Abstract: Paper honeycomb structure should avoid liquid immersion. Aiming at solving the problem that liquid coupling agent can′t be used to detect this kind of material, based on the use of air-coupled penetrating C-scan imaging to detect honeycomb structure material, a method of using air-coupled Lamb wave to detect the debonding defect between skin and honeycomb structure was proposed. A simulation model was established to detect debonding defects in honeycomb structures and visualize the ultrasonic propagation process. The interaction between Lamb wave A0 mode and workpiece structure was studied, and the influence of debonding size on acoustic propagation was analyzed. The results show that the application of air-coupled ultrasonic guided wave technology can better achieve the detection of debonding defects, and can be applied to actual in-service detection.

Key words: honeycomb structure, air-coupled ultrasound, lamb wave, CFRP, debonding defect