On the attraction power of critical state in granular materials

Na Deng, Antoine Wautier, Yannick Thiery, Zhen Yu Yin, Pierre Yves Hicher, François Nicot

Research output: Journal article publicationJournal articleAcademic researchpeer-review

Abstract

The aim of this paper is to offer a fresh perspective on the classic concept of critical state (CS) in granular materials by suggesting that CS can be defined through the use of a single proportional strain test. In classic conventional testing, CS manifests itself under constant lateral stress and controlled strain in one given direction whenever continuous shearing is applied without change being induced to material volume. However, a comparison between proportional strain tests and biaxial tests simulated with DEM has clearly shown that the CS line (CSL) characterized by stresses, void ratio and fabric indexes can act as an attractor. The mechanical responses and fabric metrics evolve along dilatant proportional strain loading paths according to similar values after the strain level has become large enough to wipe out the material memory in the homogeneous domains considered in this analysis, i.e., the shear band area in dense samples and the whole area in loose samples. This suggests that the micro-structure of a granular material subjected to any dilatant proportional strain loading paths evolves while preserving its ability to withstand shearing without volume change at any time. Therefore, the CS concept can be generalized to a wide class of loading paths which shows that CS acts as a general attractor irrespective of the loading path considered.

Original languageEnglish
Article number104300
JournalJournal of the Mechanics and Physics of Solids
Volume149
DOIs
Publication statusPublished - Apr 2021

Keywords

  • Biaxial loading path
  • Critical state
  • DEM simulation
  • Granular materials
  • Homogeneous domain
  • Proportional strain loading path
  • Shear band localization

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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