Mechanical Properties of Corn Stalks and Behavior of Particles During Compression Process Based on Discrete Element Method

The mechanical properties of corn stalks play a crucial role in the design of packing and harvesting equipment. Complete and damaged stalks were used to simulate stalk mixtures during the collection process. This study measured the mechanical characteristics of complete stalks and damaged stalks through experiments. A discrete element method (DEM) model was established which incorporated both the skin and core tissues of the samples. The compression behavior of the stalks was analyzed with the EDEM 2022 software. The results indicate that the complete stalks exhibited both a plastic and second plastic stage, while the damaged stalks fractured immediately upon reaching peak stress. The models of the complete and damaged stalks were validated through a radial compression test. An analysis of the relative errors and particle velocities enabled the quantification of experimental accuracy, ensured the reliability of the experimental data, and revealed the dynamic behavior mechanism of the materials under mechanical loading. The simulation results show that the maximum compression force is 254.11 N and 33.1 N, with a 1.5% and 12.3% relative error compared to the experiment. The particle velocity in the core part is the largest, which is 9.83 × 104 mm/s and 3.51 × 105 mm/s. This study can provide a theoretical reference for researching the mechanical behavior and compressive failure of stalks.