Effects of particle shape, physical properties and particle size distribution on the small-strain stiffness of granular materials: A DEM study

The effects of particle shape (angularity α and sphericity S), physical properties (shear modulus Gp and Poisson’s ratio νp) and particle size distribution (uniformity coefficient Cu) on the small-strain stiffness Gmax were investigated via the discrete element method (DEM) in this study. The Gmax values were obtained by DEM simulations of drained triaxial tests. Microscopic analysis indicates that Gmax uniquely depends on two microscale variants, i.e., the mechanical coordination number CNm and contact stiffness between particles. The particle shape effect was only related to CNm. The contact stiffness can be represented by the values of Gp and Cu. Accordingly, an empirical expression composed of CNm, Gp and Cu that can predict the Gmax of granular materials with different particle properties (e.g., particle size distribution, particle shape, and fabric effect) was proposed. The accuracy of the expression has been verified by comparing the data with previous studies.