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论文类型：期刊论文

发表时间：2019-11-01

发表刊物：POWDER TECHNOLOGY

收录刊物：SCIE、EI

卷号：356

页面范围：581-593

ISSN号：0032-5910

关键字：DEM; Critical state; Stress variability; Local stress fluctuation; Multi-fractal analysis

摘要：This paper uses a novel tensor-based approach to characterize the spatial variability and localization of stress fields in granular media derived from three-dimensional discrete element simulations. We use the Euclidean distance of the stress tensor of each particle to the bulk mean stress tensor to quantify local stress fluctuations and use the effective variance of the stress field to quantify the overall dispersion. We observe that the evolutions of both the local stress fluctuation and the bulk stress dispersion strongly depend on the stress state, packing density and shearing process. However, they become constant, and are uniquely related to the deviatoric stress and the void ratio when the sample is at critical state, under which the stress variability reaches an ultimate condition. Multifractal analysis further shows that the local stress field is highly heterogeneous and exhibits self-organized patterns. (C) 2019 Elsevier B.V. All rights reserved.