基于逐点去约束法的索桁张拉结构形状判定及自应力模态求解方法

Cable-truss tensile structure is one of the most competitive spatial structures of cable-strut tensile structures. The shape determination and algorithm for self-stress modes are two key problems in design. Based on sorting and analyzing of the previous research results, it showed that most of the shape determinations of cable-strut tensile structure were solved according to the equilibrium matrix theory, which was difficult to be mastered due to the necessity of programming. Most of the existed methods to solve the self-stress mode cannot be directly used in the finite element software. To solve these problems, an improved constraints moved method based on reasonable configuration was proposed to determine the rational shape and solve the self-stress mode of cable-truss tensile structures. The method proposed was firstly based on the special topological relation of cable truss structure, and a simple formula for shape determination was derived from the rational shape. Meanwhile the method was proposed based on the idea that is shape determination first and then solving self-stress mode, which could ensure reasonable shape and self-stress mode one time and avoid the defect of solving self-stress mode firstly and then repetitively determining shape of the original method. Besides, the proposed method did not use the life-and-death unit technology of the original method, which ensured the convergence of solution process. The accumulative error caused by the technology of life-and-death unit technology was eliminated and the calculation precision was improved. The coordinate transformation was avoided and the solving process was simplified. The new method could be directly applied to the finite element software. Numerical calculations showed that the proposed method had a systematic solution flow and high convergence accuracy. The proposed method offered a new idea to determine shape and solve self-stress mode of the cable-truss tensile structures.