Use warping displacement function based on shear deformation law,on the basis of differential equation of shear lag of box girder with energy variational method,a beam element with two shear lag degrees of freedom at each node was proposed considering the action of concentrated bending moment. When concentrated bending moment acted on the box girder bridge,the generalized shear lag displacement of beam element was redefined,the new shear lag coeff icient matrix and generalized load vector were derived by the boundary conditions and generalized equilibrium of shear lag as well as deformation compatibility condition. The shear lag effects along the longitudinal direction of the box girder under vertical load and concentrated bending moment were analyzed by means of relevant experimental models and engineering example. The results in this paper and the corresponding variational analysis results were compared to verify the correctness of the proposed method.%采用基于剪切变形规律的翘曲位移函数,在能量变分法箱梁剪力滞微分方程的基础上,提出一个考虑集中弯矩作用的每个结点有2个剪力滞自由度梁段单元.当箱梁桥承受集中弯矩作用时,重新定义梁段单元的广义剪力滞位移,通过边界条件及剪力滞广义平衡和变形协调条件推导出新的剪力滞系数矩阵和广义荷载列阵.借助相关试验模型及工程实例,分析不同箱梁桥形式在竖向荷载及集中弯矩作用下沿梁纵向的剪力滞效应,并与相应的变分法解析结果进行对比,验证了本文方法的正确性.
展开▼
