Automated Flexible Forming Strategy for Geometries With Multiple Features in Double-Sided Incremental Forming

Double-sided incremental forming (DSIF) is a dieless sheet metal forming process that uses two generic tools to form a part of arbitrary geometry from a clamped sheet via the accumulation of small localized deformations. In DSIF, there is a need for an automatic toolpath generation method to separate geometric features coupled with a strategy to form these features in the correct sequence such that they can be accurately formed. Traditional CNC machining toolpaths are not suitable for DSIF because these toolpaths are designed for material removal processes, which do not have to account for the motion of the virgin material during the process. This paper presents a novel and simple way to represent geometric features in a hierarchical tree structure during z-height-based slicing along with algorithms to generate different forming strategies using this tree structure. The proposed approach is demonstrated through physical experiments by forming a complex part with multiple features.