STUDY ON THE MOVEMENT CHARACTERISTICS OF RAPESEED THRESHING MATERIALS BASED ON DEM SIMULATION AND HIGH-SPEED IMAGING

To investigate the movement characteristics and distribution patterns of materials inside the threshing drum during the rapeseed threshing process, a simplified DEM model was established using three typical particle types: seeds, pods, and stalks. A simulation system of the drum's internal environment was constructed, and combined with high-speed photography experiments to analyse the material distribution and dynamic movement trajectories. The results showed that materials primarily migrated in a helical pattern along the outer edge of the drum. Seeds and pods were mainly concentrated in collection box 2, accounting for 33.6% and 27.6% of the total, respectively. The material quantity gradually decreased from collection boxes 2 to 6, while 56.5% of the partially unbroken stalks were discharged from the straw outlet and collected in box 7. To verify the accuracy of the simulation, a test platform was built and high-speed photography experiments were conducted, showing that the actual material trajectories closely matched the simulation. Both simulation and experimental results indicated the highest material concentration in collection box 2, at 24.6% and 19.2%, respectively, and the lowest in box 6, at 5.1% and 6.8%. These findings provide theoretical support and technical guidance for optimizing drum structure, achieving precise threshing control, and advancing intelligent agricultural machinery design.