Discrete Element Experiment and Simulation

Abstract

The advancement of sensing and manufacturing technologies allows us to carry out the discrete element experiment and simulation in parallel; this possibility grants us a precious opportunity to reassess the validity of discrete element method (DEM). In this study, the biaxial test of randomly packed printed elliptical rods and the corresponding DEM simulation are carried out in parallel. We first present the specially designed biaxial testing system, for which the 3D printing technique is applied to ease the manufacturing process. A packing of elliptical rods, also produced by the 3D printer, is used as the testing sample. The particle motion during shearing is traced using the particle image velocimetry (PIV) and close-range photogrammetry (CRP) techniques. In the DEM simulations, the contact model is derived and then validated by finite element analysis; other associated parameters are calibrated by different tailor-made experiments. Overall, the DEM simulation is found effective to reproduce the experimental findings of the macroscopic stress-strain-volumetric response and the microscopic strain localization.