基于离散元法的凸圆刃式深松铲减阻效果仿真分析与试验
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摘要
针对深松作业阻力大、能耗高等问题,该文在深松铲铲尖顶部设计了一种能有效减阻降耗的凸圆刃。以安装凸圆刃的凸圆刃式深松铲为研究对象,建立了土壤模型。为提高土壤模型的准确性,选用非线性粘结弹性塑形接触模型(edinburgh elasto-plastic adhesion model,EEPA),对凸圆刃式深松铲进行耕作阻力虚拟仿真。利用插件将颗粒与深松铲接触作用力导出,分析凸圆刃式深松铲应力和形变,校验其结构强度;采用EDEM软件分析不同耕深和速度对深松耕作阻力的影响,并以国标深松铲为比较对象,分析了凸圆刃式深松铲的减阻效果;通过田间试验验证了土壤模型和凸圆刃式深松铲设计的准确性和可行性。田间试验结果表明,与国标深松铲相比,凸圆刃式深松铲耕作阻力平均降低了10.24%。仿真结果与实测值较为接近,数值误差在3%～10%,证明土壤模型基本符合土壤的力学特性,能近似代替真实的土壤环境。该研究证明了采用离散元法分析深松耕作阻力可行性,可为进一步优化深松铲结构提供参考。
Due to long-term shallow ploughing,rotary tillage and tractor wheel rolling,a hard and compact Plow pan layer is formed between the tillage layer and the subsoil layer.The presence of plow pan layer can inhibit roots growing and prevent material transfer between tillage layer and the susoil layer,thus reducing crop yield.The subsoiling can improve the soil water storage,improve soil water retention capacity,promote roots growth,and effectively improve crop yield effectively,but the resistance and energy consumption of subsoiling is high.The convex blade subsoiler was designed to reduce the subsoiling resistance in the paper.The convex blade subsoiler was mainly composed of subsoiler handle,subsoiler tip and convex edge,in the process of subsoiling,the convex edge on the subsoiler tip slip cutting the soil on the upper surface of the subsoiler tip,which reducing the pressure of the soil on the upper surface of the subsoiler tip,thereby reducing the subsoiling resistance.Firstly,the curve expression of convex blade edge was calculated based on the sliding cutting condition.And then,the convex blade subsoiler with convex blade and stander subsoiler were selected as the study object by EDEM simulation and field experiment,which used to verify the drag reduction effect of convex blade and the accuracy of soil simulation model.Taking North China Plain as the research object,the physical parameters of soil particle was determined,and the soil geometry model which consists of tillage layer,the subsoil layer and plow pan layer was constructed by 3 D graphics software NVENTOR.In order to improve the accuracy of the soil model,the Edinburgh Elasto-Plastic Adhesion Model was used as soil contact model to simulate the tillage resistance of subsoiler.The EDEM software was employed to analyze the drag reduction effect of convex blade subsoiler at different tillage depths and forward speeds,which had been compared with the stander subsoiler.The experiment results showed that convex blade subsoiler had a drag reduction effect compared with stander subsoiler,and the average drag reduction was 7.56%.In addition,the EDEM_Addin plug-in was used to introduce the contact force of the soil with convex blade subsoiler into ANSYS WORKBENCH 17.0 for finite element analysis,and the results of finite element analysis showed that the convex blade subsoiler stress was mainly concentrated in the fixed position of the subsoiler handle,the maximum stress value was 123.36 MPa and the maximum deformation variable was 8.68 mm at the tip of the subsoiler,which meetting the design requirements.In order to verify the rationality of the designed convex blade subsoiler and judge the rationality of the constructed soil model,the field experiments were carried out according to the tillage depth and the working speed of the simulation.The field experiments proved that the convex blade subsoiler had dragged reduction effect compared with stander subsoiler,and the average drag reduction was 10.24%,and compared with the simulation results,the numerical error was 3%-10%.the tillage depth and forward speed could have an appreciable impact on tillage resistance and the tillage resistance increased with the tillage depth and forward velocity.The results of simulation and experiment showed that the proposed soil model basically matched the soil mechanical properties in North China Plain and could approximating substitute the real soil environment.The study proved that it was feasible to analyze the tillage resistance of the subsoiler by using the DEM and it was of great significance to further optimize the structure of subsoiler.
Due to long-term shallow ploughing,rotary tillage and tractor wheel rolling,a hard and compact Plow pan layer is formed between the tillage layer and the subsoil layer.The presence of plow pan layer can inhibit roots growing and prevent material transfer between tillage layer and the susoil layer,thus reducing crop yield.The subsoiling can improve the soil water storage,improve soil water retention capacity,promote roots growth,and effectively improve crop yield effectively,but the resistance and energy consumption of subsoiling is high.The convex blade subsoiler was designed to reduce the subsoiling resistance in the paper.The convex blade subsoiler was mainly composed of subsoiler handle,subsoiler tip and convex edge,in the process of subsoiling,the convex edge on the subsoiler tip slip cutting the soil on the upper surface of the subsoiler tip,which reducing the pressure of the soil on the upper surface of the subsoiler tip,thereby reducing the subsoiling resistance.Firstly,the curve expression of convex blade edge was calculated based on the sliding cutting condition.And then,the convex blade subsoiler with convex blade and stander subsoiler were selected as the study object by EDEM simulation and field experiment,which used to verify the drag reduction effect of convex blade and the accuracy of soil simulation model.Taking North China Plain as the research object,the physical parameters of soil particle was determined,and the soil geometry model which consists of tillage layer,the subsoil layer and plow pan layer was constructed by 3 D graphics software NVENTOR.In order to improve the accuracy of the soil model,the Edinburgh Elasto-Plastic Adhesion Model was used as soil contact model to simulate the tillage resistance of subsoiler.The EDEM software was employed to analyze the drag reduction effect of convex blade subsoiler at different tillage depths and forward speeds,which had been compared with the stander subsoiler.The experiment results showed that convex blade subsoiler had a drag reduction effect compared with stander subsoiler,and the average drag reduction was 7.56%.In addition,the EDEM_Addin plug-in was used to introduce the contact force of the soil with convex blade subsoiler into ANSYS WORKBENCH 17.0 for finite element analysis,and the results of finite element analysis showed that the convex blade subsoiler stress was mainly concentrated in the fixed position of the subsoiler handle,the maximum stress value was 123.36 MPa and the maximum deformation variable was 8.68 mm at the tip of the subsoiler,which meetting the design requirements.In order to verify the rationality of the designed convex blade subsoiler and judge the rationality of the constructed soil model,the field experiments were carried out according to the tillage depth and the working speed of the simulation.The field experiments proved that the convex blade subsoiler had dragged reduction effect compared with stander subsoiler,and the average drag reduction was 10.24%,and compared with the simulation results,the numerical error was 3%-10%.the tillage depth and forward speed could have an appreciable impact on tillage resistance and the tillage resistance increased with the tillage depth and forward velocity.The results of simulation and experiment showed that the proposed soil model basically matched the soil mechanical properties in North China Plain and could approximating substitute the real soil environment.The study proved that it was feasible to analyze the tillage resistance of the subsoiler by using the DEM and it was of great significance to further optimize the structure of subsoiler.
引文
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[5]傅巍,蔡九菊,董辉,等.颗粒流数值模拟的现状[J].材料与冶金学报,2004,3(3):172-175.Fu Wei,Cai Jiuju,Dong Hui,et al.Current status of numerical simulation of granular flow[J].Journal of Materials and Metallurgy,2004,3(3):172-175.(in Chinese with English abstract)
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[9]Shmulevich I,Horn R.State of the art modeling of soil-tillage interaction using discrete element method[J].Soil&Tillage Research,2010,111(1):41-53.
[10]赵淑红,王加一,陈君执,等.保护性耕作拟合曲线型深松铲设计与试验[J].农业机械学报,2018,49(2):82-92.Zhao Shuhong,Wang Jiayi,Chen Junzhi,et al.Design and experiment of fitting curve subsoiler of conservation tillage[J].Transactions of the Chinese Society for Agricultural Machinery,2018,49(2):82-92.(in Chinese with English abstract)
[11]Hang Chengguang,Gao Xijie,Yuan Mengchan,et al.Discrete element simulations and experiments of soil disturbance as affected by the tine spacing of subsoiler[J].Biosystems Engineering,2017,168:73-82.
[12]方会敏,姬长英,张庆怡,等.基于离散元法的旋耕刀受力分析[J].农业工程学报,2016,32(21):54-59.Fang Huimin,Ji Changying,Zhang Qingyi,et al.Force analysis of rotary blade based on distinct element method[J].Transactions of the Chinese Society of Agricultural Engineering(Transactions of the CSAE),2016,32(21):54-59.(in Chinese with English abstract)
[13]王金武,王奇,唐汉,等.水稻秸秆深埋整秆还田装置设计与试验[J].农业机械学报,2015,46(9):112-117.Wang Jinwu,Wang Qi,Tang Han,et al.Design and experiment of rice straw deep buried and whole straw returning device[J].Transactions of the Chinese Society for Agricultural Machinery,2015,46(9):112-117.(in Chinese with English abstract)
[14]Walton O R,Braun R L.Stress calculations for assemblies of inelastic speres in uniform shear[J].Acta Mechanica,1986,63(1-4):73-86.
[15]Janda A,Jin Y O.DEM modeling of cone penetration and unconfined compression in cohesive solids[J].Powder Technology,2016,293:60-68.
[16]Ucgul M,Fielke J M,Saunders C.3D DEM tillage simulation:Validation of a hysteretic spring(plastic)contact model for a sweep tool operating in a cohesionless soil[J].Soil&Tillage Research,2014,144(4):220-227.
[17]Ucgul M,Fielke J M,Saunders C.Three-dimensional discrete element modelling(DEM)of tillage:Accounting for soil cohesion and adhesion[J].Biosystems Engineering,2015,129:298-306.
[18]Ucgul M,Fielke J M,Saunders C.Three-dimensional discrete element modelling of tillage:Determination of a suitable contact model and parameters for a cohesionless soil[J].Biosystems Engineering,2014,121(2):105-117.
[19]郑侃,何进,李洪文,等.基于离散元深松土壤模型的折线破土刃深松铲研究[J].农业机械学报,2016,47(9):62-72.Zheng Kan,He Jin,Li Hongwen,et al.Research on polyline soil-breaking blade subsoiler based on subsoiling soil model using discrete element method[J].Transactions of the Chinese Society for Agricultural Machinery,2016,47(9):62-72.(in Chinese with English abstract)
[20]石林榕,赵武云,孙伟.基于离散元的西北旱区农田土壤颗粒接触模型和参数标定[J].农业工程学报,2017,33(21):181-187.Shi Linrong,Zhao Wuyun,Sun Wei.Parameter calibration of soil particles contact model of farmland soil in northwest arid region based on discrete element method[J].Transactions of the Chinese Society of Agricultural Engineering(Transactions of the CSAE),2017,33(21):181-187.(in Chinese with English abstract)
[21]全国农业机械标准化技术委员会.深松铲和深松铲柄:JB/T9788-1999[S].北京.中国标准出版社.1999:2-6
[22]寻怀义.滑切理论探讨[J].农业机械学报,1979(4):107-111.
[23]庞声海.关于滑切理论与滑切角的选用[J].华中农学院学报,1982(2):64-69.
[24]西涅阿科夫,李福桂,高尔光,等.土壤耕作机械的理论和计算[M].北京:中国农业机械出版社,1981.
[25]王燕.基于离散元法的深松铲结构与松土效果研究[D].长春:吉林农业大学,2014.Wang Yan.Simulation Analysis of Structure and Effect of the Subsoiler Based on DEM[D].Changchun:Jilin Agricultural University,2014.(in Chinese with English abstract)
[26]王宪良,胡红,王庆杰,等.基于离散元的土壤模型参数标定方法[J].农业机械学报,2017,48(12):78-85.Wang Xianliang,Hu Hong,Wang Qingjie,et al.Calibration method of soil contact characteristic parameters based on DEM theory[J].Transactions of the Chinese Society for Agricultural Machinery,2017,48(12):78-85.(in Chinese with English abstract)
[27]Das B M.Advanced soil mechanics[M].London:TAYLOR&FRANCIS,2008.
[28]Morrissey J P.Discrete Element Modelling of Iron Ore Pellets to Include the Effects of Moisture and Fines[D].Edinburgh:University of Edinburgh,2013.
[29]Thakur S C,Morrissey J P,Sun J,et al.Micromechanical analysis of cohesive granular materials using the discrete element method with an adhesive elasto-plastic contact model[J].Granular Matter,2014,16(3):383-400.
[30]EDEM 2018 documentation:Version 2018[EB/OL].(2018-07-14).https://www.edemsimulation.com/login/?redire ct_to=%2Fedem-2018-0-documentation.[2018-09-21]
[31]John P M,Subhash C T,Jin Y O.EDEM contact model:adhesive elasto-plastic model[EB/OL].(2014-06-23).https://www.edemsimulation.com/resources-learning.[2018-09-21]
[32]EDEM 2018 soils starter pack:compressible sticky materia[EB/OL].https://www.edemsimulation.com.[2018-09-21].
[33]石彦琴,高旺盛,陈源泉,等.耕层厚度对华北高产灌溉农田土壤有机碳储量的影响[J].农业工程学报,2010,26(11):85-90.Shi Yanqin,Gao Wangsheng,Chen Yuanquan,et al.Effect of topsoil thickness on soil organic carbon in high-yield and irrigated farmland in North China[J].Transactions of the Chinese Society of Agricultural Engineering(Transactions of the CSAE),2010,26(11):85-90.(in Chinese with English abstract)
[34]郭家萌,刘振朝,高强,等.深松对玉米产量和养分吸收的影响[J].水土保持学报,2016,30(2):249-254.Guo Jiameng,Liu Zhenchao,Gao Qiang,et al.Effect of subsoiling on yield and nutrient uptake of maize[J].Journal Soil and Water Conservation,2016,30(2):249-254.(in Chinese with English abstract)
[35]郑侃,何进,李洪文,等.反旋深松联合作业耕整机设计与试验[J].农业机械学报,2017,48(8):61-71.Zheng Kan,He Jin,Li Hongwen,et al.Design and experiment of combined tillage implement of reverse-rotary and Subsoiling[J].Transactions of the Chinese Society for Agricultural Machinery,2017,48(8):61-71.(in Chinese with English abstract)
[36]李惠利.深松铲工作性能实时测试系统的研究[D].保定:河北农业大学,2017.Li Huili.Research on Real-time Working Performance Test System of the Deep Shovel[D].Baoding:Agricultural University of Hebei,2017.(in Chinese with English abstract)
[2]Pikul J L,Aase J K.Water Infiltration and storage affected by subsoiling and subsequent tillage[J].Soilence Society of America Journal,2003,67(3):859-866.
[3]Mouazen A M,Neményi M.Finite element analysis of subsoiler cutting in non-homogeneous sandy loam soil[J].Soil&Tillage Research,1999,51(1/2):1-15.
[4]张强,张璐,于海业,等.复合形态深松铲耕作阻力有限元分析与试验[J].农业机械学报,2012,43(8):61-65.Zhang Qiang,Zhang Lu,Yu Haiye,et al.Finite element analysis and experiment of soil resistance of multiplexmodality subsoile[J].Transactions of the Chinese Society for Agricultural Machinery,2012,43(8):61-65.(in Chinese with English abstract)
[5]傅巍,蔡九菊,董辉,等.颗粒流数值模拟的现状[J].材料与冶金学报,2004,3(3):172-175.Fu Wei,Cai Jiuju,Dong Hui,et al.Current status of numerical simulation of granular flow[J].Journal of Materials and Metallurgy,2004,3(3):172-175.(in Chinese with English abstract)
[6]刘宏俊,韩济远,陈佳奇,等.丘陵地区刚性镇压轮性能仿真与试验[J].农业机械学报,2018,49(11):114-122.Liu Hongjun,Han Jiyuan,Chen Jiaqi,et al.Performance simulation and experiment on rigid press wheel for hilly area[J].Transactions of the Chinese Society for Agricultural Machinery,2018,49(11):114-122.(in Chinese with English abstract)
[7]Craig R F.Craig's Soil Mechanics[M].London:Spon Press,2004.
[8]Cundall P A,Strack O D L.A discrete numerical mode for granular assemblies[J].Géotechnique,1979,29(1):47-65.
[9]Shmulevich I,Horn R.State of the art modeling of soil-tillage interaction using discrete element method[J].Soil&Tillage Research,2010,111(1):41-53.
[10]赵淑红,王加一,陈君执,等.保护性耕作拟合曲线型深松铲设计与试验[J].农业机械学报,2018,49(2):82-92.Zhao Shuhong,Wang Jiayi,Chen Junzhi,et al.Design and experiment of fitting curve subsoiler of conservation tillage[J].Transactions of the Chinese Society for Agricultural Machinery,2018,49(2):82-92.(in Chinese with English abstract)
[11]Hang Chengguang,Gao Xijie,Yuan Mengchan,et al.Discrete element simulations and experiments of soil disturbance as affected by the tine spacing of subsoiler[J].Biosystems Engineering,2017,168:73-82.
[12]方会敏,姬长英,张庆怡,等.基于离散元法的旋耕刀受力分析[J].农业工程学报,2016,32(21):54-59.Fang Huimin,Ji Changying,Zhang Qingyi,et al.Force analysis of rotary blade based on distinct element method[J].Transactions of the Chinese Society of Agricultural Engineering(Transactions of the CSAE),2016,32(21):54-59.(in Chinese with English abstract)
[13]王金武,王奇,唐汉,等.水稻秸秆深埋整秆还田装置设计与试验[J].农业机械学报,2015,46(9):112-117.Wang Jinwu,Wang Qi,Tang Han,et al.Design and experiment of rice straw deep buried and whole straw returning device[J].Transactions of the Chinese Society for Agricultural Machinery,2015,46(9):112-117.(in Chinese with English abstract)
[14]Walton O R,Braun R L.Stress calculations for assemblies of inelastic speres in uniform shear[J].Acta Mechanica,1986,63(1-4):73-86.
[15]Janda A,Jin Y O.DEM modeling of cone penetration and unconfined compression in cohesive solids[J].Powder Technology,2016,293:60-68.
[16]Ucgul M,Fielke J M,Saunders C.3D DEM tillage simulation:Validation of a hysteretic spring(plastic)contact model for a sweep tool operating in a cohesionless soil[J].Soil&Tillage Research,2014,144(4):220-227.
[17]Ucgul M,Fielke J M,Saunders C.Three-dimensional discrete element modelling(DEM)of tillage:Accounting for soil cohesion and adhesion[J].Biosystems Engineering,2015,129:298-306.
[18]Ucgul M,Fielke J M,Saunders C.Three-dimensional discrete element modelling of tillage:Determination of a suitable contact model and parameters for a cohesionless soil[J].Biosystems Engineering,2014,121(2):105-117.
[19]郑侃,何进,李洪文,等.基于离散元深松土壤模型的折线破土刃深松铲研究[J].农业机械学报,2016,47(9):62-72.Zheng Kan,He Jin,Li Hongwen,et al.Research on polyline soil-breaking blade subsoiler based on subsoiling soil model using discrete element method[J].Transactions of the Chinese Society for Agricultural Machinery,2016,47(9):62-72.(in Chinese with English abstract)
[20]石林榕,赵武云,孙伟.基于离散元的西北旱区农田土壤颗粒接触模型和参数标定[J].农业工程学报,2017,33(21):181-187.Shi Linrong,Zhao Wuyun,Sun Wei.Parameter calibration of soil particles contact model of farmland soil in northwest arid region based on discrete element method[J].Transactions of the Chinese Society of Agricultural Engineering(Transactions of the CSAE),2017,33(21):181-187.(in Chinese with English abstract)
[21]全国农业机械标准化技术委员会.深松铲和深松铲柄:JB/T9788-1999[S].北京.中国标准出版社.1999:2-6
[22]寻怀义.滑切理论探讨[J].农业机械学报,1979(4):107-111.
[23]庞声海.关于滑切理论与滑切角的选用[J].华中农学院学报,1982(2):64-69.
[24]西涅阿科夫,李福桂,高尔光,等.土壤耕作机械的理论和计算[M].北京:中国农业机械出版社,1981.
[25]王燕.基于离散元法的深松铲结构与松土效果研究[D].长春:吉林农业大学,2014.Wang Yan.Simulation Analysis of Structure and Effect of the Subsoiler Based on DEM[D].Changchun:Jilin Agricultural University,2014.(in Chinese with English abstract)
[26]王宪良,胡红,王庆杰,等.基于离散元的土壤模型参数标定方法[J].农业机械学报,2017,48(12):78-85.Wang Xianliang,Hu Hong,Wang Qingjie,et al.Calibration method of soil contact characteristic parameters based on DEM theory[J].Transactions of the Chinese Society for Agricultural Machinery,2017,48(12):78-85.(in Chinese with English abstract)
[27]Das B M.Advanced soil mechanics[M].London:TAYLOR&FRANCIS,2008.
[28]Morrissey J P.Discrete Element Modelling of Iron Ore Pellets to Include the Effects of Moisture and Fines[D].Edinburgh:University of Edinburgh,2013.
[29]Thakur S C,Morrissey J P,Sun J,et al.Micromechanical analysis of cohesive granular materials using the discrete element method with an adhesive elasto-plastic contact model[J].Granular Matter,2014,16(3):383-400.
[30]EDEM 2018 documentation:Version 2018[EB/OL].(2018-07-14).https://www.edemsimulation.com/login/?redire ct_to=%2Fedem-2018-0-documentation.[2018-09-21]
[31]John P M,Subhash C T,Jin Y O.EDEM contact model:adhesive elasto-plastic model[EB/OL].(2014-06-23).https://www.edemsimulation.com/resources-learning.[2018-09-21]
[32]EDEM 2018 soils starter pack:compressible sticky materia[EB/OL].https://www.edemsimulation.com.[2018-09-21].
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