岩石破裂过程微裂纹演化规律有限元统计分析

Statistic Analysis of the Evolution Laws of Micro Cracks in Rock Failure Process by Finite Element Method

为了系统完整地研究岩石破裂过程的微裂纹演化特征,运用数值分析方法RFPA2D,对在单轴压缩条件下岩石整个破裂过程进行了数值模拟,直观再现了岩石的微裂纹演化行为.借助RFPA2D对每加载步产生的破裂集团大小及数目进行统计的功能,对岩石的微裂纹演化规律作了定量化分析.结果表明:岩石破裂失稳具有前兆性,在接近自组织临界点之前,就出现了大的破裂集团(微裂纹);岩石宏观破裂失稳后,单元破裂百分比(损伤程度)略有所增加,而总破裂集团数(总微裂纹数)却有所减少.

To study the micro-cracking characteristics in rock failure process systematically, the whole failure process of rock sample under the uniaxial testing was numerically simulated with the software RFPA^2D and the evolution behavior of micro-cracks during the failure process was visually represented. The evolution laws of micro-cracks were quantitatively analyzed by the counting on the scale and amount of damaged group produced in the numerical rock sample at every loading step. The results show that the rock unstable failure has some auspices. Before the self-organized criticality point, large damaged element group has occurred. After the macroscopic unstable failure, the percentage of element failure （damage extent） increases slightly and the total amount of damaged element groups （micro-cracks） decreases a little.