预张力斜拉结构拉索卸除后结构分析的迭代法

斜拉结构中的拉索由于各种原因导致腐蚀，就不得不进行部分或全部斜拉索卸除更换。拉索中由于有预张力，卸除拉索，不仅结构的刚度发生了改变，而且等效节点荷载也发生了改变。本文提出拉索卸除后结构分析的迭代法，推导了迭代公式，讨论了收敛速度。本文方法是计算结构变更后的新结构，利用了结构刚度局部变化的特点，且整个迭代过程是在原结构刚度变化相关的节点自由度范围内进行的，因此计算量大大地减小。该法不仅适用于卸除一根索，也适用于同时卸除多根索。

Iterative Method of Structural Analysis about Removal of Cable in Cable-stayed Structures with Pretension

Because of many kinds of factors , cable corrosion in cable-stayed structures is unavoidable. Some or all stay cables have to face the problem of being replaced after a few years. After cables with initial pretension are removed, both the stiffness of the whole structure and equivalent node loads are changed. An iterative method is presented to analyze the new structure with variation in this paper. The iterative formulate is derived and the convergence speed is also discussed. In calculating the new structure by the above method, the iterative process is performed in local variable stiffness range related degree of freedom of original structure. Therefore, the amount of calculation is greatly decreased. This method can be adapted for both situation of one removal cable and more number removal cables.