| Composite concrete-filled steel tube column to steel beam structures have a broad prospect in the field of engineering application for the advantages such as high bearing capacity of composite concrete-filled steel tube column,favorable seismic behavior,reasonable fire resistance,convenient opening for steel structures,light weight.However,composite concrete-filled steel tube column to steel beam joint owns many types and its stress state is complex,nowadays,researchers are lagging behind on such now joints at home and abroad,and there are few reports on the composite concrete-filled steel tube column to steel beam edge joints considering the reinforced concrete floor.In this article,the pseudo-static tests of composite concrete-filled steel tube column to beam joints considering action of floor slab have been carried and the specimens have been analyzed by nonlinear finite element.The main work and results in this paper are as followed: In this dissertation,three new composite concrete-filled steel tube column to steel beam edge joints and two new composite concrete-filled steel tube column to steel beam comparison cross joints were designed and pseudo-static tested.By regarding presence of reinforced concrete floor or not,column axial compression ratio,edge or cross joints as the main parameters,analyzing the hysteretic curve,ductility,energy dissipation,etc.The test results showed that the hysteretic curves of each joint is in spindle shape,favorable seismic behavior.These new joints can transfer the load from column end to beam end effectively.In addition,by increasing the column axial compression ratio of edge joints,the bearing capacity,ductility and seismic performance could be improved,but the existence of the floor enhanced the seismic performance of joints,cross joint specimen owned higher bearing capacity and better vibration resistance than edge joint specimen.Through using finite element analysis software ABAQUS,the model of composite concrete-filled steel tube column to steel beam joints were analyzed,the result showed that the hysteretic curves,skeleton curves,failure pattern of the joints got by numerical analysis were good agreement with the experimental results,It was indicated that the finite element had a good rationality in the selection of element type,material constitutive model and failure criterion. |
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