Experimental and analytical study of the bi-directional behavior of the triple friction pendulum isolator

This paper presents a non-linear, kinematic model for triple friction pendulum isolation bearings. The model, which incorporates coupled plasticity and circular restraining surfaces for all sliding surfaces, is capable of capturing bi-directional behavior and is able to explicitly track the movement of each internal component. The model is general so that no conditions regarding bearing properties, which effect the sequence of sliding stages, are required for the validity of the model. Controlled-displacement and seismic-input experiments were conducted using the shake table at the University of California, Berkeley to assess the fidelity of the proposed model under bi-directional motion. Comparison of the experimental data with the corresponding results of the kinematic model shows good agreement. Additionally, experiments showed that the performance of TFP bearings is reliable over many motions, and the behavior is repeatable even when initial slider offsets are present. Copyright (c) 2011 John Wiley & Sons, Ltd.