| Building assembly is the main development direction of China’s construction industry in the future.It fundamentally changes the original design,production,construction and other ways,and basically achieves component standardization,prefabrication and construction assembly.Beamcolumn joint is an important part of assembled steel structure,which plays a decisive role in the transfer of bending moment and shear force.Many scholars at home and abroad have done a lot of research on beam-column joint,and put forward some new forms of assembled beam-column joint.In this paper,a new type of independently assembled beam-column joint is proposed based on the traditional joint construction method,which disconnects the column at the joint area and enlarges the volume of the joint area.It can fully realize assembly construction,convenient transportation and low difficulty of field hoisting.The mechanism of "strong column and weak beam" is realized by using high strength steel for columns and low strength steel for beams.In order to study the mechanical and seismic performance of new joints more accurately,four different types of joints are designed according to the design standard of steel structure.Based on the finite element software ABAQUS,the specimens were analyzed under monotonic loading and low cycle reciprocating loading,and the typical specimens were selected for quasi-static test.The static performance,hysteretic performance,ductility performance,energy dissipation capacity and other mechanical and seismic performance of the joints are obtained.The new type of joint connects the bottom of the upper column,the top of the lower column and the end plate of the node with high strength bolts.The other two kinds of bolt connections connect the end plate of the beam with the column through high strength bolts.The other type of joint connects the beam with the column through welding.In this paper,the finite element simulation and test of joints are studied.The main research contents are as follows:In this paper,the finite element models of four kinds of joints are established,and monotonic loads are applied to them.The stress development,failure modes and bearing capacity of all beamcolumn joints are analyzed.The results show that except for the new type of independently assembled beam-column joints,the flanges of other joints are deformed to varying degrees.The flanges and joint areas of welded joints are deformed greatly,and the columns are "S" deformed with the lowest bearing capacity.On the basis of monotonic loading simulation,four kinds of joints were subjected to Lowcycle reciprocating loads by using finite element software.The results show that the hysteretic curve of high-strength bolted joints is more full shuttle-shaped than that of welded joints,which has better ductility and energy dissipation.Among them,the new type of independently assembled beam-column joints have the largest hysteretic loop area,the highest ultimate bearing capacity and good ductility,which can effectively protect the safety of the joint area and transfer the plastic hinge to the flange of the beam,so they have excellent seismic performance.In order to verify the accuracy of the finite element method,typical specimens were selected for comprehensive analysis and quasi-static tests were carried out.Combined with the results of experiment and finite element analysis,it is concluded that the factors such as test device,test measurement error and idealization of finite element modeling affect the results.The hysteretic curves and skeleton curves obtained by the test are slightly smaller than those obtained by the finite element method,but the difference is small,and the overall development law is roughly the same.Especially in the stage of structural failure,the plastic deformation of the specimens and the location of plastic hinges are basically the same. |
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