LAUSR

The discrete element method (DEM) parameters of wheat were calibrated for the modelling of a grain storage system. In addition, the effects of material parameters on the accuracy of DEM modelling of the oedometric compaction and unloading of bulk wheat were analysed. The bi-stiffness Hertz-like contact model was applied to incorporate the hysteretic behaviour of individual grains. The parameters of the contact model were calibrated based on experimental data of the loading–unloading cycle of a single wheat grain. The results of DEM simulations of the bulk behaviour of grain were validated using experimental data from oedometric tests. The observed trends indicate good correspondence between the experimental data and DEM simulations using the calibrated parameters. Simulations performed assuming spherical particles provide the best approximation of the loading–unloading cycle. The application of a special procedure for performing DEM simulations allows for the accurate reproduction of experimental values of the initial, compacted, and unloaded porosities of bulk wheat grains in the considered moisture-content range considered.