Damage detection and self-repair in hollow glass fiber fabric-reinforced epoxy composites via fiber filling

Hollow glass fiber reinforced epoxy matrix composites were produced to study whether the damage development can be followed and the self-repair can triggered by filling the fibers with suitable additives. Composite plates were manufactured by the hand layup and vacuum assisted resin transfer molding techniques. To detect subcritical transverse impact damage, hollow fibers were filled with an ultraviolet fluorescent dye, whereas for self-repair, they were filled with a polyester resin along with the corresponding accelerator. The healing process was induced at different temperatures and continued for different durations. It was demonstrated that the targeted damage detection and self-repair can be achieved using thin (10–13 μm outer diameter) reinforcing hollow fibers. The self-repairing ability was demonstrated in three point bending tests and the healing was confirmed by inspection with scanning electron microscopy.