岩石圆盘径向压缩破坏的Voronoi子块体单元DDA方法模拟  

Simulation of rock disc failure under diametrical compression by the Voronoi sub-block element DDA

作　　者：周大波 甯尤军 李春玉 王大国 ZHOU Dabo;NING Youjun;LI Chunyu;WANG Daguo(School of Mechatronic Engineering,Southwest Petroleum University,610500 Chengdu,China;School of Civil Engineering and Geomatics,Southwest Petroleum University,610500 Chengdu,China)

机构地区：[1]西南石油大学机电工程学院,成都610500 [2]西南石油大学土木工程与测绘学院,成都610500

出　　处：《应用力学学报》2023年第2期294-301,共8页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金资助项目(No.42171108);四川省自然科学基金资助项目(No.2022NSFSC0263)。

摘　　要：非连续变形分析(DDA)方法是计算离散可变形块体系统力学行为的数值计算方法,可通过子块体单元DDA方法模拟岩石的开裂破坏。考虑到Voronoi多边形颗粒与细观尺度下岩石矿物晶粒形态的相似性,提出一种基于随机圆的Voronoi颗粒单元模型生成方法;并通过完整及带预制裂纹岩石圆盘径向压缩破坏的模拟,验证岩石破裂问题Voronoi子块体单元DDA模拟方法的适用性。结果表明,当子块体单元数较小时,圆盘表现出更高的整体强度;随着子块体单元数的增大,起裂处位置更接近真实,开裂破坏路径更清晰;子块体单元数较大时不同倾角预制裂纹圆盘破坏的模拟结果与实验结果高度吻合,并能有效反映圆盘中心加工小孔对开裂破坏路径的影响。使用Voronoi子块体单元DDA方法能够有效模拟岩石的开裂破坏过程,为进一步开展基于Voronoi颗粒单元模型的岩石开裂破坏模拟创造了条件。Discontinuous deformation analysis(DDA)is a numerical method that computes the mechanical behaviors of discrete deformable-block systems,which can be used to simulate the cracking failure of rock by the sub-block method.Considering the similarity of morphology between Voronoi polygonal particles and rock mineral grains shapes at the mesoscale,a generation method of Voronoi particle element model based on random circles is proposed.By simulating the cracking failure process of intact rock disc and rock discs with a pre-existing crack,the feasibility of simulating rock cracking failure with the Voronoi sub-block element DDA is verified.Results indicate that the rock disc shows higher integral strength with the decrease of the number of sub-block elements.With the increase of the element number,the crack initiation position is closer to that in reality,and the failure path gets clearer.With a large-enough number of the elements,the cracking failure simulation results of the discs with different pre-existing crack inclinations are highly consistent with the experimental results,and the influence of the center machining hole in the disc on the failure path can be accurately captured as well.The Voronoi sub-block element DDA can effectively simulate the cracking failure process of rock,which provides conditions for the further simulation of rock cracking failure with Voronoi particle elements.

关 键 词：岩石圆盘 开裂破坏 Voronoi颗粒单元 非连续变形分析(DDA) 

分 类 号：P642.3[天文地球—工程地质学]