干颗粒系统的摩擦流变性研究  

Friction-dependent rheology of dry granular systems

作　　者：满腾 张沛 葛转 佘吉鸿 Kimberly MHill Teng Man;Pei Zhang;Zhuan Ge;Sergio A.Galindo-Torres;Kimberly M.Hill(Key Laboratory of Coastal Environment and Resources of Zhejiang Province,School of Engineering,Westlake University,Hangzhou 310024,China;College of Civil Engineering and Architecture,Zhejiang University,Hangzhou 310058,China;Saint Anthony Fall Laboratory and the Department of Civil,Environmental,and Geo-Engineering,University of Minnesota,Minneapolis MN 55455,United States)

机构地区：[1]不详

出　　处：《Acta Mechanica Sinica》2023年第1期98-109,共12页力学学报（英文版）

基　　金：supported by the General Program of the National Natural Science Foundation of China(Grant No.12172305)。

摘　　要：颗粒材料在自然界和工程应用中极为常见,深入理解并合理利用其流变性对于预测与减轻自然灾害以及描述多种工程材料力学性质至关重要.然而,现有研究仍未建立起颗粒之间摩擦特性与颗粒集合体宏观的力学特性之间的物理联系.本文利用离散单元法(DEM)考察了不同颗粒间摩擦系数对定压剪切条件下的颗粒材料的流变性的影响,试图建立基于粒间摩擦的颗粒流变学模型.本研究计算显示,增加颗粒之间的摩擦系数可以显著改变颗粒集合体的整体流变特性,增加颗粒系统的有效摩擦系数µeff,并减小定压剪切条件下的稳态固体体积分数ϕs.在此基础上,本报告提出用于描述不同粒间摩擦特性颗粒材料流变性的无量纲数M,并建立摩擦流变模型.同时考察了M和无量纲颗粒温度Θ之间的关系,分析了摩擦系数对于粒间作用力概率分布函数的影响.进一步延伸了传统的流变模型的应用范围,有助于建立更为普适的颗粒材料本构模型.Understanding the rheology of granular assemblies is important for natural and engineering systems,but the relationship between inter-particle friction(or microscopic friction)and macroscopic friction is still not well understood.In this study,using the discrete element method(DEM)with spherical particles and realistic contact laws,we investigate the mechanics of granular systems with a wide range of inter-particle frictional coefficients and aim to establish a friction-dependent rheology for dry granular flows.The corresponding results show that increasing inter-particle friction dramatically increases the effective frictional coefficient,µeff,while decreasing the solid fraction of the system and increasing the transitional inertial number that marks the division of quasi-static regimes and intermediate flow regimes.We further propose a new dimensionless number,M,as a ratio between the inertial effect and frictional effect,which is similar to the effective aspect ratio in granular column collapses,and unifies the influence of inter-particle friction with the inertial number.We then establish a relationship between M and the dimensionless granular temperature,Θ,to further universalize the influence of inter-particle frictions.Such study can broaden the application of theµ(I)rheology in natural and engineering systems and help establish a more general constitutive model for complex granular systems.

关 键 词：材料力学性质 颗粒材料 流变学模型 概率分布函数 颗粒系统 摩擦特性 无量纲数 流变模型 

分 类 号：O341[理学—固体力学]