Multifractal Analysis of Acoustic Emissions during Hydraulic Fracturing Experiments under Uniaxial Loading Conditions: A Niutitang Shale Example

Figure 12

Time-frequency characteristics of the AE signals. (a–f) correspond to the results of H1, T1, H2, T2, H3, and T3, respectively.

(a)

(b)

(c)

(d)

(e)

(f)