Evaluation of strength recovery and analysis of damage progression of notched unidirectional carbon/epoxy composites encompassing self-healing of interfacial debonding

This study examines the interfacial debonding behavior of self-healing fiber reinforced polymers (FRPs) and the performance of repair of interfacial debonding. Self-healing is accomplished by incorporating a microencapsulated healing agent and a catalyst within a coating layer on the surface of the fiber strand. Single edge notched tensile (SENT) specimens of unidirectional FRPs with coated fiber strands were prepared and tested. The healing efficiency was evaluated by the critical fracture loads of virgin and healed specimens. To investigate the release of the healing agent from microcapsules during interfacial debonding, an ultra-violet (UV) fluorescent dye was added to the healing agent and post-fracture specimens were examined by an optical microscope under UV light. In addition to conducting experiments, finite element analyses were performed using a three-dimensional model to predict the damage progression in SENT specimens.