Pre-shear and compression phenomena of spherical and cubic particles during DEM simulation of ring shear test

The sensitivity analysis investigates the effect of particles shape (made by sphere, multi-spheres or polyhedral) for various contact force models on the calibration procedure via ring shear test. Experimental shear tests were performed using a Schulze Ring Shear Tester RST-01 with spherical and cubic particles. Pre-shear stress and vertical lid position behaviour were observed using Hertz-Mindlin and Linear Spring contact models. The findings confirm the necessity to include not only the shear force but also the compress behaviour of the particles in the shear test calibration. The results clearly indicate that the position of the shear lid provides discrete element method users with an important overview of the fundamental deformation behaviour and particle displacement during the pre-shear process. The results reveal differences between particle and contact force models considering the changes due to increased shear velocity useable for different representation of real-life particulate materials. The research is intended to provide DEM modellers with general information on which parameters are affected by changing the input data for each contact force model and particle shape. These insights enhance calibration procedures in both industrial and academic settings serving as a foundation for not only time optimizing DEM models and improving their accuracy.