Modeling and Experimental Validation of Pine Nuts Based on DEM

ABSTRACT To advance the application of pine nuts in computer‐aided numerical simulations, the discrete element method (DEM) was employed to investigate their motion behavior and dynamic response during key post‐harvest processing operations such as harvesting, cleaning, and conveying. This work aims to support the design and optimization of associated mechanical components. Based on a statistical analysis of geometric shapes, the right‐angled triangular shape, isosceles triangular shape, and D‐shaped pine nuts representing the majority of the population were selected for modeling. Characteristic dimensions were defined and found to follow approximately normal distributions, with functional correlations identified among them. A multi‐sphere modeling method was adopted, using thickness ( T ) as the primary dimension, randomly generating from its distribution, while other dimensions were computed using established relationships. A pine nut particle assembly model was constructed accordingly. Fundamental physical and contact parameters were determined through measurements and angle of repose tests. The accuracy and reliability of the model were validated through cylinder lifting, piling, and bulk density tests. Results indicated that sub‐sphere counts of 36, 19, and 13 for right‐angled triangular shape, isosceles triangular shape, and D‐shaped pine nuts, respectively, provided a balance between simulation accuracy and computational efficiency.