In the first stage of the test, the defect test pieces […]
In the first stage of the test, the defect test pieces included debonding of different diameters between the carbon fiber panel, aluminum panel and core material, and debonding between two foams bonded together without a panel. . For different frequencies and probe arrangements, C display can be used to detect debonding defects between 1/16 inch and 3/4 inch diameter between the carbon fiber panel and the foam core material; it can detect between the aluminum panel and the foam core material Debonding and bonding debonding defects between foams.
-The core material of the second stage test piece is two 50mm thick WF foam glued together. Because of the inhomogeneity of the core foam material and the existence of the interface between the foam cell wall and the pores, the foam material contains an interface with a sharp change in acoustic impedance, which results in a large scattering attenuation. Ultrasonic testing at 225kHz and 400kHz failed, and the signals were all attenuated.