A computer Based System for the Design and Fabrication of Tensegrity Structures

Abstract

Tensegrity structures are composed of tension compression com­ponents, where the compression components (bars) are discontinu­ously enclosed within continuous tensile components (cables). From an engineering point of view, a tensegrity structure is characterized by geometric non-linearity and large displacements under loading. Therefore, its prestressed shape and deformation under loading are the result of the combined effect of the geometric parameters that determine the initial configuration of the structure, the level of pre­stress applied to cables, and the material properties of the compo­nent members of the structure. A method for generating the initial geometric configuration of tensegrity structures composed of tenseg­rity units and a parametric expression of this geometry have already been developed. A novel technology that makes possible the construction of tensegrity structures from the on-site assembly of deployable tensegrity units, which are fur­nished with a simple mechanism that permits bar-elongation, and, as a result, an increase of the prestress applied to the cables of each unit, is also under development. Also under development is a static analysis method that takes into account the above method for prestressing cables. This paper discusses the features of a system that supports the combined geometric and structural design of tensegrity structures, and integrates a graphical interface to display: a) models of initial geometry, b) geometry of the structure after prestress and loading are applied, and c) magnitude of forces applied to the structure’s component members (bars and cables). The system also provides numerical data to be used in component fabrication, and is therefore expected to become a very valuable tool for the design and construction of tensegrity structures.