Experimental Investigation Of Bending Behavior For Steel And High Performance Concrete Composite Girders With Concrete Filled Rectangular Tubular Up-flanges

Based on the problem of applying popular steel-concrete composite structure and steel tube with concrete filled structure to beam structures,such as causing longitudinal slip in composite beam structure and increasing the dead load of concrete in the tensile zone of beam in concrete filled structure,this paper presents two new kind of structure,i.e.concrete filled rectangular tubular up-flanges composite girders(CFRTFCG),and concrete filled rectangular tubular up-flanges and corrugate steel web composite girders(CFRTFCWCG).The enhancement in structural properties is due to the composite action between the steel plates of box and concrete.The inward buckling of the steel plates of the box is prevented by the concrete,thus increasing the local buckling strength of the structure,and more sufficient use of the strength of steel.Conversely,the confinement created by the steel plates of box enhances the material properties of concrete by putting the concrete under a tri-axial state. Besides,they have excellent properties such as high capacity,high rigidity,high ductility and convenient construction as tradition composite beam of steel and concrete.The main contents are listed as follows:1.Two specimens were tested to evaluate their bending capacity.The experimental research of the structure behavior of CFRTFCG and CFRTFCWCG are conducted.The phenomena observed during the tests of specimens are deseribed in detail,and the deflection of beams and the data of strain of steel during tests are recorded,and analyse are done.2.On the basis of finite element theory,the models of specimens are set up by ANSYS. Compared with the experimental and finite elemental result,the bending parameters were analyzed and the impaction of inner concrete in tube,the yielding strength of stress,the steel ratio of upper flange to bending behavior were analyzed.3.The theatrical analyze about the behavior of CFRTFCG and CFRTFCWCG were conducted according to the results of finite element and experiment.Then the simplified bending formula was supplied and it can be illustrated that the calculation is in good accordance with the test.4.Through the experiment and numerical analyze of the bending capacity of CFRTFCG and CFRTFCWCG,the characters of bending failure were attained.On the basis of the results from experiment and finite element,the provisions concerning the design of such innovative composite girder were proposed.