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A model for stress and plastic strain induced nonlinear, hyperelastic anisotropy in soils
Author(s) -
Gajo A.,
Bigoni D.
Publication year - 2008
Publication title -
international journal for numerical and analytical methods in geomechanics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.419
H-Index - 91
eISSN - 1096-9853
pISSN - 0363-9061
DOI - 10.1002/nag.648
Subject(s) - hyperelastic material , isotropy , elasticity (physics) , nonlinear system , anisotropy , critical state soil mechanics , stiffening , constitutive equation , plasticity , materials science , stiffness , ogden , geotechnical engineering , mechanics , nonlinear elasticity , structural engineering , finite element method , geology , composite material , engineering , physics , optics , quantum mechanics
The experimental evidence that cohesive and granular soils possess an elastic range in which the elasticity is both nonlinear and anisotropic—with stiffness and directional characteristics strongly dependent on stress and plastic strain (the so‐called ‘stress history’)—is given a formulation based on hyperelasticity. This is accomplished within the framework of elastoplastic coupling, through a new proposal of elastic potentials and a combined use of a plastic‐strain‐dependent fabric tensor and nonlinear elasticity. When used within a simple elastoplastic framework, the proposed model is shown to yield very accurate simulations of the evolution of elastic properties from initial directional stiffening to final isotropic degradation. Within the proposed constitutive framework, it is shown that predictions of shear band formation and evolution become closer to the existing experimental results, when compared to modellingin which elasticity does not evolve. Copyright © 2007 John Wiley & Sons, Ltd.