Tensile properties of a hybrid bonded/bolted joint: Parameter study

Analysis on hybrid bonded/bolted (HBB) joint is difficult due to its complex failure mechanism influenced by multiple design parameters. The effect of design parameters on HBB joint mechanical performances has not been systematically investigated. In this paper, a detailed finite element model (FEM) of a composite-steel single-lap HBB joint was established and verified by experimental results. Based on the validated model, ten major design parameters of the joint related to assembly relationship, joint geometry and material property were discussed. And the effect of design parameters on the joint tensile performances, including strength, stiffness and energy absorption, was investigated and compared comprehensively by the methods of uniform design and multiple linear regression analysis. The results indicate that increasing values of all the discussed design parameters except for bolt pre-torque, free part length ratio S/D and adhesive modulus show positive effect on tensile performances of HBB joint. Using high strength adhesive with low modulus is a key method to improve initial damage load and bonding strength of the joint. High strength bolt can effectively improve bolt hole bearing strength and energy absorption capacity of the joint. Larger width ratio W/D is effective to improve tensile stiffness of hybrid joint with single bolt.