Water‐immersion effect on radial crack initiation behavior in a fiber‐bundle‐reinforced epoxy cylinder with graphene in the interfacial region

The long‐term durability of polymer composites serviced under moist, high‐temperature conditions is a major concern in many industries. As an attempt, we filled 0.3 wt % graphene in a fiber–matrix interfacial region between glass fibers, carbon fibers, glass–carbon hybrid fibers, and epoxy resin to enhance the mechanical performance of the composites under water‐immersion conditions. The mass increment was recorded periodically while the...