|About this Abstract
||NUMIFORM 2019: The 13th International Conference on Numerical Methods in Industrial Forming Processes
||S-01: Modeling of the Anisotropic Behavior in Plasticity
||Determination of Strain Dependent Anisotropy in Layer Compression Tests and Resulting Influence on the Yield Locus Modelling
||Matthias Lenzen, Marion Merklein
|On-Site Speaker (Planned)
The improvement of the mapping accuracy in sheet metal forming simulations is an important field of research today. In this context, common materials like DC06 show a complex material behavior which makes it difficult to transfer the experimental data to a mathematical model. Especially the strain dependent material properties like the anisotropy and strain state dependent hardening are not respected adequate in conventional material models like Yld2000-2d due to the assumption of isotropic hardening. While the evolution of the Lankford coefficients in uniaxial tensile tests is well investigated, the anisotropy evolution under equi-biaxial loading is not considered strain dependent in numerical modelling yet. Therefore, layer compression tests with two 3d optical strain measurement devices are performed to identify the material characteristics in both principal strain directions. With the optical strain fields, the strain dependent anisotropy coefficient under equi-biaxial loading as well as the flow curve can be calculated. Results prove that the anisotropy value is not constant but shows a progression similar to the uniaxial material behavior. A strain dependent modelling with the identified properties leads to a significant change in yield locus geometry for DC06 at high strains. Numerical simulation with the identified strain dependent material properties should lead to a better accuracy regarding flange and sheet thickness distribution in the process design.