Finite element analysis and experimental investigations for improving precision in single point incremental sheet forming process

ABSTRACT

As it is well known, the design of a mechanical component requires some decisions about tolerances and the product has to be manufactured with a careful definition of the process set up. Although standard sheet metal forming processes are strongly controlled, new processes like Single Point Incremental Sheet Forming remain to be improved. In SPIF, the final geometry is generated by the envelopment of all positions assumed by a simple forming tool which deforms a clamped blank. No dies are required differently than any conventional sheet metal forming processes. Although ISF concept allows to increase the flexibility and to reduce set up costs, such a process has a negative effect on the shape accuracy by initiating undesired rigid movement, elastic springback and sheet thinning. This paper emphasizes the necessity to control all process parameters to improve final shape accuracy. To attend to this aim, a finite element analysis is performed in order to study the influence of forming strategy on the opening or the closing of rings taken from a truncated cone manufactured by SPIF. The results obtained allow to have a better knowledge of springback effect on parts manufactured by SPIF with the aim to improve their accuracy.