弦支穹顶结构的形态分析问题及其实用分析方法  

Morphological analysis of suspend-dome structures and practical analysis method

作　　者：郭佳民[1] 董石麟[1] 袁行飞[1] 

机构地区：[1]浙江大学,浙江杭州310027

出　　处：《土木工程学报》2008年第12期1-7,共7页China Civil Engineering Journal

基　　金：国家自然科学基金重点资助项目(50638050);浙江大学-浙江展城建设集团现代施工技术中心资助项目

摘　　要：寻找弦支穹顶在零状态下的几何构形与计算时所需施加的初应变值是其形态分析的主要目的。基于零状态下所需求解参数的不同,将其形态分析问题分为:找力、找形、找力+找形三类。这三类问题基本覆盖弦支穹顶结构中所有可能出现的形态分析问题。利用较为成熟的数值分析理论针对找力与找形这两类问题,进行计算公式的推导,并通过找力与找形的组合成功地解决了找力+找形问题,最后给出求解这三类问题的计算流程。按计算流程对同一结构模型分别进行找力与找力+找形分析。计算结果表明:由结构在零状态下施加的初应变值换算而来的内力,经内力重分布后与初始态下内力在数值大小与分布上均有较大差别,所以弦支穹顶结构的找力分析是必需的。结构经找形后在零状态下的单元下料长度与结构在已知几何构形下的单元长度相差甚微,但部分节点坐标值在两个状态下却有较大差别,建议结构在建造时可直接按已知几何构形来进行下料,但应按找形后的计算结果进行放样安装。Morphological analysis aims to determine the geometry of a suspend-dome under zero state and the corresponding pre-strain. According to the need for determining the respective state parameters under zero state, morphological analysis problems are divided into three categories, i.e., force finding, form finding and both force and form finding, which almost contain all the sub-cases involved in the morphology of suspend-domes. Analytic formulae for force finding and form finding are derived through numerical analysis, and both force and form finding are achieved through associating force finding with form finding. Furthermore, a combined flow chart of algorithm is designed to describe the real processes. A typical morphological analysis of the structures is carried out by using the force finding and both the force and form finding methods. The results show that force finding is necessary for suspend-domes due to the fact that the forces, which is recovered from the pre-strain under zero state, are different from the internal forces at initial state in both magnitudes and distributions after the internal forces are redistributed. The element blanking length after form finding is almost equal to that under known geometry, whereas the deflections are obvious for some nodes under the two states. It is suggested that the element blanking length may be calculated according to known geometry, while the structure should be assembled in terms of the results after form finding.

关 键 词：弦支穹顶 形态分析 找力 找形 迭代计算 

分 类 号：TU394[建筑科学—结构工程]