Damage Evolution During Rock Dynamic Compression Revealed by Wavelet Analysis of Acoustic Emission Signals

Acoustic emissions have been monitored during rock compression under both quasi-static and dynamic conditions. A new method is proposed in this study to study the damage evolution of rocks during dynamic compression by continuous wavelet analysis of acoustic emission signals. Wavelet analysis is first validated against conventional method using the acoustic emission data from a quasi-static compression test. The wavelet analysis is then carried out on acoustic emission signals from rock dynamic compression to obtain the time–frequency spectrum. Based on the characteristics of the time–frequency spectrums, the rock exhibits a mixed damage mode shifting from tensile to shear damage. The increase in the loading rate leads to an increase in the amount of tensile damage. The proposed method provides an effective way to analyze the dynamic damage evolution of rocks.