基于离散元的秸秆-土壤复合体载荷传递研究  

Research on Load Transfer of Straw-soil Complex Based on Discrete Element Method

作　　者：钟晓康 张祥彩 耿元乐 魏忠彩 程修沛 王宪良 Zhong Xiaokang;Zhang Xiangcai;Geng Yuanle;Wei Zhongcai;Cheng Xiupei;Wang Xianliang(School of Agricultural Engineering and Food Science,Shandong University of Technology,Zibo 255049,China)

机构地区：[1]山东理工大学农业工程与食品科学学院,山东淄博255049

出　　处：《农机化研究》2023年第3期17-24,共8页Journal of Agricultural Mechanization Research

基　　金：国家自然科学基金青年科学基金项目(32101631)。

摘　　要：针对目前玉米秸秆-土壤混合介质下土壤应力传递特性不明确的问题,以黄淮海麦玉一年两熟区土壤为研究对象,借助离散元仿真软件EDEM中Hertz-Mindlin with JKR接触模型,建立了0、30%、40%、50%含量的秸秆-土壤混合介质离散元模型。以室内平板载荷试验为基础,对建立的秸秆-土壤混合模型进行离散元模拟仿真,通过控制加载板的施加力大小和作用时间记录不同加载状态下4种秸秆含量土壤颗粒的运动规律;同时,对土壤剖面进行分割,取土壤模型的3个不同深度土层,深度分别为40、90、140mm,进一步从仿真的角度揭示秸秆含量对土壤应力传递的影响。仿真结果表明:在秸秆-土壤混合介质中,秸秆通过减小土壤颗粒间接触面积来减小土壤间摩擦力以及改变土壤颗粒的运动方向等方式对土壤应力的传递起到阻碍作用;秸秆的添加会导致应力垂直传递减少,在40mm处各应力值比无秸秆时分别降低了21.7%、52.9%、67.2%;在同一施加力情况下,土壤应力随着作用时间的增加呈先降低后增加趋势,随秸秆含量的增加呈先增加后降低趋势。综合而言,适量的秸秆含量能够显著改善土壤的力学行为,当秸秆还田比例为10%~30%时土壤应力值最佳。Aiming at the current problem of unclear soil stress transfer characteristics under the corn stalk-soil mixed medium,this paper takes the soil in the Huanghuaihai Maiyu two-year cropping area as the research object,with the help of the Hertz-Mindlin with JKR contact model in the discrete element simulation software EDEM,a discrete element model of straw-soil mixed media with 0,30%,40%,and 50%straw content was established.Based on the indoor plate load test,the established straw-soil hybrid model is simulated by discrete element simulation,and the movement laws of 4 kinds of straw content soil particles under different loading conditions are recorded by controlling the applied force and time of the loading plate;at the same time,the soil profile is segmented,and three soil layers of different depths of the soil model are taken,with depths of 40 mm,90 mm,and 140 mm,respectively,and further reveal the influence of straw content on soil stress transfer from the perspective of simulation.The simulation results show that in the straw-soil mixed medium,the straw reduces the friction between the soil particles by reducing the contact area between the soil particles and changes the movement direction of the soil particles,etc.,to hinder the transmission of soil stress;the addition of straw It will cause the stress vertical transmission to decrease,and the stress values at 40 mm are reduced by 21.7%,52.9%,and 67.2%respectively compared with the absence of straw.Under the same applied force,the soil stress first decreases and then increases with the increase of the action time.With the increase of straw content,it first increased and then decreased.In summary,an appropriate amount of straw content can significantly improve the mechanical behavior of the soil,and the soil stress value is the best when the ratio of straw returning to the field is 10%-30%.

关 键 词：玉米秸秆 离散元 土壤模型 应力传递 

分 类 号：S183[农业科学—农业基础科学]