Abstract
The maximum and yield strength of bolted tension flanges joining square hollow section members were investigated theoretically. The maximum and yield flexural resistance of flange plate were analysed by means of the yield line theory. The prying force before and after the separation were evaluated respectively. Before the separation, a rigid zone around a bolt was assumed considering the restraining effect of bolt head, but after the separation it was not taken into account. It was assumed that the separation of bolts took place instantaneously as soon as the sum of external force and prying force attained the bolt separation load, and the separation of bolts was regarded as the yield of joints. On the basis of relative strength of the flange and high-strength bolts, the maximum strength of joints were classified into six failure modes, and the yield strength into three yield modes. The theoretical maximum and yield strength of joints were compared with experimental values. Finally, design formura on bolted tension flange joints of SHS were proposed.
