Computational Design-To-Fabrication Using Spatial Grammars : Automatically Generating Printable Car Wheel Design Variants 
 Chen, T., Shea, K., (2015)., In DS 80-2 Proceedings of the 20th International Conference on Engineering Design (ICED 15) Vol 2: Design Theory and Research Methodology Design Processes, Milan, Italy, 27-30.07. 15. Link
Additive Manufacturing (AM) technologies offer new possibilities for engineers to fabricate designs that may not otherwise be possible or cost-effective with conventional methods. However, each process has constraints that must be adhered to and designers faced with such freedom do not readily explore the new search space offered. Computational design-to-fabrication, introduced in this paper, utilizes new AM opportunities by encoding the constraints of AM processes as well as considerations such as style and performance, into generative design systems that automatically generate designs that are directly printable. This paper presents the specific example of generating car wheel spoke variants using a set of 12 spatial grammar rules that conform to the DfAM constraints for the Fused Deposition Modeling printer UPrint SE Plus and FEM meshing and analysis requirements. From a set of 72,500 valid designs, 100 were generated automatically, 12 of which are fabricated. The results demonstrate the spatial grammar’s capability to automatically generate valid designs, both known and new to spark creativity, that can also be directly analyzed with FEM and fabricated using 3D printing.
Shape Generation Rules
Using the following 5 topological rules, we are able to generate wheel rim patterns that closely ressemble those in production cars. In addition, we are also able to generate novel and interesting designs.
|Replacing a starting symbol with a ring and an initial spoke.||Adding a new spoke at an angle to the initial spoke in the clock-wise direction.||Rotating a spoke out of place and lengthening it such that it overlaps the ring.|
|Splitting a spoke in two, and rotating the outer portion.||Splitting the outer spoke in two length-wise, and rotating each.|
Here we show a fraction of the generated designs grouped by their novelty. We use 3D printing to fabricate some designs for prototyping.