Analyses of two-point incremental forming for parts with complex geometries

In this study, numerical and experimental investigation of two-point incremental forming of free-form workpieces is conducted. According to researches done, only a few number of previous works regarding numerical simulation of incremental forming method are concentrated on two-point type of this technique. However, all of these works have considered simple geometries like: truncated cone, truncated hemisphere and truncated regular pyramid. In contrast, in this paper, the numerical simulation is carried out for free-form parts and the methodology is independent of the geometry of the bottom punch. Thus the methodology can be employed to examine the feasibility of two-point incremental forming for any given geometry. In this paper a numerical simulation for exhaust tube a type of helicopter has been done and the results of simulation are verified with experimental data. Comparing major and minor strain values at the end of simulation with the forming limit diagrams of sheet metals it was possible to examine the likely tearing in the sheet.