Effects of particle morphology on the macroscopic behaviour of ellipsoids: A discrete element investigation

The use of granular materials are ubiquitous in the infrastructural projects. Due to the dramatic degradation of natural resources and rapid development of urbanization, new challenges in sustainable development have led the civil engineering community to consider a breakthrough approach based on a fundamental understanding of natural scale of grains and their interactions. In this study, a three-dimensional DEM based investigation of particle morphology on the macroscopic behaviour of ellipsoids is carried out under conventional drained triaxial test conditions. Six numerical simulations are performed by controlling two parameters i.e., 3ξ and 3β, whereξ is the ratio of the smallest to the largest sphere and β is the maximum sphere-sphere intersection angle. It has been found that irrespective of ξ and β, all stress-strain curves exhibit strain-softening behaviour and a critical state is achieved at large axial strains. The shear strength of ellipsoids at both peak and critical states is found to increase with decreasing β. Moreover, the peak state friction angles are found to increase with increasing ξ, whereas critical state friction angles decrease with increasing ξ. These findings highlight the significance of particle morphology on the macroscopic response of granular materials.