非线性有限元法分析张拉整体结构初始形态

Nonlinear FEM for Form-Finding of Tensegrity Structures

目的确定自应力平衡的张拉整体结构的初始形态,明确几何和预应力态的选取原则.方法利用力法和位移法原理,针对张拉整体结构的初始平衡形态建立非线性有限元基本方程,并编写其初始形态分析程序.结果结合张拉整体结构的刚度特点,解决了程序迭代计算的收敛性问题.并应用初始形态分析程序计算确定了张拉整体三棱柱的初始形态.结论基于虚功原理迭代方程编写的初始形态分析程序可以有效确定张拉整体结构的初始形态.通过算例分析提出了张拉整体单体给定预应力态及初始几何选取的合理建议.

The purposes of this paper are focused on determining the initial equilibrium configuration of tensegrtiy structures which are self-stress equilibrium system and selected method of preset geometric configuration or prestress distribution. The force method and displacement method are implemented in order to establish the basic equations of nonlinear FEA and compile the form-finding program. In the light of stiffness characteritics of tensegrity structures, the convergency of iterative computation is solved. And the initial equilibrium configuration of tensegrtiy triangular prism is calculated and determined using the form-finding program. The form-finding program based on the virtual work theory can determine effectively the initial equilibrium configuration of tensegrtiy structures. Some reasonable advice for the preset geometric configuration and prestress distribution is given by investigating the tensegrity units.