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.

中文翻译：

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散装小麦贮藏离散元法模型参数标定

对小麦的离散元法 (DEM) 参数进行了校准，以模拟粮食储存系统。此外，还分析了材料参数对散装小麦压实和卸载的 DEM 建模精度的影响。应用双刚度类赫兹接触模型来合并单个晶粒的滞后行为。接触模型的参数根据单粒小麦装卸周期的实验数据进行校准。使用来自 oedometric 测试的实验数据验证了晶粒体积行为的 DEM 模拟结果。观察到的趋势表明实验数据与使用校准参数的 DEM 模拟之间具有良好的对应关系。假设球形颗粒进行的模拟提供了装载-卸载循环的最佳近似值。执行 DEM 模拟的特殊程序的应用允许在考虑的水分含量范围内准确再现散装小麦颗粒的初始、压实和卸载孔隙率的实验值。