Investigation of influence of particle characteristics on the non-coaxiality of anisotropic granular materials using DEM

As a result of deposition process and particle characteristics, granular materials can be inherently anisotropic. Many researchers have strongly suggested that the inherent anisotropy is the main reason for the deformation non-coaxiality of granular materials. However, their relationships are not unanimous due to the limited understanding of the non-coaxial micro-mechanism. In this study, we investigated the influence of inherent anisotropy on the non-coaxial angle using the discrete element method (DEM). Firstly, we developed a new DEM approach using rough elliptic particles, and proposed a novel method to produce anisotropic specimens. Secondly, the effects of initial specimen density and particle characteristics, such as particle aspect ratio Am, rolling resistance coefficient β and bedding plane orientation δ, were examined by a series of biaxial tests and rotational principal axes tests (RPAM). Findings from the numerical simulations are summarized as: (1) The peak internal friction angle ϕp and the non-coaxial angle i both increase with the initial density, Am and β, and they both increase initially and then decrease with ϕ in the range of 0 - 90°; (2) Among the particle characteristics, the influence of Am is the most significant; (3) For anisotropic specimens, the non-coaxial angle can be calculated using the double slip and rotation rate model (DSR2 model). Then, an empirical formula was proposed based on the simulation results to depict the relationship between the non-coaxial angle and the particle characteristics. Finally, the particle-scale mechanism of non-coaxiality for granular materials was discussed from the perspective of energy dissipation.

[1]  Pierre-Yves Hicher,et al.  An elasto-plastic model for granular materials with microstructural consideration , 2005 .

[2]  Seiichi Miura,et al.  DEFORMATION BEHAVIOR OF ANISOTROPIC DENSE SAND UNDER PRINCIPAL STRESS AXES ROTATION , 1986 .

[3]  Yang-ping Yao,et al.  Discrete element method analysis of non‐coaxial flow under rotational shear , 2014 .

[4]  J. Ooi,et al.  Experimental study of anisotropy and non-coaxiality of granular solids , 2015 .

[5]  Yannis F. Dafalias,et al.  A critical state sand plasticity model accounting for fabric evolution , 2014 .

[6]  M. Oda.  INITIAL FABRICS AND THEIR RELATIONS TO MECHANICAL PROPERTIES OF GRANULAR MATERIAL , 1972 .

[7]  Hai-Sui Yu,et al.  Kinematic variables bridging discrete and continuum granular mechanics , 2006 .

[8]  Serge Leroueil,et al.  An efficient technique for generating homogeneous specimens for DEM studies , 2003 .

[9]  M. Taha,et al.  A flow rule incorporating the fabric and non-coaxiality in granular materials , 2014 .

[10]  Koichi Hashiguchi,et al.  General non-proportional loading behavior of soils , 2005 .

[11]  G. Saussine,et al.  Quasistatic rheology, force transmission and fabric properties of a packing of irregular polyhedral particles , 2008, 0805.0178.

[12]  Tang-Tat Ng,et al.  Numerical simulations of granular soil using elliptical particles , 1994 .

[13]  Jonathan D. Bray,et al.  CAPTURING NONSPHERICAL SHAPE OF GRANULAR MEDIA WITH DISK CLUSTERS , 1999 .

[14]  Ikuo Towhata,et al.  FLOW THEORY FOR SAND DURING ROTATION OF PRINCIPAL STRESS DIRECTION , 1991 .

[15]  B. K. Menzies,et al.  Inherent anisotropy in a sand , 1972 .

[16]  C. Nouguier-Lehon.  Effect of the grain elongation on the behaviour of granular materials in biaxial compression , 2010 .

[17]  Hai-Sui Yu,et al.  Discrete element modelling of material non‐coaxiality in simple shear flows , 2014 .

[18]  R. Bathurst,et al.  Analytical study of induced anisotropy in idealized granular materials , 1989 .

[19]  Yannis F. Dafalias,et al.  Anisotropic Critical State Theory: Role of Fabric , 2012 .

[20]  Y. Dafalias,et al.  Study of anisotropic shear strength of granular materials using DEM simulation , 2011 .

[21]  Sia Nemat-Nasser,et al.  A micromechanically-based constitutive model for frictional deformation of granular materials , 2000 .

[22]  Particle-Scale Insight into Deformation Noncoaxiality of Granular Materials , 2015 .

[23]  Zhen-Yu Yin,et al.  Micromechanical Modeling for Inherent Anisotropy in Granular Materials , 2010 .

[24]  J. Santamarina,et al.  Closure of "Particle Shape Effects on Packing Density, Stiffness, and Strength: Natural and Crushed Sands" , 2006 .

[25]  François Nicot,et al.  Micro-mechanical bases of some salient constitutive features of granular materials , 2007 .

[26]  Hai-Sui Yu,et al.  Kinematic models for non‐coaxial granular materials. Part II: evaluation , 2005 .

[27]  Hai-Sui Yu,et al.  A novel discrete model for granular material incorporating rolling resistance , 2005 .

[28]  Jidong Zhao,et al.  Rotational Resistance and Shear-Induced Anisotropy in Granular Media , 2014 .

[29]  M. Jiang,et al.  A novel approach to examining double-shearing type models for granular materials , 2005 .

[30]  Mahmood A. Khwaja,et al.  An ellipse-based discrete element model for granular materials , 1993 .

[31]  A. Tordesillas,et al.  Incorporating rolling resistance and contact anisotropy in micromechanical models of granular media , 2002 .

[32]  A. Lashkari,et al.  A simple plasticity model for prediction of non-coaxial flow of sand , 2007 .

[33]  C. Thornton.  NUMERICAL SIMULATIONS OF DEVIATORIC SHEAR DEFORMATION OF GRANULAR MEDIA , 2000 .

[34]  Yunming Yang,et al.  A kinematic hardening soil model considering the principal stress rotation , 2013 .

[35]  Hai-Sui Yu,et al.  Kinematic models for non‐coaxial granular materials. Part I: theory , 2005 .

[36]  Dariusz Wanatowski,et al.  Noncoaxial Behavior of Sand under Various Stress Paths , 2013 .

[37]  Jian-Min Zhang,et al.  Drained Deformation Behavior of Anisotropic Sands during Cyclic Rotation of Principal Stress Axes , 2010 .

[38]  Leo Rothenburg,et al.  'Stress-force-fabric' relationship for assemblies of ellipsoids , 2001 .

[39]  Peter J. Bosscher,et al.  DEM simulation of granular media—structure interface: effects of surface roughness and particle shape , 1999 .

[40]  Jianfeng Wang,et al.  Distinct simulation of earth pressure against a rigid retaining wall considering inter-particle rolling resistance in sandy backfill , 2014 .

[41]  Mingjing Jiang,et al.  Experimental investigation on deformation behavior of TJ-1 lunar soil simulant subjected to principal stress rotation , 2013 .

[42]  Antonio Gens,et al.  Undrained anisotropy and principal stress rotation in saturated sand , 1984 .

[43]  J. R. F. Arthur,et al.  INDUCED AND INHERENT ANISOTROPY IN SAND , 1985 .

[44]  Masanobu Oda,et al.  Experimental micromechanical evaluation of strength of granular materials: Effects of particle rolling , 1982 .

[45]  Yannis F. Dafalias,et al.  Experimental investigation of shear strength of sands with inherent fabric anisotropy , 2014 .

[46]  Xia Li,et al.  Numerical investigation of granular material behaviour under rotational shear , 2010 .

[47]  Yannis F. Dafalias,et al.  A constitutive framework for anisotropic sand including non-proportional loading , 2004 .

[48]  P. Cundall,et al.  A discrete numerical model for granular assemblies , 1979 .

[49]  Ikuo Towhata,et al.  SAND RESPONSE TO CYCLIC ROTATION OF PRINCIPAL STRESS DIRECTIONS AS INDUCED BY WAVE LOADS , 1983 .

[50]  A. Anandarajah.  Critical State of Granular Materials Based on the Sliding-Rolling Theory , 2008 .

[51]  A.J.M. Spencer,et al.  A theory of the kinematics of ideal soils under plane strain conditions , 1964 .

[52]  Yunming Yang,et al.  A non-coaxial critical state soil model and its application to simple shear simulations , 2006 .

[53]  Kenichi Soga,et al.  Micromechanics-based stress-strain behaviour of soils at small strains , 2000 .

[54]  K. Iwashita,et al.  Influence of inherent anisotropy on mechanical behavior of granular materials based on DEM simulations , 2010 .

[55]  T. Ng,et al.  A three-dimensional discrete element model using arrays of ellipsoids , 1997 .