11-06-2015, 04:07 PM
Tensegrity is a relatively new principle (50 years old) based on the use of isolated components in compression inside a net of continuous tension members, in such a way that the compressed members (usually bars or struts) do not touch each other and the pre-stressed tensioned members (usually cables or tendons) delineate the system spatially and in a self-equilibrated state.
Tensegrity structures are 3-D trusses where some members are always in tension while others are in compression. The Tensegrity concept offers a high level of geometrical and structural efficiency and results in modular and lightweight structures. However, the concept of Tensegrity is still not a part of the main stream structural design wing due to various reasons.
The main aim of this work is to prove if it is possible to find some applications for such an atypical kind of structure, in spite of its particular flexibility and relatively high deflections. For that it is essential to understand the structural principles of floating compression or tensegrity, and to define the fundamental forces acting on it
Concept Of Tensegrity Structures
Tensegrity structures are structures based on the combination of a few simple but subtle and deep design patterns:
1. Loading members only in pure compression or pure tension, meaning the structure will only fail if the cables yield or the rods buckle.
• Preload or tensional pre-stress , which allows cables to be rigid in tension.
• Mechanical stability, which allows the members to remain in tension/compression as stress on the structure increases.
Because of these patterns, no structural member experiences a bending moment . This can produce exceptionally rigid structures for their mass and for the cross section of the components.
A conceptual building block of tensegrity is seen in the 1951 Skylon tower which follows the typical tensegrity structure concept. But there are variations such as the Needle Tower which involve more than three cables meeting at the end of a rod. These cables define the position of the end of the rod which is considered as a well-defined point in space and the other additional cables are simply attached to this well-defined point.
Eleanor Hartley points out visual transparency as an important aesthetic quality of these structures. Korkmaz put forward that the concept of tensegrity is suitable for adaptive architecture due to its lightweight characteristics.