Abstract
Health monitoring techniques for CFRP composite structures have been developed to assure the structural integrity. Electric impedance method is cost-effective and easy to apply for various structures. In order to apply the method to actual environment, the influence of moisture absorption on the electric impedance change of CFRP can not be neglected. In this paper, the influence of moisture absorption is investigated experimentally. The electric impedances both in the fiber direction and transverse direction are measured during moisture absorption. For both directions, it is found the electric impedance increases with moisture absorption. Furthermore, a monitoring method of moisture absorption rate near surface is proposed and experimentally investigated. As a result, it is shown that the change of the electric impedance follows the change of moisture absorption ratio near the surface.
