Three-Dimensional Finite Element Analysis of Rigid Flanged Shaft Coupling Subjected to Twisting Moment
A reamer bolt is commonly used when clamping a rigid shaft coupling subjected to large shear force. Although some joint design procedures assume that the applied shear force transmits only through the reamer surface, it is also supported by the friction force on the contact surfaces. Accordingly, to design the coupling clamped by reamer bolts, it is important to evaluate the ratio of the shear forces supported by the reamer surface and the friction force, which is defined as shear force transfer ratio (SFTR) here. In this study, distributions of SFTR and the bending stresses along the reamer surface are analyzed by three-dimensional FEM, focusing on the effects of the fit between the reamer bolt and bolt hole, the scatter of initial bolt stress and the misalignment of the connecting shafts. Numerical results quantitatively clarify how the amounts of the SFTR and the bending stresses as the friction coefficients, the fit and the magnitude of misalignment are changed. As for an offset misalignment, it is found that its effect on the bending moment generated in the shaft body is negligibly small, if the offset between two shafts in radial direction is less than 10mm which is 1% of the total shaft length.