Influence of aspect ratio and arrangement direction on the shear behavior of ellipsoids
纵横比和排列方向对椭球体剪切行为的影响
楕円体のせん断挙動に及ぼすアスペクト比と配置方向の影響
타원체의 전단 거동에 대한 종횡비 및 배열 방향의 영향
Influencia de la relación de aspecto y la dirección de disposición en el comportamiento de corte de los elipsoides
Influence du rapport d'aspect et de la direction de l'arrangement sur le comportement en cisaillement des ellipsoïdes
Влияние соотношения сторон и направления расположения на сдвиговое поведение эллипсоидов
Weichen Sun ¹, Kai Wu 吴恺 ², Songyu Liu 刘松玉 ², Xiang Zhang 张翔 ²
¹ School of Civil Engineering, Chongqing University, Chongqing 400045, China
中国 重庆 重庆大学土木工程学院
² School of Transportation, Southeast University, Nanjing 210096, China
中国 南京 东南大学交通学院
This work studies the macroscopic and microscopic behaviors of ellipsoids under triaxial tests using 3D discrete element method (DEM) simulation. To avoid the boundary effect, a novel stress servo-controlled periodic boundary condition is proposed to maintain the confining pressure of samples during testing. The shape features of ellipsoids are investigated, including the aspect ratio of elongated/oblate ellipsoids and the initial arrangement directions of ellipsoids.
The macroscopic properties of ellipsoidal particle samples, such as the deviatoric stress, volumetric strain, internal friction angle, as well as dilatancy angles are explored. Elongated and oblate ellipsoids with varying aspect ratios are investigated for the occurrence of stick-slips. In addition, it is demonstrated that the initial arrangement direction has a significant impact on the coordination number and contact force chains. The corresponding anisotropy coefficients of the entire contact network are analyzed to probe the microscopic roots of macroscopic behavior.