Vacuumatic Prestressed Flexible Architectural Structures

Vacuumatic pre-stressed structures (vacuumatics in short) can be defined as the rigidifying of a flexible system of enclosed structural elements by extracting the air within the structure (figure 1). The principle used is analogue to that of concrete pre-stressing, with the important difference that pressure created with vacuumatics is multi-directional and that once it is removed, the full original flexibility of the structure is restored. The advantage of the system is its form flexibility and reversibility, enabling the production of complex organic shapes for a wide variety of mutational architectural applications (figure 2). The behaviour of vacuumatic systems is highly dependent on the material properties and interaction between the individual components; the (granular) filler elements and the enclosing skin. Variations in elastic, frictional or stacking properties of the filler material and/or skin properties change the overall behaviour of the system significantly. This paper sets out to describe an ongoing parametric study to determine in a qualitative manner the structural and geometrical behaviour of vacuumatic pre-stressed structures. The parameters involved can be itemized in every level of assembly; material, element and structure (figure 3). The aim is to gain fundamental understanding in and control over the underlying design principles so as to be able to optimize structural assemblies to specific conditions and required behaviours. In the first stage of the research project the focus will be on 2-dimensional representations of vacuumatic principles.