Numerical investigation on the seismic dissipation of glazed curtain wall equipped on high-rise buildings

The dynamic interaction between glazed curtain wall stick systems and modern high-rise mega-frame buildings is investigated. In the present paper, four moment resisting frames (MRFs), consisting of thirty- and sixty-storey steel-based prototypes, are designed according to European standards: internal concentrically braced frame (CBF) core, outriggers and belt trusses are adopted to limit inter-storey drift and second order effects. Force-displacement relationships are derived from available full-scale test data performed on non-structural aluminium façade units. Therefore, 3D finite element (FE) models are developed to interpret the physical phenomena involved in façade dynamics: as a result, equivalent 1D nonlinear links are calibrated to simulate these phenomena independently. Nonlinear time history analyses (NLTHAs) are executed to investigate the potential combination of stiffness and strength of such hybrid systems, i.e. achieved through the integration of glazed curtain walls on the MRF lateral force resisting system (LFRs). Local and global performance will be shown in terms of inter-storey drifts and displacement peak profiles, forces and percentage peak variations, highlighting static-to-seismic load ratios in critical members and the sensitivity to the structural height. Conclusions point out that, even if accurately designed according to current standards, the façade omission from the seismic analyses of high-rise structures may lead to a crucial underestimation in the dissipation capacity of the building.