Prediction of shear length in blanking process by numerical analysis

Blanking process has high productivity compared with other cutting processes. Because of this feature, the blanking process is used for the manufacture of automobile parts, electronic parts and so on. However, the blanking process is the process that leads to fracture. When the cutting surface are used as the functional surface, such as gears or cams, the precision of cutting surface is important and it can be improved by applying appropriate process conditions. The appropriate process conditions have been determined by repeating many experiments and this process is very inefficient. Owing to this background, the determination of the optimal process condition by numerical method such as the finite element method (FEM) is expected. In the previous studies, blanking process analyses of round blanking process which were modeled as 2D axisymmetric problem have been carried out and the cutting surface that coincided well with the experimental result was obtained. However, the blanking shape was not taken into consideration and they were not considering whether it can be applied to complicated shape expected to be applied in the future. In this study, blanking process analysis of quadrilateral blanking process was modeled as 2D plane strain problem and the applicability of various ductile fracture criteria was examined by comparing numerical results with experimental results based on shear length. As a result, there was little difference in the applicability of Cockcroft and Latham, Ayada, Brozzo ductile fracture criterion to the prediction of shear length under the current conditions.