等截面箱形梁剪力滞效应的变分解法

Variational Method for the Shear Lag Effect in Constant Section Thin Walled Box Girder

以往的能量变分法解薄壁箱梁的剪力滞问题时,认为箱梁的上顶板、悬臂板及下底扳具有相同的纵向位移转角差函数,这种假设同实际情况并不符合.采用三个不同的纵向位移转角差函数,通过变分原理建立了薄壁箱梁弯曲变形的微分控制方程,并求得解析解.用该结果与采用相同纵向位移转角差函数的解析解及Ansys有限元法的结果进行了比较分析.结果表明作者的假设更合理.

When analyzing the shear lag effect in thin walled box girder with constant section formerly, that there are the same longitudinal displacement functions at the top, foot and contilever flanges are usually considered, but this supposition is not true.Based on the variational principles,the differential equations are derived by assuming three different longitudinal displacement functions for thin walled box girder with constant section. The closed-form solutions of the equations are obtained. The new method is applied to analyze a thin walled box girder and the result shows that the new method is more effective and accurate by compared with that of Ansys.