PSI - Issue 66

Domenico Ammendolea et al. / Procedia Structural Integrity 66 (2024) 320–330 Author name / Structural Integrity Procedia 00 (2025) 000–000

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properly defined zone of interest around the expected crack trajectory, i.e. , a uniform Delaunay triangulation and a cross-triangle quadrilateral mesh. The related Multiscale Numerical Simulation (MNS) results obtained via the proposed approach are reported in Figs. 3(a) and (b), respectively, together with the (reference) Direct Numerical Simulation (DNS) results, i.e. , those coming from a direct analysis performed on the so-called fully meshed model, for which all the microstructural details are represented in an explicit manner (see Fig. 4).

Fig. 3. TPB test results in terms of load-CMOD curves predicted by the Multiscale Numerical Simulation (MNS) for different discretizations and, for comparison, by the Direct Numerical Simulation (DNS): (a) Delaunay triangular mesh; (b) cross-triangle quadrilateral mesh.

Fig. 4. Fully detailed mesh for the Direct Numerical Simulation (DNS).

Figs. 3(a) and (b) show that the loading curves obtained by using the two considered mesh topologies are almost superposed to each other, thus clearly revealing that the proposed multiscale approach leads to mesh-independent results in terms of both peak and post-peak responses, and ultimately, in terms of predicted overall fracture energy. Moreover, after comparing the loading curves found with the Multiscale Numerical Simulations with those coming from the corresponding Direct Numerical Simulations, it can be deduced that the proposed method is characterized by a very high accuracy in both peak and post-peak regimes. This high accuracy is also confirmed by the analysis of the predicted peak load reported in Table 1. In particular, the absolute percentage errors with respect to the DNS counterpart found with the two adopted meshes are less than 0.5%, and therefore fully acceptable from the engineering point of view.