八面体桁架单元及其派生系所构成的空间伸展臂

基于空间机构学和拓扑理论，提出了5种八面体及其派生桁架单元；根据平衡矩阵的条件数和刚度矩阵的条件数与最小特征值，评价基本单元的结构特征。由基本单元构造了展开单元，进而构造了空间伸展臂；阐明了展开单元与伸展臂的工作机理，分析了机构特性，推导出单元体系转换过程的详细几何列式，验证了张力体系中力学与几何形式的统一，并更正了某些观点。

Space Masts Constructed from Octahedral Truss Units and Their Derivatives

Based on spatial mechanism and topology theory, five basic units of octahedral truss and their derivatives were proposed. The structural performances are evaluated from the condition number (CN) of equilibrium matrix, and CN and minimum eigenvalue of stiffness matrix. The fundamental deployable modules are created from the basic units, and then the corresponding space masts are formed. Furthermore, the work mechanisms were illuminated. And the knowledge of geometric formation was formulated for different deployable modules in the course of deployment transformation, especially for variable geometry truss and tensegrity space masts. Finally, the concept of unity of mechanics and form was verified for tensegrity system, and some obscure concepts were clarified.