Investigation on the Effect of Dynamic Frequency on Fracture Evolution in Preflawed Rock under Multistage Cyclic Loads: Insight from Acoustic Emission Monitoring

Figure 7

The main frequency characteristics of the tested samples during fracturing. (a–d) The dynamic loading frequency is 0.04, 0.1, 0.5, and 1.0, respectively.

(a)

(b)

(c)

(d)