【作者】 马祺瑞； 周伟； 马刚； 程勇刚；

【Author】 Ma Qirui;Zhou Wei;Ma Gang;Cheng Yonggang;School of Water Resources and Hydropower Engineering of Wuhan University、State Key Laboratory of Water Resources and Hydropower Engineering Science;

【机构】 武汉大学水利水电学院武汉大学水资源与水电工程科学国家重点实验室；

【摘要】 采用LBM-DEM方法进行不同应力水平下二元颗粒集合体的渗流侵蚀破坏形成机制的数值模拟研究,首先进行了LBM-DEM流固耦合方法的物理试验验证,随后开展二元颗粒集合体的侵蚀破坏形成机制研究,并考虑不同伺服应力下,颗粒侵蚀对于试样的力学结构特性的影响,采用渗透系数、孔隙率、等效配位数、孔隙结构分布等宏细观参量表征试样的结构与力学特征,通过这些宏细观参量的演化研究渗流侵蚀破坏对试样结构与力学特征的影响。结果表明,侵蚀破坏区域集中在低等效应力、低配位数的范畴,但在高应力下,高等效应力以及高配位数的颗粒区域由于流体的侵蚀作用和颗粒间的挤压作用同样将出现侵蚀破坏;侵蚀颗粒的侵蚀过程中,宏细观参量展现出了平衡-失稳-平衡的转换过程。更多还原

【Abstract】 The LBM-DEM method is used to clarify the internal erosion mechanism of binary particle system under different stress levels. Firstly, the comparison between physical experiment and numerical simulation of LBM-DEM coupling method is carried out to verify the method. Then, the erosion failure mechanism of binary mixtures is studied. The effect of particle erosion on the mechanical structure characteristics of samples under different servo stresses is considered. The macro and micro parameters such as permeability coefficient, porosity, effective coordination number, particle equivalent stress and pore structure distribution were used to characterize the structure and mechanical characteristics of the samples. The effects of internal erosion on the structure and mechanical characteristics of the samples were studied through the evolution of these macro and micro parameters. The results show that the distribution of erosion area concentrates in the category of low equivalent stress and low coordination number, but under high stress level, the erosion will also occur in the area of high effective force and high coordination number due to the erosion of fluid and the contact between particles. In the erosion process of binary mixtures, the macro and micro parameters show the transformation process of equilibrium-instability-equilibrium.更多还原