Shear Behavior Of Square Concrete Filled CFRP-Steel Tube(S-CF-CFRP-ST)

CFRP(Carbon Fiber Reinforced Polymer)is widely used in engineering examples due to its light weight,high strength and corrosion resistance.CFRP-steel tube concrete refers to a member formed by pouring concrete in a CFRP-steel pipe composite pipe,and also refers to a composite member formed by repairing or reinforcing damaged existing concrete with CFRP.CFRP-steel tube concrete combines the advantages of CFST and FRP pipe concrete,but its theoretical analysis is still in its infancy.In order to study the shear static performance of CFRP-steel tube concrete,this paper is divided into two parts:theoretical research and experimental research.Firstly,based on the test,the ABAQUS software is used to simulate the test according to the loading method.The force of each composite material was studied.In this paper,12 square CFRP-steel tube concrete members are tested.The test results are as follows:(1)In the early stage of test loading,the test piece has no obvious deformation.When loading to 70%of the peak load,the deformation of the test piece becomes more and more obvious.When loading to the peak load,the upper surface steel pipe of the test piece is cut,the test piece is destroyed and destroyed.The shear displacement is small and is brittle.(2)With the increase of concrete compressive strength,the bearing capacity of the test piece and the stiffness of the test piece in the elastic stage are significantly improved.The change of the lateral CFRP layer has little effect on the bearing capacity of the test piece and the stiffness of the elastic stage.(3)By comparing the simulation curve with the test curve and the deformation mode,it is found that the simulation results agree well with the test results,which proves the validity of the simulation.Based on the effective model,the parameters of concrete cubic compressive strength,steel yield strength,steel yield and transverse CFRP are simulated.The results show that with the increase of fcu,fy and a,the bearing capacity of the member is also with the improvement,the effect of the stiffness increase in the elastic stage is not significant,but with the increase of the compressive strength of the fcu concrete cube,the bearing capacity of the member and the stiffness of the elastic stage are greatly improved.(4)Combining the results of this test and simulation,and Han Linhai's definition of the shear capacity of concrete-filled steel tube,the shear capacity of the CFRP-steel tube member is defined as the corresponding shear strain of the medium section is 15000??.Shear force,based on the simulation results and parameter analysis results,fit the CFRP-shear bearing capacity calculation formula.The research results of shear static performance of square CFRP-steel tube concrete provide a basis for the research and analysis of subsequent shear hysteresis performance.