timbR foldR

Gabriel Rihaczek MSc, Maximilian Klammer MSc / MArch, Okan Basnak MSc, ITECH MSc. 2020 Master Thesis, University of Stuttgart

Thesis Advisors
Axel Körner MSc and Dr.-Ing. Riccardo La Magna

Thesis Supervisors
Prof. Dr.-Ing. Jan Knippers (ITKE) and Prof. Achim Menges (ICD)

The research was realized as a master thesis in the framework of the Integrative Technologies and Architectural Design Research M.Sc. program (ITECH) at the University of Stuttgart, led by the Institute of Building Structures and Structural Design (ITKE) and the Institute for Computational Design and Construction (ICD).
Special thanks to Camex Turkey for the monetary and logistic support in the fabrication of the final demonstator.

The construction sector today accounts for largest share of both global final energy use and energy-related CO2 emissions [1]. In regards to a growing population with rising demand for new buildings and an aggravating climate crisis, it becomes apparent that the way buildings are constructed has to change fundamentally. This research investigates, how the transformation of a structural element can help with an increase of efficiency of construction processes by flat production and transport, as well as scaffolding free erection. Curved folding is employed to allow for a shape change between flat and spatial structure, due to the simplicity of the mechanism without many mechanical parts. Since curvature is induced in plates when they are folded along a curved crease, the research is also situated in the fields of bending active structures. While bending generally allows for expressive curvature with simple flat production as well as easy customizability, limitations are still presented by the laborious forming and the upscaling of individually bent plates. Previous work by R.Maleczek et al. [2] has proven that curved folding on a large scale is feasible to speed the bending process up tremendously. Research by O. Soykasap et al. [3] has shown that a closed cross section structure can be folded from flat. The present research builds up on these two projects, but adds a design framework for volumetric curved folded components, a bistable behaviour to lock the spatial state and comprehensive detail development in regards to upscaling and increased structural capacity. The mechanism is studied on a kinematic level, considering geometrical rules of curved folding and the design space, as well as kinetic level, building up on the kinematic model but considering the materiality. Plywood was chosen for its advantageous bending capabilities and accessible CNC fabrication infrastructure. As a proof of concept, a 1:1 scale demonstrator was built. Finite element modelling software was used to analyse and optimize the shape. The demonstrator was fabricated flat, folded up within one minute and locked by the bistability and steel bases. It was able to support 12 people with a self-weight of approximately 300kg.This project shows that the transformation of a structural element can be beneficial throughout the construction process and potentially lead to a circular economy. Computational planning and available fabrication infrastructure allows for a change of building habits starting now.

[1] IEA and UNEP, “2019 Global Status Report for Buildings and Construction: Towards a zero-emissions, efficient and resilient buildings and construction sector,” 2019.
[2] R. Maleczek, G. Stern, A. Metzler, and C. Preisinger, “Large Scale Curved Folding Mechanisms,” in Impact: Design With All Senses, Springer International Publishing, 2020, pp. 539–553.
[3] O. Soykasap, A. Watt, and S. Pellegrino, “New Deployable Reflector Concept,” in 45th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, 2004.