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.

School of Civil Engineering,Chongqing University,Chongqing 400045,China;School of Transportation,Southeast University,Nanjing 210096,China

[1]Weichen Sun;Kai Wu;Songyu Liu;Xiang Zhang-.Influence of aspect ratio and arrangement direction on the shear behavior of ellipsoids)[J].颗粒学报（英文版）,2022(11):82-94

ellipsoids,Elongated

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