基于索合力线形状的车辐式结构找形方法  

THE FORM-FINDING METHOD BASED ON THE FORM OF COMPOSITION OF FORCES FOR SPOKE STRUCTURE

作　　者：尚仁杰[1] 郭彦林[2] 吴转琴[1] 张心斌[1] 孙文波[3] 

机构地区：[1]中冶建筑研究总院有限公司,北京100088 [2]清华大学土木工程系,北京100084 [3]华南理工大学建筑设计研究院,广州510641

出　　处：《工程力学》2011年第11期145-152,共8页Engineering Mechanics

摘　　要：深圳宝安体育场采用了长轴237m、短轴230m、进深54m的椭圆形车辐式张拉结构,结构找形是该项目设计的关键。该文在分析车辐式张拉结构受力特点的基础上得出车辐式张拉结构上弦、下弦拉力的合力线在一个曲面上,形成上弦、下弦合力线虚拟结构。基于平衡荷载与合力线虚拟结构拉力水平分量之间的关系,给出了计算合力线虚拟结构形状的有限元列式;根据合力线虚拟结构形状和上弦、下弦拉力水平分量的比值确定飞柱的上、下节点位置;根据索桁架上弦和下弦两端端点坐标、索拉力水平分量及吊索拉力和节点荷载,确定整个车辐式张拉结构的形状。给出了找形后结构分析和索张拉控制的初应变计算公式以及边界结构弹性变形的处理方法;对深圳宝安体育场车辐式张拉结构进行了找形。该文的找形方法计算简单、准确,既可以通过编制有限元程序计算,也可以通过现有有限元软件实现。A spoke structure with a plane shape of an ellipse with a major axis of 237m, the minor axis of 230mand 54m in depth is adopted in Shenzhen Bao＇an Stadium. The form-finding of the structure is the essential problem of the design. The mechanics analysis of a spoke structure is conducted and an important conclusion is drawn that the compositions of forces of both upper and lower cables form a virtual structure in a single layer. Based on the relationship between the balanced load and the form of the virtual structure and the horizontal components of the tensions, the FEM equation to calculate the form of the virtual structure is provided. The positions of the upper nodes and the lower nodes of flying columns can be calculated according to the ratios of the horizontal components of tensions of upper cables to the lower cables. The form of the spoke structure can be determined according to the end nodes of the cable-trusses and the loads as well as the horizontal components of the tensions of the cables. The initial strains of the cables to calculate and to tense the structure as well as the method to deal with the deformation of the boundary part of the structure are described in the paper. The form-finding of the spoke structure of Shenzhen Bao＇an Stadium is calculated. The method in the paper is easy to carry out and provides accurate results. It can be performed either by the program using the FEM equation of the paper or by the commercial FEM software.

关 键 词：车辐式结构 索桁架 合力线 平衡荷载 找形 有限元法 

分 类 号：TU394[建筑科学—结构工程] TU399