基于水稻钵苗根系生长模拟的钵体根-土复合体离散元模型研究

Discrete Element Model for Pot-type Root-Soil Composite Based on Root Growth Simulation in Rice Pot Seedlings

摘要:

针对目前缺乏水稻钵苗多株根系交织于基质形成独立钵体复合体基础模型研究的问题，同时为后续开展水稻钵苗移栽机构栽植过程探究机械-钵体互作规律提供理论基础，本文依据水稻钵苗根系物理机械特性与生长规律，提出了一种基于Matlab根系数值模拟生长的水稻钵苗钵体复合体离散元模型建立方法。通过破坏性检测对移栽期水稻钵苗根系的几何形态与根系拓扑关系及基质相关参数进行测量与分析，结合钵盘边界因素及根-根、根-钵盘间交互生长特性，建立水稻根系生长规律相关特性函数，并通过Matlab程序设计获取水稻钵苗根系生长拓扑轨迹。利用分割排序法求解完整粒子中心坐标，依托EDEM软件平台分别将所建立的水稻钵苗根-基质离散元几何模型与EdinBurgh Elasto-Plastic Adhesion with Bonding接触力学模型结合，实现水稻钵苗钵体复合体离散元模型的建立。开展水稻钵苗钵体压缩和剪切试验对比研究，结果表明，仿真结果与试验结果趋向保持一致，误差满足相关要求，验证了水稻钵苗钵体复合体离散元模型的可行性。

Abstract:

Aiming to address the current lack of fundamental models for studying the composite body system formed by intertwined multi-plant roots of rice pot seedlings within substrates, and establish a theoretical foundation for subsequent exploration of machine-pot body interactions during transplanting operations, a discrete element modeling method for rice pot seedling composite-body systems was proposed. The method integrated Matlab based root coefficient values to simulate growth patterns. Destructive testing was conducted to measure and analyze geometric morphologies, root topological relationships, and substrate-related parameters of rice seedling roots at the transplanting stage. By incorporating boundary constraints from seedling trays and root-root/root-tray interactive growth characteristics, characteristic functions describing root growth patterns were established. Matlab programming was employed to generate topological trajectories of root system growth. A segmentation sorting algorithm was developed to determine central coordinates of discrete particles. The EDEM software platform was utilized to integrate the established root-substrate discrete element geometric model with the EdinBurgh Elasto-Plastic Adhesion (EEPA) with Bonding contact mechanics model, thereby constructing the composite-body discrete element model. Validation through comparative compression and shear tests on rice pot seedling composite bodies demonstrated that simulation results exhibited consistent trends with experimental data, with errors meeting prescribed tolerances. This confirmed the feasibility of the proposed discrete element model for rice pot seedling composite-body systems.