单箱双室曲线箱梁剪力滞效应分析

Shear Lag Effect of Single-Box Double-Cell Curved Box Girder

本文运用ANSYS有限元软件研究单箱双室箱梁在不同工况下剪力滞效应的变化规律。研究表明:单箱双室箱梁各腹板在均受集中力情况下各腹板均匀承担剪力滞,可以有效减小剪力滞系数。若在曲线箱梁集中力作用处加腹板会导致该部位剪力滞系数激增,从而出现应力集中现象。由于曲线梁桥的“弯扭耦合”作用,内侧腹板剪力滞系数大于外侧。单箱双室箱梁作为多室箱梁中的代表,可以很好地模拟剪力滞的效果,得到的结论符合理论判断。

The variation rule of shear lag effect in single-box double-cell girder under the working conditions was studied by using ANSYS software. The results show that the webs of a single-box double-cell girder can bear shear lag uniformly under the concentrated force,and effectively reduce shear lag coefficient. However,the shear lag coefficient sharply increases when the web is added to the middle of curved box girder,resulting in it's stress concentration. Due to the influence of bending-torsion coupling of curved box girder bridge,the shear lag coefficient on the inner web is larger than that on the outside web. As a representative sample of multi-cell box girder,single-box double-cell girder can simulate shear lag effect well,and the conclusions are consistent with the theory judgments.