ラム波のモード変換に基づくCFRP接着構造における剥がれ検知

抄録

Carbon fiber reinforced plastic (CFRP) skin-stinger structures are expected to be used to lightweight aircraft structures. However, the adhesive joint between a stringer and a skin has a possibility to be deteriorated by the appearance of debonding. Hence, structural health monitoring (SHM) systems are desired to ensure the reliability of the adhesively bonded structures.

In this research, we attempted to use ultrasonic guided waves in a SHM method to evaluate the debonding progress in the adhesive layer of a CFRP bonded structure. As shown in Figure 1, the authors installed an ultrasonic actuator and an ultrasonic sensor on the skin for exciting and receiving Lamb waves, respectively. The waves were propagated through the stringer-bonded area to monitor the gradual growth of the debonding in the adhesive layer. Since there is a discontinuous thickness change between the plain skin and the stringer-bonded skin, the Lamb waves in the skin can convert their modes at ends of the interface between the skin and stringer.