Self-healing of impact damage in fiber-reinforced composites

Healing of impact damage in vascular fiber-reinforced composite beam specimens was explored using a flexure after impact testing protocol. Two-part epoxy and amine based healing agents were delivered to impact-damaged beam specimens using a novel air assisted reagent delivery scheme. The incorporation of microchannels into composite specimens did not alter the flexural stiffness or strength of the composites, however, the post impact flexural strength was reduced, on average, by 25.7%. Flexure testing of healed specimens demonstrated 47% recovery of strength and 83% recovery of moduli when compared to control samples in which no agents were delivered. Optical cross-sectional micrographs reveal that not all damage regions are infiltrated during healing as a result of incomplete damage connectivity. A damage filling efficiency during healing agent infiltration was calculated and was found to positively correlate with recovery of post-impact strength.