Static resistance of bolted circular flange joints under tensile force

Bolted flange joints are commonly used for both support and continuity connections of tubular members in a variety of structures such as trusses, communication tower pylons, chimneys, pylons for wind turbines and ski-lift installations as well as lighting and road signal posts. It is usual to design the flange joints such that the ultimate limit state static resistance is governed by that of the attached tubular section. A design method suited for tensile loading of the tubular section can be readily adapted to deal with bending also. Based on the work of Igarashi et al., a closed form solution for the ultimate tensile resistance of a bolted flange joint is derived. The effects of contact between the two opposite flanges are also considered. A design approach similar to that of the Eurocode 3 for T-stubs is developed. A finite element model analysis considering elastoplastic behaviour and contact shows good agreement with published experimental results and with the analytical model. A parametric study indicates that the proposed analytical model should be valid for a large range of joints.