基于离散单元法的水稻籽粒快速颗粒建模研究  

Study on apace particle modeling of rice grain basis on the discrete element method

作　　者：原建博 李骅[2] 吴崇友 齐新丹[1] 施新新 李超[2] YUAN Jianbo;LI Hua;WU Chongyou;QI Xindan;SHI Xinxin;LI Chao(School of Mechanical and Power Engineering,Nanjing Tech University,Nanjing 211816,China;Intelligent Agricultural Equipment Key Laboratory,College and Universities in Jiangsu Province/ College of Engineering,Nanjing Agricultural University,Nanjing 210031,China;Nanjing Research Institute for Agricultural Mechanization,Ministry of Agriculture and Rural Affairs,Nanjing 210014,China)

机构地区：[1]南京工业大学机械与动力工程学院,江苏南京211816 [2]江苏省高等学校智能化农业装备重点实验室/南京农业大学工学院,江苏南京210031 [3]农业农村部南京农业机械化研究所,江苏南京210014

出　　处：《南京农业大学学报》2018年第6期1151-1158,共8页Journal of Nanjing Agricultural University

基　　金：国家自然科学基金青年基金项目(51305182);农业部现代农业装备重点实验室开放课题(201602004)

摘　　要：[目的]离散单元法(discrete element method,DEM)主要用于离散颗粒物料研究领域,非规则形状颗粒建模耗费大量时间,且模型精度对颗粒间的动力学响应特性有较大影响,故本文采用离散单元法研究水稻籽粒快速颗粒建模方法,旨在提高非规则形状颗粒建模效率及精度。[方法]以‘中早39号’早稻籽粒为研究对象,通过非接触式3D激光扫描法重构籽粒3D模型;采用手动填充颗粒建模方法,设置球体坐标、接触半径及物理半径使填充颗粒模型三轴尺寸及体积接近实际籽粒;采用自动填充颗粒建模方法,对籽粒3D模型划分网格及获取网格单元坐标信息,然后通过工程离散单元法(engineering discrete element method,EDEM)中的应用程序编程接口(API)实现多球快速聚合颗粒建模;通过高斯拟合法对自动填充颗粒建模中的填充参数进行优化分析,并通过籽粒自然堆积角仿真与试验对比验证模型精度。[结果]重构籽粒3D模型与实际籽粒对比尺寸误差均在5%以内;手动填充颗粒模型填充球数164个,耗时约25 h,尺寸误差均在5%以上;自动填充颗粒模型填充球数203个,球体物理半径为1.2 mm时颗粒模型最优,耗时约1 h,尺寸误差除厚度外均在5%以下;自动填充颗粒自然堆积角仿真结果与试验结果误差为0.76%。[结论]基于EDEM中API自动填充颗粒建模方法具有高效、精确等优点,为非规则形状颗粒物料的离散单元法研究提供了一种有效的颗粒建模方法。[Objectives]The discrete element method(DEM)was utilized to simulate the process of discrete particle materials.The modeling of irregular-shaped particles took a lot of time,and the accuracy of the model had a great influence on the dynamic response characteristics between particles.This study was to improve the modeling efficiency and accuracy of irregular-shaped particle.[Methods]This research took‘Zhongzao 39’early rice grain as the sample,and achieved the 3D model of grain by 3D laser scanning system.The process of modeling particles by the manual filling method was described as that set the sphere coordinates,contact radius and physical radius and so on.Results showed that the filling particle model three-axis size and volume were close to the actual grain;the process of modeling particles using automatic filling method was described as that mesh 3D model of grain and achieve the coordinate information of mesh.Finally,the application programming interface(API)from EDEM software was used to accurately and fleetly construct the particle model of grain.We confirmed an optimum parameter for automatic filling particle model by the gauss fitting method,and verified the accuracy of the particle model by comparing simulation and experiments of the natural accumulation angle of grain.[Results]The size of 3D grain model was close to the actual grain with an error of under 5%.In the manual filling method,the particle model filled 164 balls,which took about 25 hours,and the dimensional errors were all above 5%.In the automatic filling method,the particle model filled 203 balls with a physical radius of 1.2 mm,and the particle model was optimal,which took about 1 hour,in which the dimensional errors were in 5%apart from the thickness.The simulation result of natural accumulation angle were agreed with the experiment result with an error of 0.76%.[Conclusions]The research results show that the multi-sphere apace automatic filling particle modeling method has the advantages of modeling efficiency and high model accurac

关 键 词：中早39号 水稻籽粒 离散单元法 边界包络手动填充法 应用程序编程接口 自然堆积角 

分 类 号：TP391.7[自动化与计算机技术—计算机应用技术]