GNGTS 2021 - Atti del 39° Convegno Nazionale

313 GNGTS 2021 S essione 2.2 3.1 Fragility curves parameters The actual implementation of fragility curves for glass curtain wall systems is conducted experimentally within the FEMA P-58 (Applied Technology Council (ATC) 2012) seismic fragility guidelines. Specifically, the study is based on a definition of fragility curves for a single panel. Thus, an alternative parameter derivation method should be implemented in case of analytical models despite the procedure could lead to conservative result because of neglect of interactions between components and global behaviour. In this work, the choice falls on Cloud Method which is a numerical procedure based on nonlinear dynamic analysis in which a structure is subjected to a set of ground-motion records. The outputs are in form of data pairs of IM and its corresponding structural demand parameter that takes the name of ‘cloud data’, as shown in Fig.2.Cloud data pairs in the form of lateral displacement as a function of (a) S a (T 1 ) and (b) PGA . The method, as already mentioned, consists in a simple regression in the logarithmic space to derive the first two statistical moments (e.g., mean and standard deviation). Therefore, the accelerograms were accurately selected by considering a range of moment magnitude (Mw) between 3.9 and 6.9, an epicentral distances (R) ranging between 1.4 km and 63.8 km and a soil class A or B according to EC8 classification, in order to result in a distribution of cloud data which encompass the failure or the damage threshold taken into account as descripted in the following section. Fig. 2 - Cloud data pairs in the form of lateral displacement as a function of (a) S a (T 1 ) and (b) PGA.