Studies On The Seismic Behavior Of Concrete Filled Square Steel Tube Column To Composite Slim Beam Connections

Concrete filled square steel tube(CFST) column to composite slim beam structure is a new kind of composite structure system, more widely used in the housing systems. The behavior of CFST columns and composite slim has been studied more thoroughly at present, but the CFST columns to composite slim beam connections are researched very little. So it has important theory and application value to research mechanics performance and seismic behavior of CFST columns to composite slim beam connections for the development and application of this new system in actual project.The CFST columns to composite slim beam connections pattern used suitably in the housing is suggested in this paper base on existing research achievement of the CFST columns to steel beam connections. To research the hysteretic behavior, energy dissipation capacity, ductility, strength degeneration and rigidity degeneration of the two kind joints, two kind external stiffening ring joints including four joints between the steel tube columns and composite slim beams are designed and tested under the constant axis force and reverse loads. The nonlinear finite element analysis is done to the joints using software ANSYS at the same time. The results of finite element analysis coincide to the results of the experiments. Then the influence of width of stiffening ring and thickness of stiffening ring on the seismic behavior of the external stiffening ring joints is discussed by the nonlinear finite element analysis with twelve different parameters model under reverse loading.The tests and analysis indicate that the joint patterns of this paper have enough carrying capacity, better ductility and energy dissipation behaviors. The relative research achievements could be referenced in practical application.