农业工程学报
農業工程學報
농업공정학보
2015年
5期
29-37
,共9页
齐龙%梁仲维%马旭%谭永炘%江立凯
齊龍%樑仲維%馬旭%譚永炘%江立凱
제룡%량중유%마욱%담영흔%강립개
农业机械%土壤%有限元方法%切削%除草%流固耦合%水田
農業機械%土壤%有限元方法%切削%除草%流固耦閤%水田
농업궤계%토양%유한원방법%절삭%제초%류고우합%수전
agricultural machinery%soils%finite element method%cutting%weed control%fluid-structure interaction%paddy field
为探明水稻机械除草过程中，除草轮的工作阻力大小变化及水田土壤的动态行为，该文利用 ANSYS 软件的显式动力分析模块LS-DYNA对耙压式除草轮在水田环境下的作业过程进行仿真分析。采用ALE（Arbitrary Lagrange-Euler）多物质耦合算法建立了土壤-水两物质耦合有限元模型；运用流固耦合算法分析除草轮与土壤-水模型的相互作用过程。采用有交互作用的正交试验方法选取土壤种类、水层厚度和除草轮旋转速度3个因素进行仿真试验分析，得到各因素及其一级交互作用对除草轮和土壤-水模型的耦合应力和土壤扰动率的影响规律。利用多目标优化设计方法综合评判仿真试验结果，综合评分结果表明，在不同的土壤工作环境下，除草轮在水层厚度为60 mm、转速为160 r/min的作业条件下均可获得较优的工作性能。影响除草轮和土壤-水模型耦合应力的因素主次顺序为：土壤种类＞水层厚度＞土壤种类×水层厚度＞土壤种类×除草轮转速＞除草轮转速＞水层厚度×除草轮转速。影响土壤扰动率的因素主次顺序为：土壤种类＞除草轮转速＞土壤种类×水层厚度＞土壤种类×除草轮转速＞水层厚度＞水层厚度×除草轮转速。为验证仿真结果，进行了田间试验和土槽试验，根据仿真所得耦合应力值推导出除草轮所受土壤反作用力扭矩值，与田间实测值相对误差为8.84%；仿真所得土壤扰动率与土槽试验实测值相对误差为9.86%；仿真所得综合评分结果与试验综合评分结果相对误差为7.02%。仿真分析结果可为轻简式水稻除草机应用在不同稻区的田间作业参数提供参考。
為探明水稻機械除草過程中，除草輪的工作阻力大小變化及水田土壤的動態行為，該文利用 ANSYS 軟件的顯式動力分析模塊LS-DYNA對耙壓式除草輪在水田環境下的作業過程進行倣真分析。採用ALE（Arbitrary Lagrange-Euler）多物質耦閤算法建立瞭土壤-水兩物質耦閤有限元模型；運用流固耦閤算法分析除草輪與土壤-水模型的相互作用過程。採用有交互作用的正交試驗方法選取土壤種類、水層厚度和除草輪鏇轉速度3箇因素進行倣真試驗分析，得到各因素及其一級交互作用對除草輪和土壤-水模型的耦閤應力和土壤擾動率的影響規律。利用多目標優化設計方法綜閤評判倣真試驗結果，綜閤評分結果錶明，在不同的土壤工作環境下，除草輪在水層厚度為60 mm、轉速為160 r/min的作業條件下均可穫得較優的工作性能。影響除草輪和土壤-水模型耦閤應力的因素主次順序為：土壤種類＞水層厚度＞土壤種類×水層厚度＞土壤種類×除草輪轉速＞除草輪轉速＞水層厚度×除草輪轉速。影響土壤擾動率的因素主次順序為：土壤種類＞除草輪轉速＞土壤種類×水層厚度＞土壤種類×除草輪轉速＞水層厚度＞水層厚度×除草輪轉速。為驗證倣真結果，進行瞭田間試驗和土槽試驗，根據倣真所得耦閤應力值推導齣除草輪所受土壤反作用力扭矩值，與田間實測值相對誤差為8.84%；倣真所得土壤擾動率與土槽試驗實測值相對誤差為9.86%；倣真所得綜閤評分結果與試驗綜閤評分結果相對誤差為7.02%。倣真分析結果可為輕簡式水稻除草機應用在不同稻區的田間作業參數提供參攷。
위탐명수도궤계제초과정중，제초륜적공작조력대소변화급수전토양적동태행위，해문이용 ANSYS 연건적현식동력분석모괴LS-DYNA대파압식제초륜재수전배경하적작업과정진행방진분석。채용ALE（Arbitrary Lagrange-Euler）다물질우합산법건립료토양-수량물질우합유한원모형；운용류고우합산법분석제초륜여토양-수모형적상호작용과정。채용유교호작용적정교시험방법선취토양충류、수층후도화제초륜선전속도3개인소진행방진시험분석，득도각인소급기일급교호작용대제초륜화토양-수모형적우합응력화토양우동솔적영향규률。이용다목표우화설계방법종합평판방진시험결과，종합평분결과표명，재불동적토양공작배경하，제초륜재수층후도위60 mm、전속위160 r/min적작업조건하균가획득교우적공작성능。영향제초륜화토양-수모형우합응력적인소주차순서위：토양충류＞수층후도＞토양충류×수층후도＞토양충류×제초륜전속＞제초륜전속＞수층후도×제초륜전속。영향토양우동솔적인소주차순서위：토양충류＞제초륜전속＞토양충류×수층후도＞토양충류×제초륜전속＞수층후도＞수층후도×제초륜전속。위험증방진결과，진행료전간시험화토조시험，근거방진소득우합응력치추도출제초륜소수토양반작용력뉴구치，여전간실측치상대오차위8.84%；방진소득토양우동솔여토조시험실측치상대오차위9.86%；방진소득종합평분결과여시험종합평분결과상대오차위7.02%。방진분석결과가위경간식수도제초궤응용재불동도구적전간작업삼수제공삼고。
In order to investigate the variance of the resistance on the weeding roll and the dynamic behavior of the paddy soil in the condition of paddy field, LS-DYNA, the explicit analysis module of ANSYS, was adopted to simulate and analyze the operating process of the rotary harrow weeding roll in this paper. The soil model was built by MAT147 in LS-DYNA, an elastic-plastic model using the Mohr-Coulomb yield criterion. In order to simulate the paddy field in reality when weeding, a soil-water combined model was established using the Multi-Material ALE(Arbitrary Lagrange-Euler) algorithm, which was considered to be an ALE finite element model. By using the Multi-Material ALE algorithm, the different materials were allowed to exchange and transport in the ALE mesh. The interaction process between the weeding roll and the soil-water model was analyzed by the Fluid-Structure Interaction algorithm. Type of soil (factor A), thickness of water layer (factor B) and rotary velocity of weeding roll (factor C) were selected as three factors of the orthogonal simulation experiment with reciprocal action to explore the effect regularity on coupling stress and destruction of soil caused by the factors and the primary reciprocal actions between each factor. The comprehensive evaluation of simulations results were carried out by the multi-objective optimization design method. The results show that in three types of soils the optimal performance of the weeding roll could be obtained when the water layer thickness was 60 mm and the weeding roll rotary velocity was 160 r/min. The sequence of factors in affecting the coupling stress was type of soil > thickness of water layer > type of soil × thickness of water layer > type of soil × rotary velocity of weeding roll > rotary velocity of weeding roll > thickness of water layer × rotary velocity of weeding roll. The coupling stress was reported to be the minimal in the condition of clay soil, and the maximal in the condition of sandy clay soil. The coupling stress was reported to decrease slightly with the increasing thickness of water layer, and increase first and then decrease within a narrow range with the increasing rotary velocity of weeding roll. The sequence of factors in affecting the destruction of soil was type of soil > rotary velocity of weeding roll > type of soil × thickness of water layer > type of soil ×rotary velocity of weeding roll > thickness of water layer > thickness of water layer × rotary velocity of weeding roll. The destruction of soil was reported to be the minimal in the condition of clay soil, and the maximal in the condition of sandy clay soil. The destruction of soil was reported to drop slightly first and then rise with the increasing thickness of water layer, and increase with the increasing rotary velocity of weeding roll. The field trail and the soil box test were carried out to validate the simulation results. The deviation between the torsion derived from the coupling stress and the one obtained from the field trail was 8.84%, and the deviation between the destruction of soil obtained from the simulation and the one from soil box test was 9.86%, and the deviation between the score of the comprehensive evaluation obtained from the simulation and the one from experiments was 7.02%. The results of field trail and soil box test are basically coordinated with the simulation, which prove the methods of modeling and simulation adopted in this research. The results provide references to the performance and the efficacy of the portable paddy field weeder operating in different rice growing districts and working conditions with different working parameters.
