a method to identify bonding defects relying on dynamic time warping (DTW) and simulation analysis. Based on the transfer matrix method, the propagation simulation model of the layered structure is established, and the simulation signal of the normal area and the characteristic interval of the defects are obtained. DTW is adopted to regularize the simulated and the real signals, and then the Pearson correlation coefficient is employed to calculate the regularized signals’ similarity. On this basis, the proposed scheme is considered a similarity imaging method, attaining an appealing identification error for the three- and the five-layered adhesive structure cases examined involving various defect thicknesses and glue layers. Compared to current imaging methods, the proposed one demonstrates a better and more effective imaging effect appropriate for bonding defect detection.