大跨度结构风致雪漂模拟研究

发布时间：2018-01-10 07:01

本文关键词：大跨度结构风致雪漂模拟研究　出处：《天津大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着社会的进步大跨度结构的建设得到蓬勃发展。但由于雪荷载过大或结构承载力下降等原因造成的大跨度结构屋盖倒塌事故时有发生。近年来国内外暴雪灾害不断,雪灾造成的房屋倒塌严重威胁人民的生命安全。尤其是由于风致雪漂作用在建筑物表面形成的不均匀雪荷载,往往对结构受力更不利,所以非常有必要对大跨度结构表面的风致雪漂进行研究。本文对风致雪漂的数值模拟理论基础进行总结。解释了风致雪漂现象的产生原因和运动方式,详细阐述了风致雪漂数值模拟的数学模型和风致雪漂数值模拟的各个关键参数的选取,总结出对风致雪漂进行数值模拟的两种不同方法——雪相控制方程求解法和MIXTURE多相流模型求解方法。对广饶国际博览中心展厅大跨度弦支网架结构性能进行分析,通过方案对比,发现该体系能在结构高度较小时满足大跨度大空间的要求,且结构用钢量较省,结构刚度较大,同时动力性能明显优于平板网架;不同分布的雪荷载尤其是不均匀雪荷载对结构的受力影响较大,考虑雪漂作用形成的不均匀雪荷载在结构设计时非常有必要。以气象资料为基础,通过统计分析估算出2013年至2014年冬季广饶国际博览中心附近的实际地面雪压;基于双坡屋面的风致雪漂在背风面呈三角形分布的假设,对博览中心展厅的双坡屋面在2013年至2014年冬季实际降雪情况下的由风致雪漂形成的雪漂荷载进行模拟,发现由于当地2013年至2014年冬季降雪较少,风速不大,所以双坡屋面的实际雪漂荷载较小。对计算域分别进行结构化网格、非结构化网格和混合网格划分,基于FLUENT软件采用雪相控制方程求解法和MIXTURE多相流模型求解法对一球形网壳和于家堡贝壳形网壳进行风致雪漂数值模拟。利用C语言对FLUENT软件进行二次开发,得到屋盖表面积雪发生侵蚀和沉积后产生的不均匀雪荷载。对比不同网格划分和模拟方法对风致雪漂模拟结果的影响,发现结构化网格的计算结果优于混合网格,混合网格的计算结果优于非结构化网格;雪相控制方程求解方法的计算结果优于MIXTURE多相流模型求解方法。对大跨度结构风致雪漂现象数值模拟的网格划分方式和数值模拟方法提出合理建议。
[Abstract]:With the development of society, the construction of long-span structure has been developed vigorously, but the collapse accident of long-span structure roof caused by excessive snow load or structural bearing capacity has occurred frequently in recent years. In recent years, blizzard disaster occurred at home and abroad. All the time. The collapse of houses caused by snow disaster is a serious threat to the safety of people's lives, especially because of the uneven snow load formed on the surface of buildings due to wind-induced snow drift, which is often more disadvantageous to the structure. Therefore, it is very necessary to study the wind-induced snow drift on the surface of long-span structures. In this paper, the theoretical basis of the numerical simulation of wind-induced snow drift is summarized, and the causes and motion of wind-induced snow drift are explained. The mathematical model of wind-induced snow drift numerical simulation and the selection of key parameters of wind-induced snow drift numerical simulation are described in detail. Two different methods for numerical simulation of wind-induced snow drift, snow phase control equation solution and MIXTURE multiphase flow model, are summarized. The large-span chord-supported grid structure of exhibition hall of Guangrao International Expo Center is studied. Performance analysis. Through the comparison of schemes, it is found that the system can meet the requirements of large span and large space when the height of the structure is small, and the amount of steel used in the structure is less, the stiffness of the structure is larger, and the dynamic performance of the system is obviously better than that of the plate grid. Different distribution of snow load, especially uneven snow load, has a great influence on the structure. It is necessary to take account of snow drift in the design of the structure, based on meteorological data. The actual surface snow pressure near Guangrao International Expo Center from 2013 to 2014 is estimated by statistical analysis. Based on the assumption that the wind-induced snow drifts on the leeward surface of the double-slope roof, it is assumed that the snow floats on the leeward surface. The snowdrift load caused by wind-induced snow drift is simulated on the double-slope roof of the exhibition hall of the Expo Center during the winter snowfall from 2013 to 2014. It is found that the actual snow drift load of the double-slope roof is smaller because of the small snowfall and small wind speed in the local winter from 2013 to 2014. Unstructured grid and hybrid grid partitioning. The wind-induced snow drift of a spherical reticulated shell and a shell reticulated shell of Yujiabao were simulated by using the snow phase control equation solution method and the MIXTURE multiphase flow model solution method based on FLUENT software. The second development of LUENT software is carried out. The uneven snow load caused by snow erosion and deposition on the roof surface is obtained, and the effects of different mesh generation and simulation methods on the simulation results of wind-induced snow drift are compared. It is found that the computational result of structured grid is better than that of hybrid grid, and that of hybrid grid is better than that of unstructured grid. The calculation result of snow phase control equation is better than that of MIXTURE multiphase flow model. Some reasonable suggestions are put forward for the grid generation and numerical simulation of wind-induced snow drift phenomenon in long-span structures. .
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU356;TU312.1

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