Wireless Detection of Internal Delamination Cracks for Carbon/Epoxy Composite Using Electrical Resistance Method

摘要

For a rotating composite component such as a helicopter blade, delamination of composite laminates causes low reliability. Since it is difficult to detect the delamination of rotating component in-service with a wired system, wireless detecting system is demanded to improve the reliability. In the present study, the wireless system for detecting the delamination is proposed. This method adopts an electrical resistance change method and an oscillating circuit to transmit the information of the delamination. Since this system uses the composite structure itself as a sensor and the oscillating circuit is very small, it is applicable to a rotating component. The electrical resistance change and oscillating frequency change due to the delamination creation is experimentally measured by using carbon/epoxy specimen. As a result, the method can successfully detect the embedded delamination and estimates the size of delamination wirelessly.