TETRA TUBES
TETRA TUBES is the design of a generative system that produces a single, self-supporting, inflatable structure. With this project we were specifically interested in producing a design that could be made entirely of heat-sealed developable surfaces, but was not a surface in and of itself. Rather we wanted to produce a variable, and occupiable inflated space frame. Because the air that flows inside of the inflatable would not be felt, we wanted the “strength of air” to be overt through structural expressiveness.
Beginning with the geometric fact that aggregated tetrahedrons could produce both continuity and variability, we designed an adjustable base form and used a generative script to compact a variable (n) tetrahedrons along coincident faces (fig. 1) This base form can be adjusted for dimensional and quantitative properties. This means that the form is adjustable for both interior and exterior dimensions (height, width, and depth) as well as the number of packed tetrahedrons (more tetrahedrons means more complexity) NOTE: our design above shows one of the more complex versions we tried for the dimensions specified by the competition rules.
Next we designed a script that would convert the tetrahedrons into a network of connected straight section tubes. The script in this case is adjustable for the width of the tubes themselves and produces only developable surfaces for ease of fabrication. (fig. 2) Technically, the entire inflatable can be one continuous trapped air tube. However, for practicality and redundancy, we expect that there would be many sections. This would allow for much smaller (and hidden within the tubes) fans and would also allow for fans to go off without affecting the entire structure.
Beyond the fact that the tube shape results in an ease of fabrication from flat non-stretch materials like vinyl, we also liked the tub because the shape is always unrollabe without loss (fig. 3), and because its pattern shapes always have two parallel edges. This allows for easy nesting and very, very little waste. (fig. 4)
We have built and installed inflatables before and are aware of the complex issues surrounding anchoring. In this instance we specifically designed a structure that helps resist a portion of the lateral forces through its overall form – the shape itself produces some negative pressure behind the wind force helping to reduce the resistance necessary. Also, because this form is a three dimensional lattice, it has far less force to resist than surface without (or with small) openings. Nevertheless, when being mounted outdoors, the piece will be anchored with weight in the bottoms of the tubes and with tethers anchored to the ground or stable points as needed. The design of TETRA TUBES allows for many, many points of connection and rather than being a simple material joint, our tethers can wrap the air members for far greater structural strength against lateral loads.
