Study On Mechanical Behavior And Finite Element Analysis For Joints Between Steel Beam And Steel Reinforced Concrete Columns

Steel Reinforced Concrete(SRC) is more and more applied in the field of high-rise buildings and skyscrapers structure,but now the research is not depth about it,and it can't be regulated to use,especially,we have the lack of the research to the structure with steel beam and SRC columns, these reasons are not conducive to the use of the structures in large span structures,therefore,it is required for us to further understand and analysis about it. This article uses the ANSYS finite element software to study on nonlinear mechanical behavior and analysis for joints between steel beam and SRC columns.After selected unit types and various parameters,separate-finite element model is adopted in this paper.According to the research ,6 specimens were established and carried out nonlinear analysis.By calculating ,all the results were convergence,the joints occurred shear failure and the stress cloud charts were obtained.The stress situation of steel webs and core concrete are respectively discussed when the webs are yield and the joints are destroyed.The failure process of the joints and the stress mechanism are illuminated in detail.In order to learn more the mechanical characteristics of the SRC joints,the influnce of flange frame,the stirrup in the core of the joins, concrete strength grade and different thickness of concrete cover to the mechanical properties of joints are analysised.By analyzing,these conclusion are obtained:the bearing capacity and the shear capacity of joints are improved with the increase of concrete level;Before the joints yield,concrete is the main component of resisting shear in the core area,but reached the ultimate stage, steel web is the main component of resisting shear in the core area;Moderate stirrup which is allocated in joins is good for improving the deformation ability of the joins and enhancing the coordination between steel and concrete .The flange frame can well bound the concrete in the core area,which constitute the stress system of"Steel Frame-Shear Wall",therefore, the bearing capacity and the ductility of joints can be improved.In the axial-load ratio for 0,0.25,0.4,0.55,the model SRCN-4 is analyzed.The results show that axial-load ratio has a good effect on crack loading and ultimate loading.In order to considering the influnce of bond-slip between steel and concrete to the mechanical behavior of joints,double spring element is used between the steel and concrete in the model SRCN-1 and SRCN-4.After considering the bond-slip,the stiffness of the joints has been reduced, the ductility has been improved,the yield loading and the ultimate loading have been decreased,but both the yield displacement and the ultimate displacement have been increased.