Constitutive Modelling for Granular Material under Finite Strains with Particle Slidings and Fabric Changes

The overall objective of this research is to develop a constitutive model for granular material under finite strains with explicit consideration of particle sliding and the consequent fabric change. The specific objective of this research is focused on the development of a stress strain theory that accounts for the microstructure and the non-uniform strain field of the particle assembly. The developed theoretical model is evaluated by results obtained from computer simulation and experiments of granular material. Mechanical behavior of granular media is important in many fields of studies such as soil mechanics, powder mechanics, and ceramic mechanics. the mechanical behavior of granular media has been studied by borrowing the stress-strain models, such as elastic, elasto-plastic, or plastic models, developed for continuum materials. These continuum models consider neither the discrete nature nor the deformation mechanism of granular materials. A more rational approach should be one that considers the granular system as an assemblage of particles. The stress-strain behavior for a granular material is define for a representative-volume which consists of a sufficiently large number of particles to be representative of the material. When subjected to loading, the deformation of the granular system results from particle deformation as well as slip between particles.