Fundamental Studies on the Development of Tensegrity Strutures

当连续旋转索系由在索系节点间间歇性布置的受压构件（杆件）支撑时，通过延长受压构件或缩短索系构件的方式对每个构件进行预应力，则该索系可以稳定并具有一定的抗外荷载刚度。这就是所谓的张拉整体结构。这种结构在土木工程建设领域还不实用，我们的目标是找出该系统在未来如何适用于该领域。本文的研究目的是对结构分析进行基础性的研究，为今后设计分析的实用方法奠定基础。本文的研究要点如下：(1)强调了几何非线性大变形分析的必要性，并为此编写了计算机程序。该程序是基于作者过去的研究工作的结果。(2)进行了各种数值算例研究，详细展示了结构在外荷载作用下的非线性特性，特别是在局部加载或非对称加载条件下的非线性特性。从而明确了线性理论应用的局限性。(3)由于结构的高度非线性性质，显然形状确定分析在实际设计计算中不可或缺。为此，我们利用作者过去在索结构理论方面的成果，发展了张拉整体结构的形状确定方法。定形分析结果表明，张拉整体结构对定形计算具有较高的灵敏度。(4)利用通用的数值结果，通过一个简单的设计模型验证了这种结构的适用性或可行性。

When a continuously spun cable system is strutted by compressive members (links) arranged intermittently between the nodes of the cable system and each member is prestressed either by lengthening the compressive members or by shortening the cable members, then this system can be stable and has some stiffness against external loads. This is a so-called tensegrity structure.This kind of structure is not yet practical in the field of civil engineering construction and we are aiming at finding out how this system can be applicable there in the future.The present purpose of the research is to make a fundamental investigation as to structural analysis for establishing the practical method of design analysis in the future.The outline of the research is as follows :(1) The necessity of geometrically nonlinear large deformation analysis is stressed and a computer program was developed for this purpose. The program is based on the results of the authors' past research works.(2) Various numerical case studies were conducted and nonlinear characteristics of the structure under external loads are shown in detail, especially under partial loading or non-symmetrical loading conditions. The limit of application of linear theory is thus made clear.(3) Owing to the highly nonlinear nature of the structure, it is obvious that the shape determination analysis becomes indispensable for the practical design calculation. For this purpose we developed the method of shape determination of tensegrity structure, by exploiting the authors' past results as to the theory of cable structures.The results of shape determination analysis show the high sensitivity of tensegrity structure against shape determination calculations.(4) The applicability, or feasibility, of this kind of structure was checked by a simple design model by using versatile numerical results.