不同含水状态花岗岩破裂过程时频分析

Time-frequency Analysis of Granite Fracture Process in Different Water States

岩石加载破裂过程中释放的声发射信号是一种非平稳信号,非平稳信号的统计量是一个时变函数,对非平稳信号的研究不能仅停留在时域或频域,为了进一步了解声发射信号的特征反演岩石破裂前兆信息,对不同含水状态花岗岩破裂的声发射信号进行二次时频分析。研究结果表明:花岗岩的破裂主要发生在第三与第四阶段,每个阶段基准点之前的Wigner-Ville分布比基准点之后的Wigner-Ville分布的能量分布范围大,大能量聚集区域更加明显,且随着花岗岩含水状态的增加,能量聚集程度减小。

The acoustic emission signal released in the process of rock loading and fracture is a kind of non-stationary signal, and the statistics of the non-stationary signal is a time-varying function. The research on the non-stationary signal can not only stay in the time or frequency domain.In order to further understand the characteristics of the acoustic emission signal to reverse the precursor information of rock fracture, the acoustic emission signals of different water cut states of granite fracture were processed as two steps.The secondary time-frequency analysis shows that the fracture of granite mainly occurs in the third and fourth stages, and the energy distribution range of Wigner Ville distribution before the reference point is larger than that after the reference point, and the area of large energy accumulation is more obvious, and the degree of energy accumulation of granite decreases with the increase of water content.