Effect of inclination and rotation of the sheet on sheet thinning and formability in robot assisted incremental sheet metal forming

Abstract Single point incremental forming (SPIF) has higher formability than other sheet metal forming processes. In SPIF, the existing computer numeric control (CNC) incremental forming which adopts 3-axis CNC milling machine to form the part incrementally by using a hemispherical tool has the limitation of forming steeper wall angle parts. An additional 2-degree of freedom (DOF) manipulator has been proposed to integrate with the existing 3-axis CNC milling machine to improve the formability of the sheet. In this method, to control the material flow and deformation state, the posture of the sheet has been changed by tilting the sheet along the needed direction and rotating at specific speed with respect to the vertical forming tool. Formability of the sheet has been investigated in terms of sheet thinning and strain distribution after deformation. Numerical simulation has been implemented initially and has been validated by conducting the experiments. The result of the research shows that formability can be improved by adding the 2-DOF manipulator to the existing system.