悬索桥空间缆索实用找形方法

针对现存分段悬链线法和有限元法在悬索桥空间缆索找形方面存在对初值敏感和容易发散等问题,本文提出了一种实用方法.基于空间缆索纯索体系的有限元模型,以缆索节点坐标和单元内力为未知参数,通过小弹性模量法确定迭代初值,采用内循环参数更新外循环坐标修正的嵌套循环迭代计算空间缆索线形.三个算例分析结果表明,本文方法计算精度与分段悬链线法一致,且具有迭代次数更少、收敛性更好和计算效率更高的优点,适用于纵桥向斜吊杆空间缆索的线形计算.

A practical method for shape finding of spatial cable curves of suspension bridges

A practical method is proposed to overcome the limitations (such as sensitivity to initial values and easy divergence) of the existing methods (i.e., segmental catenary method and finite element method) for shape-finding of suspension bridges with spatial cables.This method is based on the finite element model of 3-dimensional cable-hanger system and takes the coordinates of cable nodes and the internal forces of elements as unknown parameters.The initial iterative values are determined by the low elasticity modulus method and the spatial cable shape is calculated by a nested loop which updates parameters in the inner cycle and erect coordinates in the outer cycle.Three numerical examples verify that the accuracy of this method is consistent with the segmental catenary method, but with fewer iterations, more stable convergence, and higher efficiency, and it can also be used to analyze the spatial cables with longitudinally inclined hangers.