Experimental study of carbon fiber reinforced plastic with embedded optical fibers

Structural differences of interface between the embedded optical fiber and the resulting smart composite were studied. Quasi-isotropic composite laminated specimens were produced from T300 Carbon/epoxy prepregs. Optical fibers were embedded within the specimens at different locations. Micro photos of the specimens showed that ‘bridges’ formed around the embedded optical fibers. The configuration and the size of the ‘bridges’, namely, the interfacial structures, varied with the locations where the optical fiber was embedded. Tensile tests showed that the ultimate strength of the smart material was affected by different interfacial structures. As the location of the embedded fiber moved to the middle plane of the specimen, the size of the interface increased. This caused the drop of the tensile strength. Observation of the broken sections of different specimens showed that imbibitions between the coating of the optical fiber and the clad were not good enough, therefore, damages could originate at the interface between the coating and the clad foremost.