The Study On Wind Load Characteristics Of Long-span Closed Cylinder Roof Structure

The large-span roof structure is widely favored for its beautiful structural forms and good stress characteristics.Because of its low stiffness and light weight,the large-span roof structure is very sensitive to wind load.As a result,it is very important to grasp the wind load characteristics on its surface of the structure and determine the wind load information of its structure design for the wind resistant design of this structure.With the rapid development of Chinese coal industry and people’s increasing awareness of environmental protection,the long-span cylindrical stem form of large span roof structure coal shed has gradually changed from the open to closed.The change of the structure also makes the wind load on the surface of the structure change.Seeing cylindrical dry coal shed roof as engineering background,using the software of ANSYS Fluent to explore the characteristics of wind load on long-span roof structure of the closing cylindrical surface based on CFD in this paper.It mainly include following aspects:(1)Seeing cylindrical dry coal shed roof as background,geometric modeling,mesh generation and quality checking,numerical simulation,post-processing setting and numerical simulation results are carried out separately in the numerical wind tunnel.(2)The influence of wind angle on the wind load characteristics of the large-span closed cylindrical roof structure is studied by changing wind pressure coefficient and block coefficient under different wind angles.It is found that as the wind direction changes,the distribution of wind load changes significantly in most parts of the cylinder structure.What’s more,the wind load on the cylinder structure are mainly wind suction.When the wind direction angle is 0°(wind direction in the direction of vertical span),there is a large wind suction force at the front edge of the roof structure column,and the wind suction force along the wind direction cylinder surface gradually decreases;When the wind direction angle is 90°(wind direction in the direction of parallel span),there is a large wind suction force at the center of the top of the cylindrical roof structure,and the maximum negative value of the structural body block size coefficient appears.(3)In the numerical wind tunnel,nine structural geometric parameters working conditions are established.The influence of structural aspect ratio and aspect ratio on the wind load characteristics of large-span closed cylindrical roof structures is studied by changing the structural geometric parameters.The study found as the cylindrical structure span ratio increases,the wind pressure are strengthened at the bottom of the cylindrical structure of blocking area(windward)and the top center position of blocking area of the wind suction cylinder structure;The study also found as the the ratio of length to width increases,the center position at the top of the structure of blocking area are strengthened under wind load,but there is little change in other regions.(4)As the interference distance and interference mode changes,the interference effect of the surface wind load on long-span closed cylindrical roof structure is studied as the the disturbed structure is taken as the research object on the fixed wind direction.The study found that in the situation of single side arrangement,the absolute value of block coefficient decreased on most of the regional structure because of the shielding effect on disturbed structure(downstream).What’s more,as a certain interference distance increases,the interference structure(upstream)reduces the interference of most areas of the disturbed structure(downstream)within a certain range of interference distance.The situation of bilateral tandem interference(bilateral interference)is more conducive to reducing wind load structure than the situation of single tandem interference(single interference)on the same condition within a certain range of interference..