Study on Eccentric Rolling Isolation System with Additional Friction Damping

Study on Eccentric Rolling Isolation System with Additional Friction Damping

Passive isolation system is simple and effective to reduce the seismic ground acceleration. However, the responses may be magnified due to resonance for the conventional and linear passive isolation systems under near-fault earthquake. The nonlinear isolation system may avoid this situation. The proposed eccentric rolling isolation system(ERIS) with additional friction damping was investigated. The isolation performances of the ERIS were compared with a corresponding linear-restoring isolation system(linear system), which was established by the linearized frequency and the same optimization of friction parameters for energy-dissipating. If the resonance sine wave is considered, the response of the ERIS is magnified but much more slightly when compared to that of the linear system. In far-field El Centro earthquake, the two isolation systems were both found to be effective on acceleration and displacement. The nonlinear behavior of the ERIS is more obvious under near-fault Chi-Chi earthquake because of the occurrence of large displacement due to the near-fault excitation. This behavior implies more reduction in the response of acceleration. When the amplitude of the Chi-Chi earthquake becomes larger, the linear system becomes ineffective but the ERIS still works effectively. Consequently, the advantages and effectiveness of the ERIS with additional friction damping is further explained in this study.