Effects of particle angularity on micro-macro mechanical behaviors and segregation in 2D granular material

Abstract

This dissertation is devoted to investigating the effect of particles shapes in granu-lar mixtures on strength properties, microstructure, and segregation behavior. Granular material is a collection of rigid particles. These material are widely used in industrial process such as civil engineering structure, plastic industries, food industries, and phar- maceutical industries. This study was divided into two parts: under quasi-static load and under dynamic load. In the first part, the granular mixtures composed of particle shapes were subjected to biaxial sheared under quasi-static regimes by using contact dynamics simulation, which are investigated in term of strength properties and microstructure. It was found that the shear strength strongly varies with the angularity of the particle. Hence, the granular packing composed more angular particles (e.g., triangle and square) are having high shear strength. In addition, the microstructure that contributes to this strength is described in term of particle connectivity and contact and force anisotropies. The network topology may change in different directions as the angularity of the particles increases, influencing the macroscopic shear strength. In the second part, the effect of particle shapes in granular material on segregation behavior under vertical vibration was investigated by means of experiment and numerical simulation. The segregation coefficient and segregation pattern are used to classify the segregation behavior. It was found that particles shapes did not affect the segregation in granular mixture.