Research On The Shear Lag Effect Of Beams Of Cable-Stayed Bridges With Usual Cross Sections

This thesis studies shear lag effect on three representative forms of cable-stayed bridge cross sections by different theoretical methods. The work in this thesis mainly includes following parts:1.As for box girder cross section, the three-bar stimulation method under typical loads and supports has been introduced. The force and stress formulae for flanges have been derived from the three-bar method. By reasonable simplification for multi-cell box girder, the three-bar method has been applied in multi-cell box girder's shear lag analysis.2. As for side box girder, the elastic theoretical solution has been introduced. The method is based on stress function and regards side box girder as combine of plate element and shell element. Then the force and stress formulae for flanges have been derived.3. As for side web girder, the principle of minimum potential energy has been introduced. By assuming different displacement function, the force and stress formulae for flanges under uniform loading, horizontal axial force, or vertical concentrated force have been derived.4. This thesis uses finite element method, and by selecting 3-dimension eight nodes element, and takes advantage of ANSYS to stimulate the different main girders to verify the accuracy of theoretical methods above.Furthermore, combining with the experiment of Yibin Zhongba Jinshajiang cable-stayed bridge concrete model, this thesis using finite element method studies shear lag effect of the cable-stayed bridge with n cross section and offers suggestion to the project.