Evaluation of process parameters of multipoint sheet metal forming

Sheet metal forming is a method that is frequently used to produce 3D parts in several industries, such as automotive and aviation. One of the most popular sheet metal forming techniques is stamping. However, traditional forming methods created for mass production are inflexible and expensive. For this reason, it makes them economically unsuitable for small-batch and prototype production. Flexible forming techniques, such as multi-point forming (MPF), which have recently been developed, are more suitable for small-batch and prototype manufacturing. Traditional solid stamping equipment could be replaced by a set of discrete dies containing pin boxes. The damage factor, effective stress distribution, and required forming loads of aluminium 1100 parts with a thickness of 0.5 mm were examined in this study using relative fixation and active punch adjustment methods. Finite element simulations were carried out using 10 mm, 12 mm, and 14 mm diameter pins for V-shaped (F1), wavy-shaped (F2), and 3D free-form surface (F3) components. Furthermore, experiments of relative fixation for the 12 mm diameter pin were performed, and the simulations were compared with the forming loads and the thinning contact points of the pin and formed sheet metal sections. In conclusion, it was discovered that the MPF process is significantly affected by pin diameter. Higher stresses and sheet metal tearing were caused by larger diameter pins. Also, it was seen that the active punch adjustment method is better than the relative fixation method for all shapes.