The Analysis Of Seismic Performance And Shear Bearing Capacity On Circular Steel Tube Composite Column Filled With Steel Reinforced Concrete

Circular steel tube composite column filled with steel reinforced concrete is a new type of load bearing structure, which have a better seismic behavior. Based on the CFT (Concrete Filled Steel Tube) composite column, it is made up of steel tube and angle bar. Angle bar can obviously improve the ultimate bearing capacity and ductility of column according to theoretical analysis and test verification. At present, the home research to this theory is at an early stage, therefore, it is necessary to make more researches on its characteristics. Circular steel tube composite column filled with steel reinforced concrete has the advantage of reinforced concrete column and concrete filled steel tube composite column and integrates them in a systematic way. It also can reduce the section area, optimize the degree of ductility and ultimate bearing capacity of column, improve the limit value of the axial compressive ratio and the seismic behavior of composite column effectively Based on Experimental investigations, models are analyzed with the ABAQUS, and study the the deformation ability and ultimate bearing capacity by taking axial compression ratio and steel ratio consideration. It offered theoretical basis for further study and application on it.In aspect of seismic performance, based on the results of ABAQUS simulation, we draw the following conclusions, the looping curves and the skeleton curves under different axial compression ratios and different steel ratios. We draw the following results that the columns has a perfect bearing capacity by analyzed and compared stability bearing capacity under the different axial compression ratios and different steel ratios and the destructional forms is flexural failure; the looping curves is very stable even under the unfavorable conditions and show that the looping curves of the columns are perfect, no obvious draw shrinkage and the outline of looping curves is very smooth. We also draw the conclusions that steel ratio is a key factor to the component bearing capacity, the bearing capacity of columns have a obvious improved with the increase of steel ratio; In addition, the axial compression ratio is one of the key factor to the skeleton curves and ductility components. Numerous studies show that with the improving of the axial compression ratio the skeleton curves have a more obvious decline and the corresponding component ductility become worse, axial compression ratio is the main negative factors to seismic performance of columns.In aspect of the shear bearing capacity, some of the existing common reinforced concrete shear bending test shows, because of pressure, bending and shear effect, the reinforced concrete members whose shear span ratio is greater than 2 often appears adhesion failure along the longitudinal reinforcement then the protective layer of concrete spalling and bearing ability drops quickly. While the concrete filled steel tube have no concrete spalling. Finally columns are pulled and then destruction. It belongs to the flexural failure and appears good ductility[3]. Steel tube composite column filled with steel reinforced concrete and concrete filled steel tube structure have a lot of similarities in mechanical properties. So we only study the short column whose shear span ratio is less than 2 and study the columns by changing the steel ratio shear span ratio, axial compression ratio, confining index. At present,the home research to this theory is at a early stage, therefore, it is necessary to make more researches on its characteristics. So that it can be better applied to the project practice.