Onset of Motion of Curved Surface Sliders Used in Seismic-Isolation Systems

Curved surface sliders are generally preferred for the seismic isolation of buildings because of their technical features, such as the fact that the value of the vibration period is theoretically independent of the mass. Given the experimental evidence that indicates that the isolated system did not work under low seismic actions, in this paper, the influence of the static friction on the global behavior of some structures is studied in detail. By adopting a suitable model of friction, the onset of motion is analyzed with reference to simple isolation systems in which the influence of the friction values and its variability among the isolation devices are analyzed. The results pointed out that the behavior of curved surface sliders is not independent of the vertical load and highlights the importance of a suitable choice of the design friction, which must be different for devices with different vertical loads.