Investigation on shear and fatigue performance of CFRP/aluminum alloy single-lap adhesive joint

The size parameter is quite significant for the performance of adhesive joint. In order to investigate the effect of size parameters on the mechanical property and failure behavior of CFRP/aluminum alloy single-lap adhesive joint, T300 CFRP laminate and AA5182 aluminum alloy sheet were bonded by Sika Power 497 structural adhesive under different size parameters. The quasi-static shear test and fatigue test were implemented, and the failure behavior and failure mechanism were analyzed. Results showed that the increase of aluminum alloy sheet thickness or bonding area length could effectively improve the bonding strength of adhesive joint, when the strength of the aluminum alloy sheet or the adhesive layer was insufficient. The shear failure modes of adhesive joint mainly included adhesive failure, base material failure and mixed failure. The fatigue failure modes of adhesive joint were mainly adhesive cohesion failure and adhesive adhesion failure. At low stress levels, the aluminum alloy sheet might fracture. In addition, this work can provide a scientific guidance for the engineering application of adhesive bonding technology.