肋环型逐层双环索穹顶初始预应力快速计算法

Fast calculation method for initial prestress of rib-patterned cable dome with two hoops in each layer

通过将空间立体结构简化为平面桁架结构,并根据节点受力平衡关系与各索杆平面等效力的关系,分别推导了新型肋环型逐层双环索穹顶结构在不设和设有内拉环时的索杆初始预应力分布的计算公式.利用ANSYS软件建立非线性有限元模型对公式进行了验证,计算结果表明:新型结构快速计算法所得的结果与结构非线性模拟结果吻合良好.因没有考虑模型在施加初始预应力后产生的微小变形,仅在结构顶部索杆内力有微小偏差,说明无须借助结构分析软件进行繁琐的计算,仅利用快速计算法即可完成新型结构初始预应力的设计,且其计算精度满足结构设计的一般精度要求.

By simplifying a three-dimensional structure of space into a truss structure of plane, according to the relation of balanced forces of nodes and the relation of equivalent forces of each cable bar plane, the cal- culation methods for distribution of initial prestress of cable bars of the new rib-patterned cable dome with two hoops in each layer with and without inner hoops were deduced respectively. The formulas were vali- dated by setting up a nonlinear finite element model utilizing the software of ANSYS. The calculation re- sults show that the results of the fast calculation method for the new structure match well with those of the nonlinear simulation, except that the inner force of the cable bars at the top of the structure has slight de- viation because the slight deformation of the model caused by applying initial prestress has not been consid- ered. It means that it is unnecessary to carry out complicated calculation relying on the software of struc- tural analysis, and it is sufficient to fulfill the design of initial prestress of the new structure by using the fast calculation method only, and its calculation precision can meet the general precision requirements on structural design.