Characteristics Of Wind Loading On Long-Span Roofs

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.