PSI - Issue 38

Paul Catalin Ilie et al. / Procedia Structural Integrity 38 (2022) 271–282 P. C. Ilie et al./ Structural Integrity Procedia 00 (2021) 000 – 000

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Fig. 6. Embedded elliptical crack results: Comparison between MATBAB implementation and 3D FEA based explicit crack propagation technique.

Fig. 7. Corner quarter-elliptical crack results. Comparison between the two approaches.

3.2. Multiple flaw model validation A multiple site damage 3D FEA was performed to validate crack propagation predictions against test measurements using thin specimens designed to investigate crack path interaction [25]. Specimen material properties are given in Table 3 [25]. Using SimModeler, two nominal configurations that capture the test specimen dimensions and crack locations shown in Fig. 8 were modeled. The FE model parameters are provided in Table 4. Five 1 mm edge cracks were inserted at 45° with respect to the longitudinal axis as shown schematically in Fig. 8 and the FE model in Fig. 9. Rigid body motion was constrained and a tensile load of 47.15 MPa was applied across the two top and bottom model faces. The loading cycle in the 3D FE model was defined to simulate the same loading range as in the experimental procedure. The FE simulations were carried out on the basis of mixed-mode crack propagation due to the out-of-plane crack growth.

Table 3. Multiple flaw specimen material properties [25] Parameter Value Alloy Al2024-T3 Young’s Modulus 73.1 GPa Poisson’s Ratio 0.33 C coefficient (Paris) 1.18e-12 MPa √mm m exponent (Paris) 3.2