Folding-shearing: Shrinking and stretching sheet metal with no thickness change

Julian M. Allwood Christopher J.Cleaver Evripides G. Loukaides Omer Music Adam Nagy-Sochackia

50% of all sheet metal is scrapped, mainly by trimming following deep-drawing. To combat this a novel process inspired by the mechanics of spinning is proposed and its feasibility is tested with a novel experimental rig. A sheet is first folded along its long axis and then drawn through a die-set in a state of shear to reduce its width with no average reduction of thickness. The performance and limits of the process are evaluated with a novel experimental rig and new analytical and numerical simulations. The extension from this pre-cursor process to a more general forming process is discussed.