EXPERIMENTAL VALIDATION OF A ROLLING ISOLATION SYSTEM

An assessment of the ability of lightly- and heavily-damped rolling isolation systems (RISs) to mitigate the hazard of seismically-induced failures requires high-fidelity models that can adequately capture the system’s intrinsic non-linear behavior. The light damping of steel bearings rolling between steel plates can be augmented by adhering thin rubber sheets to the plates, increasing the rolling resistance and decreasing the displacement demand on the RIS. The simplified model discussed in this paper is applicable to RISs with any potential energy function, is amenable to both lightly- and heavily damped RISs, and is validated through the successful prediction of peak responses for a wide range of disturbance frequencies and intensities. The damping provided by rolling between thin viscoelastic sheets increases the allowable floor motion intensity by a factor of two-to-three, depending on the period of motion. Acceleration responses of isolation systems with damping supplied in this fashion grow with increased damping, at short-period excitations.