基于等效截面法的蝶形腹板箱梁剪力滞效应研究

Shear Hysteresis Effect of Butterfly Web Box Girder Based onEquivalent Section Method

根据等效截面原理对箱梁空腹处截面进行等效处理,考虑其横截面轴力平衡关系,建立了腹板剪切变形下的翘曲位移函数,并推导出结构平衡状态下的剪力滞效应微分方程。结合模型试验、ABAQUS有限元模型以及相关文献值,对比分析了蝶形腹板箱梁(简支)在集中荷载及均布荷载作用下的纵向应力分布规律,并得到全梁段剪力滞系数三维分布模型。结果表明:竖向荷载作用下,蝶形腹板箱梁纵向应力呈正剪力滞效应状态分布,且箱梁支点截面和跨中截面的腹板接缝处剪力滞效应较大;集中、均布荷载作用下,研究结果与试验值、有限元值均较为吻合;与文献值相比,两者相对误差(绝对值)在2.00%~2.44%。

According to the principle of equivalent section,the cross-section at the hollow web of the box girder was treated equivalently,the warpage displacement function under shear deformation of the web was established by considering the equilibrium relationship of its cross-sectional axial force,and the differential equation of the shear hysteresis effect under the equilibrium state of the structure was deduced.Combining with the model test,ABAQUS finite element model and relevant literature values,the longitudinal stress distribution laws of the butterfly web box girder(simply supported)under concentrated load and uniform load were compared and analyzed,and the three-dimensional distribution model of the shear hysteresis coefficient of the whole girder section was obtained.The results show that the longitudinal stress of the butterfly web box girder is distributed in a positive shear hysteresis state under vertical load,and the shear hysteresis effect is larger at the web joints in the pivot section and mid-span section of the box girder.The results of this paper are in good agreement with the experimental values and finite element values under concentrated loads and uniform loads.The relative errors(absolute values)of the two are in the range of 2.00%~2.44%,compared with the literature values.