Zero Gravity: a novel cantilever beam utilizing elastic torsion for structures and architecture

Abstract

This paper describes the structural geometry of a beam element, which is assembled from 4 coupled, thin elastic strips through intentionally applied torsion. Consequently, the beam element generates a self-restraining system. Our investigations are based on architectural design studies of preliminary paper models, laboratory experiments of the full-scale cantilever beam, and computational structural simulations. We are also providing a comparison between digital, physical, and photogrammetric results. We describe the production, assembly, disassembly, the shape generation principles, and the final shape of the beam element in various scales from paper model to physical prototype. We are exploring the design and application space as well as the digital generation and the digitalization of the beam geometry. The paper pays special attention to the geometrical stiffening effect, which has been described by the Föppl-von Kármán (FvK) equations. The phenomenon of notably undulating surfaces of the individual strips of the beam is associated with their length-to-width-ratio but mainly with the extremely thin material thickness. The utilization of elastic torsion as a design driver links structural efficiency, architectural potentials, and aesthetics as first demonstrated in the realized research pavilion "Zero Gravity" by the team of A"SA (Aalto University Structures and Architecture) in 2019.Peer reviewe