柔性人行悬索桥空间索面抗风缆索系统的找形计算方法

Calculation Method for the Shape-finding of Spatial Wind Cable System on Flexible Pedestrian Suspension Bridge

基于悬连线索单元理论,研究了空间索面抗风缆索系统精确计算方法。利用平面受力平衡求得节点横向坐标,再根据各索段在自重作用下呈悬链线的特性,通过不断迭代计算得到节点的竖向坐标和各索段的无应力长度。文中给出了该方法的迭代计算流程,并利用《Matlab》编写计算程序。结合某工程实例,求得抗风缆索系统成桥线形及各索段无应力长度,带入有限元软件进行几何非线性计算,结果表明,恒载状态下缆索系统节点位移小于跨度的1/40000,说明提出的方法是可行的,满足工程精度要求。

Based on the theory of catenary cable element,a reliable and accurate calculation method for the shape-finding of spatial wind cable system was studied.The transverse coordinates of cable nodes were gotten according to force equilibrium in the horizontal plane.Then,on the principle that the shape of the cable between nodes was catenary,vertical coordinates of node and the unstressed length of cable were gotten through iterative calculation.The calculating process chart was shown in this study,and programmed with Matlab.Based on a practical example of certain project,the shape of the wind cable system under condition of dead load and the unstressed length of cable were gotten through this method.According to the method in this study,the bridge line shape of wind-resistant cable system and the stress-free length of each cable segment were obtained by combining with an engineering example.The results show that the deformation is less than 1/40000 of the span.The shape-finding calculation method presented is feasible,and meets the requirement of engineering accuracy.