薄壁曲线箱梁剪力滞计算的有限段方法

Finite segment method for calculating the shear lag in thin-walled curved box girders

采用能量变分法导出的控制微分方程的齐次解作为梁段的有限元位移模式,建立了考虑初曲率的弯曲、扭转、剪力滞耦合和畸变的半解析有限段模型.由直接刚度法导出了梁段单元的刚度矩阵;由功能原理获得单元荷载列阵,提出了一种能对工程中常用的多跨连续曲线箱梁剪力滞计算的有限段法.制作了一两跨连续曲线箱梁有机玻璃实验模型,分别进行了在集中荷载和均布荷载作用下的剪力滞效应实验研究.其结果与有限段法计算结果以及有限元法的计算值均符合良好,从而验证了有限段方法的正确性.

The homogeneous solutions to the governing difference equations derived from energy variational method were used as the displacement patterns of finite segment. A finite segment model considering the initial curvature, bending, torsion, shear lag and distortion was established. The stiffness matrix and load column matrix were obtained based on the directed stiffness method and the working energy principle. A finite segment method was presented to calculate the shear lag effects with multi-span continuous curved box girder generally used in engineering. A perspex glass model of a two-span continuous curved box girder was made. The test on the perspex model were performed to study the shear lag effects respectively under concentrated load and uniformly distributed load. The calculation results of finite segment method were in agreement with the experimental results and results of finite element method, which verifies the accuracy of the finite segment method.