Simulation and experiment of kernel loss during peeling of seed maize based on DEM-MBD coupling

Abstract

To address the issue of significant kernel loss during the peeling process of seed maize, this study constructs a discrete element model (DEM) of seed maize ear aggregates based on the three-layer structure of the maize ear through hierarchical modelling and the particle filling method. At the same time, a multi-body dynamics (MBD) model of the peeling mechanism is created using the mesh delineation and flexible body method. The DEM-MBD coupling method is employed to simulate the interaction process between the seed maize and the peeling mechanism, analysing the impact of different working parameters of the peeling mechanism on the loss of maize kernels. Using the principle of the Box-Behnken experimental design, a three-factor, three-level experiment is carried out. Based on the experimental results, a quadratic polynomial regression model between the experimental factors and the indicator is established. Through multi-objective optimisation and experimental verification, the optimal combination of working parameters for the seed maize peeling mechanism is obtained: the spacing between the press-pusher and the peeling roller is 33 mm, the peeling roller rotational speed is 420 r·min⁻¹, and the peeling roller gap is - 0.8 mm, with the kernel shedding rate being 0.80 %. The error between the simulation and verification experimental results is <3 %, validating the accuracy and reliability of the simulation model in predicting kernel loss. The peeling rollers used in the experiment meet the performance requirements for seed maize peeling, and the method adopted can offer some reference for the improvement and parameter optimisation of the seed maize peeling mechanism.