SPIF of tailored sheets to optimize thickness distribution along the shaped wall

Tailored blanks are widely used in industry for reducing the parts’ weight without affecting stiffness. In this study, the authors proposed the use of the tailored blanks with an alternative aim. Specifically, the attention has been focused on the use of an initial blank with variable thickness for overcoming one of the main drawback of Single Point Incremental Forming process (SPIF), i.e. the material thinning. More in detail, blanks with variable thickness have been designed and experimentally tested for compensating the thinning phenomenon, which characterizes SPIF. An experimental and numerical research has been planned to consider the geometrical variables of the problem. Briefly, an artificial localised variable thickness has been imposed to the original blank with the aim to modify the overall strength of the sheet affecting its deformation. The idea has been analysed changing the depth and the position of the machined pockets on the sheet surface. The application of subtractive step, instead of forming or additive processes, was now preferred for time and cost saving. However, the outcomes of the experimentation can be easily transposed to any combination of processes. The feasibility of the proposed approach will be detailed in the paper.