A Computational Analysis for an Adaptive Tensegrity-Based Four-Module Roof Structure

Tensegrity structures are closely coupled, pin-jointed structures composed of a set of bars in compression, surrounded by a network of cables in tension and are held stable in a state of self-stress. The main advantage of such structures is that they have a high strength-to-weight ratio and can be deployable. Reduction of both the material required and the space required in transportation contribute to a more environmentally sustainable infrastructure alternative. However, there are a few instances of tensegrity structures present in the built environment, although it has great potential to become integral part of mainstream civil engineering structures such as bridges, roofs, and domes. A four-module tensegrity roof structure inspired from a hollow-rope tensegrity-based pedestrian bridge presented by Motro (2006) is studied for its adaptability to counteract gravity loading conditions. The structure consists of bars (or struts) to take compression and cables to take tensile stress. Sets of struts are actuated to increase its length which helps the structure to readjust its form and adapt when subjected to any loading condition. Dynamic Relaxation (DR) is a form finding method useful for geometrically non-linear tensegrity structures. The topology of this roof structure is analysed utilizing dynamic relaxation. Changes to the deformation of this topology is studied when subjected to self-stress. The study shows the importance of actuation in controlling the shape of the structure subjected to various loading conditions under service. The control of shape helps in significantly reducing the deflection and physical stress experienced by the individual elements.