Seismic Behavior Analysis Of Steel Beam-concrete Filled Steel Tubular Corner Column Joints With External Diaphragm

In recent years,with the rapid development of China’s economy and the increase of the proportion of urbanization,super-high-rise buildings have sprung up like mushrooms after a spring rain.Super-high-rise buildings are densely staffed,and it is often difficult to evacuate people in a short time in case of earthquake and other disasters.Therefore,their safety has attracted much attention.At present,the frame-core tube structure is mainly used in the super high-rise buildings,that is,the core tube structure is used in the center of the structure,and the concrete filled steel tubular column-steel beam frame structure is used in the outer side of the core tube.Because of the effect of space seismic force,any direction of structure may become the main direction of earthquake action.Compared with the mid-column and side-column joints,the stress of corner-column joints is more complex,and it is easier to damage when earthquake occurs.At home and abroad,the research on spatial joints mainly focuses on the mid-column joints and side-column joints,while the research on corner-column joints is relatively less.In this paper,ABAQUS finite element analysis method is used to establish a refined model of concrete filled steel tubular column-steel beam externally reinforced ring corner column joints,and to analyze the seismic performance of the joints.Loading can be divided into single beam loading,double-beam co-loading and double-beam reverse loading.The loading direction at the end of the column and the angle between the reference beam and the loading direction are 0 degrees,30 degrees and 45 degrees.The analysis parameters include: the ratio of width to thickness of steel tube column,the ratio of beam to width,the ratio of beam to column width,the strength of core concrete,the strength of steel and the ratio of axial compression.The main conclusions are as follows:(1)Through the comparison of finite element simulation and test,it is found that the failure process,failure mode,bearing capacity and hysteretic performance of the two are highly consistent,which verifies the reliability of the finite element analysis method.(2)The concrete-filled steel tubular column steel beam external stiffened ring corner column joint has the characteristics of high bearing capacity and strong energy dissipation capacity,and the loading process and stiffness degradation roughly go through three stages.(3)Different loading directions at the beam end mainly affect the failure mode of the joint,and have some influence on the seismic performance indexes such as the bearing capacity,stiffness degradation and energy consumption of the joint,but the degree of influence is small;the loading angle at the column end mainly affects the failure mode of the joint,and has no obvious influence on the seismic performance indexes such as the bearing capacity,stiffness degradation and energy consumption of the joint.(4)The failure mode of the joint is mainly affected by the width thickness ratio of steel tube column,steel strength and axial compression ratio,which has a certain impact on the beam height width ratio and beam column width ratio,and has a small impact on the core concrete strength;the seismic index of the joint has a greater impact on the column width thickness ratio,beam height width ratio,beam column width ratio and steel strength,and has a greater impact on the seismic performance index of the joint with the core concrete strength and axial compression ratio The impact is small.