Abstract
Granular materials are special materials, from the continuum-mechanical viewpoint, in the sense that they possess a clear microstructure of grains and intergrain contacts. In addition, the grains have translational as well as rotational degrees of freedom. Here a micromechanical expression is formulated for the average displacement gradient tensor in terms of the grain displacements and rotations for the two-dimensional case. It is based on a tessellation of the granular assembly into closed loops, along whose boundary the displacement field is defined in terms of the grain displacements and rotations. An important consideration for this expression is that it must satisfy the surface-additivity property, according to which the average displacement gradient of a combined two-dimensional surface is determined by the average displacement gradients of the constituent surfaces (and weighted by their areas). The developed micromechanical expression is verified by comparing its results with the macroscopic deformation as determined from the displacements at the boundary. Results of DEM simulations of a biaxial test (where the average rotation is equal to zero) and a shear test (where the average rotation is not equal to zero) are employed for this verification. The developed micromechanical expression for the displacement gradient is subsequently used to study deformation patterns in a complex case of a biaxial test where a shear band is formed.
Similar content being viewed by others
Notes
This definition involves not only contact forces between grains, but also inertia forces in dynamical situations (see also [20] for the associated DEM simulations).
References
Aboudi, J., Arnold, S.M., Bednarcyk, B.A.: Micromechanics of Composite Materials. Elsevier, Amsterdam (2013)
Ancey, C.: Dry granular flows down an inclined channel: experimental investigations on the frictional-collisional regime. Phys. Rev. E 65, 011304 (2002)
Aranson, I.S., Tsimring, L.S.: Continuum theory of partially fluidized granular flows. Phys. Rev. E 64, 020301 (2001)
Bagi, K.: Stress and strain in granular assemblies. Mech. Mater. 22, 165–177 (1996)
Bagi, K.: Analysis of microstructural strain tensors for granular assemblies. Int. J. Solids Struct. 43, 3166–3184 (2006)
Bonelli, S., Millet, O., Nicot, F., Rahmoun, J., de Saxcé, G.: On the definition of an average strain tensor for two-dimensional granular material assemblies. Int. J. Solids Struct. 49, 947–958 (2012)
Cambou, B., Chaze, M., Dedecker, F.: Change of scale in granular materials. Eur. J. Mech. A Solids 19, 999–1014 (2000)
Cambou, B., Jean, M.: Micromécanique des milieux granulaires. Hermes, Paris (2001)
Chang, C.S., Gao, J.: Kinematic and static hypotheses for constitutive modelling of granulates considering particle rotation. Acta Mech. 115, 213–229 (1996)
Cundall, P.A., Strack, O.D.L.: A discrete numerical model for granular assemblies. Géotechnique 9, 47–65 (1979)
Dantu P.: Contribution à l’étude mécanique et géométrique des milieux pulvérulents. In: Proc. 4th Int. Conf. Soils Mech. Found. Eng., London, pp. 144–148 (1957)
Dedecker, F., Chaze, M., Dubujet, Ph, Cambou, B.: Specific features of strain in granular materials. Mech. Cohes. Frict. Mater. 5, 173–193 (2000)
de Saxcé, G., Fortin, J., Millet, O.: About the numerical simulation of the dynamics of granular media and the definition of the mean stress tensor. Mech. Mater. 36, 1175–1184 (2004)
Durán, O., Kruyt, N.P., Luding, S.: Micro-mechanical analysis of deformation characteristics of three-dimensional granular materials. Int. J. Solids Struct. 47, 2234–2245 (2010)
Durán, O., Kruyt, N.P., Luding, S.: Analysis of three-dimensional micro-mechanical strain formulations for granular materials: evaluation of accuracy. Int. J. Solids Struct. 47, 251–260 (2010)
de Gennes, P.G.: Reflections on the mechanics of granular matter. Phys. A 261, 267–293 (1998)
Eringen, A.C.: Microcontinuum Field Theories I: Foundations and Solids. Springer, New York (1999)
Fortin, J., Millet, O., De Saxcé, G.: Mean stress in a granular medium in dynamics. Mech. Res. Commun. 29(4), 235–240 (2002)
Fortin, J., Millet, O., De Saxcé, G.: Construction of an averaged stress tensor for a granular medium. Eur. J. Mech. A Solids 22(4), 567–582 (2003)
Fortin, J., Millet, O., de Saxcé, G.: Numerical simulation of granular materials by an improved discrete element method. Int. J. Numer. Methods Eng. 62, 639–663 (2005)
Goldhirsch, I., Goldenberg, C.: Continuum mechanics for small systems and fine resolutions. In: Rieth, M., Schommers, W. (eds.) Handbook of Theoretical and Computational Nanotechnology, pp. 1–58. American Scientific Publishers, Stevenson Ranch (2005)
Hadda, N.: Aspects micromécaniques de la rupture dans les milieux granulaires (in French) [Micromechanical aspects of failure in granular materials]. Ph.D. Thesis Université de Grenoble, Grenoble, France (2012)
Horne, M.R.: The behaviour of an assembly of rotund, rigid, cohesionless particles, I and II. Proc. R. Soc. Lond. A 286, 62–97 (1965)
Kruyt, N.P., Rothenburg, L.: Micromechanical definition of the strain tensor for granular materials. J. Appl. Mech. (Transactions of the ASME) 63, 706–711 (1996)
Kruyt, N.P.: Statics and kinematics of discrete Cosserat-type granular materials. Int. J. Solids Struct. 40, 511–534 (2003)
Kruyt, N.P., Millet, O., Nicot, F.: Deformation analysis of granular materials at micro and macro scales. In: Soga, K., Kumar, K., Biscontin, G., Kuo, M. (eds.) Geomechanics from Micro to Macro. pp. 753–757. Taylor & Francis, London, UK (2014)
Kuhn, M.R.: A boundary integral for gradient averaging in two dimensions: application to polygonal regions in granular materials. Int. J. Numer. Methods Eng. 59, 559–576 (2004)
Liao, C.-L., Chang, T.-P., Young, D.-H.: Stress-strain relationship for granular materials based on the hypothesis of best fit. Int. J. Solids Struct. 34, 4087–4100 (1997)
Nicot, F., Darve, F.: A multi-scale approach to granular materials. Mech. Mater. 37, 980–1006 (2005)
Oda, M., Konishi, J.: Microscopic deformation mechanism of granular material in simple shear. Soils Found. 14, 15–32 (1974)
O’Sullivan, C., Bray, J.D., Li, S.F.: A new approach for calculating strain for particulate media. Int. J. Numer. Anal. Methods Geomech. 27, 859–877 (2003)
Pouliquen, O., Forterre, Y., Ledizes, S.: Dense granular flows down incline as a self-activated process. Adv. Complex Syst. 4, 441–450 (2001)
Radjai, F., Wolf, D., Jean, M., Moreau, J.J.: Bimodal character of stress transmission in granular packing. Phys. Rev. Lett. 80, 61–64 (1998)
Radjai, F., Roux, S., Moreau, J.J.: Contact forces in a granular packing. Chaos 9, 544–550 (1999)
Rajchenbach, J.: Granular flows. Adv. Phys. 49, 229–256 (2000)
Tordesillas, A., Muthuswamy, M.: On the modeling of confined buckling of force chains. J. Mech. Phys. Solids 57, 706–727 (2009)
Tordesillas, A., Walker, D.M., Lin, Q.: Force cycles and force chains. Phys. Rev. E 81, 011302 (2010)
Tordesillas, A., Pucilowski, S., Sibille, L., Nicot, F., Darve, F.: Multiscale characterization of diffuse granular failure. Philos. Mag. 92, 4547–4587 (2012)
Acknowledgments
The authors acknowledge data shown in Sect. 6 that was kindly provided by N. Hadda (previously with Irstea, France; currently with the Department of Civil Engineering of the University of Calgary, Alberta, Canada). NK acknowledges hospitality at Université de La Rochelle.
Author information
Authors and Affiliations
Corresponding author
Additional information
This study is an extended version of that presented by the authors [26].
Rights and permissions
About this article
Cite this article
Kruyt, N.P., Millet, O. & Nicot, F. Macroscopic strains in granular materials accounting for grain rotations. Granular Matter 16, 933–944 (2014). https://doi.org/10.1007/s10035-014-0523-3
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10035-014-0523-3