荷载横向变位对波形钢腹板箱梁剪力滞效应的影响

Shear Lag Effect of the Different Lateral Loading Position of the Composite Box Girder with Corrugated Steel Web

为了研究荷载横向变位对波形钢腹板箱梁剪力滞效应的影响,对箱梁顶板、底板、悬臂板分别取不同的纵向位移差函数,并以四次抛物线作为翼板纵向位移横向分布函数,考虑荷载横向作用位置不同对外力势能的影响,基于能量变分法推导出波形钢腹板简支箱梁在承受集中荷载及均布荷载横向变位下的剪力滞系数计算公式;基于ANSYS建立有限元模型,对有限元分析结果与理论结果进行对比分析,研究表明:荷载横向变位时顶板剪力滞效应变化较底板敏感,当荷载作用位置由肋板顶部往顶板中心移动时,顶板剪力滞效应由正剪力滞效应变化为负剪力滞效应,但悬臂板及底板均为正剪力滞效应.

In order to study the influence of varying transverse acting position on shear-lag effect in the composite box girder with corrugated steel web, this paper takes different longitudinal displacement with different function for top, bottom and cantilever slabs. Four parabola is adopted by the function of lateral distribution of vane＇ s lon- gitudinal displacement. The influence on external force potential energy occurred by the load＇ s different lateral position is taken into consideration.The calculation formula of shear-lag effect in simply supported box girder with steel webs withstand concentrated and uniform load under lateral displacement is derived on the basis of energy variational principle. Establishing a finite element model with ANSYS, and comparing finite element analysis re- sults with the theoretical results, the research reveals that the top slab＇ s shear-lag effect is more sensitive than bottom slab while the transverse acting position varying. When the load position moves from rib to roof center, the top slab＇ s shear-lag effect changes from positive to negative, but the cantilever and bottom slabs keep positive shear-lag effect all the time.