Method to design and fabricate an octahedral-tetrahedral spaceframe from repurposed scaffolding

Abstract

Spatial structures find many applications in architecture and construction as flat trusses, but few examples take advantage of the rich variety of configurations that a multi-layered octahedral- tetrahedral (octet) spaceframe can accommodate. The octet geometry is considered because of its inherent versatility, rigidity and economy. This lattice has received renewed interest in the study of nano and microscale cellular structures due to advances in material science and additive manufacturing; we revisit the octet spaceframe in steel at the macroscale using repurposed components combined with accessible methods of fabrication.

Available connection systems for octet lattices are complex and require intensive production, and existing structural systems are proprietary or purpose-engineered solutions. This provides an opportunity to simplify the art of both joint and strut system, and document an inexpensive and open technology with broad application in resource-strapped and remote environments where material efficiency and accessible assembly are essential. This thesis demonstrates a method to design and fabricate an octet spaceframe using repurposed scaffolding.

A range of configurations and forms are modelled and generated within an octet point cloud. The structure can be evaluated in terms of human factors, utility and stiffness. The members used are commoditized steel cross-bracing with a variety of sizes that are commercially available. The joints are fabricated from steel plate using computer numerically controlled (cnc) water jet and are welded together into an orthogonal gusset. We justify a scale that is appropriate for an individual or small group to handle, fabricate and erect, with only the use of a few manual tools. A kit-of-parts of a multi-layered and multi-scale octet lattice is demonstrated, and FE methods to analyze and evaluate the structure are shown.