The Project
Curved folds have been explored by artists, designers, and geometers since the 16th century and in more recent years origami artists and computational folding experts have further developed the topic. However, there exist very few examples at the scale of a pavilion. This design research project resulted in building a freestanding shell that withstands most forces within the surface. The structure was realized with vulcanized paper, a material that is malleable while moist and becomes stiff after it dries. This enables a building process in two phases: The first phase consists in making a flat assembly; the second – in lifting the assembly with pulleys, folding it into its final configuration, and setting it into a base rail.
The Team
[Student Team: Xuechen Chen (Research Assistant), Sharon Broyn, Chafiq Ennaoui, David Huh, Bharati Kodnani, Yen Chi Lee, Shaun Mehta, Jonathan Ovshayev, Massi Surratt, Yuheng Wu, Runyu Zheng]
The geometry of curved creases The geometric topic that allows for a 2D to 3D transformation is based on curved folding research. Modeling curved creases in 3D software is difficult as we still don’t know a general mathematical description of the behavior of a curved crease (Demaine, E. et al. 2015). This design research project relies on a special case, namely: mirror-reflections of a general cylinder. The digital process is controlled in 3D where the cylinder can be mirror-reflected in CAD software. This means that the user is working with the curved surfaces in 3D on the computer. The cylinder is created by extruding a curve and subsequently quasi ‘folded’ with mirror operations. The flattened crease pattern can be used to fold sketch models that behave just like large-scale surfaces would in 3D. The 2D crease pattern includes mountain and valley assignments and in this case, also determines the curve that will touch the ground (seen in bold in the diagram below). The design process is based on iterating through many versions and making paper models at every stage. Physical models made of paper serve several purposes such as receiving feedback on surface deformations under stress by pushing down on the model with one’s finger. One main goal consists in finding two appropriate base curves that can serve as guide rails on the ground.
Making a full-scale curved folding prototype
In order to create a rigorous case study, several constraints need to be established to ensure a direct correlation to the small-scale process of making models. The chosen material is vulcanized fiberboard, a paper that is treated with an acid such that the bonding properties between molecules increase. The result is a paper-like product that is much stronger. The paper is malleable while wet and can dry in a deformed state, which is useful when folding creases. Once the desired fold is achieved it can dry and stay in place. Using compliant hinges, which means folding the material without destroying it, has several advantages such as folding accuracy and force transfer within the surface. The constraint of creating the entire 2D assembly first means that the creases need to be folded while the material is wet and malleable. The flat 2D assembly requires careful coordination as sub-assemblies need to be CNC-cut and connected using specific sequences and joint details. The parametric model is set up such that it considers several conditions:
panel-to-panel seams are adjusted when seams cross creases
sub-assembly connections are reinforced by laminating patches
bolt alignments and holes for stiffeners
The pulley system made of tripod cranes supports the assembly during construction as seen in the diagram below. Once the surface is in the correct position and dry, it can be set into the floor rails.
Project Gallery
