PSI - Issue 78

Ciro Canditone et al. / Procedia Structural Integrity 78 (2026) 1855–1862

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showed noticeably smaller decreases of 1.9%, 1.0%, and 0.6%, respectively. The lower apparent decay in the FEM can be attributed to the different modelling strategies: in the AEM, cracking and progressive stiffness degradation are explicitly simulated through element separation and contact redefinition, leading to a more pronounced loss of global stiffness; in contrast, the FEM maintained largely linear behaviour with limited damage representation, thus preserving most of the initial stiffness and resulting in smaller frequency changes

Figure 5. Comparison amongst FEM (a,c,e) and AEM (b,d,f) numerical results.

6. Conclusions and future developments This study proposed a multi-model SHM strategy for cultural heritage structures, combining continuum-based FEM and discontinuum-based AEM. Both models showed good agreement in crack patterns and static results, with FEM capturing global deformation and stress states efficiently and AEM providing detailed localized damage data. Modal analysis revealed better correlation in translational modes with respect to torsional modes due to stiffness and boundary assumptions. Notably, the FEM exhibited a smaller frequency decay under damage compared to the AEM, which better reflected stiffness degradation. These findings highlight the complementary strengths of FEM and AEM in the global stability assessment, and in the detailed damage characterization. To improve comparability, domain adaptation techniques will be explored to better align FEM and AEM results. Integrating surrogate models trained on