core.form-ula

Inspired by the cellular morphology of the wing of an insect, DRAGONFLY is a highly irregular grid-shell that cantilevers 35ft (10m) from its supports. Both the overall form and the patterning of tessellations were developed through an adaptive approach that looked for emergent force path and deformation characteristics.

For instance, to control vertical deflection, the depth of the panels or the curvature of the shell might be adjusted. On the other hand, in-plane instabilities resulting from shear deformation were controlled by reconditioning or adjusting the geometry to align with the dominant force paths. In this way, factors such as the density of mesh, cell type (i.e. four, five or six-sided polygons), thickness of cell wall and overall surface topology were adjusted through a performance driven optimization.

Aluminum plate metal was the material of choice because it is light weight and easy to work with, and because it was found to be more cost effective to fabricate than steel. The assembly consisted of 455 individual bent plates that were threaded, or spliced, together in such a way that no welding was required. If indicated by analysis, additional plates could be “stacked” together to increase material were high stresses occurred. Each plate was cut from bulk 4ft x 8ft x 1/8in thick aluminum sheets using CNC technology. Buro Happold developed a fabrication model, built in CATIA, that accounted for all plates, bend locations, bend angles and bolt hole locations. The model was built parametrically such that adjustments to the geometry could be quickly implemented and the bent plates could be “unfolded” for fabrication. Once unfolded, the plates were placed onto 4’x8’ sheets using an optimization/packing algorithm to minimize waste.

Although optimization of material and form were emphasized, DRAGONFLY was meant to achieve a kind of wild, dynamic, spatial architecture. The designers sought performance and wild variation. In doing so, Dragonfly reconsiders optimality in engineering, which is often about idealized problem solving, and attempts a messy evolutionary process closer to that seen in nature. Developed through close collaboration with EMERGENT, a design firm in Los Angeles founded by Tom Wiscombe, Dragonfly is an experiment on the fluid feedback of design sensibility, engineering innovation and fabrication logic in a contemporary digital environment where these disciplines have become intertwined like never before.

DRAGONFLY
Southern California Institute of Architecture (SCI-Arc)
Los Angeles, CA USA

Services Performed by Buro Happold for the Project
Structural Design, 3D Parametric Fabrication Model within CATIA environment, Assembly and Erection
Client’s Formal Name
SCI-Arc, Gallery Installation, 18 May 2007 to 8 July 2007
Architect’s Formal Name
Tom Wiscombe, founder of Los Angeles based design firm EMERGENT