摘要
为提高离散元法对指导油菜薹有序采收装备设计与优化的准确性和可靠性,该研究以双行垄作移栽的“农大1号”双低甘蓝型油菜机械化适收期油菜薹夹段茎秆为对象,测定其本征参数、表面接触参数以及破碎力学参数,利用EDEM仿真软件Hertz-Mindlin无滑移模型和Hertz-Mindlin with bonding粘结模型建立夹段茎秆堆积仿真标定模型和破碎仿真标定模型。采用逐步调整仿真参数使仿真试验值与物理试验值逼近的方法,利用夹段茎秆堆积仿真标定模型,以休止角仿真试验值与实际物理试验值的相对误差为目标,完成夹段茎秆表面接触参数的标定与优化;利用破碎仿真标定模型,以轴向压缩和弯曲仿真试验与实际物理试验的最大轴向压缩力和最大弯曲力的相对误差为目标,利用标定后的表面接触参数完成夹段茎秆粘结参数的标定与优化。最后,利用夹段茎秆的径向压缩与剪切、内芯与表皮拉伸的破碎仿真力学试验和有序采收EDEM-Recurdyn耦合仿真试验验证标定后的表面接触参数和粘结参数。结果表明,仿真与实测试验的破碎力学参数相对误差在5%以内,且仿真与实测的“时间-载荷”曲线变化趋势一致,低速、中速和高速档的有序采收仿真试验结果与实际物理试验结果相对误差在7.0%以内。研究结果表明,采用离散元仿真方法研究油菜薹采收过程具有可行性,标定结果可用于指导油菜薹机械化生产。
Discrete element method has been widely used to design and optimize the orderly harvesting equipment for rape shoots.This study aims to improve the accuracy and reliability of discrete element parameters for the clamping section stems during rape shoot harvesting.The type of double low cabbage"Nongda No.1"rapeseed was used as the research object and then transplanted on the double row ridges.Some parameters were determined in the period of mechanized harvest,including the intrinsic,surface contact,and crushing mechanical parameters.The stacking and crushing models of simulation and calibration were established for the clamping section of stems using Hertz-Mindlin non-slip and Hertz-Mindlin with bonding model on the EDEM software.The parameters were gradually adjusted to approximate the simulation with the physical test values.The optimal model was obtained for the clamping section of stems after the stacking simulation and calibration.The contact parameters were also calibrated and optimized on the surface of the clamping section of stems.There were small relative errors in the rest angle between the simulation and physical test.The relative errors of the maximum axial compression force and the maximum bending force between the actual physical tests and simulation were taken as the targets to optimize the model.The calibrated parameters of surface contacts were applied to the bonding model.The calibration and optimization of the bonding parameters were then realized for the clamping section of stems.Finally,the calibrated parameters were verified using crushing simulation and mechanical tests of radial compression and shear,internal core and skin tension of the clamping section of stems,and orderly harvesting tests.The results showed that the diameters of the whole stem and the inner core of the mechanized harvestable-stage clamped stem were found to be 13.52 and 12.08 mm,respectively,with an epidermis thickness of 0.72 mm.The densities of the inner core and epidermis were 0.93 and 1.40 g/cm3,respectively.The col
作者
谢伟
欧阳琛
蒋蘋
孟德鑫
罗海峰
XIE Wei;OUYANG Chen;JIANG Pin;MENG Dexin;LUO Haifeng(Department of Mechanical and Electrical Engineering,Hunan Agricultural University,Changsha 410128,China;Hunan Key Laboratory of Intelligent Agricultural Machinery Equipment,Changsha 410128,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2024年第7期104-116,共13页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家重点研发计划项目(2022YFD2300103)、湖南省教育厅优秀青年基金项目(22B0220)。
关键词
离散元
模型
油菜薹
仿真
参数标定
discrete element
model
rape shoots
simulation
parameters calibration
