(a)
(b)
(c)
(d)
(e)
Figure 6: Typical variation in load and AE count rate with time for TPB tests under different loading rates: (a) 0.6 mm/min, (b) 1.0 mm/min, (c) 1.4 mm/min, (d) 1.8 mm/min, and (e) 3.0 mm/min. I, II, and III represent elastic stage, damage stage, and postpeak stage, respectively.