Testing and Calibration

An Experimental and Numerical Investigation on Vulcanized Fiber

As the automotive industry and its companies start to look for sustainability, materials made of natural fibers receive a growing interest. In the present work, the mechanical properties of a vulcanized fiber material were investigated to understand the orthotropic and rate-dependent material behavior and make it more predictable and thus practicable. *MAT_PAPER was used to represent the anisotropic elastic-plastic behavior of the material for crash and impact simulations. To confirm numerical results from explicit FEM calculations, a user material subroutine comparable to *MAT_PAPER was utilized. Therefore, it was possible to perform implicit calculations of the conducted validation experiments which were performed at low strain rates.

Yield Locus Exponent Modelling of Packaging Steel for an Optimized Simulation of Limited Dome Height Experiments

In packaging steel forming processes, conditions in-between plane strain and biaxial tension are mostly relevant as they lead to failure in deep drawing applications and characterize e.g. the process of the rivet forming in easy-open end applications. To receive precise simulation results in finite element analysis, it is important to consider an accurate modelling of the yield locus in this area. Complex anisotropic yield functions like e.g. Yld2000-2d which was proposed by Barlat and is implemented in LS-DYNA using keyword *MAT_133 do not consider the characterization of this area and maintain an uncertain variable by the yield locus exponent.