绿豆种子离散元仿真参数标定与排种试验

为提高绿豆精密排种过程离散元仿真模拟试验所用仿真参数的准确度,进一步优化排种部件,基于绿豆种子的本征参数,采用Hertz Mindlin with bonding粘结模型建立种子仿真模型,分别采用自由落体碰撞法、斜面滑动法、斜面滚动法对绿豆种子与接触材料(有机玻璃、Somos8000树脂)间仿真参数进行标定,结果表明：绿豆与有机玻璃碰撞恢复系数、静摩擦因数、滚动摩擦因数分别为0.445、0.458、0.036,与Somos8000树脂碰撞恢复系数、静摩擦因数、滚动摩擦因数分别为0.434、0.556、0.049。以种间接触参数为因素,以实测堆积角与仿真堆积角相对误差为指标,进行了最陡爬坡试验、三因素五水平旋转组合设计试验,以最小相对误差为优化目标,对试验数据寻优分析得到：绿豆种间碰撞恢复系数、静摩擦因数、滚动摩擦因数分别为0.3、0.23、0.03。对标定结果进行排种验证试验,结果表明：仿真试验漏吸率与台架试验漏播率最大相对误差为4.71%、重吸率与重播率最大相对误差为4.94%、单粒率与合格率最大相对误差为0.98%,证明标定结果可靠。该研究结果可为绿豆精密排种装置的设计与仿真优化提...

Calibration of Simulation Parameters of Mung Bean Seeds Using Discrete Element Method and Verification of Seed-metering Test

In order to improve the accuracy of the simulation parameters used in the discrete element simulation test of mung bean precision metering process, and further optimize the metering structure, based on the intrinsic parameters of mung bean seeds, the Hertz Mindlin with bonding model was used to establish the seed simulation model, the simulation parameters between the mung bean seeds and the contact material (plexiglass plate, Somos8000 resin) were calibrated by the free fall collision method, inclined sliding method, and inclined rolling method, respectively. The statistical results showed the collision recovery coefficient, static friction coefficient and rolling friction coefficient between mung bean and plexiglass were 0.445, 0.458 and 0.036, respectively;the collision recovery coefficient, static friction coefficient, and rolling friction coefficient between mung bean and Somos8000 resin were 0.434, 0.556 and 0.049, respectively. Steep climbing test, three-factor and five-level horizontal rotation combinations were designed and tested respectively, involving factors of contact parameters between seeds, and the indices of the relative error between the measured accumulation angle and the simulated accumulation angle. Then, the minimum relative error was taken as the optimization objective, and the test data were optimized and analyzed, the collision recovery coefficient, static friction coefficient, and rolling friction coefficient between mung bean seeds were 0.3, 0.23 and 0.03, respectively. Seeding verification tests were carried out on the calibration results, the statistical results showed that the maximum relative error between the leakage rate of the simulation test and the missing rate of the bench test was 4.71%, the maximum relative error between the reabsorption rate and the multiple rate was 4.94%, and the maximum relative error between the single particle rate and the qualified rate was 0.98%, which proved that the calibration results were reliable. It can provide important reference significance for the design and simulation optimization of mung bean precision metering device.