Gravitational Effect on Material Response of Granular Materials

This paper presents a study of the material response of a granular material under different gravity fields. A numerical tool, the discrete element method, is used to perform the drained triaxial compression simulations. The gravitational effect is examined with this numerical tool without using multiple samples. The results are compared with previous numerical simulations with zero gravity. The granular material is bi-dispersive porous medium. It is composed of two different kinds (shape and size) of ellipsoids. They are randomly generated and deposited with 1-g (or 10-g) conditions. Conventional drained triaxial compression simulations are performed on these samples. The simulations are loaded to very large strain until the critical state is reached. Two different loading paths are applied such that the major principal stress is either along the gravity field or perpendicular to the gravity field. The effect of the magnitude of gravity field and the effect of anisotropy of the sample due to gravity can be investigated.