The discrete element method (DEM), based on particle dynamics, is used to simulate the technological process of soil tillage using agricultural machinery. A key aspect of the DEM for obtaining accurate agrotechnical and energy indicators of soil cultivation is the formulation of particle contact rules, determined by normal and tangential interactions as well as cohesion forces. This study presents a comprehensive analysis of discrete element method (DEM) contact models used to simulate soil cultivation processes. This study addresses a key issue—the absence of a systematic approach to selecting adequate contact models, which limits the accuracy of predicting soil behavior during interaction with agricultural machinery. A detailed classification of 17 combinations of contact models implemented in the commercial software Rocky DEM was performed, grouped into three categories: normal force models (Linear Spring [LSP], Hysteresis [HLS], Hertzian [HSD]), tangential force models (Coulomb, linear spring limit [linear], Mindlin–Deresiewicz), and cohesive force models (linear cohesion [linear], constant force [constant], Johnson–Kendall–Roberts [JKR]). Experimental validation was conducted by analyzing the angle of repose for various soil types (sandy loam, light loam, medium loam, and heavy clay) with moisture contents ranging from 11 to 31%. This analysis identified the nine most effective combinations of contact models to describe normal, tangential, and cohesive forces (LSP–Coulomb–linear, HLS–linear–linear, HLS–Coulomb–linear, HSD–linear–linear, HSD–linear–JKR, HSD–Coulomb–linear, HSD–Coulomb–JKR, HSD–Mindlin–Deresiewicz–linear, HSD–Mindlin–Deresiewicz–JKR), which showed reliable agreement with experimental angle of repose measurements at approximately 85% accuracy. This study significantly contributes to advancing computer modeling methods in agriculture by providing a scientifically grounded approach for selecting DEM contact models.

Introduction. The discrete element method is the most promising method for modeling soil tillage. With the use of DEM modeling it is possible to create a digital twin for technological process of interaction of tools with soil, analyze the operation of tillage and seeding machines having various design and technological parameters, and predict energy and agrotechnical indicators of еtheir work. To improve the prediction accuracy, it is necessary to compare the obtained data with the results of field experiments. Aim of the Study. The study is aimed at developing a digital twin of the tillage bin through using the discrete element method and optimizing the main design and technological parameters of the dual-level opener. Materials and Methods. To simulate the process of the soil-opener interaction, there was used the discrete element method; the advanced Hertz‒Mindlin model was used as a contact model. For DEM modeling there is created a virtual tillage bin, which is filled with spherical particles of 10 mm diameter with the specified rheological parameters of the selected contact model. The main design factors for carrying out computer experiments in order to optimize them were the opener blade rake angle α and the furrow rake angle β. The opener traction resistance R was chosen as the output optimization parameter. Results. Implementation of multifactor experiments on the digital twin of the soil bin in the Rocky DEM program allowed to optimize the design and technological parameters of the dual-level opener: bit inclination angle α = 75o, furrow former inclination angle β = 21o, vertical distance between the bit and furrow former Δa = 11‒14 mm. Discussion and Conclusion. As a result of the modeling, it was found that the opener traction resistance increases in quadratic dependence on the opener operating speed and surface energy of the contact model.

Производство органической аграрной продукции означает производство в сельском хозяйстве чистых и экономически доступных основной массе населения продуктов питания без вредных для здоровья человека и животных примесей и не ведущих к порче их здоровья. Качество продукции, которую мы употребляем в пищу, зависит от технологии её производства, применения в ней гербицидов и больших доз минеральных удобрений, способствующих возникновению неизлечимых болезней. Современные технологии, исключающие различные виды обработок почвы, не могут существовать без применения гербицидов для уничтожения сорняков. Использование при этом энергонасыщенных тракторов и тяжёлой посевной техники ведет к переуплотнению почвы и снижению водопроницаемости почвы до метрового слоя, исключению влагонакопления, иссушению почвы и к искусственной засухе. В связи с этим коллектив учёных из различных регионов России трудится над разработкой и созданием отечественного проекта исключения продовольственной зависимости России и гарантии здорового жизнеобеспечения народа на основе исследований, проведенных в различных регионах России и одобренных на заседаниях научно-технических советов регионального и федерального уровня. Данный проект предусматривает производство органической продукции питания без применения гербицидов и химикатов на основе органических и биологических удобрений с использованием приемов влагонакопления, применением различных видов обработки почвы агрегатами отечественного...