单层网壳结构等效静风荷载分布估计

ESTIMATION OF EQUIVALENT STATIC WIND LOAD DISTRIBUTION FOR SINGLE-LAYER RETICULATED SHELLS

单层网壳对外荷载分布极为敏感,且稳定问题是其结构设计中的主要问题,因此风荷载分布的估计对其结构静力抗风分析非常重要。但目前常采用的等效静风荷载分布并不能有效反映其脉动分量对结构稳定性的可能不利影响。首先简单回顾了目前单层网壳抗风分析的方法,并介绍了一种基于风洞试验的有效风荷载分布估计方案。随后从稳定分析角度提出了一种新方法,可用来简单高效地估计单层网壳的有效风荷载分布,同时还可就风荷载的影响进行保守分析。最后,分别采用单层球面和柱面网壳作为算例,基于风洞试验结果,比较了不同估计方法在分析这类结构极限承载能力及稳定性问题时的效率,表明了所提出方法在单层网壳稳定分析中估计有效风荷载分布时的优点。

Wind load estimation is very important to single-layer reticulated shells since this system is sensitive to external load distribution, and stability analysis is a main problem in structural design. However, the current estimated equivalent static wind load may not reflect the actual effect of fluctuating wind load on the stability of the shells. In this paper, existing methods used to estimate equivalent static wind load distribution are briefly reviewed. A framework to estimate the effective static wind load distribution for the single-layer reticulated shells based on wind tunnel tests is introduced. Then, a new simple method on the basis of stability analysis is presented to give a conservative estimation of wind load effects, and to improve the efficiency in estimating the effective static wind load distribution. Finally, by comparative analysis of a spherical and a cylindrical single-layer reticulated shell with different methods mentioned and wind tunnel tests, the efficiency of the present method for limit load-carrying capacity and stability analysis of single-layer reticulated shells is demonstrated.