Deployable Textile Hybrid Structures: Design and Modelling of Kinetic Membrane-restrained Bending-active Structures

Abstract

By rapidly expanding from a compact, stowed bundle to a functional space enclosure, deployable structures can address temporary needs in a minimum amount of time. Using the intrinsic elastic behaviour of flexible elements - active bending - in the design of transformable or deployable structures leads to a wide range of kinetic concepts. This component transformation can decrease the complexity that often comes with rigid-body mechanisms. This paper presents one principle for deployable bending-active structures, based on the interaction between a deployable grid and a restraining membrane: deployable textile hybrid structures. A case study illustrates the design concept and the deployment and assembly processes that allow multiple structural transformations. The large interdependency of the form and material behaviour of bending-active structures, contrary to conventional form-active structures, requires a specific modelling approach. The approach presented in this paper allows feedback between the parametric input of starting geometry and material characteristics, and the output geometry and internal stress. Working with a high-strain fabric without cutting pattern, balancing the stresses and strains between the bending elements and tensile fabric becomes the prime focus. Although the preliminary results are acceptable in theory, a more detailed structural analysis and real-scale models should validate the assumptions of rapid assembly and the structural behaviour on a realistic and practical level.