Numerical and experimental study of the effect of adhesive quality on the repair efficiency of corroded and cracked aluminum plate under mechanical loading

A corroded aluminum plate with an inclined crack at the corrosion end was repaired by boron/epoxy composite patches, bonded with various adhesive types under mechanical loads. The aim of this study was to discover which glue types are better for the composite patch adhesive and the most efficient in transferring stresses from the aluminum plate to the patch, so in this study three-dimensional finite element analysis was used to study the changes in the damaged area of the adhesive (DR) and the stress factor (SIF) in the two modes (mode I K_I and mode II K_II), then compare them. To confirm the analytical results, we conducted a laboratory experiment using corroded aluminum plate 2024 with random cracks that were repaired with a composite patch affixed with several adhesive types, and then we calculated the ultimate tensile strength. The obtained results, both on the analytical and experimental side, showed that the adhesive type FM73 is more efficient in fixing the composite patch and more effective in transferring stress from the damaged plate towards the patch compared to the other materials used in this study (araldite, adekit and redux).