Influence Of Steel Beam-to-core Tube Connection Stiffness On Concrete Filled Steel -concrete Hybrid Structure Seismic Performance

Steel-concrete hybrid structures are widely used in tall buildings which has become a trend of China’s urban construction at present. The seismic performance of steel-concrete hybrid structures is concerned. In order to study the impact of the seismic performance of steel beam and concrete shear wall connection type on steel-concrete hybrid structure, this paper has designed a theoretical analysis model by an actual project example of concrete filled steel tubular frame-concrete core tube hybrid structure(HS) with the current norms simplified. The model uses different types of steel beam and concrete shear wall connection stiffness. Time history analysis was performed by finite element software SAP2000, to obtain the seismic performance of this kind of structure, and the factors that affect the seismic performance. Main research work and achievements are summarized as follows.1. HS-R model was established by finite element software SAP2000, the model which is suitable to be used in modal analysis extracted dynamic characteristics and time history, comparing with the results of literature to verify the feasibility of the SAP2000 modeling. To change the type of steel beam and concrete shear wall connection using pined connection, semi-rigid and rigid, while semi-rigid structure to take a different structure relative stiffness, were established model HS-P, HS-SR1, HS-SR5, HS-SR10, HS-SR15, HS-SR20, HS-R, then these models are suitable for elastic-dynamic time history analysis. The results show that the connection type of change has little effect on the overall structure of the seismic performance, using rigid connected and semi-steel then be able to reduce the height of the steel girder section, improve space utilization, and can also save steel, has a better economic applicability.2. Establishing the HS-P. HS-SR1, HS-SR5, HS-SR10, HS-SR15, HS-SR20, HS-R structure elastoplastic analysis model, then these models are suitable for time history analysis under rare earthquake. The maximum story displacement of structure, the maximum story drift angle, the internal forces of steel beams, the internal forces of the outer frame column and the bottom shear force distribution of the structure, were analyzed. The failure mechanism of these three types of structures was also analyzed. The research response is that the HS-SR structure, in the deformation of the member forces, between the HS-P and the HS-R structure. Seismic aspects, frame column of the HS-SR structure can not only assume the level of force will but also not brittle failure by assuming too large a horizontal force, the outer frame of the HS-SR structure as the seismic fortification lines with a safety reserve.3. In this paper, the impact factors of the seismic performance of steel beam and concrete shear wall semi-rigid connection of the HS-SR structure were analyzed, the main analyzed factors are the intensity of earthquakes, the stiffness characteristic values as well as the shear wall thickness. The research demonstrated that the HS frame-concrete core tube hybrid structure has excellent ductility, the stiffness characteristics value of the structure has little effect on its seismic performance. But the shear wall thickness impacts significantly, which should be controlled in a reasonable range.