Application of Carbon Fiber Smart Layer for FRP Structural Health Monitoring

Carbon fiber smart layer was covered on the lower side surface of a fiber reinforced plastic(FRP) plate where a disfigurement was performed. Through monotonic bending test until damage and constant amplitude cycle bending test, some conclusions were obtained. During the monotonic flexural failure test, the resistance change of carbon fiber smart layer existed knee point, and the appearance of this point marked the disfigurement started cracking. Before cracking, the resistance of carbon fiber smart layer changed linearly versus the disfigurement stretch. While after cracking, the resistance of carbon fiber smart layer increased steeply versus the disfigurement stretch. In the cycle of constant amplitude cycle flexural test, the resistance change of carbon fiber smart layer displayed constant amplitude change before the disfigurement cracking, but amplified change after the disfigurement cracking. The results show that health monitoring of FRP structure could be fulfilled by monitoring the resistance change of carbon fiber smart layer on the surface.