摘要
针对研究播种机覆土装置作业过程中种沟土壤及种子微观运动规律时,缺乏准确可靠的种沟土壤-种子-覆土装置三者互作离散元模型的问题,以含水率为(15.7±0.25)%的黏土为研究对象,基于EDEM软件对相关参数及模型进行标定。建立覆土装置与种沟土壤互作模型,通过Plackett-Burman试验,以覆土作业牵引阻力为响应值,筛选出对牵引阻力影响敏感的参数为土壤-土壤滚动摩擦因数、土壤-65Mn静摩擦因数、临界法向应力、临界切向应力,通过最陡爬坡试验确定各敏感参数的取值范围,通过Box-Behnken试验优化得出土壤-土壤滚动摩擦因数、土壤-65Mn静摩擦因数、临界法向应力、临界切向应力分别为0.15、0.31、18.45 kPa、18.58 kPa。以大豆种子为例,建立了种沟土壤与种子互作离散元模型,以种沟土壤与大豆种子碰撞恢复系数、静摩擦因数、滚动摩擦因数为试验因素,以仿真堆积角为评价指标,通过Box-Behnken试验优化得出各试验因素取值分别为0.57、0.33、0.08。建立了种沟土壤-种子-覆土装置三者互作离散元模型,并开展了试验验证。结果表明,牵引阻力仿真值与实测值相对误差平均值为2.22%,堆积角仿真值与实测值相对误差为1.61%,覆土厚度和种子粒距变异系数仿真值与实测值相对误差分别为4.89%、5.90%,均较小,所建立的种沟土壤-种子-覆土装置三者互作离散元模型准确。
In order to solve the problem that there is a lack of accurate and reliable discrete element interaction model of seed furrow soil-seed-covering device in the study of the micro-movement law of seed furrow soil and seed in the operation of covering device of planter.Taking the cohesive soil with moisture content of(15.7±0.25)%as research object,the relevant parameters and models were calibrated based on EDEM.The traction resistance of soil covering operation was taken as the response value.Based on Plackett-Burman test,the parameters sensitive to traction resistance were selected as soil-soil rolling friction coefficient,soil-65Mn static friction coefficient,critical normal stress and critical shear stress.The range of values for each sensitive parameter was determined based on the steepest ascent test.Based on Box-Behnken experimental optimization,the values of soil-soil rolling friction coefficient,soil-65Mn static friction coefficient,critical normal stress,and critical shear stress were obtained as 0.15,0.31,18.45kPa,and 18.58kPa,respectively.Secondly,taking soybean seeds as example,the discrete element interaction model of seed furrow soil-seed was established.The collision recovery coefficient,static friction coefficient and rolling friction coefficient between seed furrow soil and soybean seeds were taken as the experimental factors.The simulation stacking angle was taken as the evaluation index.Through the optimization of Box-Behnken test,the values of each test factor were 0.57,0.33,0.08,respectively.Finally,the discrete element interaction model of seed furrow soil-seed-covering device was established,and the experimental verification was carried out.The results showed that the average relative error between the simulated and measured values of traction resistance was 2.22%.The relative error between the simulated and measured values of the stacking angle was 1.61%.The relative errors between the simulated and measured values of soil cover thickness and seed spacing variation coefficient were 4.89%and 5.90%,respectively.They were all small.The established discrete element interaction model of seed furrow soil-seed-covering device was accurate.
作者
卢琦
刘芳建
刘立晶
刘忠军
刘云强
LU Qi;LIU Fangjian;LIU Lijing;LIU Zhongjun;LIU Yunqiang(Chinese Academy of Agricultural Mechanization Sciences Group Co.,Ltd.,Beijing 100083,China;National Key Laboratory of Agricultural Equipment Technology,Beijing 100083,China)
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2023年第10期46-57,共12页
Transactions of the Chinese Society for Agricultural Machinery
基金
中国机械工业集团有限公司重大科技专项(ZDZX2020-2)。
关键词
种沟土壤
覆土装置
离散元法
互作模型
参数标定
seed furrow soil
covering device
discrete element method
interaction model
parameter calibration
