Issue 53

D. Wang et alii, Frattura ed Integrità Strutturale, 53 (2020) 236-251; DOI: 10.3221/IGF-ESIS.53.20 247 (a) 7-channel sensor (b) 8-channel sensor (c) 11-channel sensor (d) 12-channel sensor (e) 13-channel sensor (f) 15-channel sensor Figure 15: Variation in the energy rate of S3 with time and furnace temperature. (a) 7-channel sensor (b) 8-channel sensor (c) 11-channel sensor (d) 12-channel sensor (e) 13-channel sensor (f) 15-channel sensor Figure 16: Variation in the b-value of S3 with time and furnace temperature. Figs. 14-16 show the variations in event rate, energy rate and b-value with time and furnace temperature, respectively. Coupled with macroscopic phenomena, the change laws of the three characteristic parameters in each stage were analyzed based on the three figures: 0 50 100 150 200 250 300 350 400 450 500 550 -20000 0 20000 40000 60000 80000 100000 120000 140000 160000 180000 200000 Flameout 315min Ignition 105min 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 Energy rate Mean furnace temperature Temperature (°C) Time (min) Energy rate (mv*μs/min) 0 50 100 150 200 250 300 350 400 450 500 550 -20000 0 20000 40000 60000 80000 100000 120000 140000 160000 315min 105min 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 Energy rate (mv*μs/min) Ignition Flameout Energy rate Mean furnace temperature Time (min) Temperature (°C) 0 50 100 150 200 250 300 350 400 450 500 550 -20000 0 20000 40000 60000 80000 100000 120000 140000 160000 315min 105min Energy rate (mv*μs/min) Ignition Flameout Energy rate Mean furnace temperature Time (min) Temperature (°C) 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 0 50 100 150 200 250 300 350 400 450 500 550 0 100000 200000 300000 400000 500000 600000 700000 800000 315min 105min Energy rate (mv*μs/min) Ignition Flameout Energy rate Mean furnace temperature Time (min) Temperature (°C) 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 0 50 100 150 200 250 300 350 400 450 500 550 -50000 0 50000 100000 150000 200000 250000 300000 350000 400000 450000 500000 550000 600000 315min 105min Energy rate (mv*μs/min) Ignition Flameout Energy rate Mean furnace temperature Time (min) Temperature (°C) 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 0 50 100 150 200 250 300 350 400 450 500 550 -20000 0 20000 40000 60000 80000 100000 120000 140000 160000 315min 105min Energy rate (mv*μs/min) Ignition Flameout Energy rate Mean furnace temperature Time (min) Temperature (°C) 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 0 50 100 150 200 250 300 350 400 450 500 550 1.4 1.5 1.6 1.7 1.8 1.9 2.0 b-value Mean furnace temperature Temperature (°C) Time (min) b-value Flameout 315min Ignition 105min 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 0 50 100 150 200 250 300 350 400 450 500 550 1.4 1.5 1.6 1.7 1.8 1.9 2.0 315min 105min b-value Ignition Flameout b-value Mean furnace temperature Time (min) Temperature (°C) 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 0 50 100 150 200 250 300 350 400 450 500 550 1.4 1.5 1.6 1.7 1.8 1.9 2.0 315min 105min b-value Ignition Flameout b-value Mean furnace temperature Time (min) Temperature (°C) 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 0 50 100 150 200 250 300 350 400 450 500 550 1.4 1.5 1.6 1.7 1.8 1.9 2.0 315min 105min b-value Ignition Flameout b-value Mean furnace temperature Time (min) Temperature (°C) 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 0 50 100 150 200 250 300 350 400 450 500 550 1.4 1.5 1.6 1.7 1.8 1.9 2.0 315min 105min b-value Ignition Flameout b-value Mean furnace temperature Time (min) Temperature (°C) 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 0 50 100 150 200 250 300 350 400 450 500 550 1.4 1.5 1.6 1.7 1.8 1.9 2.0 315min 105min b-value Ignition Flameout b-value Mean furnace temperature Time (min) Temperature (°C) 0 100 200 300 400 500 600 700 800 900 1000 1100 1200