PSI - Issue 44

Stefano Bracchi et al. / Procedia Structural Integrity 44 (2023) 442–449 Stefano Bracchi, Maria Rota, Andrea Penna / Structural Integrity Procedia 00 (2022) 000–000

447

6

and the single wall (with a flange’s length equal to half of the length of the transversal wall) for all the elements adopted. It can be also noted that in all the cases, consistently with the frame behavior, the downwind piers increases their axial load, whereas windward piers experience a decrease of load. However, in the entire building analyzed with the macroelement of Penna et al. (2014) and Bracchi et al. (2021) flanges are subjected to a reduction of axial load, which is not taking place with the bilinear element. Looking at the damage mechanisms (at the ultimate condition) of the West wall considered as belonging to the entire model and analyzed as single wall (Fig. 5), a consistency between the results of the analysis of single wall and entire building is evident, since the mechanism is similar. Moreover, a flexural behavior located at the second story is foreseen by all the elements used.

Single wall

Bilinear

Penna et al. (2014)

Bracchi et al. (2021)

Building

Bilinear

Penna et al. (2014)

Bracchi et al. (2021)

Fig. 4. Comparison of the pushover curves and variation of axial load of the of West wall (Building 2 – STD geometry – negative direction) between 2D and 3D model and among the different elements adopted.

Single wall

Bilinear

Penna et al. (2014)

Bracchi et al. (2021)

Building

Bilinear

Penna et al. (2014)

Bracchi et al. (2021)

Fig. 5. Comparison of the damage mechanisms of the West Wall (Building 2 – STD geometry – negative direction) between 2D and 3D model.

Results were also compared in terms of variation of axial load between the first step of the nonlinear analysis and a point representative of the ultimate condition, considering each pier at the ground level belonging to the considered wall. Therefore, results are reported in terms of an efficiency parameter η defined as: