Strain monitoring with embedded Fiber Bragg Gratings in advanced composite structures for nautical applications

Small samples were produced in order to investigate the effect of the curing process parameters on the light transmission characteristics of the embedded optical fibers. Polyimide and acrylate coated optical fibers were tested measuring the relative coefficient of attenuation by Optical Time Domain Reflectometry. In particular, carbon fiber reinforced epoxy laminas with embedded FBGs were manufactured and specimens for tensile tests extracted from the laminas. Each specimen was instrumented with FBG and conventional electrical strain gage bonded on the surface. The comparison between the FBG and SG measurements recorded during static tensile tests permitted to assess the strain monitoring capability of the FBGs and their sensitivity and accuracy.