Compressive Behavior Analysis Of Circular Tube Confined Steel Reinforced Short Columns With High-strength Concrete

As the demand of higher bearing capacity and smaller cross-section size for load-bearing structures growing in engineering field,the steel-concrete composite structure has been widely used by engineers.In this paper,the experimental and finite element was studied on the compressive mechanical properties of circular tube confined steel reinforced short columns,including 12 stub columns under concentric loading and 3 columns under eccentric loading in this investigation.According to the analysis of finite element,the formulas of bearing capacity was put forward on circular tube confined steel reinforced short columns under concentric and eccentric loading.The specific research content as follows:1.Twelve circular tube confined steel reinforced short columns with high-strength concrete under axial compression were tested.The main variable parameters for test includes: tube tensile strength,radius-thickness ratio,concrete strength,the shape of steel.According to the test results,load-longitudinal displacement curves and load-strain curves were obtained,and the failure mode and compressive behavior of concentric columns were studied.The effects of parameter variables on the bearing capacity and ductility of the specimens were analyzed emphatically.2.Three circular tube confined steel reinforced short columns with high-strength concrete under eccentric loading were tested at the variation of radius-thickness ratio.According to the test results,load-span deflection curves and load-strain curves of steel tube were obtained,and the failure mode and mechanical mechanism were studied.The bearing capacity and ductility of specimens under eccentric loading were analyzed systematically and compared with the corresponding axial compression specimens.3.The finite element model(FEM)for CTSRC was established by ABAQUS.On the basis of good agreement between the finite element results and the test results,the compressive specimens were analyzed in the whole process of stress.The axial compression bearing capacity of CTSRC was studied at the variation of tube tensile strength,radius-thickness ratio,concrete strength,the shape of steel by finite element model.According to the results of study,the axial compression bearing capacity formula of CTSTC was put forward.Compare with the experimental results,this formula is more accurate and stable than previous formulas.4.The bearing capacity of CTSRC under eccentric loading was studied by using the finite element model,which was controlled by eccentricity,concrete strength,steel tube strength and radius-thickness ratio.According to the results of the study and eccentric bearing capacity formula of SRC,the bearing capacity calculated method of CTSRC under eccentric loading was put forward.According to the formula,the N-M curves was obtained.The results were in good agreement with finite element results and experimental results,and the calculated results have certain safety guarantee coefficient.