杆系可展开结构是一种新型空间结构形式,结构的刚性是其工程设计的关键.阐述了这种结构的基本特征,讨论了杆系铰接体系静动定分类方法,并引用线性理论中过定的概念明确了体系分类的力学含义.采用平衡矩阵的奇异值分解方法确定体系的静动定参数、独立自应力模态和机构运动模态.对几种典型的杆系可展开体系的分析表明:体系为实现展开功能而具有不同的机构状态.折叠结构需要附加约束来满足结构刚性要求,而张拉整体结构内在的一阶无穷小机构使其具有了承载能力.
Deployable member structures are a new type of space structure. In the design of engineering structures, the key is to ensure the rigidity of the structures. The basic properties of the deployable member structures are explained. The classifications of pin - connected bar system are discussed based on the static and kinematic property, and its in the linear theory. The mechanical explanations are given by introducing the concept of over - determinacy singular value decomposition method for equilibrium matrix is developed to obtain the static and kinematic parameters, independent states of self - stress and of mechanisms. The geometric stability of some typical member structures is investigated. It is found that different mechanisms are existed for the deployable functions of the structures. Addition of constraints is necessary for the rigid requirement of foldable structures. The load - capability of tensegrity structures is guaranteed by the infinitesimal mechanisms.