Combined Influence of Particle Shape and Fabric on the Shear Behaviour of Granular Materials

The anisotropy feature is an important characteristic of granular materials in natural life and is caused by two facts: the anisotropy feature of particle shape, such as an elongated or flattened shape, and the anisotropy feature of the packing fabric, such as the preferable orientation of particle alignment. The discrete element method has been commonly used in the study of meso-mechanics of granular materials and is in our study to simulate the direct shear test with particles of various aspect ratios under different initial orientation alignment conditions for assessing the coupled influence of anisotropy from particle shape and fabric of particle packings on the shear behaviour of granular materials. Analysis results show that anisotropy from the particle shape has the most significant influence on the shear behaviour of a granular packing when the packing has the initial anisotropy fabric of an orientational alignment perpendicular to the shear direction. Moreover, the initial fabric anisotropy of a granular packing has an increasing influence with the rise in anisotropy of particle shape. A combined anisotropic factor is finally introduced to reflect the coupled influence of the shape anisotropy of particles and the fabric anisotropy of particle packings