国家体育场主结构扭曲箱形构件设计研究

根据国家体育场屋盖结构的构型原则,扭曲箱形构件的轴线保持在同一平面内,可视为由一系列曲率半径不同的弧形曲线构成。扭曲箱形构件受力机理复杂,影响因素较多。在设计中经过大量的计算分析、试验研究与加工工艺研讨,提出设置横向加劲肋的方法,通过在扭曲箱形构件设置内部加劲肋的方式改善扭曲箱形构件的应力分布,有效约束弧形板件的面外变形,增强构件的整体刚度。通过调整板件厚度、加劲肋间距等措施,使实体模型达到与杆件模型强度等效和刚度等效;在确定加劲肋形状时兼顾焊接操作空间、节约材料等方面的因素。

Design and research of twisted box-sections of the main structure for the National Stadium

According to the configuration principle for the roof structure of the National Stadium,the axes of the twisted box-sections are kept in the same plane,and can be deemed as being composed of a series of arcs in different curvature radiuses.Due to the complicated behavior of the twisted member and many influencing factors,a profusion of finite element analysis,experiments,researches on the fabrication technology are carried out during the design procedure.The method of placing the transverse stiffeners is proposed to improve the stiffness of the members and stress distribution,effectively restrain the out-of-plane deformations of the arc walls.By adjusting the thickness of the inner stiffeners and their intervals,the strength and stiffness of the model by using solid elements can be equivalent to that of the model by using beam element.In addition,the welding space and material cost should be considered when determining the shape of stiffeners.