GNGTS 2017 - 36° Convegno Nazionale

GNGTS 2017 S essione 2.3 445 carried out in ABAQUS, on the full 3D steel frame inclusive of the glazing envelope (Fig. 2c). The numerical modelling of the examined structural system was carried out in accordance with past numerical efforts, as for example reported in (Bedon and Amadio, 2017a, 2017b), and generally consisted of computationally efficient but accurate FE models composed of beam and shell elements, as well as properly calibrated mechanical constraints able to reproduce the actual performance of a single constructional member, as well as its interaction with the other components. For each VE device, K d was then estimated with Eq. (1) as a function of T 1 =0.326 s, as numerically calculated for the 3D frame with a rigidly restrained UGCW. A non-dimensional magnifying coefficient R K was also defined, through a FE parametric study (with 1 ≤ R K ≤ 50), to assess the input mechanical features effects: (4) By changing the R K reference value, no tangible variations were found for the fundamental vibration shapes of the building (Fig. 3a). Interesting variations were observed in terms of vibration periods, for the examined configurations (Fig. 3b). A value R K ≥50, in particular, proved to coincide with almost fully rigid brackets, hence with null benefits. R K values ≤2, conversely, gave evidence of local vibration modes of the UGCW, compared to the steel frame, hence suggesting to consider R K values in the range ≈2-30. Seismic analyses. The dynamic performance of the case study building was then properly investigated. Aset of 7 seismic records (two-component acceleration data, consistent with EC8 provisions for type ‘A’ soil, T1 topographic category, 0.35g PGA and 50 years of nominal life (ULS)) was imposed at the building base, through dynamic nonlinear analyses (see Fig. 3c). In Fig. 3d, the top drift and the VE sliding (absolute maximum envelopes from the set of seismic records) are proposed, as a function of R K . Worth of interest is the effect of dissipative Fig. 2 - a) Distributed TMD concept, with b) cross-sectional view of a VE solid damper. c) Case study building and d) reference FE model for the UGCWmodular unit (ABAQUS).