STUDY ON STRESS CONCENTRATION FACTOR OF BOLT SCREW

Stress concentration in the bolt screws of bolt-sphere joints is the main reason for bolt screw fatigue failure. These stress concentrations in bolt screws were studied through theoretical derivation and numerical analysis. Ignoring lead angle, the variation of axial force gradient was obtained according to the deformable coordination condition. In addition, thread displacement factor and thread force were determined by numerical computation. The stress concentration factor in the bolt screw was developed through iteration using local modeling. Compared with the calculation results from whole models, the method proposed in this paper has higher computing accuracy and efficiency.