Study On Anti Seismic Behavior Of Joint Bolt Connection Joints Of Beam Column Flange And Disc Of Assembled Steel Structure

The assembled steel structure has the characteristics of standardization,serialization and product.It can meet the requirements of the development of residential industrialization,and has the advantages of superior seismic performance,short construction period and comprehensive technical and economic indicators.The development of prefabricated steel structure and the expansion of the market share of the assembled steel structure will accelerate the process of housing industrialization,which is of great significance to the development of China's architecture,metallurgy and related industries.There is no doubt that an important part of the development of the assembled steel structure is the research and development of the assembled beam column joints,but the study of its form and performance is still in the initial stage in our country.Therefore,a new type of assembled steel structure beam column joint form,that is,the assembly type steel structure beam column flange joint bolt connection joints,is put forward in this paper.The design,theoretical deduction and experimental study of the joint are carried out,which is not only a kind of exploration for the joint joints of the assembled beams and columns in China,but also a beneficial supplement to the semi rigid design method of the assembled steel structure in our country.According to the domestic code for steel structure design(GB50017-2017)and the American steel structure code for seismic design(ANSI/AISC358.10),the joint bolt connection joints of the beam and column flange plate of the assembled steel structure are designed,and the size requirements of the basic nodes are given.Then,this paper designed 4 T shaped assembly beam column flange joint bolt connection joints,and carried out the pseudo static test to fully study the seismic performance,and analyzed the test results and data.Finally,combined with the experimental analysis results,the theoretical formula of the bearing capacity of the assembled flange joint bolted joints is finally presented.The specific introduction is as follows:(1)This paper puts forward a new type of assembly type bolt connection node,that is,the assembly type steel structure beam column flange joint bolt connection node,which enriches the kind of semi rigid connection node inChina.This paper gives the structural design and design steps of the node,which can provide a reference for the practical application and theoretical research of the joint.(2)In this paper,4 assembled flange joint specimens with different flange thickness and length are designed and manufactured,and pseudo static test will be carried out.In the process of testing,the assembly type flange joint joint shows sufficient bearing capacity,better stiffness,ductility and energy dissipation capacity,which proves that it has good seismic performance.(3)Through the analysis of the damage phenomenon and the damage form,it is found that,on the premise of guaranteeing the quality of the weld,the joint flange of the assembly flange is matched with the thickness and length of the flange.In the process of loading,with the increase of the loading displacement,the flange joints are flexed and formed first plastic hinges,with the plastic hinge.With continuous development,the girder web is yielding to form second plastic hinge.Because the bearing capacity of the beam end is weaker than that of other components in the node domain,the plastic hinge of the specimen is far away from the nodal domain because the flange of the flange is strengthened in the length range of the beam.Now it is higher than the 1/3 beam of the column wall.(4)When the thickness of the flange plate of the assembly flange is 8mm,that is,when the section stiffness of the node is larger,the length of the flange is increased,that is,when the plastic hinge area of the flange joint area is enlarged,the yield bearing capacity and ultimate bearing capacity of the joint can be increased,the deformation of the flange joint is greatly reduced and the node is greatly improved.Ductility and energy dissipation capacity reduce stiffness degradation.However,when the flange thickness is 6mm,that is,the stiffness of the node area is small,increasing the plastic hinge area of flange joint can not improve the bearing capacity of the joint.Therefore,when the section stiffness is large,increasing flange length is an effective means to improve the bearing capacity,ductility and energy dissipation capacity of joints.But when choosing the parameters of the flange,the economic factors should be considered to select the appropriate flange thickness and length.(5)This paper analyzes the two parts of joint bending and shear resistance,and follows the principle of strong shear and weak bending.According to theforce characteristics of each component of the node,the calculation process and calculation method for calculating the bearing capacity of the assembled flange joint are proposed,and the ultimate bending moment of the A is carried out according to the process and method.The calculation results show that the calculated values of the two groups of nodes are in good agreement with the test values,and the ratio is about 0.9,which proves that the calculation method is reliable and feasible,and can provide reference for the practical application and theoretical research of this kind of node.