Seismic Performance Study On The Weak-axis Top And Seat Angle Steel Connection Of I-Section Column With Box-shaped Panel Zone

In the American Northridge earthquake and the Japanese Hanshin earthquake,a large number of steel frame rigid joints cause brittle failure because of the poor ductility.People have doubts about seismic performance of rigid joints,and semi-rigid connections with better seismic performance have gradually become one of the research hotspots in academic and engineering fields.The steel frame top and seat angle connection is a typical semi-rigid connection.But most of the current studies focus on the strong axis connection of the I-shaped column,while the weak axis connection is relatively less.The analysis and research on the steel frame top and seat angle connection has important theoretical significance and practical engineering application value.Nonlinear simulation analysis of the box node domain weak axis top and seat angle steel connections is carried out by the finite element program ABAQUS,and there is the seismic performance research on the connections under low cycle cyclic loading.First,there is the comparison with the traditional weak axis top and seat angle steel connections,the advantages and disadvantages of the box node domain weak axis top and seat angle steel connection are obtained.Then,many node parameters are researched,including angle thickness,angle of leg length,distance of the tension bolt to the beam flange connection,axial compression ratio,skin thickness and the height of the beam.The study found that:?1?The box node domain weak axis connections belong to typical semi-rigid connection,but the bearing capacity and stiffness of the connection are weak.The deformation of the joint is mainly the tensile deformation of the top or seat angle steel,and the ultimate failure is the large plastic deformation in the area where the horizontal limb of the top or seat angle is in contact with the flange of the beam.?2?The connection bearing capacity and stiffness,ductility and energy dissipation capacity are higher of box node domain weak axis connections through the comparison with the traditional weak axis connections.On the other hand,box node domain weak axis connections have a direct connection between the skin board with angle steel instead of column web connections with angle steel,the force is transferred to the column flange directly,avoiding the destruction of the column web,improving the stress performance of connections.?3?The influence of the angle thickness,tensile steel beam flange bolts to the distance,skin thickness and the height of the beam on box node domain weak axis connections mechanical properties is big.Increase of the thickness of angle steel can improve the bearing capacity,rigidity,but the ductility and energy dissipation capacity is reduced;the distance increase of tension bolt to beam flange can improve the ductility capacity,but significantly reduced the bearing capacity,stiffness,energy dissipation capacity and hysteretic behavior;the increase of skin thickness can significantly improve the stiffness,ductility,energy dissipation capacity of nodes,but the larger or smaller thickness will reduce node bearing capacity,the increase of height of the beam section can improve stiffness,energy dissipation capacity,but the ductility decreases.According to the results of ABAQUS numerical simulation,some suggestions are given for the value of the parameters:angle steel thickness t=?0.75⁰.88?t_m,where t_m is the thickness of skin plate;the distance values between tensile bolts and beam flange s=?3.18³.64?d₀,where d₀ is the diameter of the bolt hole.?4?There is a slight influence on new weak axis connections of the angle steel length,column axis pressure.