摘要
为进一步提升基于离散元法对全膜双垄沟机械化覆土作业过程研究的准确性,结合EDEM软件进行覆膜土壤摩擦角(土壤休止角及其与钢滑动摩擦角)离散元仿真试验。通过三因素三水平正交组合试验,得出各接触参数对土壤休止角、土壤与钢滑动摩擦角的影响显著性顺序。分别建立了各关键接触参数与土壤休止角、土壤与钢滑动摩擦角的二次多项式回归模型,以自制试验装置测定结果作为优化的目标值,获得全膜双垄沟覆膜土壤离散元最优接触参数组合为:土壤与土壤静摩擦因数0. 68、土壤与土壤滚动摩擦因数0. 27、土壤与土壤恢复系数0. 21、土壤与钢静摩擦因数0. 31、土壤与钢滚动摩擦因数0. 13和土壤与钢恢复系数0. 54。为验证所标定全膜双垄沟覆膜土壤接触参数的可靠性,对模拟仿真与实际试验的土壤休止角、土壤与钢滑动摩擦角进行了对比分析,两者相对误差分别为2. 6%和3. 1%;同时应用离散元法进行全膜双垄沟覆土装置在覆膜土壤颗粒最优标定参数组合设置下的种床覆土过程仿真模拟,通过与实际作业效果对比,仿真结果与田间试验工况基本一致,验证了仿真试验与建立回归模型的有效性。
Aiming to further promotion the accuracy research on the process of the mechanized covering soil on whole plastic film mulching on double ridges.Combined with EDEM software,a discrete element simulation test was carried out on the covering soil friction angle(the repose angle of soil-soil and the sliding friction angle of soil-steel).Through the three-factor orthogonal combination test,the significant order of the contact parameters was obtained,which influenced the repose angle of soil-soil and the sliding friction angle of soil-steel.Based on the software regression analysis of Design-Expert 8.0.6 and response surface analysis method,the relationship between the influencing factors and evaluating indicator(repose angle and sliding friction angle)was established.The measured value of covering soil friction angle(the repose angle of soil-soil and the sliding friction angle of soil-steel)was selected as the chosen target;by using response surface method,the optimal aggregative index could be obtained under the condition that the static friction coefficient among soil was 0.68,the rolling friction coefficient among soil was 0.27,the restitution coefficient among soil was 0.21,the static friction coefficient of soil-steel was 0.31,the rolling friction coefficient of soil-steel was 0.13 and the restitution coefficient of soil-steel was 0.54.In order to verify the reliability of the contact parameters of discrete elements for covering soil on whole plastic film mulching on double ridges,the comparative analysis was made between the simulated test and the actual test of soil friction angle(the repose angle of soil-soil and the sliding friction angle of soil-steel),and the relative errors were 2.6%and 3.1%,respectively.The discrete element method was applied to simulate operation process of the device with covering soil on plastic-film seedbed under the condition of using the optimal contact parameters.The simulation result was consistent with the field test effect.Meanwhile,the parameters calibration method and regression model was feasible,which could provide references for the parameter setting of the soil discrete element simulation of farmland in the northwest arid area of China.
作者
戴飞
宋学锋
赵武云
张锋伟
马海军
马明义
DAI Fei;SONG Xuefeng;ZHAO Wuyun;ZHANG Fengwei;MA Haijun;MA Mingyi(College of Mechanical and Electrical Engineering,Gansu Agricultural University,Lanzhou 730070,China;Gansu Tao River Tractor Manufacturing Co.,Ltd.,Dingxi 730500,China)
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2019年第2期49-56,77,共9页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家自然科学基金项目(51775115
51405086)
现代农业产业技术体系专项(CARS-14-1-28)
关键词
覆膜土壤
全膜双垄沟
覆土装置
离散元法
参数标定
covering soil on plastic film
whole plastic film mulching on double ridges
covering soil device
discrete element method
parameters calibration
