Effect of fabric anisotropy on shear localization in sand during plane strain compression

Summary The paper focuses on the effect of fabric anisotropy on shear localization in cohesionless granular materials. For the numerical simulation, a hypoplastic constitutive model was used. In order to take into account a characteristic length of the micro-structure, the constitutive model was extended to include the second gradient of the Euclidian norm of the deformation rate. The hypoplastic model captures the salient features of granular bodies in a wide range of density and pressure with a single set of parameters. Transversal isotropy is described by the dyadic product of the normal vector of the space orientation of the plane of symmetry. FE-simulations of plane strain compression under constant lateral pressure were carried out with a medium dense specimen for both uniform and stochastic distribution of the initial void ratio. The effect of the direction of the bedding plane and the initial void ratio distribution on the load-deformation behavior was investigated. Moreover, the location, thickness and inclination of the shear zone were also analyzed.