Authors

Abstract

Rotary tillage is an energy-intensive process, especially in the cohesive, salt-affected soils. As a result, optimizing the geometry of tillage blades is crucial for reducing soil-cutting resistance and improving tillage efficiency. Biomimetic designs inspired by effective biological structures that interact with soil offer a promising approach to achieving this optimization. In this study, a bio-inspired blade was designed based on the contour curves of the brown bear's claw (Ursus arctos). A Discrete Element Method (DEM) model was chosen and calibrated to accurately simulate soil–tool interactions under the specific soil conditions of the Yellow River Delta. This calibrated model was subsequently used to assess the performance of the bio-inspired rotary blade. The key parameters of the proposed DEM model were initially identified through a Plackett-Burman screening test. Subsequently, a Central Composite Design was used to determine the optimal combination of these parameters, using the experimentally measured draft force of a chisel shank as the calibration response. The performance of the bio-inspired blade was then compared with that of a conventional IT-type blade through DEM simulations and soil bin experiments. The focus was primarily on torque demand and soil fragmentation rate as the main evaluation metrics. The trapezoidal rule for numerical integration was used to determine the disturbed soil area. The simulation results showed that the bio-inspired blade produced less torque, with reductions of up to 13% at rotational speeds ranging from 160 to 320 rpm and up to 11% at tillage depths of 60-140 mm. Soil-bin tests indicated that the bio-inspired blades produced a rotary torque that was 17.8% lower than that of the IT-type blades. In contrast, the IT-type blades achieved a slightly higher soil fragmentation rate, exceeding the bio-inspired blades by 3.9%. This study demonstrates that biomimetic design principles, particularly those derived from digging-adapted biological structures, can significantly reduce the energy requirements of rotary tillage tools while maintaining effective agricultural performance. Furthermore, the calibrated DEM framework serves as a reliable tool for future studies on soil-tool interaction in salt-affected soils of the Yellow River Delta, supporting the development of energy-efficient machinery for challenging soils.

Abstract in Chinese

旋耕作业属于高能耗工序，尤其在黏性盐渍土壤中更为显著。因此，优化耕刀几何结构对降低土壤抗剪切阻力、提升耕作效率至关重要。受自然界生物结构启发的仿生设计，为实现这一优化提供了可行方案。本研究基于棕熊爪（Ursus arctos）的轮廓曲线设计了仿生耕刀。采用离散元法（DEM）模型并进行校准，以精确模拟黄河三角洲特定土壤条件下的土-刀具相互作用。通过校准模型评估仿生旋耕刀的性能表现。首先通过Plackett-Burman筛选试验确定DEM模型的关键参数，随后采用中心复合设计法，以凿柄实验测得的拉力作为校准响应，确定参数最优组合。通过DEM模拟和土壤箱实验，将仿生耕刀与传统IT型耕刀的性能进行对比，主要以扭矩需求和土壤破碎率作为评估指标。数值积分采用梯形法则计算扰动土体面积。模拟结果显示，仿生叶片产生的扭矩显著降低，在160至320转/分钟的转速范围内降幅可达13%，在60-140毫米耕作深度时降幅最高达11%。土壤箱测试表明，仿生叶片产生的旋转扭矩比IT型叶片低17.8%。相比之下，IT型叶片的土壤破碎率略高，比仿生叶片高出3.9%。本研究证明，仿生设计原则（特别是源自挖掘适应性生物结构的设计）能在保持农业效能的同时，大幅降低旋耕工具的能量需求。此外，经过校准的离散元模型框架为未来研究黄河三角洲盐渍化土壤中的土-机相互作用提供了可靠工具，为开发适用于复杂土壤的节能机械提供了支持。