Edinburgh Napier University

  An optical fibre Bragg grating (FBG) based strain sensor network incorporated in a functionalized textile-based carbon structure (FTCS) that can be used for structural health monitoring (SHM) is introduced. The aim of the design is not only to monitor strain, but also to act as a structural strengthening mechanism in the target application. The integration of the optical fiber, i.e. incorporating the FBG sensors, on the FTCS is achieved by “interweaving” the two elements, i.e. optical fiber and carbon filaments, on a polymer textile substrate in a grid formation using a specialized fabrication process. The thus obtained sensors was then characterized and calibrated where a variation in the fibre length, i.e. resulting from strain, would induce a variation in the reflection wavelength of FBG sensors. To do so, the functionalized skein sample (incorporating FBG sensors) was subjected to varying elongation using a tensile testing machine by carefully incrementing the applied force. A good correlation between the applied force and measured Bragg wavelength change was observed, showing the value of the dual-achievement of the proposed optical fiber-based mechanism in obtaining strain measurement while being utilized as a strengthening agent.