3.2.2. Case II

According to Table 2, the differences between this case and the previous case were the initial crack length and its position from the mid-span, which were 38.1 mm and 127 mm, respectively. The crack moved above the lower hole in this specimen and stopped at the central hole from the left. The results of the crack trajectory during propagation were excellently close to the experimental results of the crack trajectory obtained by [32], XFEM results using ABAQUS software obtained by [34], as well as the numerical results obtained by [35] using the coupled extended meshfree–smoothed meshfree method, as shown in Figure 13a–d, respectively. The distribution of the von Mises stress is shown in Figure 14.

**Figure 11.** Non-dimensional stress intensity factors for case I of the PMMA specimen.

**Figure 12.** Predicted crack growth path for case I of the PMMA specimen.

**Figure 13.** Final crack growth path for case I: (**a**) present study, (**b**) experimental results [32], (**c**) [34] with permission of Elsevier 2018, and (**e**) [35] with permission of Elsevier 2020.

**Figure 14.** Von Mises stress distribution of case II for the PMMA specimen.

The findings of the study for the dimensionless stress factor were compared with those achieved in XFEM with the smooth nodal stress system [37], as seen in Figure 15, with identical results.

**Figure 15.** Comparison of the dimensionless stress intensity factors for case II for the PMMA specimen.
