08 June 2011

Voussoir Cloud

This project called Voussoir Cloud is a site specific installation created (2008) by IwamotoScott Architecture and Buro Happold for the Southern California Institute of Architecture gallery, Los Angeles.

Voussoir Cloud explores the structural paradigm of pure compression coupled with an ultra-light material system. The design fills the gallery with a system of vaults to be experienced both from within and from above. The edges of the vaults are delimited by the entry soffit and the two long gallery walls. Spatially, they migrate to form greater density at these edges. Structurally, the vaults rely on each other and the three walls to retain their pure compressive form. The fourteen segmented pieces also resolve to make a series of five columns that support the interior and back edge. See more;

The overall design draws from the work of engineer/architects such as Frei Otto and Antonio Gaudi, who used hanging chain models to find efficient form. We used both computational hanging chain models to refine and adjust the profile lines as pure catenaries, and form finding programs to determine the purely compressive vault shapes.

The three dimensional petals are formed by folding thin wood laminate along curved seams. The curve produces an inflected and dished form that relies on the internal surface tension of the wood and folded geometry of the flanges to hold its shape. At the same time, materially, the flanges want to bulge out along the curved edge. This is what allows for the structural porosity within the constraints of sheet material. The flanges of the resulting dimpled, concave petals pack together as compressive elements and press upon each other. This attribute naturally creates vaulted forms and led initially to the overall design.

By beginning with a material operation of folding using small handmade models to test geometric relationships of bending along a curved seam, the design and construction process that followed focused on calibrating the relationship of digital model to physical corollary through iterative empirical testing. There are four cell types in Voussoir Cloud with zero, one, two, or three curved edges. Each cell behaves in a slightly different manner based on its size, edge conditions, and position relative to the overall form.

The curvature of each petal -- its dished shape – is dependent upon its adjacent voids. First, the plan curvature at each petal edge is defined by its end points and a set of tangents with neighboring modules based on the centroid of the adjacent void. The sectional deformation of the petal is then proportionally related to this plan curvature. If the flanges of the petal are perpendicular to the original cell surface, the proportion is one to one. At any other flange angle, the amount the petal dishes in section varies proportionally with the plan curvature at each edge. Because the flange angles are dictated by the normals of the vaults rather than the cell itself, the amount the petal dishes, and therefore its size (the petal shrinks in plan the more it dishes) has a unique geometry that needed to be calibrated to fit into the overall form. To do this, a computational script was developed for the Rhino model that managed the petal edge plan curvature as a function of tangent offset -- the more the offset, the greater the curvature. Though mathematically, this proportional relationship of tangent offset to sectional height is non-linear, it is simplified here as a simple percentage.

In the design, the petals are defined with less offset, and are therefore flatter towards the base and edges where they gain density and connect to purely triangulated cells. They have greater offset, and more curvature at the top to create the dimpled effect on the interior. The Rhinoscript instantiated each of the 2,300 petals according to these criteria. Once the three dimensional petal geometries were digitally modeled, a second batch process was developed to unfold each petal for laser cutting. Finally, the petals are reconstituted by folding along the curved score lines, and simply zip tied together. In the end, Voussoir Cloud attempts to defamiliarize both structure and the wood material to create conflicted readings of normative architectural typologies. It is a light, porous surface made of compressive elements that creates atmosphere with these luminous wood pieces, and uses this to gain sensorial effects.


Design, fabrication and assembly: IwamotoScott
Project Team: Stephanie Lin (leader), Manuel Diaz, John Kim, Alan Lu, Tiffany Mok

Scripting: Chris Chalmers, John Kim - Scripting Consultant: Andrew Kudless

SCIArc Student Installation Team: Joanne Angeles (leader), Oliver Liao (leader), Liona Avery, Mathew Cavender, Jimmy Chan, Tim Francis, Channah Levy, Marisol Mejia, Zarmine Nigohossian, Davis, O’Reagan, Nicholas Paradowski, Brett Phillips, Justin Rice, Sarah Strauch, Ali Sykes, Judson Terry, Yohei Uchino, Vincent Wu

Structural Engineering: Buro Happold, LA
Materials: Lenderink Technologies
Laser Cutting: Advanced Laser