Mechanical Behavior Analysis Of Unilateral Bolt T Joint Under Dynamic Load

Steel tubular members have great torsional stiffness and good local stability,which make them widely used in some large buildings,high-rise buildings and assembly buildings.However,as far as steel pipe is concerned,it is very difficult to tighten the bolts in the closed section of steel pipe members,so it is necessary to open the holes in order to realize the connection,which increases the amount of construction and labor costs.Unilateral bolts have the basic mechanical properties of ordinary high-strength bolts.They can be installed unilaterally and tightened unilaterally.They can solve the connection problem between steel members of closed section steel very well.At present,the domestic research results on mechanical properties and stress process of unilateral bolted connections are very scarce,which limits the application of unilateral bolts in practical engineering.By equivalent the connection between steel tube and H-section steel column to simulate the mechanical properties of T-joints,the tensile properties of T-joints under static loads and the dynamic properties of T-joints under earthquake loads were studied.The failure mode,stress process and tensile capacity of T-joints are analyzed.T-joints are deeply studied by changing the relevant parameters.The results show that the tensile strength and stiffness of T-joints can be improved by increasing the end plate and bolt diameter of T-joints,and the failure mode and ultimate tensile strength of T-joints can not be affected by increasing the pretension force,but the initial stiffness of T-joints can be slightly increased by pretension force.The verified finite element model is subjected to seismic loads.The failure modes,failure mechanisms and reaction time history curves of T-joints under different parameters are analyzed.The analysis results show that the failure modes of T-joints have not changed under earthquake;there are three failure modes;the mechanical properties of T-joints will be improved with the increase of end plate thickness and bolt size;and the preload has little effect on the bearing capacity of T-joints.Figure 56;Table 17;Reference 49.