Description
In the adhesive bonding method of steel plates or FRP plates to restore the performance of steel members, the evaluation of delamination of adhesive joints in design and verification is an important concern. In particular, there are few data on debonding strength under cyclic loading, and standards for fatigue design have not yet been established. In this study, specimens were prepared by bonding a patch plate to a steel plate using epoxy resin adhesive, and repeated bending loads were applied to them to measure the occurrence and propagation of debonding. The types of the patch plates and adhesives were parametrically examined. As a result, S-N diagrams were organized by the ratio of the principal stress range in the fatigue test to the principal stress in the debonding in the static test, the bending fatigue durability of the debonding could be evaluated with high accuracy. Comparisons with experimental cases under tensile loading showed a similar tendency, indicating that the fatigue lives of debonding can be evaluated regardless of the type of applied force.
