【摘要】 对于施工阶段松弛悬索体系的找形分析,体系的几何不稳定性将引起结构的刚度奇异,使仅适用于稳定结构分析的常规方法失效.针对此问题,基于"力密度法"的基本思想,提出一种给定单元原长的松弛悬索体系的找形方法.从单索特性分析入手,直接推导节点坐标和外荷载之间关系的基本方程,避免了刚度矩阵的建立.同时采用抛物线索单元,考虑了索的垂度效应.通过一个正交索网和一个悬挂索环的算例分析,验证了该找形方法的精确性和有效性.更多还原

【Abstract】 Conventional form finding methods are merely suitable for stable structures and inapplicable to slack cable assembly during erection process for its unstable geometry and singular structural stiffness. Based on the principle of the force density method, a new form finding method of slack cable system with given unstrained elements lengths was developed. Starting from analysis of properties of single cable, the governing equation that reflects the relationship between the nodal coordinates and the nodal forces was deduced directly without establishment of stiffness matrix. Parabolic cable element was applied in this method to sufficiently consider the effects of sag. An orthogonal cable net and a suspended cable ring were illustrated to verify the accuracy and validity of the method respectively.更多还原