DESIGN AND EXPERIMENT OF A DRAG-REDUCTION DIGGING SHOVEL FOR PEANUT HARVESTERS IN SALINE-ALKALI SOIL

To address the challenges of difficult soil penetration and high digging resistance encountered by peanut harvesters in saline-alkali soils due to compaction, this study designed a drag-reducing digging shovel for peanuts in such environments, using the dung beetle head as a bionic prototype and incorporating agronomic requirements. Basic physical parameters of the saline-alkali soil were calibrated, and Bonding-model bond parameters were configured to establish a discrete element model of the soil-root system. The Hertz-Mindlin with JKR contact model was selected as the discrete element simulation model for the soil. A 3D scanner was employed to capture the morphology of the dung beetle, obtaining its precise three-dimensional model. The curve equation of the bionic digging shovel was determined, and its 3D model was constructed. Comparative simulation tests between the bionic and conventional digging shovels were conducted, during which particle flow velocities were tracked and their vector distributions analyzed to elucidate the drag reduction mechanism. Furthermore, by comparing the resistance forces acting on the conventional and bionic shovels at speeds of 0.4 m/s, 0.6 m/s, and 0.8 m/s, drag reduction rates of 4.82%, 3.03%, and 3.85%, respectively, were achieved for the bionic shovel. These results validate the accuracy of the mechanical model and the rationality of the bionic structural design.