Finite element formulation and shaking table tests of direction-optimized-friction-pendulum system

Recently, in several countries the application of base isolation technology has already been proven as the effective and economically viable method to enhance the capability of structures in seismic mitigation. In this study, an advanced base isolation system called the direction-optimized-friction-pendulum system (DO-FPS) is proposed and investigated to determine its mechanical behavior through finite element formulation and examine its efficiency in seismic mitigation by conducting the shaking table test. Based on finite element formulation, we infer that the natural period, the capacity of the bearing displacement and damping effect for a DO-FPS isolator change continually during earthquakes. Therefore, DO-FPS can avoid the resonance and provide an effective capacity for bearing displacement and damping during the earthquakes. Simultaneously, the shaking table test also illustrates that DO-FPS possesses outstanding seismic mitigation capabilities. (C) 2008 Elsevier Ltd. All rights reserved.