摘要
弦支穹顶结构为目前新兴的空间结构体系。本文建立了120 m大跨度弦支穹顶结构模型,分析其自振特性及其影响因素。分别以荷载状况、矢跨比、拉索预应力以及支座约束为控制因素,当以上控制因素取不同数值时,分别计算其前30阶自振频率。结果表明:弦支穹顶结构质量轻、柔性大,频谱密集、自振频率低,具有一定程度的非线性特征;弦支穹顶结构的基频会随着均布荷载的增加而减小,在结构刚度不变的情况下,基频随着质量的增大而减小;弦支穹顶结构初期自振频率随着矢跨比的增加而逐渐增加,当矢跨比超过某值后基频下降;预应力的存在,对单层网壳的自振特性有很大的改善,但其大小对结构自振特性影响较小;弦支穹顶结构的支座约束情况对自振频率影响较大。
The suspendome structure is an emerging spatial structure system. A large span suspendome model of 120 meters was established to analyze the natural vibration characteristics of this structure and its influencing factors. Loading condition,rise-span ratio,cable prestress and support restraint are controlling factor respectively. It is found that the suspendome structure has such properties as light quality,lager flexible,and its frequency distribution is intensive and low. The suspendome structure has a certain degree of nonlinear characteristics. The fundamental frequency of suspendome structure decreases with the increase of uniform load,and decreases with the increase of quality under the condition of the stiffness of the structure is unchanged. The natural vibration frequency suspendome structure increases with the rise-span ratio increases at first,but drops when the rise-span ratio has reached one particular value. The natural vibration characteristics of single-layer lattice shells can be improved by the existing prestress greatly,but not the value of prestress. The support constraint conditions of suspendome structure have great influence on its natural vibration frequency.
出处
《四川建筑科学研究》
北大核心
2016年第1期23-25,共3页
Sichuan Building Science
关键词
大跨
弦支穹顶
模态分析
large span
suspendome
modal analysis
