Emerging Architectural Potentials of Tunable Materiality through Additive Fabrication Technologies
volumetric entities under the scale-dependent structural conditions. For the creation of watertight meshes the volumetric modeller Symvol for Rhino (Uformia AS 2011) was used, which allows a blending between the individual volumetric geometries. Additive fabrication is very suitable for even highly complex structures that are populated by auxetic knots as demonstrated in the following illustration (Ill. 78) of a catenoid helicoid-based surface with a periodic distribution of auxetic cellular members. Additive fabrication can easily reproduce such designs that are impossible to fabricate with conventional manufacturing processes.
Ill. 78 Catenoid-helicoid surface with a periodic tiling of maximum-re-entrant 3D auxetic knots
The proposed experiment constructs a single-layered array of three-dimensional auxetic knots with a gradient distribution of re-entrant values responsible for the expected Poisson ratio. The structure consists of a twodimensional array of 13 x 5 cells with each individual cell 30mm x30mm x 30mm in size. The overall dimensions of the test are 390 mm x 180 mm x 30 mm. The structure shows the maximum re-entry values in its centre and their gradual reduction towards the outer cells (Ill. 79). 165