Experimental Study On Axial Compressive Behavior Of Spatial Steel Frame Concrete Short Columns Embedded Circular Steel Tube

In order to pursue the large space,the modern high-rise buildings no longer use the "fat column" with large section area,but choose the steel-concrete composite column with better bearing capacity and ductility.On the basis of circular steel tube compile column filled with steel reinforced concrete,a new steel and concrete composite column is proposed in this paper,which is spatial steel frame concrete short columns embedded circular steel tube.This paper uses the method of experimental research to analyze the whole process,failure mode,load-deformation curve and bearing capacity of the new structure.In this paper,theoretical analysis and numerical calculation are used to analyze the parametric performance of the composite column.In this paper,experimental study on axial compressive behavior of 5 spatial steel frame concrete tube short columns embedded circular steel and a spatial steel frame concrete column is carried out.The whole process,failure characteristics,axial bearing capacity,ductility,stress,strain and other stress performance indexes are analyzed,and the influence of parameter variation on structural bearing capacity is analyzed.The test results show that the ultimate bearing capacity of the specimens can be improved by the embedded circular steel tube in the concrete column of space steel frame.Increasing the length of the angle steel and reducing the spacing of strips can improve the ductility of the composite column and improve the bearing capacity of the short column.In this paper,ABAQUS is used to simulate axial compressive behavior of spatial steel frame concrete short columns embedded circular steel tube.On the basis of the validation of the finite element model,19 specimens are designed for finite element simulation with the length of the angle steel,the spacing of strips,the width of the strip,the hoop coefficient of the circular steel tube,the strength of concrete and different steel forms as the parameters.The results show that,with the increase of the length of the angle steel,the bearing capacity of the composite column is not unrestricted,and the outer angle steel has a certain extent to the concrete constraint.Reducing the spacing and increasing the width of the strip can improve the bearing capacity and ductility of the composite column.In combination with the actual situation of the project,proper encryption of the top and bottom of the column can prevent the premature failure of the column.Finally,the relationship between the comprehensive influence coefficient and the axial bearing capacity is proposed.In this paper,considering the constraint of the spatial steel frame on the outer concrete and steel tube to core concrete constraints,the influence of the concrete outside the steel tube on the core concrete in the steel tube is also considered.The mechanism of this new structure is analyzed and the calculation formula of bearing capacity is put forward.