Characterization and Modeling of the In‐Plane Multi‐directional Behavior of a Rolling Pendulum Isolation System

ABSTRACT

The social and economic losses caused by an earthquake can be mitigated by using a rolling pendulum (RP) isolation system to protect vital non‐structural building contents. In this paper, a physics‐based mathematical model for an RP bearing—as well as an isolation systems comprised of these bearings—is derived. An experimental campaign for multi‐directional characterization of RP isolators was conducted. A single, full‐scale (four RP bearings) isolation system was tested. These tests were performed using an in‐plane multi‐directional shake table. Restoring forces and moments were measured by restraining the top of the isolation system from moving horizontally by using three struts with uniaxial load cells. Controlled‐displacement characterization tests were defined to capture the envelope performance of the isolation system subjected to a variety of multi‐directional conditions, by specifying combinations of slow and fast tests, various in‐plane (, , and ) amplitudes and frequencies, and different orbits. The experimental results were used to calibrate and validate the mathematical model.