基于离散元法的岩石细观能量转化特征及影响因素分析  

Study on Characteristics and Influence Factor of Meso-energy Transformation in Rock Based on Discrete Element

作　　者：程虹铭[1] 韩锋勇 李永明[1] CHENG Hongming;HAN Fengyong;LI Yongming(College of Coal Engineering,Shanxi Datong University,Datong 037003,China;Linfen Hongda Hongya Coal Industry Co.,Ltd.,Shanxi Coking Coal Group,Linfen 041000,China)

机构地区：[1]山西大同大学煤炭工程学院,山西大同037003 [2]山西焦煤临汾宏大洪崖煤业有限公司,山西临汾041000

出　　处：《金属矿山》2023年第4期58-64,共7页Metal Mine

基　　金：山西省高校科技创新项目(编号:2020L491)。

摘　　要：为揭示荷载作用下岩石细观能量转化特征及查明其影响因素,基于离散元PFC2D软件建立砂岩数学计算模型,通过试错法匹配试验应力—应变曲线标定细观力学参数,对不同围压、加载速率和颗粒直径下砂岩受压试验进行离散元研究。分析砂岩变形破坏全过程细观能量演化及转化特征,探讨细观能量转化机制及细观能量转化影响因素。研究结果表明:细观线应变能和黏结应变能在峰值应力前随变形增大而增大,峰值应力后释放并逐渐平缓发展;摩擦耗散能随变形增大而增大,阻尼耗散能演化趋势与宏观贯通裂纹形成相关;以耗散能转化率为例,能量转化经历了4个阶段,与裂纹发展趋势一致,且其极小值对应岩石损伤应力;损伤应力后,围压、加载速率的增大降低耗散能转化及其增长速率,颗粒直径的增大仅降低耗散能转化率,不影响其增长速率。In order to reveal the characteristics and influencing factors of meso-energy transformation in rock,the mathematical calculation model of sandstone was established based on discrete element PFC2D software,and the meso-mechanical parameters were calibrated by the trial-and-error method to match the experimental stress-strain curve,and the discrete element method was used to study the compression test of sandstone under different confining pressures,loading rates and particle diameter.The characteristics of mesoscopic energy evolution and transformation in the whole process of sandstone deformation and failure were analyzed,and the mechanism and influencing factors of mesoscopic energy transformation were discussed.The results showed that the meso-line strain energy and bonding strain energy increase with the increase of deformation before the peak stress,and release and gradually develop gently after the peak stress.The friction dissipation energy increased with the increase of deformation,and the evolution trend of damping dissipation energy was related to the macroscopic crack formation.Taking the dissipation energy transformation rate as an example,the energy transformation went through four stages,which was consistent with the crack development trend,and its minimum value corresponded to the rock damage stress.After damage stress,the increase of confining pressure and loading rate reduced the dissipation energy transformation and its growth rate,while the increase of particle diameter only reduced the dissipative energy transformation rate without affecting its growth rate.

关 键 词：离散元 细观能量转化 围压 加载速率 颗粒直径 

分 类 号：TD315[矿业工程—矿井建设]