SANISAND-F: Sand constitutive model with evolving fabric anisotropy
Journal article, 2020

In order to incorporate the very important role of evolving fabric anisotropy on the mechanical response of sand, a constitutive model is developed within the frameworks of Bounding Surface plasticity and Anisotropic Critical State Theory in multiaxial stress space. The main new constitutive ingredient is a fabric anisotropy variable A, a scalar measure of the relative orientation between an evolving fabric tensor F and the deviatoric plastic strain rate direction. The variable A affects scalar ingredients of the model quantifying the plastic strain rate, i.e. the plastic modulus and the dilatancy. A comprehensive calibration procedure is fully described and an extensive validation is performed against a very large dataset from 55 monotonic element tests on Toyoura sand provided by various laboratories, loaded under drained and undrained conditions. The introduction of A into the model is the main reason why successful simulation of data is achieved for loading at various orientations of the stress tensor under otherwise same initial conditions of void ratio and confining pressure, and this even if the data often exhibit huge difference of response because of the difference in loading orientation.

Constitutive model


Anisotropic critical state theory


Bounding surface


Alexandros Petalas

Chalmers, Architecture and Civil Engineering, GeoEngineering

Yannis F. Dafalias

Institute of Thermomechanics of the Academy of Sciences of the Czech Republic

National Technical University of Athens (NTUA)

University of California

Achilleas G. Papadimitriou

National Technical University of Athens (NTUA)

International Journal of Solids and Structures

0020-7683 (ISSN)

Vol. 188-189 12-31

Subject Categories

Applied Mechanics

Other Materials Engineering

Vehicle Engineering



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