Granular Materials: Fundamentals And Applications,Used

Excerpt. Reprinted by permission. All rights reserved.Granular MaterialsFundamentals and ApplicationsBy S. Joseph Antony, W. Hoyle, Yulong Ding The Royal Society of ChemistryCopyright 2004 The Royal Society of ChemistryAll rights reserved.ISBN: 9780854045860ContentsFundamentals,Chapter 1 Rates of Stress in Dense Unbonded Frictional Materials During Slow Loading Matthew R. Kuhn, 3,Chapter 2 Snapshots on Some Granular States of Matter: Billiard, Gas, Clustering, Liquid, Plastic, Solid P. Evesque, 29,Chapter 3 Constitutive Modelling of Flowing Granular Materials: A Continuum Approach Mehrdad Massoudi, 63,Chapter 4 High Temperature Particle Interactions Stefaan J. R. Simons and Paolo Pagliai, 108,Chapter 5 Critical State Behaviour of Granular Materials Using Three Dimensional Discrete Element Modelling T. G. Sitharam, S. V. Dinesh and B. R. Srinivasa Murthy, 135,Chapter 6 Key Features of Granular Plasticity F. Radjai, H. Troadec and S. Roux, 157,Chapter 7 Influence of Polymers on Particulate Dispersion Stability: Scanning Probe Microscopy Investigations Simon Biggs, 185,Applications,Chapter 8 Applications of Atomic Force Microscopy to Granular Materials: Interparticle Forces in Air Robert Jones and Christopher S. Hodges, 229,Chapter 9 InProcess Measurement of Particulate Systems Cordelia Selomulya and Richard A. Williams, 255,Chapter 10 Fluidization of Fine Powders J. Zhu, 270,Chapter 11 The Kinetics of HighShear Granulation G. K. Reynolds, C. F. W. Sanders, A. D. Salman and M. J. Hounslow, 296,Chapter 12 Dynamics of Particles in a Rotary Kiln D. M. Scott and J. F. Davidson, 319,Chapter 13 Granular Motion in the Transverse Plane of Rotating Drums Yulong Ding, S. Joseph Antony and Jonathan Seville, 336,Subject Index, 355,CHAPTER 1Rates of Stress in Dense Unbonded Frictional Materials During Slow LoadingMATTHEW R. KUHNUniversity of Portland, 5000 N. Willamette Blvd, Portland, OR 97203 U.S.A. Email: kuhn@up.edu1 IntroductionThis chapter concerns the transmission and evolution of stress within granular materials during slow, quasistatic deformation. Stress is a continuum concept, and its application to assemblies of discrete grains requires an appreciation of the marked nonuniformity of stress when measured at the scale of individual grains or grain clusters. As an example, numerous experiments and simulations have demonstrated that externally applied forces are borne disproportionately by certain grains that are arranged in irregular and everchanging networks of force chains. Although much attention has recently been given to the transmission of force at low strains, the current work focuses on the transmission of stress within granular materials at both small and large strains.When a densely packed assembly of unbonded particles is loaded in either triaxial compression or shear, the behaviour at small strains is nearly elastic, and the volume is slightly reduced by the initial loading (an initial Poisson ratio less than 0.5, Figure 1). Plastic deformation ensues at moderate strains, at which an initially dense material becomes dilatant, and this trend of increasing volume continues during strain hardening, at the peak strength, and during strain softening. At very large strains, the material reaches a steady condition of flow, referred to as the 'critical state' in geotechnical engineering practice, in which the material flows at a constant, albeit expanded, volume while sustaining a constant shearing or compressive effort. Besides studying behaviour at the initial and peak states, we will also consider experimental results at this steady state condition and the manner in which the intergranular forces are distributed and changed during steady state flow. These conditions are investigated with numerical simulations of an idealized assembly of circular disks. We will explore mechanisms that underlie the changing stress by separating the stress rate into various constituents and then s