Abstract
This work is devoted to the numerical modeling of highly polydisperse granular materials in view of investigating the texture and mechanical behavior in quasi-static shearing. The polydispersity is modeled in terms of size span and curvature of the particle size distributions. A method is proposed to generate representative size distributions both in number and volume of size classes, and the accessible polydispersity parameters are determined for tractable number of particles. A geometrical method is used to construct large samples and to study the resulting texture in a systematic manner as a function of size distribution. These samples are then subjected to simple shear with periodic boundary conditions by means of the contact dynamics method. We show that: 1) The highest level of solid fraction corresponds to uniform distribution by particle volume fractions; 2) The shear strength in the steady state is independent of polydispersity; 3) A detailed analysis of the texture and force transmission indicates that this property results from the mutual compensation between the anisotropies of contact orientations and branch-vector lengths, and also from the fact that the strong force chains are mainly captured by the largest particles; 4) In the presence of adhesion between particles, the Coulomb cohesion increases with size span.