波形钢腹板PC组合箱梁剪力滞效应的变分解法

Variational Method for Shear Lag Effect of PC Composite Box Girder with Corrugated Steel Webs

为分析波形钢腹板PC组合箱梁的剪滞剪切变形效应,提出选取广义位移φ(x)、w′(x)、u_1(x)、u_2(x)、u_3(x)作为5个独立的变量,采用反映底板、顶板和悬臂板不同宽度的剪滞变化幅度的多次抛物线作为纵向翘曲位移差函数,运用能量变分原理导出了基于多广义位移的基本微分方程及相应的边界条件,并得到相应的解析解.通过有限元法和模型试验验证了本文方法的正确性,得到的公式比以往剪力滞理论更具有一般性,为波形钢腹板PC组合箱梁剪力滞效应的分析提供有效手段和方法.

A new analysis method based on energy-variational principle is proposed to analyse the shear lag effect and shear deformation of PC compositebox girder with corrugated steel webs.The generalized displacementsφ（x）,w′（x）,u1（x）,u2（x）,u3（x）as five independent variables are proposed and high-order parabolas longitudinal warping displacement function,which reflects the law of the variation range of shear lag at different lengths of the bottom plate,the top plate and the cantilever plate,is also introduced.According to energy-variational principle,the basic differential equation based on the multi generalized displacements and the corresponding boundary conditions are introduced,and obtaining the corresponding analytical solution.The correctness of the method is verified by the finite element method and the model test,and the formula is more general than that of the previous shear lag theory.The result would have provided effective means and methods for the analysis on the shear lag effect of PC composite box girder with corrugated steel webs.