Yw Yvonne Stegeman

An experimental and numerical study of a planar blanking process

Abstract Aiming at a validated model of the blanking process, an in situ study of the displacement and strain fields is carried out in a blanking experiment using a digital image correlation technique. Specimens of 13% Cr steel, 1 mm thick, are blanked at low speed, using a planar configuration with two different clearances (2 and 10% of the specimen thickness). In addition to the displacement and strain fields, load–penetration curves are also determined for both clearances. The experimental results are in good agreement with numerical simulations, the latter of which are carried out using a plane-strain finite-element model based on an operator split arbitrary Lagrange Euler (OS-ALE) method.

Can a new experimental and numerical study improve metal blanking

Abstract Blanking is still commonly used in high volume production. Yet, since high-tech products are becoming smaller and smaller, product specifications are becoming more severe. This usually leads to lengthy trial and error in developing industrial blanking applications. The fact that the blanking process is not yet fully understood and that the process is based on empirical knowledge, leads to this trial and error. Therefore, industry needs a suitable model to help overcome the long cycle time in developing a particular blanking process. We developed a finite element model and validated it using a planar experimental set-up. We not only measured the punch load, but also the logarithmic strain-fields. Using digital image correlation, we measured the displacement fields, coupled with a second order method to calculate strain-fields. For both small and large clearances, we concluded that the numerical model describes the blanking process well, up to ductile fracture initiation. This validated model will be a good starting point from which we tackle the issue of ductile fracture in future research.