Yang Jiaxuan, Lei Jin, Qin Xinyan, Wang Zhi, Zhang Jianglong, Lu Lijian
College of Mechanical and Electrical Engineering, Shihezi University, Shihezi, 832000, China.
Xinjiang Production and Construction Corps Key Laboratory of Modern Agricultural Machinery, Shihezi, 832000, China.
Sci Rep. 2025 Jul 1;15(1):21143. doi: 10.1038/s41598-025-07931-5.
To address the problem of poorly defined mechanical parameters in discrete element simulations of mechanized pepper harvesting, a discrete element model was developed to accurately represent the biomechanical characteristics of pepper stems. This research presents a parameter calibration and optimization approach using both Hertz-Mindlin and Hertz-Mindlin with bonding methods. The basic properties of the pepper stems were determined by mechanical property testing, while the stacking angle was assessed using the cylinder lift technique. The stacking angle and maximum bending damage force were used as evaluation indexes. Significant parameters influencing the model were identified using the Plackett-Burman test, followed by a steepest ascent test to define the central test group. The Central-Composite and Box-Behnken tests were then used to formulate quadratic regression equations and optimal parameter combinations for the significant factors were derived using an optimization solver to validate the accuracy of the model. The results showed that the relative errors between simulated and actual values for the two models under optimal conditions were 0.86% and 1.02%, respectively. The discrete element model of pepper stems closely approximates real-world conditions and reflects the mechanical behavior of pepper stems as they bend and break upon impact during harvesting. This research provides a basic framework for mechanistic analysis of the pepper harvesting process.
为了解决机械化辣椒收获离散元模拟中力学参数定义不明确的问题，开发了一个离散元模型来准确表征辣椒茎杆的生物力学特性。本研究提出了一种同时使用赫兹 - 明德林和带粘结的赫兹 - 明德林方法的参数校准和优化方法。通过力学性能测试确定辣椒茎杆的基本特性，同时使用圆筒提升技术评估堆积角。将堆积角和最大弯曲破坏力用作评估指标。使用普拉科特 - 伯曼试验确定影响模型的显著参数，随后进行最速上升试验以确定中心试验组。然后使用中心复合试验和Box - Behnken试验建立二次回归方程，并使用优化求解器得出显著因素的最优参数组合，以验证模型的准确性。结果表明，在最佳条件下，两个模型的模拟值与实际值之间的相对误差分别为0.86%和1.02%。辣椒茎杆的离散元模型非常接近实际情况，反映了辣椒茎杆在收获过程中受到冲击弯曲和折断时的力学行为。本研究为辣椒收获过程的机理分析提供了一个基本框架。
