The bolts are notched members, the stress concentration and notcheffect at the root of threads are significant [34,35,36]. An FE-model ofthe test setup, with some simplifications, was built to investigate thestress state of the bolt in BSJ using the ABAQUS programme. Only onehalf of the BSJ was modeled due to the symmetry, and the rising angleof threads was ignored, as shown in Fig. 12(a). All materials were assumedlinear elastic and isotropic, and Young’s modulus of 206 GPa andPoisson’s ratio of 0.28 were used. A reference point RP-1 was established20 mm away from the center of the upper surface of the bolthead, and coupling constraint was set between the upper surface andthe reference point. The lower end of sphere section was fixed, and thebolt was loaded with non-pretension. An axial tensile load of 100 kNwas applied on the reference point, and the concentrated force wasuniformly distributed on stress surface.