一种钢箱梁弯曲剪应力的有限元分析方法

A finite element method for calculating bending shear stress of steel box girder

钢箱梁的弯曲剪应力的求解为超静定问题。提出从平截面假定出发,根据壁板间的变形协调条件,建立平面线单元刚度矩阵,用有限元法求解壁板剪应力,并对计算所得的剪切变形进行修正,利用修正后的剪切变形来计算弯曲正应力的不均匀分布,来反映箱梁受力情况下的剪力滞效应,以简明算例说明计算理论,为钢箱梁的剪应力求解及剪力滞效应的计算提供了一种新的计算思路。

The solution of bending shear stress of steel box girder is statically indeterminate. This paper present a kind of finite element method,in which the stiffness matrix of plane line element is establisheda ccording to the condition of deformation coordination between the panels,and the shear stress of the panel is solved by finite element method. The shear deformation calculated is corrected,and the non-uniform distribution of bending normal stress is calculated by the modified shear deformation,so as to reverse the shear lag effect of reflected box girder under stress. In this paper,a simple example is given to illustrate the calculation theory,which provides a new way for the calculation of shear stress and shear lag effect of steel box girder.