玉米秸秆粉料致密成型离散元模型参数标定

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...

Parameters Calibration of Discrete Element Model for Corn Stalk Powder Compression Simulation

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 0.05J/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.