Discrete Element Modeling and Testing of Camellia oleifera Fresh Fruits Based on Double Suture Structure

This study aims to improve the simulation accuracy of the dehulling process of Camellia oleifera fresh fruits. A discrete element model of Camellia oleifera fresh fruits based on BPM (Bond Particle Model) and double suture structure was constructed using the Discrete Element Method (DEM). The intrinsic parameters and contact parameters of Camellia oleifera fresh fruit were determined through experiments, and the structural fragility and critical compression force variation range at the suture structure of Camellia oleifera fresh fruit were revealed through uniaxial compression tests. On this basis, innovative double suture structure shell models, seed models, and Camellia oleifera fresh fruit composite models were constructed, and the models were validated based on fresh fruits with a diameter of 34 mm. The "compression load-displacement" curve and physical test results are analyzed through uniaxial compression simulation experiment, and the error of both is 3.21%, which verifies the accuracy of the model. The results indicate that the model can accurately simulate key phenomena such as shell cracking and seed separation, and the simulation data is highly consistent with the physical experimental data. This study provides reliable theoretical basis and technical support for the research on the mechanism of Camellia oleifera fresh fruit dehulling and the optimization of dehulling equipment.