13th International Conference on Fracture June 16–21, 2013, Beijing, China -6- rate becomes constant. After stopping the forced displacement, several oscillations appear again, then it eventually converges to zero. From the comparison between Case 3 and Case 4, it is seen that the same maximum strain rate max ε and the same converged strain rate const ε are observed although the final displacement max u of Case 3 is 15 times larger than that in Case 2. It may be concluded that the strain rate concentration is controlled by the tensile speed. Figure 8 shows the -6000 -4000 -2000 0 2000 4000 6000 8000 0 0.001 0.002 0.003 0.004 0.005 Strain rate ε yA at the notch root A [s-1] Time[s] -6000 -4000 -2000 0 2000 4000 6000 8000 0 0.001 0.002 0.003 0.004 0.005 Time [s] Strain rate ε yA at the notch root A [s -1 ] max ε ④ ④ const ε ④ (d) Case 4 (b) Case 2 ⋅ -400 -200 0 200 400 600 0 0.001 0.002 0.003 0.004 0.005 Strain rate ε yA at the notch root A [s-1] Time[s] -400 -200 0 200 400 600 0 0.001 0.002 0.003 0.004 0.005 Strain rate ε yA at the notch root A [s -1] Time [s] max ε ⑤ ⑤ const ε ⑤ Figure 7. Strain rate at notch root A for ρ=0.03mm (Continued) (e) Case 5 max ε ② ② const ε ② A ⋅ ③ const ε ③ max ε ③ A ⋅ (c) Case 3 ⋅ y x y x A A ⋅ ⋅
RkJQdWJsaXNoZXIy MjM0NDE=