In this study, FEM analysis was conducted using a numerical analysis model that can consider the contact pressure dependence of the friction coefficient between joint surfaces, to verify the validity of the new slip capacity formula and to study the details of joint structures that can be expected to improve the slip strength. The analysis of a small joint flange thickness, in which an enlarged washer was inserted to reduce the contact pressure when the bolt axial force is introduced, resulted in a larger slip strength than that of a large joint flange thickness. The increase in the slip strength was similar to that expected by the new slip resistance equation.
