Process Planning for Precision Incremental Forming of Complex Parts

The incremental sheet forming (ISF) process is a relatively new sheet forming technology that enables creating parts with relative ease compared to conventional forming process such as stamping or hydroforming. The majority of the research regarding ISF has been on defining the relationship between the process parameters and the formability of the material. There has been limited research investigating the geometric accuracy of the part formed using ISF and this research is limited to relatively simple shapes such as cones and pyramids. In this study, a complex aircraft fuel cover part with 4 separate features is investigated. The sequence of forming the features was changed and the effect of the feature sequence on geometric accuracy and stress distribution was investigated during and after each stage of forming. It can be observed that certain geometrical features induce different boundary conditions during forming and result in differences in stress state and geometry in the surrounding region. It is concluded that the geometrical characteristic of the feature and its sequence has to be considered in ISF to produce parts with optimal stress distribution.