可变体系的几何稳定平衡状态及受力分析

Study of form and force for unstable systems in geometrical stable equilibrium state

索和撑杆组成的张拉集成体系，膜结构及悬索体系，一般都要施加预应力使其成为能承受荷载的几何不变体系，整体受力表现为几何非线性。本文将其受力状态分解为两部分，一是几何稳定平衡状态，二是弹性稳定平衡状态。文中提出几何稳定平衡状态的分析计算方法，证明增量迭代法的收敛性。结果表明，所提出的方法收敛快，精度高。

\ The tensegrity, membrane, suspension cable are belong to unstable systems. This paper divides the equilibrium state of unstable system into two state:one is geometrical stable equilibrium state, the other is elastic stable equilibrium state. A method is developed to calculate the form and internal forces in geometrical stable equilibrium state, and the convergence is provided. The results of calculating the chain, suspended cable and tensegrity show that the method proposed has a good convergence and a high precision.