Mesostructural investigation of micron-sized glass particles during shear deformation – An experimental approach vs. DEM simulation
Lutz Torbahn, Alexander Weuster, Lisa Handl, Volker Schmidt, Arno Kwade, and Dietrich E. Wolf
(Borosilicate Glass: 30um)
The interdependency of structure and mechanical features of a cohesive powder packing is on current
scientific focus and far from being well understood. Although the Discrete Element Method provides a
well applicable and widely used tool to model powder behavior, non-trivial contact mechanics of micron-sized
particles demand a sophisticated contact model. Here, a direct comparison between experiment and simulation
on a particle level offers a proper approach for model validation. However, the simulation of a full scale sheartester
experiment with micron-sized particles, and hence, validating this simulation remains a challenge. We
address this task by down scaling the experimental setup: A fully functional micro shear-tester was developed
and implemented into an X-ray tomography device in order to visualize the sample on a bulk and particle level
within small bulk volumes of the order of a few micro liter under well-defined consolidation. Using spherical
micron-sized particles (30 µm), shear tests with a particle number accessible for simulations can be performed.
Moreover, particle level analysis allows for a direct comparison of experimental and numerical results, e.g.,
regarding structural evolution. In this talk, we focus on density inhomogeneity and shear induced heterogeneity
during compaction and shear deformation.