Wind-resistant Research Of Closed Type Multi-span Double Slope Roof Of Steel Structure

In recent years,incidents about destructions of buildings due to wind occur frequently.Most of these accidents are part of roof damage,the main body of the structure is noy destroyed,or the destruction is very small.with the development of structure forms as well as the application of efficient steel,light steel structure house development toward the direction of lightweight and high strength,resulting in the structure is more sensitive to wind load.In addition,in China’s newly revised Load Code (GB50009-2012), the provisions of the wind loads shape coefficient on the roof is still very general,lacking of adequate normative guidance.wind-resistant design of the structure’s roof has become a very necessary part of the design of light steel structure, therefore it is very necessary to a comprehensive understanding of light steel roof wind pressure and its distribution patterns.At present,field measurement,wind tunnel test and numerical simulation are the three major methods to study the wind load on the structures.Among them,the wind tunnel test is more mature,is the most important method.With the development of computational technology and Computational Fluid Dynamics, numerical simulation technology plays a more and more important role in the wind engineering community by its unique merits and promising prospect in the past three decades.Numerical simulation was used in this paper.The full-scaled rigid model of these structures were constructed, grids for the fluid zones were generated properly,and the velocity profile of atmospheric boundary layer were simulated accurately.The turbulent model used here is Realizable k-ε and Non-equilibrium Wall Function is used to solve the flow in the near wall regions.Firstly,the closed single-span,two-span,three-span double slope light steel structure was simulated in the wind farm under0°and90°wind angle.Roof pressure distribution was obtained by analyzing the roof air pressure contour map and building flow field figure.Concluded that multi-span structure is beneficial for roof wind-resistant.Next, the closed two-span and double slope light steel roof under different slope wind farm was simulated.Through the analysis of simulation results, we fond that we can not say which the slope of the roof for roofing wind resistance more favorable,the position of the roof high negative pressure zone change with the change of the roof slope.The correct approach was to use the numerical simulation to simulate building’s wind field.Finally, how in practical engineering application of numerical simulation method are discussed. Compared the results of numerical simulation with norms, given a simple way how get the roof wind load local shape coefficient about closed multi-span and double slope light steel structure when the roof slope angle from10°to25°.Provided a reference method for the actual project.