Macroscopic softening in granular materials from a mesoscale perspective

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:193

Article

Liu, Jiaying^1,3  Wautier, Antoine^2,3  Bonelli, Stephane²  Nicot, Francois³  Darve, Felix⁴ 

[1] Wuhan Univ, State Key Lab Water Resources & Hydropower Engn S, Wuhan 430072, Peoples R China

[2] Aix Marseille Univ, UR RECOVER, INRAE, 3275 Rte Cezanne,CS 40061, F-13182 Aix En Provence 5, France

[3] Univ Grenoble Alpes, UR ETGR, INRAE, 2 Rue Papeterie,BP 76, F-38402 St Martin Dheres, France

[4] Univ Grenoble Alpes, Lab 3SR UMR5521, G INP, CNRS, F-38000 Grenoble, France

关键词: DEM;    Granular materials;    Softening;    Mesomechanics;    Force chains;    Strain localization;    Rotation;   

DOI  :  10.1016/j.ijsolstr.2020.02.022

来源: Elsevier

【 摘 要 】

Stress-oftening is one of the significant features experienced by cohesive-frictional granular materials subjected to deviatoric loading. This paper focuses on mesoscopic evolutions of the dense granular assembly during a typical drained biaxial test conducted by DEM, and proposes mesoscopically-based framework to interpret both hardening and softening mechanisms. In this context, force chains play a fundamental role as they form the strong contact phase in granular materials. Their geometrical and mechanical characteristics, as well as the surrounding structures, are defined and analyzed in terms of force chain bending evolution, local dilatancy, rotation and non-coaxiality between the principal stress and the geometrical orientation of force chains. By distinguishing two zones inside and outside shear band, force chain rotations are shown to be of opposite sign, which may contribute to the observed macroscopic softening as one of the origin of the structural softening. (C) 2020 Elsevier Ltd. All rights reserved.

【 授权许可】

Free