Development and testing of a deployable double layer tensegrity grid

Tensegrity is a structural principle based on the use of isolated or contiguous pin jointed components in compression inside a net of continuous tension. Although the concept has been studied for many decades, relatively few examples of tensegrity structures have been used for civil engineering purposes. This paper describes the development and testing of a ‘Deployable Double Layer Tensegrity Grid’ (DDLTG). This type of structure can be easily stored, transported, and erected within a short time frame, allowing for many uses such as temporary shelters, exhibition roof structures, etc. A large scale 4×4 m grid structure was designed and constructed using the ‘Quastruts-S’ tensegrity module. A series of novel functional nodes were developed to cater for the connection of multi-directional cables and struts, while allowing for member rotations to permit folding the structure. The overall behaviour of the DDLTG proved satisfactory, and the structure folded into a compact cluster 0.56 m in diameter. A comparison of preliminary experimental results with theoretical predictions is provided and discussed.