Qingqiu Cao, Shengwei Zhang, Tao Li, Gaixia Zhai, Hongfang Yuan
College of Biological and Agricultural Engineering, Jilin University, Changchun, China.
Research Center, Hohhot Branch of Chinese Academy of Agricultural Mechanization Sciences, Hohhot, China.
Front Plant Sci. 2024 Oct 31;15:1457243. doi: 10.3389/fpls.2024.1457243. eCollection 2024.
The forage crop Kom. is of high quality, and the biomechanical properties of its plant system are of great significance for the development of harvesting equipment and the comprehensive utilisation of crop resources. However, the extant research on the biomechanical properties of Kom. is inadequate to enhance and refine the theoretical techniques for mechanised harvesting. In this study, we established a discrete element model of CKS based on the Hertz-Mindlin bonding contact model. By combining physical experiments and numerical simulations, we calibrated and validated the intrinsic and contact parameters. The Plackett-Burman design test was employed to identify the significant factors influencing bending force, and the optimal parameter combination for these factors was determined through response surface analysis. When the shear stiffness per unit area was 3.56×10 Pa, the bonded disk scale was 0.93 mm, the normal stiffness per unit area was 9.68×10 Pa, the normal strength was 5.62×10 Pa, the shear strength was 4.27×10 Pa, the discrete element numerical simulation results for three-point bending, radial compression, axial tension, and shear fracture exhibited a maximum failure force error of 3.32%, 4.37%, 4.87% and 3.74% in comparison to the physical experiments. In the cutting experiments, a smaller radial angle between the tool edge and the stem resulted in less damage to the cutting section, which was beneficial for the smoothness of the stubble after harvesting and the subsequent growth of the stem. The discrepancy in cutting force between the physical and numerical simulations was 3.89%, and the - (force versus displacement) trend was consistent. The multi-angle experimental validation demonstrated that the discrete element model of CKS is an accurate representation of the real biomechanical properties of CKS. The findings offer valuable insights into the mechanisms underlying crop-machine interactions.
饲料作物Kom.品质优良，其植物系统的生物力学特性对于收获设备的研发以及作物资源的综合利用具有重要意义。然而，目前关于Kom.生物力学特性的研究不足以完善和优化机械化收获的理论技术。在本研究中，我们基于赫兹-明德林粘结接触模型建立了CKS的离散元模型。通过结合物理实验和数值模拟，我们校准并验证了固有参数和接触参数。采用Plackett-Burman设计试验来确定影响弯曲力的显著因素，并通过响应面分析确定这些因素的最优参数组合。当单位面积剪切刚度为3.56×10 Pa、粘结盘尺度为0.93 mm、单位面积法向刚度为9.68×10 Pa、法向强度为5.62×10 Pa、剪切强度为4.27×10 Pa时，三点弯曲、径向压缩、轴向拉伸和剪切断裂的离散元数值模拟结果与物理实验相比，最大破坏力误差分别为3.32%、4.37%、4.87%和3.74%。在切割实验中，刀具边缘与茎杆之间较小的径向角度对切割部位的损伤较小，这有利于收获后茬口的平整度以及茎杆的后续生长。物理模拟和数值模拟的切割力差异为3.89%，力-位移趋势一致。多角度实验验证表明，CKS的离散元模型准确反映了CKS真实的生物力学特性。这些研究结果为作物-机械相互作用的机制提供了有价值的见解。
