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-  2018 

复杂形状颗粒DEM模拟及其对宏观力学响应影响研究 Study of DEM modeling of irregular shaped particle and its influence on macromechanical response

Keywords: 离散元法,复杂形状,力学响应,细观机理

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Abstract:

借助有限元网格划分技术,提出了一种复杂形状颗粒的DEM模拟方法,实现了包括凹多边形在内的复杂形状颗粒的模拟,通过参数控制使得生成的颗粒形状更加真实.生成6组不同形状的颗粒集合体,采用双轴压缩试验研究了颗粒形状对力学响应的影响,并解释了细观影响机理.计算结果表明,在最密实状态下,颗粒间的孔隙填充效率与颗粒边数有关,颗粒边数越少,孔隙率越小;不同形状颗粒集合体在双轴压缩过程中,加载初期的变形模量相近,偏应力和体积变形规律相似,峰值摩擦角与形状系数呈线性关系;颗粒边数越少,加载过程中颗粒转动越剧烈.规则颗粒边数为5~10时,颗粒集合体的峰值强度和体积变形差异较小,这主要是受颗粒旋转的影响:颗粒绕形心转动时,颗粒边数越少,局部剪胀越明显,所需外界功越大;当颗粒绕接触点旋转时,偶数边颗粒所需外界功和导致的体积剪胀比奇数边颗粒试样大.随着颗粒集合体凹凸度的增大,颗粒间的排列更加密实,咬合作用更强,但颗粒形状随机多样性与颗粒间的咬合作用并无单调关系,当λ=0.2时,颗粒集合体的峰值强度和体积应变最大

References

[1]  周伟,常晓林,周创兵,等.堆石体应力变形细观模拟的随机散粒体不连续变形模型及其应用[J].岩石力学与工程学报,2009,28(3):491-499.Zhou Wei,Chang Xiaolin,Zhou Chuangbing,et al.Stochastic granule discontinuous deformation model of rockfill and its application[J].Chinese Journal of Rock Mechanics and Engineering,2009,28(3):491-499.
[2]  马刚,周伟,常晓林,等.锚杆加固散粒体的作用机制研究[J].岩石力学与工程学报,2010,29(8):1577-1584.Ma Gang,Zhou Wei,Chang Xiaolin,et al.Study of anchorage mechanism of granular mixture[J].Chinese Journal of Rock Mechanics and Engineering,2010,29(8):1577-1584.
[3]  Wang L,Park J Y,Fu Y.Representation of real particles for DEM simulation using X-ray tomography[J].Construction and Building Materials,2007,21(2):338-346.
[4]  金磊,曾亚武,李欢,等.基于不规则颗粒离散元的土石混合体大三轴数值模拟[J].岩土工程学报,2015,(5):829-838.Jin Lei,Zeng Yawu,Li Huan,et al.Numerical simulation of large-scale triaxial tests on soil-rock mixture based on DEM of irregularly shaped particles[J].Chinese Journal of Geotechnical Engineering,2015,(5):829-838.
[5]  蒋明镜,李秀梅,胡海军.含抗转能力散粒体的宏微观力学特性数值分析[J].计算力学学报,2011,28(4):622-628.Jiang Mingjing,Li Xiumei,Hu Haijun.Numerical investigation on macro-micro mechanical behaviours of granular materials incorporating rolling resistance[J].Chinese Journal of Computational Mechanics,2011,28(4):622-628.
[6]  蒋明镜,王富周,朱合华.单粒组密砂剪切带的直剪试验离散元数值分析[J].岩土力学,2010,31(1):253-257.Jiang Mingjing,Wang Fuzhou,Zhu Hehua.Shear band formation in ideal dense sand in direct shear test by discrete element analysis[J].Rock and Soil Mechanics,2010,31(1):253-257.
[7]  Barrett P J.The shape of rock particles,a critical review[J].Sedimentology,1980,27(3):291-303.
[8]  孔亮,彭仁.颗粒形状对类砂土力学性质影响的颗粒流模拟[J].岩石力学与工程学报,2011,30(10):2112-2119.Kong Liang,Peng Ren.Partical flow simulation of influence of particle shape on mechanical properties of quasi-sands[J].Chinese Journal of Rock Mechanics and Engineering,2011,30(10):2112-2119.
[9]  Oda M,Konishi J,Nemat-Nasser S.Experimental micromechanical evaluation of strength of granular materials:effects of particle rolling[J].Mech.of Mater.,1982,1(4):269-283.
[10]  严成增,郑宏,孙冠华,等.粗粒料多边形表征及二维FEM/DEM分析[J].岩土力学,2015,(S2):95-103.Yan Chengzeng,Zheng Hong,Sun Guanhua,et al.Polygon characterization of coarse aggregate and twodimensional combined finite discrete element method analysis[J].Rock and Soil Mechanics,2015,(S2):95-103.
[11]  Zhao G J.Fourier-Voronoi-based generation of realistic samples for discrete modelling of granular materials[J].Granular Matter,2012,14(5):621-638.
[12]  刘洋,李晓柱,吴顺川.多块体形状堆石体碾压颗粒破碎数值模拟[J].岩土力学,2014,35(11):3269-3280.Liu Yang,Li Xiaozhu,Wu Shunchuan.Numerical simulation of particle crushing for rockfill of different particles shape under rolling compaction[J].Rock and Soil Mechanics,2014,35(11):3269-3280.
[13]  Cundall P A.Formulation of a three-dimensiona distinct element model-part I:A scheme to detect and represent contacts in system composed of many polyhedral blocks[J].Int.J Rock Mech.,Min.Sci.&Geomech.Abstr.,1988,25(3):107-116.
[14]  Jensen R P,Bosscher P J,Plesha M E,et al.DEM simulation of granular media—structure interface:effects of surface roughness and particle shape[J].International Journal for Numerical and Analytical Methods in Geomechanics,1999,23(6):531-547.
[15]  Ferellec J F,McDowell G R.A simple method to create complex particle shapes for DEM[J].Geomechanics and Geoengineering:An International Journal,2008,3(3):211-216.
[16]  Mollanouri Shamsi M M,Mirghasemi A A.Numerical simulation of 3Dsemi-real-shaped granular particle assembly[J].Powder Technology,2012,221:431-446.
[17]  李立青,蒋明镜,吴晓峰.椭圆形颗粒堆积体模拟颗粒材料力学性能的离散元数值方法[J].岩土力学,2011,(S1):713-718.Li Liqing,Jiang Mingjing,Wu Xiaofeng.A developed discrete element model NS2Dfor simulating mechanical properties of elliptical particles assemblages[J].Rock and Soil Mechanics,2011,(S1):713-718.
[18]  周健,池毓蔚,池永,等.砂土双轴试验的颗粒流模拟[J].岩土工程学报,2000,22(6):701-704.Zhou Jian,Chi Yuwei,Chi Yong,et al.Simulation of biaxial test on sand by particle flow code[J].Chinese Journal of Geotechnical Engineering,2000,22(6):701-704.
[19]  蒋明镜,李立青,申志福.双剪类流动模型的非圆形颗粒离散元数值验证[J].岩土工程学报,2013,(4):619-626.Jiang Mingjing,Li Liqing,Shen Zhifu.Evaluation of double-shearing type kinematic models for granular flows by use of distinct element methods for non-circular particles[J].Chinese Journal of Geotechnical Engineering,2013,(4):619-626.
[20]  黄青富,詹美礼,盛金昌,等.基于颗粒离散单元法的获取任意相对密实度下级配颗粒堆积体的数值方法[J].岩土工程学报,2015,(3):537-543.Huang Qingfu,Zhan Meili,Sheng Jinchang,et al.Numerical method to generate granular assembly with any desired relative density based on DEM[J].Chinese Journal of Geotechnical Engineering,2015,(3):537-543.

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