Formability is a relevant issue in Single Point Incremental Forming (SPIT) process since it is one of the main point of strength together to the possibility to avoid any dedicated die. Several researches agree that depending on working material and process parameters, in SPIF operations there is a threshold slope of the wall that cannot be overcame without material breaking. If deep Incremental Forming is taken into account, despite the previous statement it is possible to demonstrate that, when the threshold angle is imposed, there is a relation between the actual workpiece depth and the material breaking approaching. In this paper, the latter relationship was investigated and formally derived by using a proper statistical regression.
AMBROGIO G, FILICE L, MANCO L, MICARI F (2007). A depth dependent analytical approach to determine material breaking in SPIF. In AIP Conference Proceedings (pp.331-336) [10.1063/1.2729534].