基于剪切变形规律的剪力滞分析的有限梁段法

Finite segment method of shear lag analysis of box girders based on flange-slab shear deformation law

选取基于剪切变形规律的翘曲位移函数的有限梁段法分析箱梁的剪力滞效应。该翘曲位移函数的定义是从剪力滞效应是由于翼板剪切变形引起的这一基本机理出发的,原理更加明确并且分析精度高。建立基于最小势能原理的变分法的箱梁剪力滞控制微分方程及边界条件,在此变分法微分方程的基础上,导出相应梁段单元剪力滞系数矩阵和广义荷载列阵,运用有限梁段法来分析剪力滞效应,分析试验模型及铁路简支箱梁分别在均布荷载和跨中集中荷载作用下以及悬臂箱梁箱在均布荷载作用下的剪力滞效应。分析简支梁和悬臂梁分别在均布荷载和跨中集中荷载作用下的剪力滞效应。并与相应的变分法解析结果进行比较,结果吻合良好,从而验证本文方法的正确性。

Through the finite segment method based on the warping displacement function is caused by shear deformation analyzes the shear lag effect of the thin-wall box girder. The warping displacement function is defined from the shear lag effect caused by the shear deformation of the wing plate. The principle is more explicit and high degree of precision. The governing differential equation for shear lag of box girders and the corresponding boundary calculus method based on the variation principle of the minimum potential energy. Based on the method to define the warping displacement function of shear lag and the governing differential equations by variational principle, derived the shear lag coefficient matrix and generalized load vector, using finite element method to analyze shear lag effect. The shear log effect of the simply supported box girder indude experimental model and railway under uniform load or mid-span load and the cantilever box girder under uniformly distributed load are analyzed. The results obtained from the finite segment procedure accurately agree with those from variational analysis method. which validates the effectiveness of the present analytical method.