Development and Experimental Validation of Flexible Discrete Element Model for Seed Maize Ears

Abstract:

Aiming to address high kernel loss and breakage rates during seed maize husking and insufficient modeling precision, a flexible composite discrete element method (DEM) model for seed maize ears was developed. The intrinsic parameters and contact parameters of different components of seed maize ears were determined through physical experiments. A flexible composite DEM model comprising bract-kernel-cob was constructed based on the Hertz-Mindlin with Bonding V2 contact model. The combination of Plackett-Burman design, steepest ascent method, and Box-Behnken response surface methodology was employed to calibrate and optimize the key bonding parameters of cob shaft and kernels, establishing a DEM model capable of accurately characterizing kernel detachment and breakage during husking. The simulation results showed high calibration accuracy, with relative errors of 3.89% for cob shaft three-point bending, 8.79% for kernel compression, and 7.58% and 6.89% for kernel detachment in axial and tangential directions respectively compared with physical experiments. In husking simulation validation, kernel detachment and breakage rates were 1.774% and 0.457% respectively, compared with bench test results of 1.697% and 0.432%, with relative errors of 4.54% and 5.79%. All results met seed maize husking quality standards, confirming the model realistically reflects kernel detachment and breakage characteristics during husking. The research result can provide reliable reference for refined modeling of seed maize ears and optimization design of husking devices.