力学与实践 ›› 2019, Vol. 41 ›› Issue (3): 308-313.DOI: 10.6052/1000-0879-19-008

• 应用研究 • 上一篇    下一篇

粒间摩擦对含有点缺陷的二维颗粒堆积体底部力链的影响 1)

刘源2), 徐同桐3), 赵宪锋   

  1. 兰州交通大学土木工程学院,兰州 730070
  • 收稿日期:2019-01-07 出版日期:2019-06-20 发布日期:2019-06-27
  • 通讯作者: 2)刘源,副教授,主要研究方向为颗粒介质力学、连续统力学、岩土工程的研究。E-mail:liuy@mail.lzjtu.com;3)徐同桐,硕士生,主要研究方向为颗粒介质力学、土木工程中的力学应用。E-mail:414622074@qq.com
  • 基金资助:
    1)国家自然科学基金青年基金(11302091)资助项目

EFFECT OF INTERGRANULAR FRICTION ON THE BOTTOM FORCE CHAIN OF TWO-DIMENSIONAL PARTICLE PILES WITH POINT DEFECTS1)

LIU Yuan2), XU Tongtong3), ZHAO Xianfeng   

  1. School of Civil Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China
  • Received:2019-01-07 Online:2019-06-20 Published:2019-06-27

摘要: 力链对颗粒物质的宏观与微观力学性质起着决定性的作用。在离散元法的基础上,建立二维规则排列的颗粒物质系统,分别研究无缺陷颗粒系统在集中载荷变化与有缺陷颗粒系统在缺陷区域改变时,粒间摩擦系数对颗粒系统底部接触力分布规律的影响。结果表明:在无缺陷颗粒系统中,颗粒系统底部接触力的分布形式受摩擦系数和集中载荷的大小影响。随摩擦系数的增大,底部接触力由双峰形式经平台过渡,逐渐向单峰形式转变。在有缺陷颗粒系统中,摩擦系数和缺陷尺寸对底部接触力分布均有影响。同种载荷作用下,随缺陷尺寸的增大,底部接触力峰值显著增大;底部平均力被明显削弱,力向边界的传递增强。系统中轴线上缺陷的存在使底部中间区域受力削弱,当缺陷尺寸超过2 层以上时,底部中间力随摩擦系数的变化特征由递增曲线演变为线形衰减曲线。

关键词: 粒间摩擦, 点缺陷, 颗粒系统, 力链网络

Abstract: The force chain plays a decisive role in the macroscopic and microscopic mechanical properties of granular matter. Based on the discrete element method (DEM), a two-dimensional regular particle system is established to study the influence of the friction coefficient between the particles on the contact force distribution at the bottom of the system under different loads and different defect sizes. The results show that in a defect-free particle system, the contact force distribution at the bottom of the system is affected by the friction coefficient and the point load. As the coefficient of friction increases, the bottom contact force turns from the bimodal form through the platform, gradually to a single peak form. In a system with point defects, the coefficient of friction and the size of the defect have an effect on the force distribution. With a fixed load, as the size of the defect increases, the peak value of the bottom contact force increases significantly; the average value of the force on the bottom is significantly weakened, and the force transmission to the boundary is enhanced. The presence of defects on the central axis of the system weakens the bottom intermediate region. When the defect size exceeds 2 layers, the variation curve of the bottom intermediate force against the friction coefficient changes from an increasing curve to a linearly decreasing curve.

Key words: intergranular friction, point defects, particle system, force chain network

中图分类号: