Fabric evolution and strain localisation in inherently anisotropic specimens of anisometric particles (lentils) under triaxial compression

Abstract Inherent anisotropy is often observed in natural soils and other granular materials formed during gravity deposition. Fabric characterisation evolution have been mainly studied using numerical simulations, given the difficulty of retrieving contact network kinematics particles physical experiments. This work presents results five triaxial compression tests on inherently anisotropic lentil specimens imaged with x-ray tomography. Each specimen prepared a way such that all present unique mean orientation, as from deposits - this can be called “bedding effect”. Particles are identified tracked first image through test novel tracking algorithm, enabling measurement particle fabric evolution, well strain localisation within specimens. The reveal deformation processes take place essentially planar scenario, both at micro mesoscale. Additionally, it under deviatoric loading two mechanisms responsible for evolution: rotation main orientation tensor, increase anisotropy. Finally, shear band found to independent initial particles. Graphical abstract