摘要
为从矿物晶质尺度研究非均质岩石动态断裂损伤的细观发展过程,采用颗粒流程序-等效晶质模型构建能够反映微观结构特征的非均质岩石模型,同时利用有限差分法FLAC2D和离散元法PFC2D建立耦合分离式霍普金森压杆系统,对不同冲击载荷下非均质岩石的动态冲击破坏过程进行模拟分析。通过自编Fish语言,对动态破坏过程中矿物的晶内及晶间微裂纹进行细化分组及数量统计,从细观发展的角度剖析非均质岩石的动态断裂损伤演化过程。结果表明:在静态单轴压缩条件下,沿晶破坏是主导非均质岩石破坏的重要原因,晶间裂纹和穿晶裂纹逐步贯通,最终使试样展现出宏观的破坏模式;在动态冲击条件下,各矿物晶内及晶间的微裂纹增长过程均存在萌生期、快速增长期、缓慢增长期和停止增长期4个阶段;与静态单轴压缩条件下微裂纹数的增长模式相似,动态破坏初期晶间裂纹数明显高于晶内裂纹数,岩石主要发生沿晶损伤破坏,随着加载的进行和岩石破坏程度的提升,动态破坏的晶内裂纹数逐渐超过晶间裂纹数。此外,模拟中不同冲击载荷下峰值应变率与对应的峰值载荷以及动态峰值强度与对应的峰值载荷均表现出良好的线性关系,为快速确定岩石相关动态力学参数提供了简便的方法。
In order to investigate the mesoscale development in the dynamic fracture damage of heterogeneous rocks at the mineral crystal scale,a heterogeneous rock model that can reflect the microstructure characteristics was constructed based on the particle flow code-grain based model(PFCGBM)method.By establishing the split Hopkinson pressure bar(SHPB)system using finite difference method FLAC2D and discrete element method PFC2D,the dynamic impact failure process of heterogeneous rock under different impact loading was simulated and studied.Through the self-compiled Fish language,the number of intragranular and intergranular microcracks in different minerals during the dynamic failure process was grouped and counted.The microscopic evolution process of dynamic fracture damage of heterogeneous rocks was deeply analyzed from a mesoscopic perspective.The research results show that intergranular failure is an important reason for the failure of the dominant heterogeneous rock under the static uniaxial compression condition.Under impact loading condition,the growth process of microcracks within and between crystals of each mineral had four stages:initiation,rapid growth,slow growth and stop growth.Similar to the growth pattern of the number of microcracks under static uniaxial compression condition,the number of intergranular cracks at the initial stage of dynamic failure was significantly higher than the number of intragranular cracks in each mineral.The rock mainly suffered intergranular damage.As the degree increases,the number of intragranular cracks in dynamic failure gradually exceeds the number of intergranular cracks.In addition,the peak strain rate and the corresponding maximum pressure as well as the dynamic peak strength and the corresponding maximum pressure under different impact loads in the simulation show good linear relationships,which provides a simple method to quickly determine the relevant dynamic mechanical parameters of the rock.
作者
崔年生
危剑林
袁增森
徐振洋
刘鑫
王雪松
CUI Niansheng;WEI Jianlin;YUAN Zengsen;XU Zhenyang;LIU Xin;WANG Xuesong(Fujian Xinhuadu Engineering Co.Ltd.,Xiamen 361000,Fujian,China;Minerals(Handan)Mine Engineering Co.Ltd.,Handan 056000,Hebei,China;College of Mining Engineering,University of Science and Technology Liaoning,Anshan 114051,Liaoning,China;School of Architecture and Civil Engineering,Shenyang University of Technology,Shenyang 110870,Liaoning,China)
出处
《高压物理学报》
CAS
CSCD
北大核心
2023年第4期122-133,共12页
Chinese Journal of High Pressure Physics
基金
国家自然科学基金(51974187)
辽宁省教育厅项目(LJKZ0282)。
关键词
岩石
非均质
动态损伤
微裂纹
细观特征
rock
heterogeneity
dynamic damage
microcracks
mesoscopic features
