Benmebarek Mohamed Amine, Movahedi Rad Majid, Benmebarek Sadok
Department of Structural and Geotechnical Engineering, Faculty of Architecture, Civil Engineering and Transport Sciences, Széchenyi István University, Egyetem tér 1, 9026 Győr, Hungary.
NMISSI Laboratory, Department of Civil Engineering and Hydraulic, Biskra University, Biskra 07000, Algeria.
Materials (Basel). 2023 Jul 16;16(14):5025. doi: 10.3390/ma16145025.
This paper explores the effect of particle breakage on the mechanical behavior of coarse sand through 3D Discrete Element Method (DEM) simulations of direct shear tests (DST). The objective is to gain insights into the macro- and micro-mechanical behaviors of crushable coarse sand, with a particular focus on the stress-strain relationship, volumetric deformation, and evolution of grain crushing. The simulations involve a comparison between non-crushable and crushable particle models, where the crushable particles are implemented in the shear zone of the DST subjected to different high normal stresses. The findings indicate that the crushable particles experience partial crushing at peak shear stress, with further particle crushing leading to the production of finer particles at the shearing plane during shearing at the critical state. The migration of these finer particles under pressure and gravity generates their accumulation predominantly in the lower section of the simulation box. Importantly, the presence of crushing in the DST induces a decrease in the shear stress and an increase in the volumetric strain leading to contractive behavior instead of dilation, which gradually stabilizes the volumetric deformation at higher normal stresses.
本文通过直接剪切试验（DST）的三维离散元法（DEM）模拟，探讨了颗粒破碎对粗砂力学行为的影响。目的是深入了解可破碎粗砂的宏观和微观力学行为，特别关注应力应变关系、体积变形和颗粒破碎的演化。模拟涉及不可破碎颗粒模型和可破碎颗粒模型之间的比较，其中可破碎颗粒在承受不同高法向应力的DST剪切区中实现。研究结果表明，可破碎颗粒在峰值剪应力处经历部分破碎，在临界状态下剪切过程中，进一步的颗粒破碎导致在剪切平面产生更细的颗粒。这些更细颗粒在压力和重力作用下的迁移主要导致它们在模拟箱的下部堆积。重要的是，DST中颗粒破碎的存在导致剪应力降低和体积应变增加，从而导致收缩行为而非膨胀行为，这在较高法向应力下逐渐稳定了体积变形。
