Authors

Abstract

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.

Abstract in Chinese

针对当前花生收获机挖掘铲在盐碱地工作时，由于盐碱地土壤板结导致花生收获机械挖掘部件入土困难、挖掘阻力大等问题，本文以蜣螂头部为研究对象，结合农艺要求，设计了一款盐碱地花生减阻挖掘铲，通过对盐碱地土壤进行进本物理参数标定，设置Bonding键参数建立三七根茎的离散元模型。选用Hertz-Mindlin with JKR模型作为土壤的离散元仿真模型。利用三维扫描仪对蜣螂进行扫描，获取蜣螂的三维模型。确定仿生挖掘铲的曲线方程，并建立仿生挖掘铲的三维模型。通过开展仿生挖掘铲与普通挖掘铲的仿真对比试验，并对颗粒的流速进行追踪，分析颗粒流速的矢量分布明晰了挖掘铲的减阻机理。再通过对比普通挖掘铲与仿生挖掘铲在0.4m/s、0.6m/s、0.8m/s的速度下挖掘铲所受的阻力大小。得到仿生挖掘铲在这三个速度下的减阻率分别为4.82%、3.03%、3.85%。验证了挖掘铲力学模型构建准确，仿生结构设计合理。