车辐式结构找形分析的逐点去约束法

车辐式结构是一种双层索系的柔性结构,需要通过找形分析确定结构的初始预应力态.与索膜、索网结构等柔性结构不同,车辐式结构的找形分析不是用给定的预应力值寻找结构位形,而是从给定的位形出发求解可能存在的预应力分布情况.目前已有的找形方法有平衡矩阵理论、力密度法、动力松弛法、非线性有限元法等.除了非线性有限元法外,其他方法都难以直接通过通用有限元软件进行找形分析.本文在平衡矩阵理论的基础上,将车辐式结构整体找形问题转化为针对每个节点处3个索杆单元的计算.通过使每个节点在预应力作用下达到设计位形,求出结构初始应力态的预应力分布.这种方法不但能够直接用于有限元软件的计算,还能够判定结构的初始应力态是否存在.

Constraints removal method for form-finding problem of spoke structures

Spoke structures are kind of double-layer cable structures,whose initial stress state is achieved through form-finding process.Form-finding problems of spoke structures is needed for finding the distribution of the pre-stress according to the designed configuration which is different from cable-membrane structures or cable-net structures,whose form-finding problem is to get the shape of the membrane or cable-net under particular pre-stress.Except for the nonlinear finite element method,other methods such as...