岩石尺寸效应对其声发射影响的数值模拟研究

对6种同一高径比、不同尺寸的同性质岩石试样进行数值模拟,研究其对岩石破坏过程声发射的影响。结果表明:试样尺寸小时,大声发射事件在主破裂前后都有显著出现,其分布由当初无序性到峰值后在试样中部集聚成核;残余变形阶段,有相当数量和能量的声发射出现,且有几次出现在数量和能量上均较显著的声发射带。当试样尺寸较大时,在达到峰值前声发射较少,且随机分布在试样中,大声发射事件出现次数较少且仅在峰值应力时出现,其数量和能量均最显著,声发射在两处聚集成核;残余变形阶段,声发射很少发生,其分布又呈无序性。根据声发射时间序列和空间分布的特征关系,对利用声发射特性预测不同尺寸岩石试样破裂来临及其位置有一定的参考意义。

Numerical Studies of the Influence of Scale Effect on Rock Acoustic Emission

The rock acoustic emission（AE）under six kinds of different scales with the same homogeneity and ratio of height to diameter was studied using numerical simulation code,which centers on the impact of the failure process of the rock AE.The result show that the AE event is significant before and after the main fracture with the smaller specimen scale,which in the distribution of specimens from the initial stage of the disorder after the peak to gather in central nucleation. After the residual deformation stage, few in number and energy significantly AE zone are appearing. When the larger the specimen scale is, the less AE number, disorderly in the all specimen regions,a large number of AE events less and only reached the stress peak,the number and energy are the most significant,AE gathered in the two nucleation.In the residual deformation phase,the AE is rare and distribute disorderly.Depending on the characteristics relationship of time series and spatial distribution of the scale of the rock specimens AE,which was used to predict the arrival of the breakdown of rock and its location has some reference value.