Influence of cyclic effect and extra-design displacement demands on Curved Surface Slider devices

Curved Surface Slider devices are widely used for seismic isolation applications in structural engineering. The response of the superstructure is significantly mitigated, thanks to the high dissipative capacity of the resulting isolation layer, and consequently low force and displacement demands can be achieved during earthquake excitations. Nonetheless, extreme seismic events can occur during the life-cycle of the structure, and consequently devices can be subjected to severe motions along both planar directions. In some cases, especially for earthquake with high return period, the induced displacement demand could exceed the design value. Recent experimental campaign carried out at the Laboratory of EUCENTRE Foundation in Pavia (Italy) have revealed a certain extra-design displacement capacity for Curved Surface Slider devices, with a stable force response. The present endeavor analyses such effects, in addition to the commonly known dependencies of frictional properties on some response parameters.