Strength analysis of CFRP hybrid adhesive-bolt interference connection structures under tensile load

This study investigates the strength characteristics and adhesive layer damage/failure mechanisms of CFRP hybrid bonded-bolted interference connection structures under tensile load using combined experimental and finite element simulation methods. Experimental results show that the joint’s synergistic load-bearing capacity correlates positively with bondline interface roughness and bonded area and negatively with adhesive layer thickness. A damage prediction model based on a coupled CZM and XFEM algorithm was developed to simultaneously characterize adhesive layer interfacial debonding and cohesive fracture, s and its effectiveness was validated. During tensile loading, interfacial debonding failure, dominated by out-of-plane peel stress, initiates at the lap edge and propagates towards the bolt region, ultimately leading to a sudden stiffness drop. This research provides theoretical and experimental foundations for optimizing the design and enhancing the load-bearing performance of hybrid bonded-bolted joints.