考虑滑移和剪切变形的单箱双室组合箱梁剪力滞效应

为准确分析单箱双室组合箱梁的剪力滞效应,考虑钢混凝土的界面滑移效应和钢腹板的剪切变形,针对顶底板和翼板定义不同的剪力滞翘曲位移函数,基于能量变分法推导出单箱双室组合箱梁剪滞效应的控制微分方程及其闭合解。以单箱双室组合箱梁算例为基础,利用该方法分析其剪力滞效应的规律,结果表明:在同时考虑滑移和剪切变形时,组合箱梁的挠度比初等梁理论解大,且其挠度随界面滑移刚度的增大而减小;组合箱梁在均布荷载作用下,滑移量与荷载值近似成正比关系;在相同条件下,钢箱梁底板的剪力滞效应较混凝土顶板显著。

Shear lag effect of twin-cell composite beams considering slip and shear deformation

The effect of slip of the steel-concrete interface and shear deformation of the steel webs were considered to accurately analyze the shear lag effect of the double-cell composite box girder.The different shear lag warping displacement functions for the top and bottom plates are defined.Based on energy method, the control differential equation and the closed-form solution for the double-cell composite box girder are derived.As an example, the shear lag effect of a single box double-cell composite box girder is analyzed by using proposed method.The results show that the deflection of the composite box girder when considering the slip and the shear deformation is obviously larger than that obtained by the elementary beam solution, and which will decrease with the increase of interface slip stiffness.The slip value is approximately proportional to load heavy.The effect of shear lag on bottom steels lab of the box girder is more significant than that on top concrete slab.