PSI - Issue 79

Osman Bayrak et al. / Procedia Structural Integrity 79 (2026) 413–420

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analyses for both test models are given in Figure 4. Inset images are given side-by-side with microstructural images that were obtained with permission from the publishers.

Figure 4 Major toughening mechanisms were simulated with both tensile and bending test FE models: Filler pull-out (a), (f); crack bridging (b),(g); filler separation (c), (h); crack deflection (d), (i); crack branching (e), (j). Right to each simulated toughening mechanisms, real microstructural images are given (from (k) to (o)). Microstructural images were reproduced with permission from: Scripta Materialia , 149, 42, (Ramírez et al., 2018) for (k); J. Eur. Ceram. , 32, 3395, (Dusza et al., 2012) for (l), (n), (o); J. Eur. Ceram., 35, 91, (Rutkowski et al., 2015) for (m).

4. Conclusion This study presented a finite element modeling approach to simulate the major fracture toughening mechanisms in graphene-reinforced silicon nitride (Si ₃ N ₄ ) nanocomposites. By incorporating experimentally informed microstructural features—such as orientation distribution, platelet geometry, and interface porosity—into two dimensional FE models, key toughening behaviors were successfully reproduced. The simulations captured filler pull-out, crack bridging, crack deflection, crack branching, and interface separation mechanisms, aligning well with experimental observations reported in literature. The study demonstrated that the presence and quasi-random dispersion of interfacial porosities have a critical influence on crack propagation paths and the activation of energy dissipating mechanisms. Based on the approach followed in this study, a future work, that is concerned with the analysis of elastic and fracture toughness behaviours of the nanocomposites, is planned.