Issue 51

B. Zaoui et alii, Frattura ed Integrità Strutturale, 51 (2020) 174-188; DOI: 10.3221/IGF-ESIS.51.14 181 0,0 2,5 5,0 7,5 10,0 12,5 15,0 17,5 20,0 22,5 25,0 -20 -10 0 10 20 30 40 50 60 K (MPa.mm 1/2 )    (10 - 6 K -1 ) K I ( Mode I ) K II ( Mode II ) K III ( Mode III ) Figure 4: Variation of the stress intensity factor in modes I, II and III as a function of the gap of the thermal expansion coefficients of the matrix and the fiber: a = 13mm, ΔT = 800 ° C. 0,000 0,005 0,010 0,015 0,020 0,025 -450 -400 -350 -300 -250 -200 -150 -100 -50 0 50 100 150 200 K I ( MPa.mm 1/2 ) a (mm)  T = 400°C  T = 600°C  T = 800°C Fiber Matrix a) 0,000 0,005 0,010 0,015 0,020 0,025 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 a (mm) K II ( MPa.mm 1/2 )  T = 400°C  T = 600°C  T = 800°C Matrix Fiber b) 0,000 0,005 0,010 0,015 0,020 0,025 -25,0 -22,5 -20,0 -17,5 -15,0 -12,5 -10,0 -7,5 -5,0 -2,5 0,0 2,5 K III (MPa.mm 1/2 ) a (mm)  T = 400°C  T = 600°C  T = 800°C Matrix Fiber C) Figure 5: Effect of elaboration temperature of the composite on the matrix crack propagation. a) in mode I, b) in mode II, c) in mode III.