Mechanical Properties Of Unilateral Bolted T-Joints Under Low Cyclic Cyclic Loading

In modern steel structures,T-joints between steel beams and steel columns have become an important force transfer component.For the common connection problems of H-shaped and T-shaped steel beam-column,the traditional bolt or welding method is usually used to realize the connection of steel beam-column joints.When the steel beamcolumn section is a closed section,it is difficult to tighten the nut inside the steel beamcolumn section because there is a shielding part in the closed steel beam-column section that can not be crossed by hand.Unilateral bolts can be installed unilaterally and tightened unilaterally without holes in the closed section,thus avoiding the shortcomings of traditional bolt installation.At present,the research on mechanical properties of unilateral bolted T-joints under low cyclic load is insufficient in China.In this paper,unilateral bolted T-joints are used to model T-joints,and ABAQUS finite element analysis software is used to model T-joints.Then unidirectional tension load is applied to the joints.The data obtained from the model are compared with the experimental data to complete the model validation.Then the T-joints are subjected to Low-cycle reciprocating loads,and the failure modes,hysteresis curves,skeleton curves and stiffness degradation of the joints are analyzed.The variable parameters of joints are bolt diameter,flange thickness with thread and bolt diameter.The results show that the diameter of bolt,the thickness of flange with thread and the strength of flange have obvious effects on the mechanical properties of T-joints.With the increase of bolt diameter,the thickness of flange with thread and the strength of flange,the mechanical properties of T-joints tend to be good,while the pre-tightening force of bolt has no obvious effect on the mechanical properties of joints,but it improves.Pre-tightening force of bolts can improve the initial stiffness of joints slightly.Unilateral bolts can not only save nuts,but also achieve the mechanical properties of traditional bolts.Figure60;Table13;Reference 45.