Discrete element simulation of mechanical characteristics of sands under principal stress axes rotation

Abstract

The mechanical behavior of sands and other granular materials subjected to rotation of principal stress axes is significantly dependent on the micro fabric properties and their evolution. The discrete element simulation for sands under cyclic rotation of principal stress axes was validated by comparing the numerical simulation and laboratory test results on the development of two normal strains,the relationship between shear stress and shear strain,the evolution of the volumetric strain,and the effects of initial void ratio and stress ratio. Four variables characterized by the spatial distribution features of particle major axis orientation and interparticle contact normal directions were used to describe the fabric properties of granular materials. The evolution of the four fabric variables in a single cycle was studied for granular materials subjected to cyclic rotation of principal stress axes. The effects of initial void ratio and stress ratio on the evolution of fabric variables were also investigated in detail.