岩石破坏过程声发射信号的级频维数特征

Rank spectrum dimension of rock AE during rock deformation process

为了解岩石损伤变形破坏过程中产生的声发射信号的级频维数特征,利用先进的MTS815岩石力学性能试验系统和PAC的DISP-II声发射仪,对大理岩试样进行了常温下力学性能的实验研究和理论分析,系统地分析了岩石变形破坏过程中的声发射特征及其力学机制.研究结果表明:在同一应力水平下,随着嵌入空间维数m值增大,声发射过程的关联维数也相应增加,而自相似程度随着m值的增大而减弱;级频分形维数随着岩样所受应力的增加呈降低的趋势,试件破坏时级频分形维数达到某一最小值,这体现了岩样破坏前损伤局部化特征.

Acoustic emission signal is generated during the process of rock damage and deformation, which reflects the internal variations of rock mass. Currently the acoustic emission technique （AE） is one of the most important means for studying rock damage and fracture. In this study, an experimental test and theoretical analysis on griotte mechanical characteristics are conducted under a normal temperature using MTS815 and PAC DISP- II acoustic emission instruments. In addition, the acoustic emission characteristics and mechanical mechanism during the process of rock deformation and damage are systematically analyzed. In the same stress level, with the embedded space dimension rn increases, the relevant dimension number of acoustic emission process also increases accordingly while the self-similar degree decreases with the increase ofm value. With the stress increase, the rank spectrum dimension of rock tends to decrease. When the specimen is damaged, the rank spectrum dimension will reduce to a minimum. This reflects the localization characteristics of rock damage before fracture.