Experimental methods and finite element are used to study the failure mechanism of mechanical joints and adhesive-bolt hybrid joints. The load-displacement curve is analyzed by tensile-shear test

and the microstructure of the section is analyzed combining the stress distribution of the finite element simulation results. The results show that the perforated carbon fiber tow of the bolted joint structure is deformed by the bolt pressing force

which is passed to the resin matrix

so the fiber is subjected to buckle deformation

and the resin matrix is squeezed into a cluster by a short bundle of fibers that are uniformly distributed. Therefore the formed weak structure is due to uneven structure. Adhesive-bolt hybrid joints exhibits tensile fracture failure

the carbon fiber tow at the fracture is pulled out from the epoxy resin matrix under tensile-shearing and damages the fracture

and the direction of the tow is disorderly arranged. The resin matrix attached to the fiber changes to be agglomerated

and the joint structure fractures after reaching the ultimate load. And the adhesive between the sheets has a retarding effect on the destruction of the fibers after the redistribution of the load. Factors such as material strength

bolt strength

adhesive strength and bolt width to diameter ratio will be factors that affect the failure of the joint structure.