索膜结构平衡法找形分析

目前,索膜结构的找形分析以非线性有限元法等数值分析法为主.这些方法依据本构关系建立节点位移与节点不平衡力间的刚度方程,进而迭代求解.计算时若初始形状与找形形状差异较大,则会使迭代计算发散.笔者从平衡条件出发,将索膜结构的找形过程视为大位移小应变的形状几何问题,从而引入平衡方法进行了找形分析.通过算例计算分析,得出该方法在初步找形方面具有简单、快捷、不依赖经验等优点,但尚需与荷载分析、裁剪分析结合来进一步探讨该方法的优势和不足.

Equilibrium Form-Finding Analysis of Cable-Membrane Structure

At present,form-finding analyses of cable-membrane structures are mainly performed by the numerical methods,such as nonlinear finite element method,etc.The stiffness equations of nodal displacements and nodal non-equilbrium forces are firstly established according to constitutional relationships,then are solved in iteration.Unfortunately,the iteration is easy to diverge and difficult to control.In this paper,an equilibrium method is suggested to use in form-finding analysis of cable-membrane structure,which is found to get the satisfactory shape more simply,efficiently and without depending on experience as before.In the used equilibrium method the form-finding process is considered as geometrical problem of large displacement and small stress.However it is more reasonable to evaluate the advantages and disadvantages of this method combining with load modes and cutting analysis.