抄録
In the present study, internal strain monitoring and detection of cure shrinkage in matrix resins by using EFPI optical fiber sensors have been investigated for CFRP during autoclave cure. EFPI sensors were embedded into quasi-isotropic CFRP laminates composed of carbon fiber/heat-resistant tough epoxy resin prepregs for aircraft structures. In order to examine the monitoring ability of EFPI sensors, measured internal strains were compared with specific volume of matrix resins determined by PVT measurement during cure, which indicates their cure shrinkage and thermal expansion/contraction. The results show that the cure shrinkage terminates at a certain degree of cure before the resin cures completely, and the EFPI sensors can detect this phenomenon. From these results, it is found that the EFPI sensors can measure the internal strains corresponding to the specific volume change of the matrix resins after the degree of cure reaches approximately 30%.
