13th International Conference on Fracture June 16–21, 2013, Beijing, China -9- 7.2. One single tough flaw ahead the initial crack tip. Fig. 7. One single tough inclusion in the test material. On the contrary, a tough e length flaw ( 2 0 Γ ≥Γ ) is embedded in the regular test material ( 1 0 / R Γ =Γ , with the fixed value 3 R= ), at a distance d ahead the initial crack tip (fig. 7). The influence of the flaw features d , e and 2Γ on the crack kinematics is investigated. If the flaw is sufficiently long (in our specific case 0 / 6% e > l , see fig.8), the crack is immediately stopped inside the flaw. In the other hand where 0 / 1% e < l the crack kinematics is very close to that without flaw. In the intermediate situations, a transient crack arrest takes place in the flaw (the longer the flaw, the longer the transient arrest time), followed by a crack restart with either a reduced final crack arrest ( for 0 / 5% e = l ) or a regular one ( for 0 / 3% e = l ). Fig. 8. Influence of the flaw length. 0 l A l 2Γ e 0 Γ d 1Γ Crack kinematics depending on the single flaw length (d/L0=0.03, Γ2=Γ0 ) 1 1,1 1,2 1,3 1,4 1,5 1,6 1,7 1,8 0,00E+00 3,00E‐04 6,00E‐04 time (s) L/L0 no flaw e/L0=0.01 e/L0=0.03 e/L0=0.051 e/L0=0.063
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