【作者】 孙瑛；

【导师】 沈世钊；

【作者基本信息】 哈尔滨工业大学 ， 结构工程， 2007， 博士

【摘要】 大跨屋盖结构作为一类新颖结构形式,在结构设计方面具有许多区别于传统结构的特点,特别是对风荷载的考虑,往往成为该类结构设计中的重点和难点问题。这其中一个很重要的原因在于,对屋盖风荷载特性的研究还相对薄弱,至今尚未提出一套成熟的阵风荷载描述方法。从钝体空气动力学的角度来看,大跨屋盖表面风荷载的复杂性源于其自身形状的多样性、风荷载作用的随机性以及脉动风压的时空相关性。这些因素的综合作用使得屋盖表面的风压统计规律不仅与来流的脉动特性有关,还会更多地受到由结构自身几何形状引起的特征湍流的影响。因此,对屋盖风荷载特性的研究在本质上可归结为对特征湍流作用机理的研究。基于以上思想,本文采用风洞试验和CFD数值模拟方法,对若干具有典型形状的大跨屋盖表面风荷载(包括平均风压和脉动风压)特性进行了系统研究,重点探讨了特征湍流的形成机理及其对屋盖风压统计规律的影响;在此基础上,提出了利用风荷载数据库技术对屋盖风荷载进行精确描述的方法。主要内容包括以下几方面:(1)对若干典型形状的大跨屋盖结构进行了刚性模型风洞动态同步测压试验研究,并将试验结果与CFD数值模拟结果进行对比,验证了数据的可靠性。(2)提出了利用屋盖表面风压分布信息进行特征湍流参数识别的方法,并重点对一种典型的特征湍流形式——锥形涡进行研究,得到了平屋盖和鞍形屋盖表面锥形涡的涡心位置、作用范围以及运动模式等特征参数的定量结果。(3)基于点涡势流理论,建立了特征湍流作用区的平均风荷载分布模型,这种风荷载描述方式更接近于风荷载的实际分布规律且可以用于实际工程应用。(4)分别从时域和频域两方面,研究了特征湍流对屋盖风荷载脉动特性的影响。在时域内,采用越界峰值法研究了屋盖风压的尖峰脉冲现象,并研究了屋盖风压的非高斯统计特性,给出了利用高阶统计矩划分非高斯区的方更多还原

【Abstract】 As an innovative style of structure, large span roofs differ significantly from conventional buildings, especially in the consideration of wind loading during design. The decision of wind loads acting on large span roofs is usually the key and challenging problem for this kind of structure. One of the important reasons is that the studies of characteristics of wind loading on large span roofs is still very weak, and there does not exist a mature method to describe the gust loading on roofs yet.From the point of view of bluff aerodynamics, the complexity of wind loading acting on long span roofs arises from the variety of the building shapes, the randomness of fluctuating wind pressure and the time/space and spatial correlation of wind pressure fluctuations. Combining with these factors, the statistics characteristics of wind pressure is not only related to the characteristics of oncoming flow, but also mostly to the signature turbulence which induced by the building itself. Therefore, the investigations on the characteristics of wind loading on large span roofs can be regarded as the researches on the mechanism of signature turbulence in nature.Based on above thinking, studies on the characteristics of wind loading on some typical types of long span roofs have been carried out systematically, including the mean and fluctuating features of wind pressures, by using wind tunnel tests and Computational Fluid Dynamic (CFD) numerical simulation techniques. The analysis of the vortex flow mechanism and its effect on the statistics laws of wind pressure signals is focused. Finally, an exact method is proposed to describe wind loading acting on roofs by wind Loads database technique. The main contents in this paper are shown as following,(1) Wind tunnel multi-channel pressure measuring tests for many kinds of long span roofs with typical shapes were carried out. At the same time, the wind pressures on these roofs were simulated by using a commercial CFD code, FLUENT. And the comparison between simulated results and wind tunnel test data were made to prove the validity of the data.更多还原