Isotropic compression behavior of granular assembly with non-spherical particles by X-ray micro-computed tomography and discrete element modeling

The particle morphological properties, such as sphericity, concavity and convexity, of a granular assembly significantly affect its macroscopic and microscopic compressive behaviors under isotropic loading condition. However, limited studies on investigating the microscopic behavior of the granular assembly with real particle shapes under isotropic compression were reported. In this study, X-ray computed tomography (μCT) and discrete element modeling (DEM) were utilized to investigate isotropic compression behavior of the granular assembly with regard to the particle morphological properties, such as particle sphericity, concavity and interparticle frictions. The μCT was first used to extract the particle morphological parameters and then the DEM was utilized to numerically investigate the influences of the particle morphological properties on the isotropic compression behavior. The image reconstruction from μCT images indicated that the presented particle quantification algorithm was robust, and the presented microscopic analysis via the DEM simulation demonstrated that the particle surface concavity significantly affected the isotropic compression behavior. The observations of the particle connectivity and local void ratio distribution also provided insights into the granular assembly under isotropic compression. Results found that the particle concavity and interparticle friction influenced the most of the isotropic compression behavior of the granular assemblies.