根据薄壁曲线梁理论和势能变分原理,针对悬臂板、顶板和底板假设3个不同的剪力滞翘曲位移函数,导出薄壁曲线箱梁在弯、扭、剪力滞耦合时的曲线箱梁几何非线性控制微分方程。由样条配点法得到残值方程组,再采用同伦延拓法进行求解,得到结构在荷载作用下的半解析解。计算表明:剪力滞效应对翼缘板宽度的变化较敏感,而受翼缘板厚度的影响很小;当翼缘板各部分宽度不同时,要合理可靠地分析结构的受力状态,应对翼缘板的悬臂板、顶板和底板分别取不同的剪力滞翘曲位移函数进行计算。几何非线性对曲线箱梁内力、位移的影响程度取决于荷载的数值,对于三跨等跨连续曲线箱梁,当q,5/(Ehw^2)〉1.0×10^-3时,应考虑结构的几何非线性效应。
According to thin-walled curved box theories and potential various principles, three different shear lag functions to cantilever, top and bottom plates are assumed, the nonlinear governing equation of thin-walled curved box girders in considering moment, torsion, shear lag coupling is deduced. The residual equation group is obtained by spline allocation point method, which is solved with homotopy algorithms. The half analytic solution of structure in the action of loads is obtained. It is shown from the calculation that the shear lag effect has more sensitivity for the change of the flange width and little influence by the flange thickness. If the width of each part in flanges is different, the calculation should be made by taking into account different shear lag functions to the cantilever, top and bottom plate of flanges for the propose of analyzing the force behavior of structure reasonably and reliably. The influence degree of the geometric nonlinearity on the internal force and displacement of curved box girders depends on the number of the load. When qzs2〉 (Ehw^2) 2〉1. 0× 10^-3, the geometric nonlinear effect of the structure should be considered for three-span continuous curved box girders.