Mesostructural investigation of micron-sized glass particles during shear deformation – An experimental approach vs. DEM simulation

¹ Institute for Particle Technology (iPAT), Braunschweig University of Technology, Braunschweig, Germany
² University of Duisburg-Essen and Center for Nanointegration Duisburg-Essen (CeNIDE), Duisburg, Germany
³ Institute of Stochastics, Ulm University, Ulm, Germany

^* e-mail: l.torbahn@tu-braunschweig.de
^** e-mail: dietrich.wolf@uni-duisburg-essen.de

Published online: 30 June 2017

Abstract

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 shear-tester 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.