Combining experiments and DEM simulations for characterization of physical and mechanical properties of rice, glutinous rice, corn and sesame for discrete element modeling

Accurate characterization of micro-parameters is essential for achieving reliable Discrete Element Method (DEM) simulations of agricultural granular materials. However, due to the natural variability in shape, size, and surface characteristics, experimental calibration of these parameters remains challenging. This study presents a systematic approach to characterize the DEM micro-parameters for four representative agricultural granular materials, rice, glutinous rice, corn, and sesame, together with simulation of grain transportation using pneumatic conveying method. The physical and mechanical properties, including particle size distribution, circularity, elongation, mass density, restitution coefficient, static and rolling friction coefficients, were measured through dedicated experiments. A series of numerical characterization tests, such as angle of repose, particle-wall collision, and silo discharge tests, were conducted using Altair EDEM software to verify the parameters until good agreement with experimental observations was achieved. Such a methodology provides a reliable reference for future studies involving numerical modeling of agricultural granular materials in handling, conveying, and storage systems.