Analysis On Seismic Performance Of Space Joint Of Steel Tubular Columns Filled With Steel-Reinforced Concrete

As a new type of composite structure with good ductility and high bearing capacity,steel tubular columns filled with steel-reinforced concrete combines the advantages of concrete filled steel tubular columns and steel reinforced concrete columns.The core concrete is in three-dimensional confining pressure state,which effectively restrained the lateral deformation and provides space for application of high strength concrete;as the important anti-seismic line,steel tube and steel has improved the bearing capacity and energy dissipation capacity of the columns at the same time.The advantages of steel tubular columns filled with steel-reinforced concrete make it has a broad prospects for development in super high-rise and large span structure.As the transmission of structural system,joints have a complex function of bearing shear force,bending moment and axial force,which has an important influence on bearing capacity and stability of the whole building.A large number of earthquake disasters show that the failure of joints is much larger than expected,and there is a big difference from test results of planar joint.This is mainly caused by earthquake action and structure response.At present,the research on space joint of steel tubular columns filled with steel-reinforced concrete is relatively less,which hinders its application and popularization in engineering.Based on the above situation,the analysis on seismic performance of this new spatial composite joints has an important reference value for further theoretical research and engineering application.In this paper,the finite element software ABAQUS is used to study the mechanical properties and deformation properties of space joint.The main contents and achievements of the research as follows:(1)In accordance with the terms of real component,boundary and loading conditions,this paper first established the model of steel tubular columns filled with steel-reinforced concrete in ABAQUS to analysis mechanism and characteristics of joints for the simulation of entire process characteristics on a computer.The beam-column combination of the anti bending point takes into account back stress of steel,singer effect of the package and damage factor about concrete.(2)The paper explored spatial coupling effect through planar joint,border joint,corner connection,interior joint and analyzed performance of different bidirectional loading ratio on interior joints.The author has a analysis of the joint through stress nephogram and to carry on the discussion about load displacement curve,skeleton curve,ductility,strength degradation,stiffness degradation and energy dissipation capacity,etc.The results show that the spatial joints have a coupling effect under the bidirectional displacement load,and the stress mechanism of the planar joints is different.The planar joint test results can not appropriate reflect the stress and deformation.(3)Based on the above interior joints,this paper analyses the influence of steel,axial pressure ratio,strength grade of different materials,beam web thickness and floor participation by finite element simulation software.The author comprehensive evaluation the performance of interior joint of steel tubular columns filled with steel-reinforced concrete in the last.