Analysis Of Shear Deflection Of Flat Steel Box Girder Of Cable-Stayed Bridge

In this study,the theories of differential equation method, unit load method based on virtual work principle, generalized coordinate method and finite element method are expounded respectively,and then the flexibility equation of the beam considering the shear deflection is deduced.Shear deflection coefficients are used to express the influence degree of the shear deflection to the totle deflection of the beam.But when the shape of the across section is too complicated,it is anble to get the material numerical value of the shear deflection by analytical method. This study adopts the general finite element software ANSYS as the tool, in the context of abuilding Sutong bridge, considers three different cases to calculate and analyse the girder.This paper adopts two different models BEAM44 and SHELL63 to calculate the vertical deflection of some girder, and compares the two deflections to get the shear deflection coefficient. BEAM44 does not take into account of the shear deflection and SHELL63 does.The conclusion is that the influence of the shear deflection of the flat steel box girder is not ignored. And provide a feasible method to calculate the shear deflection of the complicated sections.Different types of longitudinal clapboards have different influence on the shear deflection. Also adopts the general finite element software ANSYS as the tool, in the context of abuilding Sutong bridge, considers three different cases to calculate and analyse the girder and analyse the deflection of two kinds of different girders, that is solid longitudinal clapboard girder and truss longitudinal clapboard girder.Get the shear deflection coefficient and compare them.Educe the ultimateness finally.The same case and the same position,the deflections and the shear deflection coefficient of the solid longitudinal clapboard girder are both smaller than the truss longitudinal clapboard girder.That is the solid longitudinal clapboard can minish the deflection of the girder better,and it can reduce the influence degree of the shear deflection. And enhance the shear stiffness.Make the solid longitudinal clapboard girder simply support, and make the dimension of the cross section and the interrelated parameters unchangeable. Analyse the deflections of the girds with different span. The conclusion is that as the span of the gird becoms larger, the the influence degree of the shear deflection becomes smaller. When the span of the steel box girder is large enough,the influence of the shear deflection can be ignored.