Experimental Study And Simulated Analysis Of Stainless Steel-concrete-carbon Steel Composite Beams Under Bending Load

As a new form of composite structure,traditional CFDST members have many advantages,such as high bearing capacity,good plasticity and toughness,constructing convenience,good fire res istance,good economic effects,unfolding cross-section,high flexural stiffness,light weight and good seismic performance.So the application of this structure form is very broad in the field of engineering.But the poor resistance to corrosion of this structure form also greatly limits its application.Stainless steel not only has high strength,good plastic ity and toughness,but also has good corrosion resistance at the same time.As stainless steel is expensive,so this also determines that it cannot be used in large quantities in the project.Changing the outsourcing steel pipe of traditional CFDST members to stainless steel,so the new component has all the advantages of both traditional CFDST members and stainless steel at the same time,all of these make it possible to use stainless steel-concrete-carbon steel composite structures in real project.In this paper,the flexural performance of stainless steel-concrete-carbon steel composite beams is experimentally and theoretically investigated.The completed works are summarized as follows:(1)Firstly,the studies related to this thesis,includ ing the mechanical properties of traditional CFDST members and concrete filled stainless steel tube members,are reviewed,the main studies of this thesis are clarified as well.(2)To investigate the effect of hollow ratio and shear span ratio on the flexural performance of stainless steel-concrete-carbon steel composite beams,a total of 18 specimens are tested.The failure patterns and patterns load versus deformation curves of specimens are received.(3)Based on the determination of reasonable constitutive models of stainless steel,concrete and carbon steel,by using finite element software ABAQUS,the finite element analysis model is developed for the simulation of flexural members.By comparison,the simulated failure patterns,load versus deformation curves and bearing capacities agree well with the experimental results.Therefore,the method of finite element modeling can be used to make a deep analys is on the other factors affecting the flexural performance of specimens.(4)Firstly,by choosing the typical specimen,its working mechanism under bending load is studied using the FEA model.Secondly,by using the method of finite element modeling,the influences of restriction effect coefficient,type of stainless steel,hollow ratio,shear span ratio,thickness of inner steel tube and strength grade of inner steel tube on the load versus deformation curves and ultimate bending moment of specimens.Lastly,using the method of finite element modeling,the difference in bending mechanical properties between stainless steel-concrete-carbon steel composite beams and traditional CFDST beams has been studied by comparison and analysis.