| Large-span toroidal folding plate steel tent structure has the advantage of light quality,small damping and modal shape is complex,the characteristics of natural vibration frequency distribution dense,and the complexity of wind load make its sensitivity to wind load,the instantaneous maximum wind can make roof suction of local produce very big effect,easy to edge of the tent structure area of coating surface structure and steel column and the connection of the tent structure cause damage;In addition,some parts of the structure,such as nodes and supports,may suffer from fatigue damage after a long time of wind vibration,which may lead to local damage and thus reduce the safety of the structure.In under the action of strong wind,however,buildings can withstand the wind load depends not only on the surface structure of wind pressure,also depends on the internal pressure,especially for building open,half open,when the outside air into the indoor,strong wind force inner pressure pulsation is closed sharply increases,the whole curtain wall,the structure of the long-span flexible steel tent without wind resistance design,the internal and external pressure under the joint action of wind-induced damage more easily.The large-span circular folding steel awning structure with complex shape is a wind-sensitive structure,which is easily damaged by wind.Reducing the surface wind pressure is one of the key problems in structural wind engineering.Based on the basic principle of aerodynamics,acting on the structure of wind load on the surface of the building and its shape is closely related to the aerodynamic measures is the most effective way to reduce the static and dynamic wind-induced load,and the common aerodynamic measures is to change the structure of the external shape of the aerodynamic parameters,can significantly reduce the wind-induced load and wind-induced response of structures.Taking helan mountain stadium in yinchuan city as an example,the wind load distribution characteristics of large-span folded steel awning structure are studied in detail through wind tunnel test,and the most unfavorable position of such structure is put forward.A simple and practical aerodynamic wind resistance measure is proposed based on CFD numerical simulation technology,which provides reference for the wind resistance research and engineering design of such structures.The main work includes the following aspects:(1)Systematically studied the large-span folding plate just tent structure wind load distribution-in the engineering instance of helan mountain stadium,on the 1:15 0 rigid model wind tunnel test,the model forward to flow according to the class B surface roughness simulation of 36 wind flow to Angle within 0～360°,interval of 10 °,analyze the test results,the helan mountain stadium wind pressure distribution on a larger extremum,namely the most unfavorable position.(2)Based on the stadium project example,the computational fluid dynamics software analysis model is established,and compared with wind tunnel test results for analysis,to verify the rationality of the numerical simulation of parameter setting,reliability,in addition to the analysis of the average wind pressure coefficient and wind load shape coefficient,also to the actual structure of the flow field are analyzed.(3)For the most unfavorable position,aerodynamic optimization model is set up,by changing the opening location,hole quantity,analysis of large-span folding plate steel structure surface wind pressure effect,the tent and sums up the hole location,opening the influence degree of the amount of wind pressure distribution law,from the overall consideration is given has obvious effects of wind pressure reduction of opening position and number of openings.Finally,through the visualization of the flow field and the analysis of the flow field around each model,the mechanism of the aerodynamic anti-wind measure is explained. |
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