Application of EFPI optical fiber sensors to the monitoring of internal strains in FRP laminates during the autoclave molding

摘要

In the previous study, it was found that the discrepancy between the optical axes in the EFPI sensor affected the strain values measured by the sensor embedded in the perpendicular direction to the reinforcing fibers. In the present study, an optical fiber strain measurement system different from that used in the previous studies was used in the experiment of measuring internal strains in GFRP laminates during the autoclave molding. In the experiments, the internal strains were measured simultaneously with two kinds of the strain measurement systems and the differences of their performances were investigated. From the results, it was found that the measuring ability of the internal strains in the FRP laminates during the autoclave molding and the sensitivity of the optical fiber strain measurement systems seriously depended on the structure of their sensors, even if they were based on the same EFPI system.