Loading rate effect on mechanical property of metallic structure repaired with bonded composite patch

In light of the viscoelastic property of the adhesive and resin matrix of the composite patch, a series of specimens were prepared by UV curing and conventionally thermal curing methods. The effect of the resin formula on the strain rate was investigated. And the effect of the loading rate on the bonded composite repair structure was studied. Results show that the crosslinking degree of the resin is an important factor affecting the strain rate effect. The lower crosslinking degree may mean the more pronounced strain rate effect. The increase of the loading rate can enhance load-share fraction of the composite patch. However, the stress redistribution function of the composite and adhesive by deformation may be reduced. The loading rate can affect the failure modes of the bonded composite repair structure.