A new flexible multi-point incremental sheet forming process with multi-layer sheets
Xuelei Zhao, Hengan Ou
Abstract
In this research, a new flexible multi-point incremental sheet forming process with multi-layer sheets (F-MPIF-MLS) was proposed. The novelty of this new forming process is demonstrated by two specific aspects of contribution. The first is the development of a new flexible multi-point die system to replace the conventional multi-point die, in which the multi-point pins are in contact with and provide support to the blank sheet from the start to the end of the forming operation. The second is the use of multi-layer sheets, which allows the target blank sheet to be deformed without clamping constraints. The new F-MPIF-MLS process clearly shows the benefits of overcoming the limitations of excessive sheet thinning and poor surface finish of the existing conventional multi-point incremental sheet forming (MPIF) process. A detailed comparative investigation into the new F-MPIF-MLS and the conventional MPIF processes is conducted through experimental testing and finite element (FE) simulation. The results show a noticeable reduction of wrinkling by using the new flexible multi-point die over the conventional multi-point die system with multi-layer sheets to form a dome shape. Moreover, in using the new F-MPIF-MLS process, the maximum thickness reduction is significantly reduced from 35% to 5% as compared to the conventional MPIF process to achieve a more uniform thickness distribution of the formed part.