FAE方法在屋盖结构雪荷载研究中的应用

Application of FAE Method to Study of Snow Load of Roof Structure

雪荷载设计是大跨屋盖结构设计中的重要环节,目前国内工程实践中的设计雪荷载通常是采用规范条文,个别重要的工程还会结合CFD数值模拟的结果。由于试验设备和条件的限制,较少采用实验对其进行验证。有限面元法结合了常规风洞试验模拟和计算机仿真技术,是一种研究大跨度屋盖结构雪荷载分布的有效方法。本文对其进行概述和分析,并以高低屋盖结构为例,采用有限面元法研究了风速和风向角对屋面积雪分布系数的影响。结果表明:与我国现行《建筑结构荷载规范》比较,二者整体分布规律基本一致,但在具体分布数值上略有差异;风速、风向亦对高低屋盖的积雪分布系数具有重要影响,就本文研究的高低屋盖结构而言,积雪分布系数随风速增大而增大,在270~337.5°风向角范围内屋盖的雪荷载分布较为不利,但在规范中并不考虑这种斜风向不利分布工况。

Snow load design is an important part in the design of long-span roof structure. Currently, the design of snow load in the domestic engineering practice usually adopts the standard provisions, and some important cases need to refer to the results of the CFD numerical simulation. Due to the limitations of test equipment and conditions, it is seldom verified by experiments. The Finite Element method is an effective method to study the snow load distribution of long-span roof structures, which combined conventional wind tunnel test simulation and computer simulation technology. The method was summarized and analyzed in this paper fully. Taking the high and low roof structure as an example, the influence of wind speed and wind direction on the snow distribution coefficient of roof is studied by finite element method. The results show that, the snow distribution shows the same rule compared with the current“ Load Code of Building Structure”,but there is a slight difference in the specific distribution values. The speed and direction of wind have a significant influence on the snow distribution coefficient. For the case in this paper, the snow distribution coefficient increases with the increase of wind speed. For the wind direction angle of 270-337.5°,the snow load distribution is unfavorable for the structure, however, this is not considered in the current design code.