敞开式大跨空间桁架结构风荷载分布特性研究

Wind Load Distribution Research of Open Large-Span Truss Structure

敞开式空间结构的桁架由于直接受气流作用,其流场空间分布复杂,风荷载确定困难,且风洞试验受模型缩尺比限制难于获取桁架结构上的气动力.借助数值风洞技术,利用高性能计算平台,本文数值求解了敞开式桁架结构的空间流场及风荷载分布.敞开式空间桁架结构整体风荷载表现为水平向为主,竖向不显著的特点,该点与封闭式桁架结构整体通常表现出竖向较强吸力作用明显不同.敞开式空间桁架结构整体风荷载对风向角表现并不敏感,其原因在于敞开式空间桁架的流场多处分离且相互干扰严重,其整体特征紊流不易在某个风向角下特别占优.

Since the open space truss structure is directly affected by the airflow,the spatial distribution of the flow field is complicated,and the determination of wind load is difficult.In addition,from the wind tunnel test it is difficult to directly obtain the aerodynamic force on the truss structure due to the limitation of the model scale ratio.With the numerical wind tunnel technology and high performance computing platform,the spatial flow field and the wind load distribution of the open truss structures are numerically solved.The horizontal wind load on the open space truss structure is stronger than the vertical wind load,which is generally different from the closed truss structure which shows strong vertical suction.The overall wind load of the open space truss structure is not sensitive to the wind direction.The reason is that the flow field of the open space truss is separated,with strong mutual interference.As a result,the overall characteristic turbulence is not likely to be dominant in a certain wind direction.