Smart CFRP Systems— Fiber Bragg Gratings for Fiber Reinforced Polymers

Since 1970 the development of optical fiber measurement systems has begun. Especially the measuring of strain and temperature with Fiber Bragg Gratings (FBG) is interesting, because there are a large number of advantages in opposite to electrical measuring methods. Examples are small dimensions, low weight, high static and dynamic resolution of measured values, corrosion resistance, variable forms, multiplex behavior, long distance monitoring and high durability. In the past there were several attempts to use optical systems for monitoring of concrete structures. One example is the strain measurement in bar reinforcement. Another possibility is the embedding of optical fibers with FBG in Carbon Fiber Reinforced Polymers. Fiber Re-inforced Polymers (FRP) have got more and more important during the last decade. In civil engineering the main usage of FRP is the repair of concrete structures. CFRP systems for retrofitting of concrete structures with optical sensors have already been discussed in several publications. It could be shown, that the reinforcing function of the CFRP can be ideally connected with the measurement and monitoring functions of the optical sensors like FBGS. The main problem is the fixing of the glass fiber and the small FBG at the designated position. In this paper the possibility of setting the glass fiber with embroidery at the reinforcing fiber material will be presented. Experiments will show the functionality of the method.