Experimental Study On Semi-rigid Joints Of Fabricated Lattice Beams And Columns

In the fabricated steel structure,the solid web beam and column often have less advantages in the multi-layer steel structure due to the relatively large self weight of the component,which requires heavy equipment for installation.However,the lattice fabricated component has gradually attracted the attention of scholars at home and abroad due to its advantages of small environmental pollution,saving steel consumption and light self weight.Compared with the solid web beam column joints,the research on lattice beam column joints is insufficient.Therefore,it is necessary to develop an economical and reasonable new semi-rigid beam column joint.The main contents and results are as follows:(1)In view of the research on the construction mode of lattice beam column joint,the research group proposed a new type of fabricated lattice beam column channel steel I-shaped composite joint.In this paper,four groups of new joint specimens are designed and manufactured,mainly taking the thickness and height of channel steel at the joint as the control parameters.Through the quasi-static test and ANSYS finite element software simulation,the mechanical and seismic performance of the new joint is studied,and the feasibility of the joint in the actual project is evaluated.The results show that the joint has enough bearing capacity,good ductility and energy dissipation capacity,and the new joint has good seismic performance,which can be used in practical projects.(2)The results show that:in order to improve the bearing capacity and seismic performance of the members,it is necessary to strengthen the channel steel at the joints;a single increase in the thickness or height of the channel steel is not an effective way to improve the bearing capacity and seismic performance of the members;compared with a single increase in the thickness or height of the channel steel,a significant increase in the height and thickness of the channel steel can be achieved The bearing capacity and seismic performance of the component.(3)The comparison between the test results of the lattice beam column joint and the simulation results of the finite element software shows that the hysteretic curve and the skeleton curve of both fit well;the failure of the specimens is caused by the bending and torsion of the channel steel,and the deformation of the channel steel is serious.Using the finite element software to simulate and analyze the internal stress state of the channel steel,it is found that increasing the height and thickness of the channel steel can improve the distribution of the maximum normal stress,thus significantly improving the bearing capacity of the components.(4)The finite element simulation results show that:when the thickness of channel steel is small,the single increase of the height of channel steel is not an effective way to improve the bearing capacity of components;when the thickness of channel steel is increased,the bearing capacity of components is significantly increased,which can be increased by 35%in theory;at the same time,when the height and thickness of channel steel are increased,the bearing capacity of components is significantly increased,which can be increased by 60%in theory,compared with the single increase Compared with the thickness or height of channel steel,the effect of improving the bearing capacity of members is more significant.(5)The finite element software is used to analyze the high-strength bolt.The results show that the maximum stress of two groups of specimens with a thickness of 4.8mm of channel steel appears at the middle bolt,which means that the bolt in the middle part is damaged first;the maximum stress of two groups of specimens with a thickness of 6mm of channel steel appears at the upper bolt cap,which means that the bolt at both ends is damaged first.It is found that when the height of channel steel is fixed,the slip value decreases by 14.6%with the increase of channel steel thickness,and decreases by 15.8%with the increase of channel steel height.It is found that the high strength bolt is affected by the shear force at the same time.