关键词: 花生荚果, 堆积角, 离散元仿真, 参数优化, 参数标定

Abstract: In order to ensure the accuracy of the parameters used in the simulation test of peanut pods, the study uses the method of combining actual physical test and simulation test to calibrate the discrete element simulation parameters. First of all, the basic physical parameters of peanut pods (including dimensions, density, moisture content, bulk density, elastic modulus, Poisson wave and shear modulus) are measured through actual physical experiments, and the simulation is determined based on the results of various physical quantities measured by actual physical experiments. The value range of the test parameters is carried out, and the PlackettBurman test is carried out. The factors that have a significant influence on the stacking angle are selected: peanut podpeanut pod static friction coefficient, rolling friction coefficient, peanut podsteel plate static friction coefficient. The value range of the significant factor is further determined by the steepest climb test. BoxBehnken test is carried out to establish the quadratic regression equation between the accumulation angle and the significant factor, and solve the equation with the actual physical test accumulation angle (31.63°) as the target value, and obtain the best simulation parameters:the static friction coefficient and rolling friction coefficient of peanut pods, and the static friction coefficient between peanut pods and steel plates are 0.74, 0.24 and 0.58, respectively. Finally, a simulation test on the best simulation parameters determined after the experimental analysis is performed, and an independent sample T test on the obtained simulation value and the actual test value is performed, with P>0.05, which shows that there is no significant difference between the actual test accumulation angle and the simulation test accumulation angle, and the relative error is 2.877%,  the accuracy of the simulation test is also verified. By comparing the methods and test results used in the calibration of other material parameters, it further shows that the calibrated parameters can provide references for related research.

Key words: peanut pods, stacking angle, DEM simulation, parameter optimization, parameter calibration