Analysis Of Seismic Isolated Structures Using Friction Pendulum Bearing

Friction pendulum bearing (FPB) is a kind of seismic isolation bearing with excellent overall performance. In this paper, different modeling aspects of structures isolated using the frictional pendulum bearings and subjected to earthquake ground motions are studied herein. Specifically, three analytical models for FPB, i.e., equivalent linear model, nonlinear link element model and structure-FPB integrated model, were studied.Based on nonlinear link model in the SAP2000 Nonlinear program, parametric design and seismic response analysis were conducted for a multiple-story building and a practical bridge structure, respectively, subjected to horizontal biaxial earthquake excitations.Based on structure-FPB integrated model, strong nonlinear differential equations were derived, which can take into account the coupling effect of horizontal and vertical vibration components, and a nonlinear dynamic analytical program was developed. The effect of vertical component of earthquake excitation on the seismic response of structure and FPB was analyzed, subjected to far-field and near-fault earthquake excitations. The seismic response characteristics of FPB base isolated structure were discussed through response spectra analysis. The effect of FPB's parameters, i.e., curvature radius of the sliding surface, frictional coefficient of the slider and the sliding surface, mass ratio of isolation layer to superstructure, on the isolation effect was discussed.