Figure
7 shows the variation of the number of existing cracks, Z, with\(\frac{N}{N_{f}}\) for some CSA virtual tests. The activity of the
coalescence of adjacent cracks increases as the applied stress
and/or\(\ \frac{N}{N_{f}}\) increase. Thus, the following two
observations presented in Fig. 7 are obvious. For the same applied
stress, Z deceases with increasing\(\ \frac{N}{N_{f}}\). At a given\(\frac{N}{N_{f}}\) , Z decreases with increasing the applied stress.
Fig. 7 Examples of the assessment of the present simulation for the
number of existing cracks plotted against cycle ratio due to the
application of CAL having different stress amplitudes utilizing
specimens with different surface configurations.