考虑不均质度的岩石声发射数值模拟研究

Study of numerical simulation of acoustic emission in rock of inhomogeneity

利用离散元颗粒流软件模拟了岩石单轴压缩破坏过程,采用内嵌FISH语言,通过设置随机缺陷来建立不同均质度的岩石数值试样对岩石的声发射规律进行了研究。结果表明,不均质度对于岩石声发射特性有着重要影响,随不均质度的增加,试样的峰值强度下降,声发射总数大幅增加,空间分布也更为分散,声发射出现时间更早,持续时间更长,峰值后的声发射保持更高的强度;单轴应力状态下声发射最大强度出现时间相比峰值破坏时间有不同程度滞后,不均质度越高,滞后效应越明显,显示岩石破坏要早于声发射峰值出现时间。

The failure process of rock in uniaxial compression tests is simulated by using the particle flow code（PFC）.Fish language embedded within PFC2D is used to generate random imperfections and to develop the rock numerical specimens with different homogeneous degrees.The results show that inhomogeneous degree has great influence on characteristics of acoustic emission in rock.With the increase of inhomogeneous degree,peak strength of rock specimens decreases and the total number of AE increases greatly.The spatial distribution of AE becomes more extensively.Meanwhile,AE of rock samples appear earlier and sustain for longer duration.The intensity of AE after the peak failure retains higher level.The maximum intensity of AE under uniaxial stress state lags behind the peak damage to different extents.With the increase of inhomogeneous rock,the hysteresis effect of AE becomes obvious which suggests that rock failure appears earlier than the maximum intensity of AE.