Study on Dynamic Behavior of Nonlinear Rolling Isolation System with Viscous Damping

Study on Dynamic Behavior of Nonlinear Rolling Isolation System with Viscous Damping

Resonance may be induced in linear isolation system under near-fault earthquake. In this paper, nonlinear rolling isolation system with viscous damping is investigated. The equation of motion of the nonlinear system is derived by using Lagrange’s equation. Numerical simulation is conducted for the nonlinear isolation system and the corresponding linear system under far-field and near-fault earthquakes. With the presence of viscous damping, the systems show better isolation effect in both acceleration ratio and maximum displacement regardless the isolation system is linear or nonlinear, and the earthquake is far-field or near-fault. When the damping coefficient is relatively small, the nonlinear isolation possesses much better performance over the linear one under near-fault earthquake. When the damping coefficient becomes larger, the performance of the linear isolation system is closer to that of the nonlinear one.