Investigating the design and process parameters of folded perforated sheet metal

Origami-based sheet metal (OSM) bending is an extension of rigid origami technique, where the final 3D structure is created from a single 2D flat pattern by bending. The key aspect of OSM is material discontinuity (MD), which helps achieve a unique dieless bending process. MD is a feature along bend line of blank sheet and it can be fabricated using laser or water jet cutting. Even though a number of successful implementations of OSM bending have been found, these cases are limited only to product development and industrial application. The mechanics of OSM bending with respect to parameters that define MD, blank sheet, as well as the bending process have not been studied. Thus, this study identifies parameters and investigates the effect of identified parameters associated with OSM bending. Parameters studied in this work include design parameters and process parameters. Design parameters are kerf-to-thickness (k/t) ratio, web-to-width (w/b) ratio, and thickness of sheet (t). These are associated with MD design. The process parameters are related to OSM bending process, and they include punch placement (t+g), offset distance (s), and punch radius (RP). Finite element analysis (FEA) is performed to investigate the effect of these parameters on the OSM bending process. The simulated OSM bending cases resulted in successful bending without using a die. The general recommendation is provided for selecting parameters of OSM bending based on results. In addition, the shape of MD is an important factor when designing the OSM bending process.