Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : November 25, 2025 - November 29, 2025
Adhesive bonding is a joining method for CFRP structures, but it may cause kissing bonds that are difficult to detect by nondestructive testing. Therefore, it is difficult to use adhesive bonding alone in joints where reliability is required, and adhesive bonding and fasteners are used together. However, the use of fasteners increases the weight of the joint structure, and the advantages of adhesive bonding cannot be fully utilized. On the other hand, even if a crack occurs or propagates at the adhesive joint, there is no problem with structural integrity if there is enough time before the unstable crack propagation starts and if it can be detected by nondestructive inspection before the unstable crack starts. For example, a crack arrester could be installed in the crack propagation path before the critical crack length where unstable crack propagation occurs, and a crack detection function could be added to the crack arrester itself or its surrounding area to guarantee the integrity of the joint. In this study, we investigated a method to detect crack propagation around the crack arrester by adding crack arrester performance to the adhesive layer by adding a convex shape to a part of the surface of the adhesive layer. As a result, it was confirmed that the method was effective in suppressing crack growth sufficiently, and a health monitoring method using the convex shape was devised without installing a sensor.
