摘要 为了提升秸秆粉料致密成型过程中离散元仿真所需参数的准确性,以玉米秸秆粉料为研究对象,利用EDEM软件中的Hertz-Mindlin with JKR粘结接触模型进行玉米秸秆粉料致密成型离散元仿真模型参数标定研究。首先,以接触参数的物理试验结果作为仿真参数选择依据,应用Plackett-Burman试验对初始参数进行筛选,方差分析结果表明,玉米秸秆粉料间滚动摩擦因数、粉料与不锈钢板间静摩擦因数以及JKR表面能对堆积角影响显著;其次,以堆积角为评价指标,应用Box-Behnken试验建立了堆积角与3个显著性参数的二次多项式回归模型,以物理试验得到的实际堆积角42.60°为目标值,对显著性参数进行寻优,得到最优组合为:秸秆粉料-粉料滚动摩擦因数为0.05、秸秆粉料-不锈钢板静摩擦因数为0.47、JKR表面能为0.05 J/m2;最后,在标定的参数下进行堆积角和模孔压缩试验对比,结果表明,仿真堆积角与实测堆积角相对误差为0.68%,仿真与实际试验压缩位移相对误差为0.98%,通过对比分析两次试验中秸秆粉料模孔压缩位移变化曲线的拟合情况,得出两曲线间的决定系数R~2为0.962 7,说明所得相关参数可用于秸秆粉料致密成型离散元仿真。 In order to improve the accuracy of the parameters needed in the discrete element simulation process of the corn stalk powder,the Hertz Mindlin with JKR Bonding contact model in EDEM software was used to calibrate the contact parameters of the discrete element model of corn stalk powder.Firstly,the physical test results of contact parameters were used as the basis for the selection of simulation parameters.Plackett Burman test was used to screen the initial parameters.The results of variance analysis showed that the rolling friction coefficient between corn stalk powder,static friction coefficient between powder and stainless steel plate and surface energy JKR had significant effects on accumulation angle.Secondly,taking the relative error of accumulation angle as the evaluation index,the quadratic polynomial regression model of accumulation angle and three significant parameters was established by Box Behnken test.Taking the measured accumulation angle of 42.60°obtained by physical experiment as the target value,the significance parameters were optimized,and the optimal combination was obtained as follows:corn stalk powder corn stalk powder rolling friction coefficient was 0.05,corn stalk powder stainless steel plate static friction coefficient was 0.47,and surface energy was 0.05 J/m2.Finally,the accumulation angle and die hole compression test were compared under the calibrated parameters.The results showed that the relative error of simulation accumulation angle and measured accumulation angle was 0.68%,and the relative error of simulation compression displacement and measured compression displacement was 0.98%.By comparing and analyzing the fitting of the change curve of the compression displacement of the corn stalk powder in the mold hole in the two tests,the coefficient of determination between the two curves was 0.9627.The parameters obtained from the calibration can be used for DEM simulation of corn stalk powder mold hole densification.
机构地区 安徽农业大学工学院 安徽省智能农机装备工程实验室
出处 《农业机械学报》 EI CAS CSCD 北大核心 2021年第3期127-134,共8页 Transactions of the Chinese Society for Agricultural Machinery
基金 国家自然科学基金项目(52005008) 安徽省科技重大专项(202003a06020013) 安徽省重点研发与开发计划项目(202004a06020058)。
关键词 玉米秸秆粉料 致密成型 堆积角 离散元 参数标定 corn stalk powder dense forming accumulation angle DEM parameter calibration
