等参有限元法在平面曲线梁桥中的应用

Application of Isoparametric Finite Element Method in Planar Curved Beam Bridge

以单纯扭转理论假定为基础,采用三节点的等参曲梁有限元来分析曲线梁桥,根据推导的刚度矩阵编制了计算程序并给出了2个算例。这种具有9个自由度的曲梁有限元方法,可以认为是三节点等参直梁有限元和圆弧曲杆有限元的有机结合,相对于二节点的圆弧曲杆有限元,考虑了曲梁的横向剪切变形的影响。同时直接计算出对设计比较重要的剪力值,既能适用于薄梁,也能适用于中厚梁。

Based on the assumption of pure to.ion theory, three-node isoparametric curved beam element was adopted to analyze the curved bridge. The calculation .software was worked out according to the stiffness matrix and two calculation examples were provided. This finite element method, which had nine degrees of freedom, combined the three-node isopararnetric straight beam element and the curved beam element effectively. This method considered the effect of transverse shear deformation of the curved beam, which was.ignored in the two-node curved beam element. At the same time, the shearing force, which played a comparatively important role in design, could be directly calculated. This method could be used for slender beams as well as medium-thick beams.