CALIBRATION AND EXPERIMENTS OF THE DISCRETE ELEMENT SIMULATION PARAMETERS FOR RICE BUD DAMAGE

Rice buds are easily bruised or broken during sowing, which affects the seedling rate, and the discrete element simulation of rice buds lacks an accurate model in this process. The EDEM simulation software was used to calibrate the parameters of the discrete element simulation model for different states of rice bud seeds damage. The Hertz-Mindlin model was used to simulate the accumulation of rice bud seeds. Through a series of tests, the interspecific static friction factor was 0.644, and the rolling friction factor was 0.062. The normal contact stiffness and tangential contact stiffness were determined for the bud germination state and the 1-3 mm bud length state, respectively, by using the meta-particle function to build rice seed sprouts and applying the bonding model to conduct Box -Behnken response surface tests for shear damage of rice seed sprouts. Finally, experiments were carried out with a hole-belt-type seed meter. The results showed that under different belt speeds, the relative error between the measured value and the simulated value of the rice bud damage rate was not more than 0.9%, indicating that the calibration parameters were accurate and reliable.