Ways To Improve The Flexural Performance Of Steel-Concrete Composite Beams Experimental Research

Steel-concrete composite beams can give full play to the material performance advantages,and have the advantages of strong bearing capacity,small section height,and light weight.They are widely used in actual projects.The development of society has a higher demand for the bearing performance of steel-concrete composite beams.In this paper,the steel and concrete in the steel-concrete composite beam are used as the variable parameters to explore the influence of different materials on the bending performance of the steel-concrete composite beam.The method of combining experimental research and theoretical analysis is adopted.The following work is mainly carried out and obtained Draw relevant conclusions:(1)The force analysis of the steel-concrete composite beam is carried out,and the cross-section conversion algorithm,the cross-section conversion algorithm considering the relative slip,the reduced stiffness method and the limit equilibrium method are analyzed,deduced and summarized.Taking strain failure as the criterion,the calculation methods of steel-concrete composite beams under each failure mode are analyzed,and the design methods of steel-concrete composite beams are summarized.(2)Through the steel tensile test,the tensile constitutive relationship of Q355 steel and T700 steel was explored,and the C50,C75,C100 concrete and C50 concrete used in the test were obtained through the axial compression and split tensile tests of concrete cubes.Based on concrete,the axial compressive strength and splitting tensile strength of concrete cubes with volume additions of 0.5%,1.0%,and 1.5% respectively.Designed and produced 9 groups of steel-concrete composite beams.Q355 steel and C50 concrete,C50 corresponding to the volume of 0.5%,1.0%,1.5% steel fiber concrete,C75,C100 concrete combination to make 6 beams,T700 steel and C50,C75,C100 concrete combination,production 3 beams.(3)Through the processing and analysis of the test data,the analysis shows that with the increase of the steel fiber content in the concrete flange plate of the steel-concrete composite beam,the mid-span deflection corresponding to the ultimate load increases significantly,which is mainly represented by steel-improving the ductility of concrete composite beams;enhancing the strength of concrete and increasing the yield strength of steel can enhance the ultimate load-bearing capacity of steel-concrete composite beams,and enhancing the strength of concrete improves the flexural rigidity of the elastic stage,thereby increasing the ultimate load-bearing capacity and The steel yield strength will extend the elastic stage of the steel-concrete composite beam,thereby increasing the bearing capacity and the corresponding deflection of the ultimate load;the effect of increasing the concrete strength on the ultimate bearing capacity of the composite beam will weaken with the increase of the steel yield strength;The steel-concrete composite beam satisfies the assumption of a flat section in the elastic stage,and the section transformation algorithm can be used to predict the section strain.The deflection obtained in the test is close to the calculation result of the reduced stiffness method in the elastic stage,and the ultimate bearing capacity is close to the calculation result of the limit equilibrium method.(4)Summarized the constitutive relationship of steel fiber concrete and highperformance concrete for tensile and compression resistance,the constitutive relationship of studs,and simulated 9 groups of steel-concrete composite beams using ANSYS software,the simulation results and the test results It is more consistent,the finite element simulation method can be used to calculate and analyze the variable parameters of the steel-concrete composite beam.