PSI - Issue 44

Giovanni Rebecchi et al. / Procedia Structural Integrity 44 (2023) 1180–1187 Giovanni Rebecchi et al. / Structural Integrity Procedia 00 (2022) 000 – 000

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Spectral Density matrix. This operation based on a Singular Value Decomposition, obtained from the recorder acceleration output of the building.

Fig. 3. Stability diagram of one dataset.

4. Elaboration of the FE model 4.1. Modeling technique The FE model considered beam elements representing the structural walls in their exact positions and with their effective dimensions. In fact, rigid links connecting the beams have been created both at the bottom and top of the deck to define the width of the walls. Furthermore, links with non-linear properties have been modelled for the simulation of the mono lateral stiffness and strength of connections of the structural elements, following the information collected from the preliminary investigations. Non-linear elements have also been inserted within adjacent walls, in order to take into account contacts and frictions between adjacent walls, due to their mutual collaboration along vertical interfaces. As for the internal walls carrying only gravitational loads, they were simply modelled with beam elements with hinges at the bottom end.

Fig. 4. a) global FE model in its solid view and b) in its wireframe view modelled in Straus7. A further modelling feature is the insertion of rigid links in the horizontal plane for the simulation of the concrete deck slab. These rigid links essentially connect all the top ends of the beams representing the structural walls (Fig. 4). A complex FE model has been developed, consisting in 20791 nodes, 13523 beams and 17722 links. Nevertheless, it was well manageable by the power of the new 64-bit solver of Straus7 software, and thanks to its full versatility. In fact, by means of the API tool, it was possible to customize and speed up the management of the numerical outputs according to every type of need.