PSI - Issue 44

Marco Furinghetti et al. / Procedia Structural Integrity 44 (2023) 1490–1497 Marco Furinghetti et al. / Structural Integrity Procedia 00 (2022) 000 – 000

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As can be noticed from graphical results, the adopted performance point in the design procedure has led to the proper definition of the mechanical properties of the isolation system, and consequently the response returned by the experimental hybrid simulations shows similar characteristics, in terms of peak displacement demand, friction coefficient and restoring stiffness, for all the considered earthquakes. In Fig. 5 results are provided by considering the peak displacement demand at the isolation system, normalized with respect to the design value, which is the displacement spectral coordinate of the assumed performance point.

Fig. 5. Analysis of results: isolation displacement response

Results are presented for both experimental hybrid simulations and numerical non-linear time history analyses. For all the seismic events the displacement demand is lower than or approximately equal to the design value; just for Event #1 the peak displacement for both experimental and numerical analyses exceeds the target value, even though a limited variation percentage can be noticed (less that 15%). In addition, if the attention is focused on the mean value among the selected events, it can be noticed that 90% of the target design displacement is achieved in the worst case (numerical analyses): therefore is could be assessed that the adopted design procedure leads to reasonable and safe estimations of the peak displacement demand of the isolation system, as a consequence of the implemented mechanical properties. Finally, in order to evaluate the level of seismic protection of the building provided by the isolation system, in Fig. 6 results are presented in terms of peak base shear values of the building, normalized by the maximum strength of the building itself, returned by the fixed-base capacity curve.