Finite Element Analysis of Origami-Based Sheet Metal Folding Process

Origami-based sheet metal (OSM) folding is a novel approach regarded as extension of the origami technique to sheet metal. It requires creating numerous features along the bend line, called material discontinuities (MD). Material discontinuities control the material deformation and result in reduced bending force (BF), minimal tooling, and machinery requirements. Despite the promising potential of OSM, there is little understating of the effect of the selected MD shape and geometry on the final workpiece. Specifically, this is of interest when comparing the manufacturing energy and cost allocations for OSM with a well-establish process for sheet metal such as stamping. In this work, wiping die bending of aluminum sheet with different MD shapes and geometries along the bend line is investigated using finite element analysis (FEA) and compared to traditional sheet bending in terms of stress distribution along the bending line, required bending force and springback. The FEA results are validated by comparing it to the available empirical models in terms of bending forces. This study found that OSM technique reduced the required bending force significantly, which has important significance in energy and cost reduction. The study also found each MD resulted with different bending force and localized stress. Hence, MD are ranked in terms of the required force to bend the same sheet metal type and thickness for further future investigation. Springback is decreased due to application of MD. Meanwhile, MD generated localized high stress regions along the bending line, which may affect load-bearing capability of the final part.