非规则颗粒形态表征与离散元模拟方法研究

Granular materials widely exist in nature, industry, and human life. The physicomechanical characteristics of irregular particles are closely related to their geometry morphology. This paper summarizes the relevant studies performed by our research group and collaborators. The research progress in image acquisition, geometric reconstruction, morphological characterization, random generation, and discrete element modeling of irregular particles is presented. In addition, the advantages and disadvantages of different methods for the image acquisition of irregular particles are summarized. Two- and three-dimensional general-shape particles are divided into two categories, namely star- and nonstar-like particles. The computational geometric methods for the morphological reconstruction of the particles in each category are introduced. Moreover, the definitions and calculation formulas for the morphological evaluation indices of irregular particles are systematically summarized. The random generation method for the star-like particles based on the inverse Monte Carlo method and that for the nonstar-like particles are introduced considering the inherent relationship of the first-order coefficients and the empirical correlation between the coefficients at different orders. For the discrete element modeling methods of irregular particles, the progress on the core issues, such as geometric representation, contact detection, and contact law, is summarized.