PSI - Issue 78

Adriano Andrés Del Fiol et al. / Procedia Structural Integrity 78 (2026) 1713–1720

1719

capacity in comparison to the bare frame. This outcome is consistent with the established behaviours of non engineered masonry infills, which enhance initial strength but compromises post-peak flexibility and energy dissipation under seismic loading, leading to a more brittle and unpredictable response.

300

200

100

0

-120 -100 -80 -60 -40 -20 0 20 40 60 80 100 120

-100

Force [kN]

-200

-300

Displacements [mm]

Fig. 6. Comparison of numerical results: bare frame (blue) vs. masonry infill (red).

5. Final Remarks The present study aims to develop and calibrate a reliable finite element modeling strategy for infilled frames, by replicating a well-known experimental benchmark. The numerical approach was developed for bare- and infilled frame in the software ABAQUS, with the aim of reproducing the main features of the specimen and retrieve the correct experimental behavior. To ensure consistency and accuracy, the numerical models were developed using the mechanical properties and geometric characteristics of the tested structure, as reported in the original experimental campaign. The finite element models well reproduced the failure mechanisms and the difference in the response to lateral loads between bare- and infilled frame. The presence of a masonry infill panel, if on one hand increases the system strength, on the other hand, increases stiffness and reduces the ductility of the system, leading to a more brittle response. The implementation of the benchmark calibration facilitated the identification of critical modeling parameters, including material properties, boundary conditions, and interaction definitions. These parameters will be employed in subsequent analyses involving hybrid configurations. The modeling of CLT panel infill is currently under development and will constitute the next step in the numerical simulation program. These models will be used to investigate the structural response of RC frames with timber-based infill systems under seismic loading, and their validity will be validated through full-scale experimental tests. Future work will concentrate on refining the numerical models, extending the analyses to different infill solutions, and contributing to the development of innovative seismic-resistant design strategies for hybrid structures. References Abaqus Theory manual, 2024. Aloisio A., Pelliciari M., Sirotti S., Boggian F, Tomasi R., 2021. Optimization of the structural coupling between RC frames, CLT shear walls and asymmetric friction connections. Bulletin of Earthquake Engineering 20(8), 3775–3800. Blasi, G., De Luca, F., Aiello, M. A., 2018a. Brittle failure in RC masonry infilled frames: The role of infill overstrength. Engineering Structures, 177, 506-518. Blasi, G., Perrone, D., Aiello, M. A., 2018b. Fragility functions and floor spectra of RC masonry infilled frames: Influence of mechanical properties of masonry infills. Bulletin of Earthquake Engineering 16(12), 6105-6130. Calvi, G. M., Bolognini, D., 2001. Seismic response of reinforced concrete frames infilled with weakly reinforced masonry panels. Journal of Earthquake Engineering 5(2), 153–185. https://doi.org/10.1080/13632460109350390. Casolo S., Tateo V., Uva G., 2018. RBSM approach for the quasi-static analysis of infill panels under later loads: an application, International Masonry Society Conference 2018. https://www.masonry.org.uk/downloads/s04-513-rbsm-approach-for-the-quasi-static-analysis-of-infill panelsunder-later-loads-an-application/