achieved as steady state condition ensues. Vitek [6] obtains a variation similar to the one shown in Figure 3 for the transient stress distribution ahead of crack tip arising due to non-uniform deposition of matter from the tip onto the grain boundary. It is also found (but not shown here) that the peak stress away from the cavity tip is higher for larger a/b ratios. This would imply that the chances for nucleation of new cavities, during transient stages, increase with initial cavity radius-to-spacing ratio. 1.00 10.00 100.00 1000.00 1.0E-06 1.0E-05 1.0E-04 1.0E-03 1.0E-02 1.0E-01 1.0E+00 1.0E+01 0.01 0.1 0.25 0.5 a/b t / τ VFEM / VHull-Rimmer 0.75 1.00 1.25 1.50 1.75 2.00 2.25 0.00 0.10 0.20 0.30 0.40 0.50 0.01 0.1 0.25 0.5 a/b VFEM / VHull-Rimmer t / τ Figure 2. Temporal variation ratio of void growth rate predicted by FEM and by the Hull-Rimmer model for several a/b ratios in γ-Fe. Inset shows the transition from transient to steady state. 0.00 0.60 1.20 1.80 0.00 0.20 0.40 0.60 0.80 1.00 3.82E-06 2.71E-05 3.3E-04 3.77E-03 1.92E-02 9.66E-02 2.47 X / (b - a) t / τ Figure 3. Temporal changes in stress distribution ahead of the cavity tip along the grain boundary in γ-Fe for a/b = 0.1.
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