PSI - Issue 44

Marialaura Malena et al. / Procedia Structural Integrity 44 (2023) 2052–2057 M. Malena et al. / Structural Integrity Procedia 00 (2022) 000 – 000

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2.2. Numerical results Fig.s 5 and 6 show the results of the non-linear static analyses in terms of concentration of plastic strains. About the first analysis (Fig.5), almost vertical cracks develop only in the lower part of the bell tower and in the walls of the vestry, with a slight concentration at the diaphragms. The expected crack development is in good agreement with the actual damage state observed in the bell tower after the Central-Italy earthquake. The collapse multiplier value is 0.10.

Fig. 5. Plastic strain concentration for analysis 1

The results of the numerical analyses reflect what actually happened to the bell tower: the presence of the rigid diaphragms gave the structure a box-like behaviour, preventing the development of a local collapse mechanism in the upper part of the bell tower and shifting the damage to the lower part of the bell tower and the vestry wall, which was heavily damaged by the Central-Italy earthquake.

Fig. 6. Plastic strain concentration for analysis 2

Fig.6 shows the results of the analysis 2. With regard to this last analysis, cracks develop on the transverse walls involving the masonry arches. Plastic strains also develop at the masonry-curb interface on the south longitudinal wall and over the openings in the same wall as effectively happened in the building after the last earthquake. It is worth noting that, also in this case, a good match was obtained between the results of the numerical model one and the damage survey. The collapse multiplier value for this last analysis is 0.12.