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.