Guide Wave-Based Inspection of Adhesively Bonded Structures in Composite Plates

The existence of weakly bonded areas will greatly affect the reliability of adhesively bonded structures in composite plates which are widely used in engineering applications. The timely and effective inspection of the adhesively bonded structure is crucial. In this paper, a simulation method of bonded quality based cohesive zone model(CZM) and the RAPID imaging method based ultrasonic guided wave detection technology are proposed to realize the detection and imaging of weakly bonded areas of adhesively bonded structures in composite plates. The CZM is innovatively used for the simulation of different bonded quality, it is achieved by modifying the constitutive relation curve of bilinear traction-separation law. Then, the influence of the degradation of bonded quality on the propagation characteristics of guided waves was explored. The results show that different bonded conditions have a significant impact on the guided wave propagation characteristics which enable the inspection of weakly bonded areas. Finally, based on the guided wave detection method and the cross covariance-based RAPID imaging algorithm, the detection and imaging of the weakly bonded area of the adhesively bonded structures are realized.