Study On The Interaction Between Steel Tube And Concrete Of Round-ended Concrete-Filled Steel Tube Tower Column

The interaction between the two different materials of steel tube and concrete of concrete-filled steel tube (CFST) in the course of being compressed, that is, the con--finement to the core concrete from the steel tube, makes the core concrete in the state of being compressed from three dimensions, so that the core concrete has a higher compressive strength, plasticity and toughness performance.At the same time, due to the existence of the core concrete, the occurrence of local buckling of the steel tube is avoid or delayed,which can guarantee the property of it getting into full play.At present, both at home and abroad, the application and study of CFST are mainly focused on circular section , square cross-section and polygonal section. A round-ended concrete-filled steel tube coupled tower column is used in Houhu bridge in Huangpi district in Wuhan,which is a novel structure and applicated lessly. The study of this structure's mechanical performance and the related literature about it are also rare at home and abroad.In this paper,based on Houhu bridge round-ended concrete-filled steel tube coupled tower column numerical simulation and stress mo--nitoring technology project,consulting a large number of literature references, stress monitoring tests, static analysis of finite element and finite element contact analysis are applicated in the mechanical performance and the interaction between steel and concrete of the CFST tower column in its construction stage.The specific works incl--ude:1. Based on previous literature and analysis of the results of CFST ,the principles of the interaction between steel and concrete, the interface state of CFST,the defini--tion of bond strength of CFST, as well as the main influencing factors about the bond strength between steel and concrete are discussed in this paper.The methods used in the study of the interaction between steel and concrete are being introduced and the meaning of studing the interaction between steel and concrete is also being understan--ded.2. The stress monitoring tests in Houhu bridge is introduced and the test data is analysed in this paper.The results of the analysis initially reflected the mechanical performance of the tower column in the construction stage. Then, the interaction between steel and concrete will not be considered, steel and concrete will be as a combination of materials to create a ANSYS finite element model with methods of sharing nodes.The finite element static analysis about the mechanical properties of the CFST tower in different conditions in construction stage is done.3. Considering the interaction between steel and concrete, ANSYS finite element contact analysis about the CFST tower is done. Based on the principle of contact analysis,according to the two different materials of steel and concrete, the right contact approach, the appropriate units ,the corresponding real constant ,the constituti--ve relations as well as the KEYOPTS are selected. Then,the interaction between steel and concrete of the CFST tower is analysed with the methods of ANSYS contact analysis. The contact analysis method used in this paper is of fastly convergence and the results are in accordance with the results of the stress monitoring test.