Cluster modelling of short-range correlation of scattering signals of acoustic emission

Dongjie Xue · Lele Lu · Jie Zhou · Lan Lu· Yintong Liu

Abstract

As a widely used measurement technique in rock mechanics, the spatial correlation modelling of the acoustic emission scattering signals is attracting more and more focus on its quantitative description of mechanical behaviours. Dissimilar to the statistical description of the spatial distribution of random generation of AE signals, the spatial correlation modelling is mainly based on the short-range correlation considering the interrelationship of adjacent signals. A new idea of covering strategy from the percolation model is adopted to build the most representative cube cluster. Its modelling process seriously depends on the complete connection of the main fracture network and the corresponding cube for coverage is termed the critical cube. The criticality is not only the transition of local-to-whole connection of the fracture network but also the increment-to-decrement of deviator stress with an obvious stress drop in the brittle failure of granite. The reasonable determination of critical cube guarantees the best observation scale to investigate the failure process. Besides, the topological connection induces the geometrical criticality of three descriptors, i.e. anisotropy, pore fraction and specific surface area, which are effectively evaluated separately. The result shows the cluster modelling based on the critical cube is effective and with the property of criticality both in topology and geometry, as well as the triaxial behaviour. And the critical cube length presents a high confidence probability being correlated to the mineral particle size. Besides, its pore fraction is seriously influenced by the critical cube length and confining pressure.

Keywords

acoustic emission; spatial correlation modelling; cover strategy; criticality; critical cube; cluster modelling

引用格式：

Xue DJ, Lu LL, Zhou J, Lu L, Liu YT. Cluster modeling of the short-range correlation of acoustically emitted scattering signals. Int J Coal Sci Technol.2020; 1-15

DOI: 10.1007/s40789-020-00357-6

创新点：

1. 首次引入团簇模型分析三维声发射散点空间关联性

2. 创立了分析声发射云团大数据的逾渗重构算法

3. 基于团簇模型描述了岩石破坏临界力学行为和多重分形特性

临界团簇尺寸和矿物颗粒大小的关联

团簇结构的各向同性描述（图片版权所有，侵权必究）

团簇结构的各向异性描述（图片版权所有，侵权必究）

不同围压下团簇结构的多重分形谱