确定斜拉屋盖结构拉索预应力的逐步去约束法  

Removing Constraint Method Step-by-step for Force-finding Analysis of Cable-stayed Structures

作　　者：朱博莉[1] 郭彦林[2] 马建勋[1] 

机构地区：[1]西安交通大学人居环境与建筑工程学院,陕西西安710049 [2]清华大学土木工程系,北京100084

出　　处：《施工技术》2014年第14期90-92,127,共4页Construction Technology

基　　金：清华大学自主科研杰出专项资助(2012Z10134)

摘　　要：斜拉钢结构是典型的刚柔组合结构,其找形分析是一个"由形找力"的过程,即依据结构设计或施工确立的几何位形,确定拉索的预应力值,使结构在预应力和恒荷载作用下,能够达到结构设计要求的几何位形。针对斜拉结构的组成与受力特点,提出了确定拉索预应力值的逐步去约束迭代法:按照设计要求的结构成型态,将整体结构按照一定顺序分为若干个基本单元,通过给结构控制点施加约束并有规律地逐步释放约束,依次确定结构中拉索中的预应力值。论文通过一个简单的平面模型介绍了逐步去约束法的基本原理与实施步骤,最后结合一实际工程计算确定了其拉索的预应力值及拉索的下料长度。Because the cable-stayed steel structures are typical combination of tensile cables and rigid roofs, force-finding analysis of cables in the cable-stayed structures is required to determine the cable pre-stress values, based on the structural geometrical configuration specified by architectural and structural designers. From the mechanical characteristics and composition of cable-stayed structures, this paper presents a new method for finding cable pre-stress values, and this method is defined as Removing Constraint Method Step-by-step （RCMS）. Firstly, the whole structure is required to impose displacement constrains at the key points of the whole structure, and then to release it one by one to determine cable pre-stress values according to the structural geometric configuration, as well as the cable length and final cable forces. It leads to higher calculation efficiency and higher convergence speed than traditional forcefinding analysis. In this paper, it is firstly used in a simplified structural model to validate it, and further applied in practical engineering design to find cable pre-stress values of a real cable-stayed structure.

关 键 词：屋盖 斜拉结构 找形分析 逐步去约束法 有限元分析 

分 类 号：TU311[建筑科学—结构工程] TU758