Design Analysis for Origami-Based Folded Sheet Metal Parts

1 The manufacturing of Origami based sheet metal products is a promising technology, mostly in terms of reducing the tooling and process complexity. This procedure can also be called fold forming, as it depends on exclusively shaping the required geometry via sequence of bends. However, the design analysis and modeling of folded sheet metal products are not fully mature, especially in terms of determining the best approach for transferring the analysis from a three-dimensional (3D) to a two-dimensional (2D) context. This manuscript discusses the extension of the Origami technique to the fold forming of sheet metal products represented in modeling approach and design considerations for the topological variations, the geometrical validity, and the variance of stress-based performance. This paper also details the optimization metrics that were developed to reflect the design and manufacturing differences among the possible topological and geometrical options for a single part design. These metrics target five different optimization objectives: material utilization, cost, ease of manufacturability, ease of handling, and mechanical behavior estimation. A boundary representation is first used to embody the 3D geometry of the sheet metal part. Next, the face adjacency matrix is used to translate the topological information into a generic format valid for numerical analysis. The uniqueness of this approach lies in analyzing the topological aspect of the part's 2D layout by graph modeling and a developed graph traversal algorithm. The analysis then involves a subsequent investigation of the geometrical validity using a proposed scheme for overlapping detection. Finally, the authors estimate the variance in mechanical behavior among all possible 2D layouts for a single part by adopting the structural matrix analysis and propose a modification factor suitable for sheet metal applications. In this manuscript, three design case studies for automotive components made of Origami based sheet metal products are described: i) a battery pack tunnel for electrical vehicles, ii) a vehicle's interior (dashboard and floor pan), iii) and a shock tower.