Designing Grid Structures Using Asymptotic Curve Networks

Abstract

Doubly-curved grid structures pose great challenges in respect to planning and construction. Their realization often requires the fabrication of many unique and geometrically-complex building parts. One strategy to simplify the fabrication process is the elastic deformation of components to construct curved structures from straight elements. In this paper, we present a method to design doubly-curved grid structures with exclusively orthogonal joints from flat and straight strips of timber or steel. The strips are oriented upright on the underlying surface, hence normal loads can be transferred via bending around their strong axis. This is made possible by using asymptotic curve networks on minimal surfaces. We present the geometric and structural fundamentals and describe the digital design method including specific challenges of network and strip geometry. We illustrate possible design implementations and present a case study using a periodic minimal surface. Subsequently, we construct two prototypes: one timber and one in steel, documenting bespoke solutions for fabrication, detailing and assembly. This includes an elastic erection process, by which a flat grid is transformed into the spatial geometry. We conclude by discussing potential and challenges of this methods, as well as highlighting ongoing research in façade development and structural simulation.