箱梁的剪力滞效应分析

SHEAR LAG ANALYSIS OF BOX GIRDERS

在变分法薄壁箱梁剪力滞基本微分方程的基础上,提出了一种与现有普通梁单元配合使用的分析箱梁剪力滞效应的有限元方法,导出了剪力滞单元系数矩阵和广义荷载列阵计算公式。针对变分法分析剪力滞问题的特点,给出了按照剪力滞广义平衡与变形协调条件进行结构系统分析、组集结构总剪力滞系数矩阵的方法。分析了连续梁和悬臂梁这两种不同结构类型、不同边界支承条件的箱梁在不同荷载条件下的剪力滞效应,并与变分法解析结果作了对比,验证了该文方法的广泛适用性和可靠性。

Based on the governing differential equations by variational principle, a finite element method for analyzing shear lag effect of box girder is proposed. The shear lag coefficient matrix and the generalized load vector are obtained. In addition, a procedure for assembling structural shear lag coefficient matrix and generalized load vector is demonstrated according to the boundary condition and the continuous condition of generalized shear lag displacements in structural system analysis. The shear lag effects of continuous and cantilever box beams, which have different boundary conditions, are analyzed under different loads. It is shown that the results obtained from the trmite element method agree well with those from analytical method. The reliability and wide applicability of proposed method are also verified by the examples.