A comparative study of the hypoplasticity and the fabric‐dependent dilatant double shearing models for granular materials

Abstract

SUMMARYIn this paper, we consider the mechanical response of granular materials and compare the predictions of a hypoplastic model with that of a recently developed dilatant double shearing model which includes the effects of fabric. We implement the constitutive relations of the dilatant double shearing model and the hypoplastic model in the finite element program ABACUS/Explicit and compare their predictions in the triaxial compression and cyclic shear loading tests. Although the origins and the constitutive relations of the double shearing model and the hypoplastic model are quite different, we find that both models are capable of capturing typical behaviours of granular materials. This is significant because while hypoplasticity is phenomenological in nature, the double shearing model is based on a kinematic hypothesis and microstructural considerations, and can easily be calibrated through standard tests.

Implicit Continuum Mechanics Approach to Heat Conduction in Granular Materials

“…From the above equations, it can be seen that constitutive relations are needed for T , q , and r . Modeling of the stress tensor, T , in both implicit and explicit forms, has received much attention. − [In recent years, Rajagopal , has provided a rigorous implicit methodology where constitutive relations for a class of fluids whose viscosity depends on pressure and shear rate can be obtained.] However, constitutive modeling of heat flux vector, q , and the radiation term, r , are still in the early stages of development.…”

Multi-mechanism anisotropic model for granular materials

“…Numerical triaxial simulations are provided in Balendran and Nemat-Nasser (1993), Zhu et al (2006a) and Nemat-Nasser and Zhang (2002). In a recent paper, Zhu et al (2006c) compared the results from the doubleshearing theory with the results of a hypoplastic theory, verified using triaxial data, and showed good agreements.…”