Study Of Wind Load Characteristics On Long-span Spherical Shell Roof

The large span roof structure is often favored by designers because of its beautiful shape and reasonable force.However,because of its large span,low stiffness and so on,it is easily damaged by wind load.In recent years,the large span roof structure has been frequently occurred in the event of storm damage,so it is of great practical significance to study the wind load characteristics of large span roof structures.As one of the typical large span structure forms,the spherical shell structure has the characteristics that the large span roof structure is easily destroyed by the wind.It is necessary to study the wind load characteristics of the different forms of the spherical shell structure for the design reference.In recent years,with the development of computer technology,numerical simulation method has become more and more popular in structural wind engineering.Based on the theory of wind load characteristics and the basic principle of computational fluid mechanics,this paper studies the wind load characteristics of large span spherical shell roof structures by using fluent as the computing platform.The main work is as follows:(1)Simulation of a 1/4 vector span ratio spherical shell with a combination of different turbulence models and mesh division methods,By comparing the distribution of the wind pressure of the spherical shell under different schemes,analysis of the characteristics of different methods,to determine the turbulence model and mesh form to use in the following numerical simulation.(2)To establish the geometric model of the actual size,discusses the distribution of wind pressure on the surface of spherical shell with different span ratio,different supporting height and different landforms,calculate the wind load shape coefficient,and the calculation results were compared and analyzed,provide a reference for the wind resistant design of structures.The results show that the maximum positive(negative)wind pressure system of the structural surface increases with the increase of the ratio of the sagittal span,as a whole,the absolute value of the partition coefficient of the shell roof is also increasing.The support height has little influence on the wind pressure distribution of front edge of the upwind surface,and has great influence on the wind pressure distribution in the roof,side and leeward area.The geomorphologic type has little influence on the wind pressure distribution in the front and leeward side of the roof structure of the spherical shell roof,which has a great influence on the wind pressure distribution on the top and side of the shell.(3)Considering the influence of the interference effect,to study the wind pressure distribution of the two adjacent spherical shell structures under the 0° and 90° air direction angle at different distances,calculate the wind load figure coefficient of shell roof under two kinds of spacing and compare with the results of the single spherical shell under the condition of no interference,the influence rule of the interference effect on the wind pressure distribution of two adjacent spherical shells under two wind angles is obtained.The study shows that the influence of the interference effect under the wind direction of 0° and 90° decreases with the increase of the distance.The interference effect of the two spherical shell under the 0° wind direction is mainly composed of the slit effect and the shielding effect under the wind direction of 90°.