Study On The Mechanical Behavior Of Steel Tube Columns Filled With Unsymmetrical I-Steel Reinforced Concrete

With the development of building structure towards heavy load,high-rise and long-span,the load of load-bearing columns is getting higher and higher,so people begin to study new steel-concrete composite members.In recent years,due to the good ductility and high bearing capacity of steel-reinforced concrete-filled steel tubular composite columns,people pay more attention to the research of this kind of composite columns,but most of them focus on symmetrical steel distribution.In engineering,because of the influence of the layout and environment of the building,the load-bearing columns are often not uniformly loaded.Considering the special situation of load-bearing columns arranged on side columns,The method of changing the position of the inner steel and the style of the inner steel is adopted.The steel-reinforced concrete-filled steel tubular composite columns with built-in displaced I-steel and I-steel with changed flange are proposed.So that the components can bear high loads at the same time,but also meet the needs of the structure,improve the utilization rate of materials,reduce engineering costs.In this paper,the finite element software ANSYS is used to simulate the mechanical behavior of asymmetric steel reinforced concrete-filled steel tubular composite columns.The main work is as follows:(1)On the basis of the test and Simulation Analysis on the mechanical behavior of steel-concrete composite columns by predecessors,and combined with the characteristics of asymmetric I-shaped steel-reinforced concrete composite columns,with appropriate material parameters,contact model and constitutive relationship,four simulation analysis models of asymmetric I-steel reinforced concrete filled steel tubular composite columns are established.(2)ANSYS simulation was carried out on the axial compression behavior of four types of asymmetric I-shaped steel reinforced concrete composite short columns.The stress mechanism and bending failure characteristics of short column members are analyzed,and the factors affecting their mechanical properties are studied,the results of finite element analysis provide a basis for fitting the bearing capacity formula of short column members.(3)ANSYS simulation is carried out on the axial compressive behavior of four types of asymmetric I-shaped steel-reinforced concrete-filled steel tubular composite columns.The mechanical mechanism and bending failure characteristics of long column members are analyzed,the factors affecting their mechanical properties are studied,andthe influence of slenderness ratio on the force of long column members is discussed,the results of finite element analysis provide a basis for fitting the bearing capacity formula of long column members.(4)The ANSYS simulation of the mechanical behavior of four types of asymmetric I-shaped steel-reinforced concrete-filled steel tubular composite columns under eccentric compression is carried out.The mechanical mechanism and bending failure characteristics of long column members are analyzed,the factors affecting their mechanical properties are studied,and the scientific and reasonable layout of members is put forward.the results of finite element analysis provide a basis for fitting the bearing capacity formula of eccentrically loaded columns.(5)On the basis of the formulas of bearing capacity of steel-concrete composite columns studied by predecessors,the formulas for calculating the axial bearing capacity of short columns of asymmetric I-steel reinforced concrete filled steel tubular composite columns,long columns of asymmetric I-steel reinforced concrete filled steel tubular composite columns and eccentric bearing capacity of asymmetric I-steel tubular composite columns are obtained.and using the results of the above finite element analysis,the formulas are compared with the simulated values of ANSYS finite element analysis,and the results are in good agreement.