Micromechanics of Granular Materials

This proceedings volume contains papers from researchers in Japan, the United States and England who have made fundamental contributions to the micromechanics of granular materials. The purpose of the seminar was to facilitate an exchange of ideas between scientists working with statistical and continuum theories, computer simulations and experiments on both static and dynamic behaviour. In describing the solid like behaviour of granular materials, many new ideas on the constitutive relations are introduced in this volume. As an application of the analysis, the mechanism of liquefaction is discussed. Computer simulations have become a vital tool in establishing the micromechanical approaches which otherwise would not be experimentally tested. In numerical simulations and theoretical analyses of rapid granular flow, various modifications on the nature of materials and boundaries are given. Possible applications of the techniques of the stereology and analysis based on geometrical statistics are also included. The papers collected in this volume signify that the promotion of a good understanding of the mechanics of granular materials has been and will continue to be valued in a variety of technical disciplines.

Stereological estimation of microstructures in materials (K. Kanatani). Morphological analysis of particulate materials (J.K. Beddow). The microgeometry of dense random packings (H.J. Frost). Experiments on disc arrays: coordination and void entropies (C.B. Brown). A note on fabric in terms of voids (J. Konishi, F. Naruse). Some considerations on shearing resistance angles of sands (N. Moroto). Measurement of the bulk density structure of granular materials in a powder vessel (K. Makino, K. Kuramitsu). Consideration on the stress-dilatancy equation through the work increment tensor (M. Satake). A simple theory of instantaneously induced anisotropy (S.C. Cowin). Introduction of inherent anisotropy of soils in the yield function (M. Oda, H. Nakayama). Is the fabric tensor sufficient? (H. Horii, K. Sahasakmontri). Dynamic shear moduli and their relationship to fabric of granular materials (I. Ishibashi, Y.C. Chen). A discrete limit analysis of granular materials including effects of the solid contact (N. Takeuchi, T. Kawai). Computer simulations of dense sphere assemblies (P.A. Cundall). Granular assembly simulation for ground collapse (K. Iwashita et al.). Applications of theoretical contact mechanics to solid particle system simulations (C. Thornton, C.W. Randall). Disc model analysis of granular media (Y. Kishino). Particle-dynamics calculations of gravity flow of inelastic, frictional spheres (O.R. Walton et al.). Boundary interactions for two-dimensional granular flows: Asymmetric stresses and couple stresses (C.S. Campbell). Description of cyclic deformation behaviour of sand by an anisotropic hardening model (E. Yanagisawa, Y. Tobita). Modeling of cyclic behaviour of sand in multi-directional shear (Y. Yamada). Plasticity approach to sand behaviour under principal stress axes rotation (I. Towhata et al.). Effect of fabric on liquefaction and densification of saturated soil: experiments and theory (S. Nemat-Nasser). The validity of the effective stress concept in soil mechanics (F. Oka). Stress analysis on the compaction of granular materials by FEM (T. Nagao et al.). Application of Markov model to Ko-compression and consolidation of particulate material (R. Kitamura, M. Shinchi). Distributed disturbance and constraint in soils (O.O. Ogunbekun et al.). Volume change in small strain axisymmetric deformations of a granular material (J.T. Jenkins). Some basic theoretical and experimental results on micromechanics of granular flow (M.M. Mehrabadi et al.). Contact tensor in constitutive model for granular materials (Y. Tobita, E. Yanagisawa). Micromechanical modelling of constitutive relations for granular materials (C.S. Chang). New optimality theory in nature and coaxiality between stress and strain increment tensors (S. Niiseki). A constitutive model for granular materials evaluating principal stress rotation (H. Matsuoka et al.). A unified mechanical quantity for granular materials in three-dimensional stresses (T. Nakai). Extended subloading surface model for elastoplastic deformation (K. Hashiguchi). A combined hardening model of anisotropically consolidated clay (H. Hirai). Stability of a radial flow of granular material (A.J.M. Spencer). Kinetic theoretical analysis of a rapidly deforming disk assembly (M. Nakagawa). Experiments on chute flows of granular materials (H. Ahn et al.). A Monte Carlo simulation of a simple shear flow of granular materials (M.A. Hopkins, H.H. Shen). Physical experiments and numerical simulation of two dimensional chute flow (B.E. Sanders et al.).