• 固体力学 •

粒料固有各向异性的离散元模拟与细观分析1)

1. 同济大学 道路与交通工程教育部重点实验室, 上海 201804
• 收稿日期:2018-03-12 出版日期:2018-09-18 发布日期:2018-10-18
• 通讯作者: 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
• 基金资助:
1) 中央高校基本科研业务费专项资金资助项目(22120170129).

SIMULATION AND MICRO-MECHANICS ANALYSIS OF INHERENT ANISOTROPY OF GRANULAR BY DISTINCT ELEMENT METHOD1)

Qian Jinsong2), Chen Kangwei, Zhang Lei

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