基于Bonding V2模型的蒜种离散元建模与参数标定

Discrete Element Modelling Method and Parameter Calibration of Garlic Species Based on Bonding V2 Model

摘要:

针对利用离散元法进行大蒜精准播种及收获等关键作业过程仿真分析时，蒜种内部黏结参数缺乏的问题，选取邳州白蒜为研究对象，利用EDEM软件建立了一种可破碎的蒜种离散元柔性模型，并对其黏结参数进行标定。以处理后不带皮蒜种块临界破碎载荷（105.5N）及位移（4.7mm）为参考依据，通过Plackett-Burman、最陡爬坡试验和Box-Behnken试验，对蒜种离散元模型进行显著性筛选和寻优。结果表明：最优参数中单位面积法向刚度、单位面积切向刚度、法向强度、剪切强度和黏结半径比例分别为5.115×108N/m3、2.3×107N/m3、1.265×106Pa、54454.594Pa、1.716。此时，仿真不带皮蒜种块临界破碎载荷和位移分别为116.6N、5.13mm，与前期不带皮蒜种试验误差分别为9.5%、12.7%，与带皮蒜种试验（临界破碎载荷和位移分别为107.5N和4.8mm）误差分别为7.8%、7.4%，验证了模型的准确性。建立的蒜种离散元模型可为后续振动充种受力分析及姿态调整提供参考。

Abstract:

Aiming at the lack of internal bonding parameters of garlic species when using the discrete element method for the simulation and analysis of garlic precision sowing and harvesting and other key operational processes, Pizhou white garlic was selected as the research object, and a discrete element flexible model of crushable garlic species was established by using the EDEM software, and the bonding parameters of the species were calibrated. Taking the critical crushing load (105.5 N) and displacement (4.7mm) of the processed garlic species pieces without skin as the reference basis, the significance screening and optimization searching of the discrete element model of garlic species were carried out by Plackett-Burman, the steepest climb test and Box-Behnken test. The results showed that the optimal parameter combinations of normal stiffness per unit area, tangential stiffness, normal strength, shear strength and adhesion radius ratio were 5.115×108N/m3, 2.3×107N/m3, 1.265×106Pa, 54454.594Pa, and 1.716, respectively. At this time, the critical crushing load and displacement of simulated non-peeled garlic species pieces were 116.6N and 5.13mm, with the previous test without skinned garlic species, the error was 9.5% and 12.7%, and with the test with skinned garlic species (critical crushing load and displacement of 107.5N and 4.8mm, respectively), the error was 7.8% and 7.4%, which verified the accuracy of the model. The establishment of the discrete element model of garlic species can provide a reference for the subsequent vibratory species filling force analysis and attitude adjustment.