Auxetic Bending-Active Formwork System for Free-Form Continuum Shells

Author

Nakayama, Kazunori and Awaji, Hiroki and Sakai, Yusuke and Yoshikawa, Ryo and Hayashi, Sei and Gondo, Tomoyuki and Kimura, Toshiaki

Abstract

Technological advancements in computational design have enabled the realization of free-form structures. However, it is still challenging to rationalize the construction in the case of non-developable surfaces. This paper proposes a novel approach to designing and constructing free-form shell surfaces effectively, using an Auxetic Bending-Active Gridshell (ABAG) as a formwork, and experimental models were constructed to validate the design and construction feasibility. To generate a curved surface with both positive and negative Gaussian curvatures, we propose a numerical method for the ABAG formwork, where a flat grid with both auxetic and non-auxetic patterns is generated by controlling a parameter. For building a pavilion, referring to the geometry of Tachira Club designed by E. Torroja, we conducted full-scale experiments to rationalize the connections and identify effective methods for utilizing Glass Fiber Reinforced Cement (GFRC) by examining its casting and demoulding processes for potential reusability. We constructed a 0.9 × 1.8 (m) experimental model to evaluate construction feasibility and to verify the accuracy of surface. Due to its material efficiency and lightweight, ABAG has the potential to rationalize the construction system for various free-form continuum shells.