Revisiting formability limits in incremental sheet forming

Abstract. The digital transition in manufacturing is driving significant advancements toward mass customization, enabling the production of tailored products at lower costs and shorter lead times. Single Point Incremental Forming (SPIF) is a promising technology in this context, offering the flexibility needed for producing complex, customized geometries without the need for dedicated tooling. Unlike conventional forming processes, SPIF relies on unique deformation mechanics that allow for higher formability, with the fracture forming line (FFL) as the process limit. This work revisits the analysis of formability limits in SPIF for aluminium sheets, revealing that fracture strains can occur beyond the FFL strain levels.