Reproducibility of the repose angle, porosity, and coordination number of particles generated by spherical harmonic-based principal component analysis using discrete element simulation

Most of the raw material in the mining and manufacturing industries is in a granular state, and its bulk properties (e.g., repose angle) are thus of interest. Discrete element method (DEM) simulation of numerous particles is used to determine these properties. As numerous particles are simulated by DEM, and particle shapes affect the bulk properties, the effective modeling of realistic particle shapes is required. Spherical harmonic-based principal component analysis (SH-PCA) has been used to randomly generate particle shapes that retain the original par-ticles' morphological features. Previous studies confirmed that the morphological features of original particles were reproduced in particles generated by SH-PCA, but there have been few studies on the related bulk prop-erties. In this study, the shapes of four types of ore particles were obtained by X-ray computed tomography and analyzed, new particle shapes were generated by SH-PCA, the bulk properties (repose angle, porosity, and co-ordination number) simulated by DEM using the generated particle shapes were compared with those using the original particle shapes, successful reproduction was confirmed. A further DEM simulations, involving particle systems composed of copies of original particle-shape types, revealed that from 200 to 1100 shape varieties were required to reproduce the bulk properties of all the differently-shaped particle systems, suggesting the impor-tance of particle-shape variety.