Moisture absorption of FRP is important because the mechanical properties, such as compressive and fatigue strength, significantly degrade due to moisture absorption. It is difficult to apply conventional measuring methods to FRP because of its inhomogeneity and low moisture absorption ratio. In this study, a new method to measure the moisture absorption ratio of FRP by the change of the dielectric constant, which corresponds to the capacitance, of a micro polyimide sensor embedded in FRP is proposed. At first, the relationship between the moisture absorption ratio and the dielectric constant change of the sensor itself is investigated. Then, GFRP specimens in which the sensor is embedded in the midplane are immersed in water, and the moisture absorption ratio of the specimen and the dielectric constant change of the sensor are monitored. As a result, it is shown that the moisture absorption ratio of GFRP can be easily measured by the proposed method.
展开▼
