Funicular Explorations: Cardboard Box Curves Achieved through External Post-Tensioning
Structural designers often face the challenge of developing forms optimal for a broad range of requirements, but inefficient in terms of structural behavior. In these cases, bending moments often occur under normal loading, resulting in oversized, inelegant, and materially intensive structures. This paper presents a pavilion, designed and constructed for the IASS Expo 2015, that exemplifies new research that addresses this critical issue: the design tradeoff between geometric freedom and structural performance. In separately presented paper , a new method is introduced for designing external post-tensioning systems to eliminate bending moments in planar geometries that are nonfunicular. Instead of taking loading as a given and searching for funicular geometry, this approach takes geometry as a given and computes the loading(s) for which it is funicular. Using graphic statics, a range of possible post-tensioning systems to apply this loading can then be explored. This pavilion, called Funicular Explorations, serves as both a validation and demonstration of this new method, expressing the creative freedom of designers and the structural performance of the results. The proposed design is an array of eight two-dimensional curves, made from custom-cut corrugated cardboard and nylon webbing. The array begins with a funicular parabolic arch, and progresses toward a visually expressive but structurally arbitrary shape. The external post-tensioning system contributes increasingly from one curve to the next, finally allowing the terminal free-form shape to be achieved with axial forces only. The result is visually exuberant but also didactic, illustrating the possibilities and tradeoffs in funicular explorations for architectural design.
Record created on 2016-06-15, modified on 2016-08-09