索结构静力分析的新型拉索单元研究

STUDY ON THE DEVELOPMENT OF NEW-TYPE CABLE ELEMENTS FOR STATIC ANALYSIS OF CABLE STRUCTURES

总结和分析不同工况下索结构中拉索的受力特点,将拉索行为归纳为已知原长和已知索力两种典型受力情况。利用悬链线拉索解析解的线性展开,并引入适当的约束条件,建立两种新型的拉索单元,给出单元切线刚度矩阵的显式表达。提出索结构非线性静力分析的一般迭代算法,算法中利用等效线自重考虑弹性变形对拉索静力状态的影响。以斜拉悬臂结构的多阶段安装为例,分别采用该文方法和传统方法针对不同工况进行了索结构分析,对比计算结果证明了该文新型单元和算法的效率和精度。

Based on an investigation of the mechanical characteristics of cables under different working conditions, cables can be categorized into two types, those with a given unstressed length and those with a given tension force. Two new cable elements are developed by using first-order expansions of the analytical solutions for the catenary cable and introducing appropriate constraint conditions, and explicit expressions of element tangent stiffness matrices are derived. A new iteration algorithm is then proposed for solving nonlinear structural responses, in which the influence of elastic deformations on the cable is included through an equivalent self weight per unit length. The erection process of a cable-stayed cantilever structure is considered as an example. The proposed method and an existing method are applied to the structural analysis of the structure under different loading conditions. The numerical results are presented and compared to show the efficiency and accuracy of the proposed elements and algorithms.