粒料固有各向异性的离散元模拟与细观分析

钱劲松; 陈康为; 张磊

doi:10.6052/0459-1879-18-061

粒料固有各向异性的离散元模拟与细观分析

doi: 10.6052/0459-1879-18-061

同济大学道路与交通工程教育部重点实验室, 上海 201804

基金项目: 1) 中央高校基本科研业务费专项资金资助项目(22120170129).

详细信息

作者简介:
2) 钱劲松, 副教授, 主要研究方向: 交通岩土工程. E-mail: qianjs@tongji.edu.cn

通讯作者:
钱劲松

中图分类号: TU441;
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出版历程
- 收稿日期: 2018-03-12
- 刊出日期: 2018-09-18

SIMULATION AND MICRO-MECHANICS ANALYSIS OF INHERENT ANISOTROPY OF GRANULAR BY DISTINCT ELEMENT METHOD

Key Laboratory of Road and Traffic Engineering of the Ministry of Education, Tongji University, Shanghai 201804, China

摘要

摘要: 料在摊铺后形成的颗粒定向排列将导致其力学性质的固有各向异性. 依据粒料的实际不规则形状, 构建了可模拟粒间咬合嵌挤作用的三维离散元复杂形状颗粒; 生成了5 种不同沉积方向的各向异性试件和1种各向同性试件, 对比了各试件在三轴压缩试验中的宏观力学特性差异; 引入组构张量以量化各向异性程度, 利用玫瑰图表达接触法向与接触力的分布特征, 探究了粒料各向异性的细观发展规律. 结果表明: 颗粒长轴愈趋向水平排布, 峰值应力比愈大, 剪缩与剪胀程度愈明显; 相较于各向同性试件, 沉积角$\theta$为$0^\circ$时, 峰值应力比和最大体积压缩应变分别提高了12.6\%和18.8\%, 其原因在于加载过程中颗粒旋转和滑动百分比更小, 内部调整时间更短、更易被剪密; 固有各向异性对颗粒法向接触力分布的影响不大, 但显著影响接触法向分布特征; 剪切过程中, $\theta$为$90^\circ$时的接触法向各向异性系数先快速减小后逐渐增大, 而$\theta$为$0^\circ$到$60^\circ$时则呈现出增大后稍有回落或趋于稳定的趋势, 且$\theta$ 愈小的试件各向异性系数增大愈快.
- 颗粒材料 /
- 离散元 /
- 三轴压缩 /
- 固有各向异性 /
- 组构
Abstract: The particles tend to be spatially arranged in directional orientation after the paving of granular materials, and thus leading to the inherent anisotropy of mechanical property. Based on the actual irregular shape of granular materials, three-dimensional complex shape particles were modelled utilizing distinct element method to simulate the interlocking between particles. Five numerical test specimens with different bedding angles and an isotropic specimen were established respectively, and the mechanical properties of various specimens were compared during the triaxial compression simulations. Besides, the fabric tensor was introduced to quantify the anisotropy, the rose diagram was drawn to exhibit the distribution characteristics of contact normal and contact force, and then the development of anisotropy was investigated. It is shown that, as the long axis of particles change toward the horizontal direction, the stress ratio and the shear dilatancy of specimen increase continuously. Compared with isotropic structure, the peak stress ratio and the maximal volume compression strain of anisotropic structure when the bedding angle $\theta=0^\circ$ is 12.6% and 18.8% larger respectively. This is because the rotation and contact sliding ratio of particles is smaller, the internal adjustment time is shorter, and specimen can be sheared more densely. The inherent anisotropy has little effect on the distribution characteristics of contact force, but significantly affects the distribution characteristics of contact normal. When $\theta$ is $90^\circ$, the contact normal anisotropy coefficient drops quickly and then gradually increases during the shear process. Otherwise, the coefficient shows a steady or slight drop trend after an increase, and the coefficient grows faster as the $\theta$ decreases.
- granular materials /
- distinct element method /
- triaxial compression /
- inherent anisotropy /
- fabric

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参考文献(1)

[1]	Hosseininia ES.Investigating the micromechanical evolutions within inherently anisotropic granular materials using discrete element method. Granular Matter, 2012, 14(4): 483-503
[2]	Masad S, Little D, Masad E.Analysis of flexible pavement response and performance using isotropic and anisotropic material properties. Journal of Transportation Engineering, 2006, 132(4): 342-349
[3]	Luo X, Gu F, Zhang YQ, et al.Mechanistic-Empirical Models for Better Consideration of Subgrade and Unbound Layers Influence on Pavement Performance. Transportation Geotechnics, 2017, 13: 52-68
[4]	Cao W, Wang R, Zhang JM.Formulation of anisotropic strength criteria for cohesionless granular materials. International Journal of Geomechanics, 2017, 17(7): 04016151
[5]	姚仰平, 祝恩阳. 横观各向同性土的简明破坏机制解释. 岩土力学, 2014(2): 328-333
[5]	(Yao Yangping, Zhu Enyang.Concise interpretation of damage mechanism for cross-anisotropic soil. Rock and Soil Mechanics, 2014(2): 328-333 (in Chinese))
[6]	Guo P.Modified direct shear test for anisotropic strength of sand. Journal of Geotechnical & Geoenvironmental Engineering, 2008, 134(9): 1311-1318
[7]	Oboudi M, Pietruszczak S, Razaqpur AG.Description of inherent and induced anisotropy in granular media with particles of high sphericity. International Journal of Geomechanics, 2016, 16(4): 04016006
[8]	Kawajiri S, Kawaguchi T, Yamasaki S, et al.Strength Characteristics of Compaction Soil with Particular Reference to Soil Structure And Anisotropy. International Journal of Geomate, 2017, 13(38): 178-185
[9]	Sazzad MM, Suzuki K, Modaressi-Farahmand-Razavi A. Macro-micro responses of granular materials under different b values using DEM. International Journal of Geomechanics, 2013, 12(3): 220-228
[10]	章青, 顾鑫郁, 杨天.冲击载荷作用下颗粒材料动态力学响应的近场动力学模拟. 力学学报, 2016, 48(1): 56-63
[10]	(Zhang Qing, Gu Xinyu, Yang Tian.Peridynamics simulation for dynamic response of granular material under impact loading. Chinese Journal of Theoretical and Applied Mechanics, 2016, 48(1): 56-63 (in Chinese))
[11]	费明龙,徐小蓉,孙其诚. 颗粒介质固?流态转变的理论分析及实验研究. 力学学报, 2016, 48(1): 48-55
[11]	(Fei Minglong, Xu Xiaorong, Sun Qicheng.Studies on the transition between soil-and fluid-like states of granular materials. Chinese Journal of Theoretical and Applied Mechanics, 2016, 48(1): 56-63 (in Chinese))
[12]	Jiang MJ, Li T, Shen ZF.Fabric rates of elliptical particle assembly in monotonic and cyclic simple shear tests: A numerical study. Granular Matter, 2016, 18(3): 1-14
[13]	Yang H, Xu WJ, Sun QC, et al.Study on the meso-structure development in direct shear tests of a granular material. Powder Technology, 2017, 314: 129-139
[14]	Dai BB, Yang J, Zhou CY, et al.DEM investigation on the effect of sample preparation on the shear behavior of granular soil. Particuology, 2016, 25: 111-121
[15]	Lu XL, Zeng S, Qian JG, et al.DEM analysis of the shear strength of cross-anisotropic sand with non-spherical particles. Géotechnique Letters, 2017, 7(3): 230-236
[16]	Jiang MJ, Sima J, Li LQ, et al. Investigation of influence of particle characteristics on the non-coaxiality of anisotropic granular materials using DEM. International Journal for Numerical and Analytical Methods in Geomechanics, 2017, 41(2): 198-222
[17]	张坤勇, 李威, 罗兴军等. 基于PFC2D的砂土原生各向异性微观机理数值试验. 岩土工程学报, 2017, 39(3): 518-524
[17]	(Zhang Kunyong, Li Wei, Luo Xingjun, et al.Numerical experiments of microscopic mechanism of inherent anisotropy for sand based on PFC2D. Chinese Journal of Geotechnical Engineering, 2017, 39(3): 518-524 (in Chinese))
[18]	Cai Y, Yu HS, Li X, et al.Noncoaxial behavior of sand under various stress paths. Journal of Geotechnical & Geoenvironmental Engineering, 2013, 139(8): 1381-1395
[19]	邵磊, 迟世春, 贾宇峰. 堆石料大三轴试验的细观模拟. 岩土力学, 2009,30(S1): 239-243
[19]	(Shao Lei, Chi Shichun, Jia Yufeng.Meso-mechanical simulation of a large scale triaxial text of rockfill materials. Rock and Soil Mechanics, 2009, 30(S1): 239-443 (in Chinese))
[20]	Mahmood Z, Iwashita K.Influence of inherent anisotropy on mechanical behavior of granular materials based on DEM simulations. International Journal for Numerical and Analytical Methods in Geomechanics, 2010, 34(8): 795-819
[21]	Hosseininia ES.Discrete element modeling of inherently anisotropic granular assemblies with polygonal particles. Particuology, 2012, 10(5): 542-552
[22]	Gu XQ, Huang MS, Qian JG.DEM investigation on the evolution of microstructure in granular soils under shearing. Granular Matter, 2014, 16(1): 91-106
[23]	Kim BS, Park SW, Kato S.DEM simulation of collapse behaviours of unsaturated granular materials under general stress states. Computers and Geotechnics, 2012, 42: 52-61
[24]	Taghavi R.Automatic clump generation based on mid-surface//11 Proc. 2nd International FLAC/DEM Symposium, Melbourne, 2011: 791-797
[25]	Goldenberg C, Goldhirsch I.Friction enhances elasticity in granular solids. Nature, 2005, 435(7039): 188-191
[26]	Minh NH, Cheng YP.A DEM investigation of the effect of particle-size distribution on one-dimensional compression. Geotechnique, 2013, 63(1): 44-53
[27]	吴越, 杨仲轩, 徐长节. 初始组构各向异性对砂土力学特性及临界状态的影响. 岩土力学, 2016, 37(9): 2569-2576
[27]	(Wu Yue, Yang Zhongxuan, Xu Changjie.Effects of initial fabric anisotropy on mechanical behavior and critical state of granular soil. Rock and Soil Mechanics, 2016, 37(9): 2569-2576 (in Chinese))
[28]	蔡氧, 张磊, 钱劲松. 细砂路基碾压密实的颗粒流模拟与试验验证.同济大学学报(自然科学版), 2017, 45(4): 527-532
[28]	(Cai Yang, Zhang Lei, Qian Jinsong.Discrete element method simulation and experimental verification on roller compaction of fine sand. Journal of Tongji University (Natural Science). 2017, 45(4): 527-532 (in Chinese))
[29]	Andrade JE, Chen Q, Le PH, et al.On the rheology of dilative granular media: Bridging solid-and fluid-like behavior. Journal of the Mechanics and Physics of Solids, 2012, 60(6): 1122-1136
[30]	Lam WK, Tatsuoka F.Effects of initial anisotropic fabric and $\sigma_2$ on strength and deformation characteristics. Soils and Foundations, 1988, 28(1): 89-106
[31]	Guo N, Zhao J.The signature of shear-induced anisotropy in granular media. Computers and Geotechnics, 2013, 47(1): 1-15
[32]	Zhao J, Guo N.The interplay between anisotropy and strain localisation in granular soils: A multiscale insight. Géotechnique, 2015, 65(8): 642-656
[33]	Gu X, Huang M, Qian J.DEM investigation on the evolution of microstructure in granular soils under shearing. Granular Matter, 2014, 16(1): 91-106
[34]	Oda M, Koishikawa I, Higuchi T.Experimental study of anisotropic shear strength of sand by plane strain test. Soils and Foundations, 1978, 18(1): 25-38
[35]	Wang R, Fu PC, Zhang JM, et al.Evolution of various fabric tensors for granular media toward the critical state. Journal of Engineering Mechanics, 2017, 143(10): 04017117
[36]	Sitharam T, Dinesh SV, Shimizu N.Micromechanical modelling of monotonic drained and undrained shear behaviour of granular media using three-dimensional DEM. International Journal for Vumerical and Analytical Methods in Geomechanics, 2002, 26(12): 1167-1189
[37]	Rothenburg L, Bathurst RJ.Analytical study of induced anisotropy in idealized granular materials. Geotechnique, 1989, 39(4): 601-614