玉米田耕层典型土壤离散元模型建立与参数标定  

Discrete Element Modeling and Parameter Calibration of Typical Soil in Maize Field Tillage Layer

作　　者：周华 车海龙 耿端阳[1,2] 陈美舟 张银平 ZHOU Hua;CHE Hailong;GENG Duanyang;CHEN Meizhou;ZHANG Yinping(School of Agricultural Engineering and Food Science,Shandong University of Technology,Zibo 255000,China;Shandong Provincial Collaborative Innovation Center of Dry-farming Intelligent Agricultural Equipment,Zibo 255000,China)

机构地区：[1]山东理工大学农业工程与食品科学学院,淄博255000 [2]山东省旱作智能农机装备协同创新中心,淄博255000

出　　处：《农业机械学报》2023年第11期49-60,113,共13页Transactions of the Chinese Society for Agricultural Machinery

基　　金：山东省自然科学基金项目(ZR2022QE150);国家重点研发计划项目(2021YFD2000401-2);山东省重点研发计划项目(2019GNC106087)。

摘　　要：为获取玉米田耕层不同土壤的各项参数,本文将玉米田耕层典型土壤分为未与玉米根茬接触的普通土壤(PT)和与玉米根茬结合形成根土复合体的土壤(GT),采用物理试验与离散元仿真相结合的方法,分别对离散元参数进行标定。基于Hertz-Mindlin(no slip)接触模型,采用中心组合试验设计方法,以土壤堆积角为目标值,进行了四因素五水平仿真试验。基于Hertz-Mindlin with bonding接触模型,采用Design-Expert软件,应用Plackett-Burman设计敏感性分析试验、最陡爬坡试验、Box-Behnken试验,以土壤硬度为目标值,对显著性参数进行寻优,得到PT最优解组合为:粘结键法向刚度4.37×10^(7)N/m^(3)、粘结键切向刚度1.46×10^(7)N/m^(3)、切向极限应力3.24×105Pa;GT最优解组合为:粘结键法向刚度5.19×10^(7)N/m^(3)、粘结键切向刚度4.25×10^(7)N/m^(3)、法向极限应力4.52×105Pa。基于两种土壤标定的参数对其进行了土壤直剪验证试验,结果表明,所标定的两种土壤仿真和实测最大剪应力的相对误差均低于10%,仿真参数可靠。本文提出的土壤颗粒建模方法、标定方法及其所标定的参数值准确可靠,可为玉米田耕层土壤模型构建提供理论依据。To obtain the parameters of different soil in the maize field tillage layer,the typical soil of the maize field tillage layer was divided into ordinary soil(PT)that was not in contact with maize stubble and soil(GT)that combined with maize stubble to form a root-soil complex.The discrete element parameters were calibrated by combining physical experiments and discrete element simulation.Based on Hertz-Mindlin(no slip)contact model,a four factor and five level simulation test was conducted with the central composite design of experiments method and the soil accumulation angle as the target value.Based on the Hertz-Mindlin with bonding model,the Plackett-Burman test,steepest climbing test and Box-Behnken test were designed by using Design-Expert software.The significance parameters were optimized with soil hardness as the target value,and the optimal solution combination for PT was obtained as follows:normal stiffness per unit area was 4.37×10^(7)N/m^(3),shear stiffness per unit area was 1.46×10^(7)N/m^(3),critical shear stress was 3.24×105Pa.The optimal solution combinations for GT as follows:normal stiffness per unit area was 5.19×10^(7)N/m^(3),shear stiffness per unit area was 4.25×10.7N/m^(3),and critical normal stress was 4.52×105Pa.A soil direct shear validation test was conducted based on the parameters calibrated for two types of soil.The results showed that the relative error of maximum shear stress between the simulation and measurement of the two types of soil was less than 10%,indicating that the simulation parameters were reliable.The soil particle modeling method and calibration method proposed as well as the calibrated parameter values were accurate and reliable,and can provide a theoretical basis for the construction of soil models in maize fields.

关 键 词：玉米田耕层土壤 玉米根土复合体 离散元 参数标定 

分 类 号：S222.4[农业科学—农业机械化工程]