Buckling Of Web Restrained By Flanges In Steel-concrete Composite Girder Under Bending–The Experimental Research

The steel-concrete composite girder bridge not only has the advances of good mechanical properties, good seismic performance, light weight, convenient for construction, large span is another significant advantage of the steel-concrete composite girder bridge. When in the great demand of the span of bridge, steelconcrete composite girder bridge is a priority of the bridge shape. With the increase of the span of the steel-concrete composite girder bridge, the height of the web of the steel-concrete composite girder bridge increases, the depth-span ratio of the steel-concrete composite girder bridge girder is 1/20~1/25. While the web height of the steel-concrete composite girder bridge increases, which give the new challenges to the design of the steel-concrete composite girder bridge, the design code of china can’t fulfill the web design at present.In the steel-concrete composite girder bridge, the stability problem of high web is ultimately a matter of the stability of the plate. Ensure the boundary conditions of the plate is the key to the stability analysis of the plate, the stability theory supposed that the boundary condition of webs were simplied or clamped supported. The concrete deck and steel girder was connect each other with the shear stubs. The concrete deck, shear stubs, steel flanges restrained the web boundary rotationally, the boundary of steel flanges and web has obvious rotationally restrained property, the actual boundary is between simplied and clamped boundary. The research group I belong to considering the rotational restraint of concrete deck, shear studs, steel flanges, an effective buckling theory model of high web based on the elastic rotational restraint boundary in long-span steel-concrete composite bridge was obtained, and started the experimental research of buckling of web restrained by flanges in steel-concrete composite girder under shearing, verified the applicability and accuracy of the buckling theory model under shear load. Based on above research, the test completed the experimental research of buckling of web restrained by flanges in steel-concrete composite girder under bending, the mainly completed work is as follows:(1) Analysis of the present situation of research on plate stability at home and abroad. Through checking a large number of literature, give a deeply understanding of the present situation of research on plate stability at home and abroad, analysis of shortcomings in existing research, show the importance of starting the experimental research of buckling of web restrained by flanges in steel-concrete composite girder under bending. Based on above research, aiming at these problems give primary coverage and the key scientific problems of this test.(2) Introduce the analysis theory of bending buckling of web restrained by flanges in steel-concrete composite girder. Introduce buckling theory model of high web based on the elastic rotational restraint boundary in long-span steel-concrete composite bridge detaily, considering the rotational restraint of concrete deck, shear studs, steel flanges, laying the theoretical foundation for further experimental study.(3)The finite element numerical analysis of bending buckling of web restrained by flanges in steel-concrete composite girder. With the finite element numerical analysis method, modeling the girder with ANSYS, analysis the buckling of the finite element model under two-central load. Obtained displacement of mid span, plane displacement, stress distribution, the buckling results of finite element mode. By comparing the results of finite element and theoretical analysis, verified the applicability and accuracy of the buckling theory model.(4) The experimental research of buckling of web restrained by flanges in steel-concrete composite girder under bending. By means of research, started the experimental research of buckling of web restrained by flanges in steel-concrete composite girder under bending. By comparing the results of research and theoretical analysis, verified the applicability and accuracy of the buckling theory model. Research on the influence of the shear studs arrangement on χ and critical buckling stress, obtained bending buckling results of the steel-concrete composite girder with different shear studs arrangement.