CAJ | 학술논문

针对圆形和单粒组颗粒模拟试验的缺陷,基于PFC2D的clump命令,开发了非圆形颗粒组,采用单向法、各向同法和沉积法生成不同初始组构特征的试验样品,模拟了砂土直接剪切试验过程.探讨了初始组构各向异性对砂土抗剪强度与剪胀性的影响规律,研究了剪切过程中力链的演化形式,分析了颗粒旋转以及剪切带内外颗粒长轴定向的变化特征.数值试验结果表明：颗粒初始组构的差异对抗剪强度的影响较大,对材料的剪胀性以及内摩擦角的影响较小;剪切过程应力主轴发生了偏转,颗粒接触角向主应力方向靠拢;颗粒旋转主要发生在8倍于平均颗粒半径的条带内,颗粒长轴定向也发生了偏转,偏转方向与主应力偏转方向相同,但滞后于主应力的偏转速度;初始组构的不同影响剪切带内颗粒的旋转速度.
침대원형화단립조과립모의시험적결함,기우PFC2D적clump명령,개발료비원형과립조,채용단향법、각향동법화침적법생성불동초시조구특정적시험양품,모의료사토직접전절시험과정.탐토료초시조구각향이성대사토항전강도여전창성적영향규률,연구료전절과정중력련적연화형식,분석료과립선전이급전절대내외과립장축정향적변화특정.수치시험결과표명：과립초시조구적차이대항전강도적영향교대,대재료적전창성이급내마찰각적영향교소;전절과정응력주축발생료편전,과립접촉각향주응력방향고롱;과립선전주요발생재8배우평균과립반경적조대내,과립장축정향야발생료편전,편전방향여주응력편전방향상동,단체후우주응력적편전속도;초시조구적불동영향전절대내과립적선전속도.
Considered the defect of circular and the group of single-particle,a non-circular particle group has been developed,based on the order of clump in PFC2D.Different initial deposition and fabric characteristics of the test samples have been generated with one-way method,uniform method and deposited method.The direct shear test has been simulated.The shear strength and the dilatancy affected by initial fabric anisotropy have been studied,and how the force chain derived in shear process has been analyzed,and how the particle rotated inside or outside of the shear zone has also been studied.Numerical results show that: the original fabric has great impact on shear strength,but little on material dilatancy and internal friction angle;stress axis deflects during shear process,and the contact angle moves closely to the principal stress direction;grains rotate mainly in 8 times the average particle radius of the band,and the particle long axis orientation also deflects with the same direction of main stress;the particle rotation speed in the shear zone is also affected by the initial fabric of the group.