单箱双室组合箱梁剪力滞效应分析
Analysis of Shear Lag Effect of Single box Twin-cell Composite Box Girder

通过对组合箱梁底板、混凝土顶板与悬臂翼板引入不同的剪滞翘曲位移函数，利用能量变分法推导出考虑界面相对滑移、钢腹板剪切变形和剪力滞效应的微分方程及均布荷载作用下的解析解。以带有悬臂翼板的单箱双室组合箱梁为例，运用提出的解析法对其剪力滞效应进行分析，并与ANSYS有限元结果对比。结果表明：提出的解析法所得结果与ANSYS空间有限元计算结果吻合良好；界面滑移量和挠度随着滑移刚度的增大而增加，而剪力滞效应则无较明显的变化，因此在一定条件下可忽略滑移刚度对剪力滞效应的影响；混凝土顶板应力随着滑移刚度的增大而增大，且中腹板部位处顶板的剪力滞效应较边腹板部位处大，而钢箱梁底板则与之相反。
The different shear warping displacement functions were introduced into the composite box girder plate, the concrete roof and the cantilever plate. The differential equations were deduced by energy variational method for the shear lag effect, the relative slip of the interface and the shear deformation of the steel web. A closed-form solution for the case of uniform loading was derived. Taking the single？？box double？？cell composite box girder with cantilever wing as an example, the shear lag effect was analyzed by using the proposed analytical method and compared with the finite element numerical solution analyzed by the software of ANSYS. The results show that the results obtained by the analytical method are in good agreement with the finite element calculation results of ANSYS. With the increase of the sliding stiffness, the interface slip and the deflection increase, while the shear lag effect has no obvious change.Therefore, the influence of the sliding stiffness on the shear lag effect can be neglected under certain conditions. The stress of the concrete roof increases with the increase of the sliding stiffness, and the shear lag effect of the roof in the middle web part is larger than the edge web part, while the steel box girder floor is opposite