13th International Conference on Fracture June 16–21, 2013, Beijing, China -6- 0 2 4 6 8 1012141618202224 -9 -6 -3 0 3 6 9 a-as=19.95mm y/mm a-as=10.77mm a-as=17.14mm 2as=10mm σmax=60MPa R=0.1 x/mm 0 2 4 6 8 1012141618202224 -9 -6 -3 0 3 6 9 a-as=11.91mm y/mm a-as=21.60mm 2as=10mm σmax=85MPa R=0.1 x/mm a-as=18.02mm 0 2 4 6 8 1012141618202224 -9 -6 -3 0 3 6 9 a-as=13.27mm y/mm a-as=17.60mm 2as=15mm σmax=60MPa R=0.1 x/mm a-as=22.80mm Figure 9. Variation of delamination between inner aluminium alloy sheet and prepreg 0 2 4 6 8 101214161820 0 2 4 6 8 10 12 14 16 σmax=60MPa, a-as=10.77mm σmax=85MPa, a-as=11.91mm 2as=10mm am=12mm R=0.1 d/mm x/mm 0 2 4 6 8 1012141618202224 0 2 4 6 8 10 12 14 16 18 20 σmax=60MPa R=0.1 2as=10mm, a-as=10.77mm 2as=15mm, a-as=13.27mm 2as=10mm, a-as=17.14mm 2as=15mm, a-as=17.60mm 2as=10mm, a-as=19.95mm 2as=15mm, a-as=22.80mm d/mm x/mm Figure 10. Influence of saw-cut length and stress level on delamination size Delamination size in the higher stress level is clearly larger than it in lower stress level, as shown in Fig. 10(a). Stress level has a significant impact on delamination behavior. Previous work had shown that the bridging stress becomes too low in case the delamination growth is high, resulting in inefficient fiber bridging[15]. As a result, for AHL, in the condition of high stress level, the bridging effect drops so that the fatigue crack propagation property reduces. However delamination size seems to be same with different saw-cut length, as shown in Fig. 10(b). Thus it can be seen that the influence of saw-cut length on delamination behavior for AHL is not distinct. (a) (b) (c) (a) (b)
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