Eccentric rocking bearings with a designable friction property for seismic isolation: Experiment and analysis

The friction coefficient plays a critical role in a friction-type isolator, since it determines the transmitted seismic force and the energy dissipation capacity of the isolator, simultaneously. However, the choice of feasible sliding materials that possess appropriate friction coefficients is very limited, and this has restricted the development and applications of friction-type isolators. To overcome this, an isolator called the eccentric rocking bearing (ERB) with the property of designable friction is introduced in this study. By using an eccentric rolling mechanism, the ERB bearing is self-centering and its effective friction coefficient is adjustable by a geometric parameter that can be designed by engineers. The results of a shaking table test conducted on an ERB-isolated full-scale structure have confirmed the feasibility and efficiency of the ERB bearings for seismic isolation. Additionally, the high consistency between the simulated and experimental dynamic responses verifies the method developed to analyze the ERB.