Double-Skin Façades as Vibration Absorbers in the Presence of Imprecise Seismic Excitation

Double-skin façades (DSFs) are commonly employed in buildings to improve their aesthetic, thermal, acoustic isolation, and lighting aspects. Recently, the application of DSFs as vibration absorbers, capable of reducing the effects of dynamic actions on structural systems, has been suggested. The present study addresses the stochastic analysis of a shear-type frame equipped with a DSF, subjected to seismic acceleration characterized by an imprecise Power Spectral Density (PSD) function. The assumed spectral model of the imprecise PSD function of ground motion acceleration depends only on three parameters that are described as interval variables by applying the so-called Improved Interval Analysis. The effect of imprecision of the seismic excitation on the performance of the DSF is herein investigated by evaluating the bounds of the interval fractiles of order p for a selected displacement process of the frame structure. This is achieved by interval extension of an approximate analytical expression, applicable within the framework of the Vanmarcke assumption of out-crossing in clumps. A six-story shear-type frame equipped with a DSF, consisting of two independent panels, is selected as case study.