|About this Abstract
|NUMISHEET 2022: The 12th International Conference on Numerical Simulation of 3D Sheet Metal Forming Processes
|Automated Nakazima Experiments for Studying Anisotropy and Loading Path Dependence of Necking Failure
|Vincent Grolleau, Christian C. Roth, Dirk Mohr
|On-Site Speaker (Planned)
Forming limit experiments such as the Nakazima test are important for the development accurate sheet metal failure models. However, the testing procedure is tedious and very few experimental campaigns include different material orientations combined with pre straining experiments. Here, we present an automated device for high-throughput Nakazima testing made of hardware components that are standard in the forming industry. Stereo digital image correlation is used for strain calculations, while a machine learning based algorithm is used to detect specimen failure. The machine is equipped with an automated specimen charger holding 35 specimens. Two aluminum alloys are tested in up to five orientations. Pre-straining is performed at two strain levels, under uniaxial (0°, 45° and 90° from the rolling direction) and equi-biaxial conditions. More than 800 tests are performed and post-processed, and the corresponding Forming Limit Curves as a function of the loading path are presented and discussed in detail.
|Definite: At-meeting proceedings